Communication systems and synchronization techniques for energy storage systems

Abstract

Exemplary embodiments of systems, devices, and methods are provided herein for an energy system including an array of cascaded modules configured to output a voltage waveform and / or a current waveform to a load. Each module can include an energy source, a switch circuit, and a local control device. Each module can have an identifier. The energy system can include a master control device communicatively coupled to each local control device via a communication path. The master control device can be configured to transmit control information data elements to the local control devices via the communication path.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Provisional Application No. 63 / 323,359, filed March 24, 2022, which is incorporated by reference in its entirety for all purposes.

[0002] The subject matter described herein relates generally to communication systems for module-based energy systems, as well as systems, devices, and methods that facilitate connection and control of modules within a module-based energy system. [Background technology]

[0003] In electrical engineering, power engineering, and the electrical power industry, power conversion is the transformation of electrical energy from one form to another (e.g., conversion between AC and DC, regulation of voltage or frequency, or some combination of these). The proliferation of devices for generating, harnessing, and utilizing electrical energy in various forms has forced the development of high-capacity electrical energy storage systems, sometimes referred to as energy storage systems (ESS). These ESS include those used in stationary applications (e.g., energy storage devices for buffering from the grid) and mobile applications (e.g., electric vehicle battery packs). ESSs often have power conversion capabilities placed at a discrete interface between the ESS as a whole and some other power consuming or generating entity, such as a load or grid. ESSs often rely on a combination of many smaller electrochemical batteries connected in a single serial chain to receive and store electrical energy from the grid before outputting it to the load. The process of receiving and outputting electrical energy may involve some power conversion performed at the discrete interface between the ESS and the grid or load. However, the power conversion performance in this discrete interface is relatively non-dynamic and can introduce losses, thereby reducing the efficiency of the ESS and making it expensive. Furthermore, reliance on a single serial chain of batteries significantly limits the capabilities of the ESS, as the serial chain can only output a single voltage, is susceptible to failure in any one of the serial batteries, and has a limited lifespan as each battery in the serial chain degrades differently due to structural and chemical differences inherently present within each.

[0004] For these and other reasons, a need exists for new systems, devices, and methods for storing electrical energy, outputting electrical energy, and performing power conversion in an improved manner. Summary of the Invention [Means for solving the problem]

[0005] Exemplary embodiments of systems, devices, and methods are provided herein for module-based energy systems that are broadly relevant to many applications and include a communication interface that allows a master control device to send control information to the local control devices of various modules. In general, the communication interface allows the master control device to communicate with the local control devices of an array of cascaded modules configured to output voltage and / or current waveforms to a load via a communication path. For example, a module can selectively operate in a voltage source mode to output a voltage waveform or in a current source mode to output a current waveform. The communication interface can be a serial or parallel interface that provides unidirectional data communication from the master control device to the individual local control devices of each cascaded module. The master control device periodically transmits control information data elements, such as packets, to the local control devices, for example, to enable the local control devices to adjust their individual output power characteristics.

[0006] Each control information data element may include a single reference signal for all modules of the array of cascaded modules and a modulation index for one of the modules in the array. To enable the cascaded module to determine whether the modulation index is for that cascaded module, each control information data element may also include an identifier for the cascaded module to which the modulation index applies. The master control device may cycle through the cascaded modules in a sequence such that the local control device for each cascaded module receives an updated modulation index in one of the control information elements transmitted in the sequence. This may reduce the length of the control information data element and increase the sampling of the reference signal at each module. For example, this may allow the master control device to transmit the reference signal more frequently per the same period of time. This more frequent sampling increases the voltage and / or current regulation accuracy and reduces the time response in changing the reference signal.

[0007] Each control information data element may also include one or more safety signals, for example, each control information data element may include Cyclic Redundancy Check (CRC) information for error detection and data correction.

[0008] The local control device of each cascaded module can use its most recently received modulation index to scale the most recently received reference signal of its most recently received control information data element and use the scaled reference signal to control the switch circuit of the cascaded module. The local control device can use the scaled reference signal to control the switch circuit to output the appropriate voltage or current waveform.

[0009] An additional communication interface can provide bidirectional data communication between the master control device and each local control device. This allows the local control devices to provide status information (e.g., temperature, charge state, etc.) to the master control device. The master control device can then adjust the modulation index for the cascaded modules based on those statuses.

[0010] The master and local control devices may utilize synchronization techniques, such as Pulse Width Modulation (PWM), to synchronize receipt of control information data elements and / or synchronize control of module switching circuits. The master control device may be configured to generate and transmit a synchronization signal to each local control device indicating when a control information data element is being transmitted to the local control device and / or when control of the switches of the modules controlled by the local control device should be synchronized. For example, when the local control device detects a PWM synchronization event based on the synchronization signal, the local control device may reset a PWM counter used to create a carrier signal. Similarly, when the local control device detects a data reception synchronization event, the local control device may capture the control information data element being transmitted from the master control device.

[0011] In some embodiments, the local control device is configured to detect a synchronization event (e.g., a PWM synchronization event and / or a data reception synchronization event) based on the absence of data being transmitted along a path or link between the master control device and the local control device. The local control device can monitor the duration of time elapsed after the end of each data segment, and if the duration reaches a threshold without another data segment being received, the local control device can determine that a data absence event has occurred and, correspondingly, a synchronization event has occurred.

[0012] Other systems, devices, methods, features, and advantages of the subject matter described herein will be or become apparent to one with skill in the art upon review of the following drawing description and detailed description. All such additional systems, methods, features, and advantages are intended to be included within this specification, be within the scope of the subject matter described herein, and be protected by the accompanying claims. Features of the example embodiments should not be construed as limiting the scope of the appended claims unless there is an express recitation of those features in the claims. [Brief description of the drawings]

[0013] Details of the subject matter described herein, both as to its structure and operation, may be apparent from consideration of the accompanying drawings, in which like reference numerals refer to like parts. The components in the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the subject matter. Moreover, all illustrations are intended to convey the concept that relative sizes, shapes, and other detailed attributes may be illustrated generally, rather than literally or precisely.

[0014] [Figure 1-1] FIG. 1 is a block diagram illustrating an exemplary embodiment of a modular energy system. [Figure 1-2] FIG. 1 is a block diagram illustrating an exemplary embodiment of a modular energy system. [Figure 1-3] FIG. 1 is a block diagram illustrating an exemplary embodiment of a modular energy system.

[0015] [Figure 1-4] FIG. 1 is a block diagram illustrating an example embodiment of a control device for an energy system.

[0016] [Figure 1-5] FIG. 1 is a block diagram illustrating an example embodiment of a modular energy system coupled to a load and a charging source.

[0017] [Figure 2-1] FIG. 1 is a block diagram illustrating an example embodiment of a module and a control system within an energy system. [Figure 2-2] FIG. 1 is a block diagram illustrating an example embodiment of a module and a control system within an energy system.

[0018] [Figure 2-3] FIG. 2 is a block diagram illustrating an exemplary embodiment of a physical configuration of modules.

[0019] [Figure 2-4] FIG. 1 is a block diagram illustrating an example embodiment of a physical configuration of a modular energy system.

[0020] [Figure 3-1] 1A-1C are block diagrams illustrating exemplary embodiments of modules having various electrical configurations. [Figure 3-2] 1A-1C are block diagrams illustrating exemplary embodiments of modules having various electrical configurations. [Figure 3-3] 1A-1C are block diagrams illustrating exemplary embodiments of modules having various electrical configurations.

[0021] [Figure 4] FIG. 2 is a schematic diagram illustrating an exemplary embodiment of an energy source.

[0022] [Figure 5A] FIG. 2 is a schematic diagram illustrating an exemplary embodiment of an energy buffer. [Figure 5B] FIG. 2 is a schematic diagram illustrating an exemplary embodiment of an energy buffer. [Figure 5C] FIG. 2 is a schematic diagram illustrating an exemplary embodiment of an energy buffer.

[0023] [Figure 6-1] FIG. 1 is a schematic diagram illustrating an exemplary embodiment of a converter. [Figure 6-2] FIG. 1 is a schematic diagram illustrating an exemplary embodiment of a converter.

[0024] [Figure 7-1] 1A-1D are block diagrams illustrating example embodiments of modular energy systems having various topologies. [Figure 7-2] 1A-1D are block diagrams illustrating example embodiments of modular energy systems having various topologies. [Figure 7-3] 1A-1D are block diagrams illustrating example embodiments of modular energy systems having various topologies.

[0025] [Figure 8-1] 1 is a plot illustrating an example output voltage of a module.

[0026] [Figure 8-2] 1 is a plot illustrating an example multi-level output voltage of a module array.

[0027] [Figure 8-3] 1 is a plot illustrating exemplary reference and carrier signals that can be used in a pulse width modulation control technique.

[0028] [Figure 8-4] 4 is a plot illustrating an example switch signal generated in accordance with a pulse width modulation control technique.

[0029] [Figure 8-5] 1 is a plot illustrating an exemplary multi-level output voltage produced by superposition of output voltages from an array of modules under a pulse width modulation control technique.

[0030] [Figure 8-5] 1 is a plot illustrating an exemplary multi-level output voltage produced by superposition of output voltages from an array of modules under a pulse width modulation control technique.

[0031] [Figure 9]FIG. 2 is a block diagram illustrating an example embodiment of a controller for a modular energy system.

[0032] [Figure 10-1] FIG. 1 is a block diagram illustrating an example embodiment of a multi-phase modular energy system having interconnected modules.

[0033] [Figure 10-2] FIG. 10B is a schematic diagram illustrating an exemplary embodiment of an interconnection module in the multi-phase embodiment of FIG. 10A.

[0034] [Figure 10-3] FIG. 1 is a block diagram illustrating an example embodiment of a modular energy system having two subsystems connected together by an interconnection module.

[0035] [Figure 10-4] FIG. 1 is a block diagram illustrating an example embodiment of a three-phase modular energy system having interconnected modules supplying auxiliary loads.

[0036] [Figure 10-5] FIG. 10E is a schematic diagram illustrating an exemplary embodiment of an interconnection module in the multi-phase embodiment of FIG. 10D.

[0037] [Figure 10-6] FIG. 2 is a block diagram illustrating another exemplary embodiment of a three-phase modular energy system having interconnected modules supplying auxiliary loads.

[0038] [Figure 11-1] FIG. 1 is a block diagram illustrating an example embodiment of a modular energy system having communication paths connecting a master control device to local control devices. [Figure 11-2] FIG. 1 is a block diagram illustrating an example embodiment of a modular energy system having communication paths connecting a master control device to local control devices.

[0039] [Figure 12-1] FIG. 1 is a block diagram illustrating an example embodiment of a single phase energy system. [Figure 12-2] FIG. 1 is a block diagram illustrating an example embodiment of a single phase energy system.

[0040] [Figure 13] FIG. 1 is a block diagram illustrating an example embodiment of a split phase energy system.

[0041] [Figure 14-1] FIG. 1 is a block diagram illustrating an example embodiment of a three-phase energy system. [Figure 14-2] FIG. 1 is a block diagram illustrating an example embodiment of a three-phase energy system.

[0042] [Figure 15] FIG. 2 is a block diagram illustrating an interface of an exemplary embodiment of a master control device.

[0043] [Figure 16-1] FIG. 2 is a block diagram illustrating exemplary components of an exemplary embodiment of a combination module. [Figure 16-2] FIG. 2 is a block diagram illustrating exemplary components of an exemplary embodiment of a combination module.

[0044] [Figure 17] FIG. 2 is a block diagram illustrating an exemplary embodiment of a local control device.

[0045] [Figure 18] FIG. 11 is a flow diagram illustrating an example embodiment of a method for transmitting control information data elements to a local control device and outputting a voltage waveform based on a control information data packet.

[0046] [Figure 19]FIG. 11 is a flow diagram illustrating an example embodiment of a method for transmitting control information data elements to a local control device.

[0047] [Figure 20] FIG. 1 is a flow diagram illustrating an example embodiment of a method for receiving control information data elements.

[0048] [Figure 21] 1 is a schematic diagram of an exemplary data stream.

[0049] [Figure 22] FIG. 2 is a flow diagram illustrating an example embodiment of a method for receiving control information data elements using a synchronization signal.

[0050] [Figure 23] 1 is a schematic diagram of an exemplary data stream.

[0051] [Figure 24] FIG. 1 is a flow diagram illustrating an example embodiment of a method for waking up a local control device.

[0052] [Figure 25-1] FIG. 2 is a block diagram of an exemplary embodiment of a local control device.

[0053] [Figure 25B] FIG. 2 is a schematic diagram illustrating an exemplary embodiment of a communication connection between a master control device and a local control device.

[0054] [Figure 25-3] FIG. 2 is a schematic diagram illustrating an exemplary embodiment of a communication connection between a master control device and a local control device.

[0055] [Figure 26-1] FIG. 2 is a block diagram of an exemplary embodiment of a synchronization unit.

[0056] [Figure 26-2] FIG. 2 is a schematic diagram of an exemplary embodiment of a comparator.

[0057] [Figure 26C] 1 is a plot showing waveforms of signals associated with a synchronization unit; [Figure 26D] 1 is a plot showing waveforms of signals associated with a synchronization unit;

[0058] [Figure 27] 11 is a plot showing a frequency modulated synchronization signal and voltage levels on a capacitor of a synchronization unit.

[0059] [Figure 28] 4 is a plot showing a frequency modulated synchronization signal and a reset signal generated based on a frequency modulated synchronization signal.

[0060] [Figure 29] FIG. 1 is a flow diagram illustrating an example embodiment of a method for synchronizing data capture events and PWM events.

[0061] [Diagram 30] FIG. 1 is a flow diagram illustrating an example embodiment of a method for synchronizing data capture events and PWM events.

[0062] [Diagram 31] FIG. 31 is a plot showing the jitter present on a switching signal output by a local control device.

[0063] [Diagram 32] FIG. 32 is a plot illustrating the reduced jitter present on a switching signal output by a local control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0064] Before describing the present subject matter in detail, it is to be understood that this disclosure is not limited to particular embodiments described, which may, of course, vary. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, since the scope of the present disclosure will be limited only by the appended claims.

[0065] Before describing exemplary embodiments of modular energy systems and their communication interfaces, it is useful to first describe these underlying systems in more detail. With reference to Figures 1A-10F, the following sections describe various applications in which embodiments of modular energy systems, embodiments of control systems or devices for modular energy systems, configurations of embodiments of modular energy systems relative to charging sources and loads, embodiments of individual modules, embodiments of topologies for placement of modules in a system, embodiments of control methods, embodiments of balancing operational characteristics of modules in a system, and embodiments of use of interconnected modules may be implemented.

[0066] Application Examples A stationary application is one in which the modular energy system is located at a fixed location when in use, but may be capable of being transported to an alternate location when not in use. The module-based energy system resides at a static location while supplying electrical energy for consumption by one or more other entities, or storing or buffering energy for later consumption. Examples of stationary applications in which the embodiments disclosed herein may be used include energy systems for use by or within one or more residential structures or locales, energy systems for use by or within one or more industrial structures or locales, energy systems for use by or within one or more commercial structures or locales, energy systems for use by or within one or more government structures or locales (including both military and non-military uses), energy systems for charging the mobile applications described below (e.g., charging sources or charging stations), and the like. Stationary applications include, but are not limited to, systems that convert solar, wind, geothermal energy, fossil fuels, or nuclear reactions into electricity for storage. Stationary applications often supply loads such as grids and microgrids, motors, and data centers. Stationary energy systems can be used in either storage or non-storage roles.

[0067] Mobile applications, sometimes referred to as traction applications, are generally those in which a module-based energy system is located on or within an entity to store and provide electrical energy for conversion to power by a motor to move or assist in moving the entity. Examples of mobile entities that may use the embodiments disclosed herein include, but are not limited to, electric and / or hybrid entities that move on or under land, on or under the sea, above and out of contact with land or sea (e.g., flying or hovering in the air), or through space. Examples of mobile entities that may use the embodiments disclosed herein include, but are not limited to, cars, trains, trams, ships, watercraft, aircraft, and spacecraft. Examples of mobile vehicles that may use the embodiments disclosed herein include, but are not limited to, those with only one wheel or truck, those with only two wheels or trucks, those with only three wheels or trucks, those with only four wheels or trucks, and those with five or more wheels or trucks. Examples of mobile entities that may use the embodiments disclosed herein include, but are not limited to, automobiles, buses, trucks, motorcycles, scooters, bicycles, industrial vehicles, mining vehicles, air vehicles (e.g., airplanes, helicopters, drones, etc.), maritime vessels (e.g., commercial ships, ships, yachts, boats, or other watercraft), submarines, locomotives or rail-based vehicles (e.g., trains, trams, etc.), military vehicles, spacecraft, and satellites.

[0068] In describing embodiments herein, reference may be made to a particular stationary application (e.g., grid, microgrid, data center, cloud computing environment) or mobile application (e.g., electric vehicle). Such references are made for ease of description and are not meant to imply that a particular embodiment is limited to use only in that particular mobile or stationary application. Embodiments of a system for powering a motor may be used in both mobile and stationary applications. While certain configurations may be more suitable for some applications than others, all exemplary embodiments disclosed herein may be used in both mobile and stationary applications unless otherwise specified.

[0069] Example of a module-based energy system FIG. 1A is a block diagram illustrating an exemplary embodiment of a module-based energy system 100. Here, the system 100 includes a control system 102 communicatively coupled to N converter source modules 108-1 through 108-N via communication paths or links 106-1 through 106-N, respectively. The modules 108 are configured to store energy and output energy to a load 101 (or other modules 108) as needed. In these embodiments, any number of modules 108 greater than or equal to two can be used (e.g., N is 2 or greater). The modules 108 can be connected together in various manners, as described in more detail with respect to FIGS. 7A-7E. For ease of illustration, in FIGS. 1A-1C, the modules 108 are shown connected in series or as a one-dimensional array, with the Nth module being coupled to the load 101.

[0070] The system 100 is configured to supply power to a load 101. The load 101 can be any type of load, such as a motor or a grid. The system 100 is also configured to store power received from a charging source. FIG. 1F is a block diagram illustrating an exemplary embodiment of the system 100 with a power input interface 151 for receiving power from a charging source 150 and a power output interface for outputting power to the load 101. In this embodiment, the system 100 can receive and store power via the interface 151 while simultaneously outputting power via the interface 152. FIG. 1G is a block diagram illustrating another exemplary embodiment of the system 100 with a switchable interface 154. In this embodiment, the system 100 can select, or can be instructed to select, between receiving power from the charging source 150 and outputting power to the load 101. The system 100 can be configured to supply multiple loads 101, including both primary and auxiliary loads, and / or receive power from multiple charging sources 150 (e.g., a utility-operated power grid and a local renewable energy source (e.g., solar)).

[0071] 1B illustrates another exemplary embodiment of system 100, where control system 102 is implemented as a master control device (MCD) 112 communicatively coupled to N different local control devices (LCDs) 114-1 through 114-N via communication paths or links 115-1 through 115-N, respectively. Each LCD 114-1 through 114-N is communicatively coupled to one module 108-1 through 108-N via communication paths or links 116-1 through 116-N, respectively, such that there is a 1:1 relationship between LCD 114 and module 108.

[0072] 1C illustrates another exemplary embodiment of system 100, in which MCD 112 is communicatively coupled to M different LCDs 114-1 through 114-M via communication paths or links 115-1 through 115-M, respectively. Each LCD 114 is coupled to and can control two or more modules 108. In the illustrated example, each LCD 114 is communicatively coupled to two modules 108, such that M LCDs 114-1 through 114-M are coupled to 2M modules 108-1 through 108-2M via communication paths or links 116-1 through 116-2M, respectively.

[0073] The control system 102 may be configured as a single device for the entire system 100 (e.g., FIG. 1A), distributed across multiple devices (e.g., FIGS. 1B-1C), or implemented as multiple devices (e.g., FIGS. 1B-1C). In some embodiments, the control system 102 may be distributed among the LCDs 114 associated with the modules 108 such that the MCD 112 is not necessary and may be omitted from the system 100.

[0074] The control system 102 can be configured to perform the control using software (instructions stored in a memory that are executable by a processing circuit), hardware, or a combination thereof. One or more devices of the control system 102 can each include a processing circuit 120 and a memory 122, as shown herein. Exemplary implementations of the processing circuit and memory are described further below.

[0075] The control system 102 may have a communication interface for communicating with devices 104 external to the system 100 via a communication link or path 105. For example, the control system 102 (e.g., the MCD 112) may communicate data or information related to the system 100 to another control device 104 (e.g., an Electronic Control Unit (ECU) of a vehicle in a mobile application or a motor control device). The output can be sent to a control unit (Motor Control Unit, MCU) in a stationary application, a grid controller in a stationary application, etc.

[0076] The communication paths or links 105, 106, 115, 116, and 118 (FIG. 2B) can each be a wired (e.g., electrical, optical) or wireless communication path that communicates data or information bidirectionally, in a parallel or serial manner. The data can be communicated in a standard (e.g., IEEE, ANSI) format or a custom (e.g., proprietary) format. In an automotive application, the communication path 115 can be configured to communicate according to a FlexRay or Controller Area Network (CAN) protocol. The communication paths 106, 115, 116, and 118 can also provide wired power to directly provide operating power for the system 102 from one or more modules 108. For example, operating power for each LCD 114 can be provided only by the one or more modules 108 to which it is connected, and operating power for the MCD 112 can be provided indirectly (e.g., via the automotive power network) from one or more of the modules 108.

[0077] The control system 102 is configured to control one or more modules 108 based on status information 160 received from the same or different one or more modules 108. The control may also be based on one or more other factors, such as the requirements of the load 101. Controllable aspects include, but are not limited to, one or more of the voltage, current, phase, and / or output power of each module 108.

[0078] The status information 160 of each module 108 in the system 100 can be communicated to the control system 102, which can control each module 108-1...108-N independently. Other variations are possible. For example, a particular module 108 (or a subset of modules 108) can be controlled based on the status information 160 of the particular module 108 (or subset), based on the status information 160 of a different module 108 that is not the particular module 108 (or subset), based on the status information 160 of all modules 108 other than the particular module 108 (or subset), based on the status information 160 of the particular module 108 (or subset) and the status information 160 of at least one other module 108 that is not the particular module 108 (or subset), or based on the status information 160 of all modules 108 in the system 100.

[0079] The status information 160 may be information about one or more aspects, characteristics, or parameters of each module 108. Types of status information 160 may include, but are not limited to, the following aspects of a module 108 or one or more of its components (e.g., energy source, energy buffer, converter, monitoring circuitry): the State of Charge (SOC) of one or more energy sources of the module (e.g., the charge level of an energy source relative to its capacity, such as a fraction or percent), the State of Health (SOH) of one or more energy sources of the module (e.g., a figure of merit of an energy source compared to its ideal state), the temperature of one or more energy sources or other components of the module, the capacity of one or more energy sources of the module, the voltage of one or more energy sources and / or other components of the module, the current of one or more energy sources and / or other components of the module, the State of Power (SOP) (e.g., the available power limit of an energy source during discharging and / or charging), the State of Energy (SOE) (e.g., the current level of available energy of an energy source relative to the maximum available energy of the energy source), and / or the presence or absence of a fault in any one or more of the components of the module.

[0080] The LCD 114 can be configured to receive status information 160 from each module 108 or to determine the status information 160 from monitoring signals or data received from or within each module 108 and communicate that information to the MCD 112. In some embodiments, each LCD 114 can communicate raw collected data to the MCD 112, which then algorithmically determines the status information 160 based on the raw data. The MCD 112 can then use the module 108 status information 160 to make control decisions accordingly. The decisions can take the form of instructions, commands, or other information (such as a modulation index as described herein) that can be utilized by the LCD 114 to maintain or adjust the operation of each module 108.

[0081] For example, the MCD 112 may receive the status information 160 and evaluate the information to determine differences between at least one module 108 (e.g., its components) and at least one or more other modules 108 (e.g., its comparable components). For example, the MCD 112 may determine that a particular module 108 is operating in one of the following states compared to one or more other modules 108: relatively low or high SOC, relatively low or high SOH, relatively low or high capacity, relatively low or high voltage, relatively low or high current, relatively low or high temperature, or with or without a fault. In such an example, the MCD 112 may output control information to decrease or increase (depending on the state) a relevant aspect (e.g., output voltage, current, power, temperature) of that particular module 108. In this manner, the utilization of an outlier module 108 (e.g., operating at a relatively low SOC or higher temperature) may be decreased to cause a relevant parameter (e.g., SOC or temperature) of that module 108 to converge toward the parameter of one or more other modules 108.

[0082] The decision to adjust the operation of a particular module 108 may be made by comparing the status information 160 to a predefined threshold, limit, or condition, without necessarily comparing it to the status of other modules 108. The predefined threshold, limit, or condition may be a static threshold, limit, or condition, such as set by a manufacturer that does not change during use. The predefined threshold, limit, or condition may be a dynamic threshold, limit, or condition that may or may not change during use. For example, the MCD 112 may adjust the operation of a module 108 if the status information 160 for that module 108 indicates that the module 108 is operating in violation of (e.g., above or below) a predefined threshold or limit, or outside a predefined range of acceptable operating conditions. Similarly, the MCD 112 may adjust the operation of a module 108 if the status information 160 for that module 108 indicates the presence of an actual or potential fault (e.g., an alarm or warning), or indicates the absence or removal of an actual or potential fault. Examples of faults include, but are not limited to, actual failure of a component, potential failure of a component, short circuit or other excessive current condition, open circuit, excessive voltage condition, failure to receive communications, reception of corrupted data, etc. Depending on the type and severity of the fault, utilization of the faulty module may be reduced to avoid damaging the module, or utilization of the module may be halted entirely. For example, if a given module fails, MCD 112 or LCD 114 may cause that module to enter a bypass state as described herein.

[0083] The MCD 112 may control the modules 108 in the system 100 to achieve or converge towards a desired goal. The goal may be, for example, operation of all modules 108 at the same or similar levels relative to one another, or within certain thresholds, limits, or conditions. This process may include determining whether the operation or behavior of the modules 108 is consistent with the desired goal. This is also referred to as balancing operational characteristics or seeking to achieve balance. As used herein, the term "balance" is used broadly to convey that it does not require absolute equivalence between modules 108 or their components, but rather that operation of the system 100 can be used to actively reduce differences in operation (or operating conditions) between modules 108 that would otherwise exist.

[0084] The MCD 112 may communicate control information to the LCD 114 for purposes of controlling the module 108 associated with the LCD 114. The control information may be, for example, a modulation index and reference signal, a modulation reference signal, or otherwise, as described herein. Each LCD 114 may use (e.g., receive and process) the control information to generate switch signals that control the operation of one or more components (e.g., converters) in the associated module 108. In some embodiments, the MCD 112 generates the switch signals directly and outputs them to the LCD 114, which relays the switch signals to the intended module components.

[0085] All or a portion of the control system 102 may be combined with a system external control device 104 that controls one or more other aspects of the mobile or stationary application. When integrated into this shared or common control device (or subsystem), control of the system 100 may be implemented in any desired manner, such as one or more software applications executed by the processing circuitry of the shared device, the hardware of the shared device, or a combination thereof. Non-exhaustive examples of external control devices 104 include a vehicle ECU or MCU having control capabilities for one or more other vehicle functions (e.g., motor control, driver interface control, traction control, etc.), a grid or microgrid controller responsible for one or more other power management functions (e.g., load interface, load power requirement prediction, transmission and switching, interfacing with charging sources (e.g., diesel, solar, wind), charging source power prediction, backup source monitoring, asset dispatch, etc.), and a data center control subsystem (e.g., environmental control, network control, backup control, etc.).

[0086] 1D and 1E are block diagrams illustrating an example embodiment of a shared or common control device (or system) 132 in which the control system 102 may be implemented. In FIG. 1D, the common control device 132 includes a master control device 112 and an external control device 104. The master control device 112 includes an interface 141 for communication with the LCD 114 via path 115, as well as an interface 142 for communication with the external control device 104 via an internal communication bus 136. The external control device 104 includes an interface 143 for communication with the master control device 112 via the bus 136, and an interface 144 for communication with other entities throughout the application (e.g., vehicle or grid components) via communication path 136. In some embodiments, the common control device 132 may be integrated as a common housing or package with the devices 112 and 104 implemented as discrete integrated circuit (IC) chips or packages contained therein.

[0087] In FIG. 1E, the external control device 104 functions as a common control device 132, with the master control functionality implemented as a component within the device 104. This component 112 can be or include software or other program instructions stored and / or hard-coded in the memory of the device 104 and executed by its processing circuitry. The component can also include dedicated hardware. The component can be a self-contained module or core with one or more internal hardware and / or software interfaces (e.g., application program interfaces (APIs)) for communication with the operating software of the external control device 104. External control device 104 can manage communications with LCD 114 via interface 141 and other devices via interface 144. In various embodiments, devices 104 / 132 can be integrated as a single IC chip, multiple IC chips in a single package, or multiple semiconductor packages in a common housing.

[0088] 1D and 1E, the master control functionality of the system 102 is shared with the common device 132, although other divisions of shared control may be or are permitted. For example, some of the master control functionality may be distributed between the common device 132 and the dedicated MCD 112. In another example, both the master control functionality and at least some of the local control functionality may be implemented in the common device 132 (e.g., with the remaining local control functionality implemented in the LCD 114). In some embodiments, all of the control system 102 is implemented in the common device (or subsystem) 132. In some embodiments, the local control functionality is implemented in a device shared with another component of each module 108, such as a Battery Management System (BMS).

[0089] Example of a module in a cascaded energy system The module 108 may include one or more energy sources, a power electronics converter, and optionally, an energy buffer. FIGS. 2A-2B are block diagrams illustrating additional exemplary embodiments of the system 100 having a module 108 with a power converter 202, an energy buffer 204, and an energy source 206. The converter 202 may be a voltage converter or a current converter. Although the embodiments are described herein with reference to a voltage converter, the embodiments are not limited as such. The converter 202 may be configured to convert a direct current (DC) signal from the energy source 206 to an alternating current (AC) signal and output it via a power connection 110 (e.g., an inverter). The converter 202 may also receive an AC or DC signal via the connection 110 and apply it to the energy source 206 in either polarity, continuous or pulsed form. The converter 202 may be or include an arrangement of switches (e.g., power transistors), such as a half-bridge of a full bridge (H-bridge). In some embodiments, the converter 202 includes only switches, and the converter (and the module as a whole) does not include a transformer.

[0090] Converter 202 may also (or alternatively) be configured to perform AC to DC conversion (e.g., a rectifier), DC to DC conversion, and / or AC to AC conversion, such as for charging a DC energy source from an AC source (e.g., in combination with an AC-DC converter). In some embodiments, such as performing AC-AC conversion, converter 202 may include a transformer, either alone or in combination with one or more power semiconductors (e.g., switches, diodes, thyristors, etc.). In other embodiments, such as where weight and cost are important factors, converter 202 may be configured to perform the conversion without a transformer, with only power switches, power diodes, or other semiconductor devices.

[0091] The energy source 206 is preferably a robust energy storage device capable of outputting direct current and having an energy density suitable for energy storage applications for powering devices. The energy source 206 can be an electrochemical battery, such as a single battery cell or multiple battery cells connected together in a battery module or array, or any combination thereof. Figures 4A-4D show a single battery cell 402 (Figure 4A), a battery module having a series connection of multiple (e.g., four) cells 402 (Figure 4B), a battery module having a parallel connection of single cells 402, and a battery module having a parallel connection of single cells 402. 4C is a schematic diagram illustrating an example embodiment of an energy source 206 configured as a battery module (FIG. 4D) with legs and parallel connections each having two cells 402. A non-exhaustive list of examples of battery types is provided elsewhere herein.

[0092] The energy source 206 can also be a high energy density (HED) capacitor, such as an ultracapacitor or a supercapacitor. HED capacitors can be configured as double layer capacitors (electrostatic charge storage), pseudocapacitors (electrochemical charge storage), hybrid capacitors (electrostatic and electrochemical), or otherwise, as opposed to the solid dielectric types of typical electrolytic capacitors. In addition to higher capacitance, HED capacitors can have an energy density that is 10-100 times (or more) that of electrolytic capacitors. For example, HED capacitors can have a specific energy of greater than 1.0 watt-hours per kilogram (Wh / kg) and a capacitance of greater than 10-100 Farads (F). Similar to the batteries described with respect to FIGS. 4A-4D, the energy source 206 can be configured as a single HED capacitor or multiple HED capacitors connected together in an array (e.g., in series, parallel, or a combination thereof).

[0093] The energy source 206 can also be a fuel cell. The fuel cell can be a single fuel cell, multiple fuel cells connected in series or parallel, or a fuel cell module. Examples of fuel cell types include proton-exchange membrane fuel cells (PEMFCs), phosphoric acid fuel cells (PAFCs), solid acid fuel cells, alkaline fuel cells, high temperature fuel cells, solid oxide fuel cells, molten electrolyte fuel cells, and the like. Similar to the batteries described with respect to FIGS. 4A-4D, the energy source 206 can be configured as a single fuel cell or multiple fuel cells connected together in an array (e.g., in series, parallel, or a combination thereof). The foregoing examples of source classes (e.g., batteries, capacitors, and fuel cells) and types (e.g., chemical and / or structural configurations within each class) are not intended to form an exhaustive list, and one of ordinary skill in the art will recognize other variations that are within the scope of the present subject matter.

[0094] The energy buffer 204 compensates for fluctuations in current across the DC line or DC link (e.g., +V DCL and -V DCL ) may be attenuated or filtered. These fluctuations may be relatively low (e.g., kilohertz) or high (e.g., megahertz) frequency fluctuations or harmonics caused by switching of converter 202, or other transients. These fluctuations may be absorbed by buffer 204 instead of being passed to source 206 or ports IO3 and IO4 of converter 202.

[0095] The power connection 110 is a connection for transferring energy or power to, from, and through the module 108. The module 108 can output energy from the energy source 206 to the power connection 110 where the energy can be transferred to other modules or loads in the system. The module 108 can also receive energy from other modules 108 or charging sources (DC chargers, single-phase chargers, multi-phase chargers). Signals can also pass through the module 108 bypassing the energy source 206. The routing of energy or power to and from the module 108 is performed by the converter 202 under the control of the LCD 114 (or another entity of the system 102).

[0096] In the embodiment of Figure 2A, the LCD 114 may be implemented as a separate component from the module 108 (e.g., not in a shared module housing) and may be connected to and communicate with the converter 202 via communication path 116. In the embodiment of Figure 2B, the LCD 114 may be included as a component of the module 108 and may be connected to and communicate with the converter 202 via an internal communication path 118 (e.g., a shared bus or a discrete connection). The LCD 114 may also be capable of receiving and transmitting signals from the energy buffer 204 and / or the energy source 206 via paths 116 or 118.

[0097] The module 108 may also include monitoring circuitry 208 configured to monitor (e.g., collect, sense, measure, and / or determine) one or more aspects of the module 108 and / or its components, such as voltage, current, temperature, or other operating parameters that constitute (or may be used to determine, for example, the status information 160 by the LCD 114). A primary function of the status information 160 is to describe the state of one or more energy sources 206 of the module 108 to enable a decision of how much to utilize the energy source relative to other sources in the system 100, although status information 160 describing the state of other components (e.g., voltage, temperature, and / or presence of a fault in the buffer 204, temperature and / or presence of a fault in the converter 202, presence of a fault elsewhere in the module 108, etc.) may also be used in the utilization decision. The monitoring circuitry 208 may include one or more sensors, shunts, dividers, fault detectors, coulomb counters, controllers, or other hardware and / or software configured to monitor such aspects. The monitoring circuitry 208 may be separate from the various components 202, 204, and 206, or may be integrated with each of the components 202, 204, and 206 (as shown in FIGS. 2A-2B), or any combination thereof. In some embodiments, the monitoring circuitry 208 may be part of or shared with a battery management system (BMS) of the battery energy source 206. Because one or more types of status information 160 may be monitored with a single circuit or device, or may otherwise be determined algorithmically without the need for additional circuitry, discrete circuitry is not required to monitor each type of status information 160.

[0098] The LCD 114 can receive status information 160 (or raw data) regarding the module components via communication paths 116, 118. The LCD 114 can also transmit information to the module components via paths 116, 118. The paths 116 and 118 can include diagnostic, measurement, protection, and control signal lines. The transmitted information can be control signals for one or more module components. The control signals can be switch signals to the converter 202 and / or one or more signals requesting status information 160 from the module components. For example, the LCD 114 can cause the status information 160 to be transmitted via paths 116, 118 by directly requesting the status information 160 or by applying a stimulus (e.g., a voltage) to generate the status information 160, possibly in combination with a switch signal that places the converter 202 in a particular state.

[0099] The physical configuration or layout of the module 108 can take a variety of forms. In some embodiments, the module 108 can include a common housing in which all module components, such as the converter 202, buffer 204, and source 206, are housed along with other optional components, such as an integrated LCD 114. In other embodiments, the various components can be separated into discrete housings that are fixed together. FIG. 2C is a block diagram illustrating an exemplary embodiment of a module 108, which includes the module's energy source 206 and associated components, such as monitoring circuitry. The module 108 includes a first housing 220 that holds the electronics for the converter 202, the energy buffer 204, and other associated electronics such as monitoring circuitry, a second housing 222 that holds the module electronics, such as the converter 202, the energy buffer 204, and other associated electronics such as monitoring circuitry, and a third housing 224 that holds the LCD 114 (not shown) for the module 108. In alternative embodiments, the module electronics and the LCD 114 can be housed within the same single housing. In yet other embodiments, the module electronics, the LCD 114, and the energy source can be housed within the same single housing for the module 108. Electrical connections between the various module components can proceed through the housings 220, 222, 224 and can be exposed to the exterior of any of the housings for connection with other modules 108 or other devices such as the MCD 112.

[0100] The modules 108 of the system 100 can be physically arranged relative to each other in various configurations depending on the application needs and the number of loads. For example, in a stationary application where the system 100 supplies power to a microgrid, the modules 108 can be placed in one or more racks or other frameworks. Such a configuration may also be suitable for larger mobile applications such as offshore vessels. Alternatively, the modules 108 can be fastened together and located in a common housing called a pack. The rack or pack may have its own dedicated cooling system shared by all modules. The pack configuration is useful for small mobile applications such as electric vehicles. The system 100 can be implemented in one or more racks (e.g., for parallel supply to a microgrid), or one or more packs (e.g., servicing different motors of a vehicle), or a combination thereof. FIG. 2D is a block diagram illustrating an example embodiment of the system 100 configured as a pack with nine modules 108 electrically and physically coupled together in a common housing 230.

[0101] Examples of these and further configurations are described in International Application No. PCT / US20 / 25366, filed March 27, 2020, and entitled Module-Based Energy Systems Capable of Cascaded and Interconnected Configurations, and Methods Related Thereto, which is incorporated by reference in its entirety for all purposes.

[0102] 3A-3C are block diagrams illustrating exemplary embodiments of modules 108 having various electrical configurations. These embodiments are described as having one LCD 114 per module 108, the LCDs 114 being housed within the associated module, but may be otherwise configured as described herein. FIG. 3A illustrates a first exemplary configuration of modules 108A within system 100. Module 108A includes an energy source 206, an energy buffer 204, and a converter 202A. Each component has a power connection port (e.g., terminal, connector), referred to herein as an IO port, through which power can be input and / or through which power can be output. Such ports may also be referred to as input or output ports, depending on the context.

[0103] The energy source 206 can be configured as any of the energy source types described herein (e.g., a battery, HED capacitor, fuel cell, or others, as described with respect to FIGS. 4A-4D). Ports IO1 and IO2 of the energy source 206 can be connected to ports IO1 and IO2, respectively, of the energy buffer 204. The energy buffer 204 can be configured to buffer or filter high and low frequency energy pulsations that reach the buffer 204 through the converter 202 and that may otherwise degrade the performance of the module 108. The topology and components for the buffer 204 are selected to accommodate the maximum allowable amplitude of these high frequency voltage pulsations. Several (non-exhaustive) exemplary embodiments of the energy buffer 204 are shown in the schematic diagrams of FIGS. 5A-5C. In FIG. 5A, the buffer 204 is configured to filter electrolytic and / or film capacitors C EB 5B, the buffer 204 is connected to two inductors L EB1 and L EB2 and two electrolytic and / or film capacitors C EB1 and C EB2 5C, the buffer 204 is formed by two inductors L EB1 and L EB2 and two electrolytic and / or film capacitors C EB1 and C EB2 and diode D EB and a quasi-Z source network 720 formed by

[0104] The ports IO3 and IO4 of the energy buffer 204 can be connected to the ports IO1 and IO2 of the converter 202A, which can be configured as any of the power converter types described herein. FIG. 6A is a schematic diagram illustrating an example embodiment of the converter 202A configured as a DC-AC converter that can receive DC voltages at ports IO1 and IO2 and switch to generate pulses at ports IO3 and IO4. The converter 202A can include multiple switches, where the converter 202A includes four switches S3, S4, S5, S6 arranged in a full-bridge configuration. The control system 102 or the LCD 114 can independently control each switch via the control input line 118-3 to each gate.

[0105] The switches can be any suitable switch type, such as power semiconductors, such as metal oxide semiconductor field effect transistors (MOSFETs) as shown here, insulated gate bipolar transistors (IGBTs), or gallium nitride (GaN) transistors. The semiconductor switches can operate at relatively high switching frequencies, thereby allowing the converter 202 to operate in a pulse width modulation (PWM) mode and respond to control commands within a relatively short time interval, if desired. This can provide high tolerance for output voltage regulation and fast dynamic behavior in transient modes.

[0106] In this embodiment, the DC line voltage V DCL can be applied to the converter 202 between ports IO1 and IO2. Different combinations of switches S3, S4, S5, and S6 allow DCL By connecting the +V DCL , 0, and -V DCL The switch signal provided to each switch controls whether the switch is on (closed) or off (open). DCLTo obtain -V, switches S3 and S6 are turned on while S4 and S5 are turned off. DCL can be obtained by turning on switches S4 and S5 and turning off S3 and S6. The output voltage can be set to zero (including near zero) or a reference voltage by turning on S3 and S5 with S4 and S6 turned off, or by turning on S4 and S6 with S3 and S5 turned off. These voltages can be output from the module 108 via the power connection 110. Ports IO3 and IO4 of the converter 202 can be connected (or formed) to module IO ports 1 and 2 of the power connection 110 to generate output voltages for use with output voltages from other modules 108.

[0107] The control or switch signals for the embodiments of converter 202 described herein can be generated in different ways depending on the control technique utilized by system 100 to generate the output voltage of converter 202. In some embodiments, the control technique is a PWM (pulse width modulation) technique, such as space vector pulse-width modulation (SVPWM) or sinusoidal pulse-width modulation (SPWM), or variations thereof. WM techniques. FIG. 8A is a voltage versus time graph showing an example of an output voltage waveform 802 of converter 202. For ease of description, the embodiments herein are described in the context of PWM control techniques, but the embodiments are not limited to such. Other classes of techniques can also be used. One alternative class is based on hysteresis, examples of which can be found in WO 2018 / 231810 A1, WO 2018 / 232403 A1, and WO 2019 / 183553 A1.

[0108] Each module 108 can be configured with multiple energy sources 206 (e.g., two, three, four, or more). Each energy source 206 of a module 108 can be controllable (switchable) to supply power to the connection 110 (or receive power from a charging source) independently of the other sources 206 of the module. For example, all sources 206 can output power (or be charged) to the connection 110 at the same time, or only one (or a subset) of the sources 206 can supply power (or be charged) at any one time. In some embodiments, the sources 206 of a module can exchange energy between themselves, e.g., one source 206 can charge another source 206. Each of the sources 206 can be configured as any energy source described herein (e.g., a battery, a HED capacitor, a fuel cell). Each of the sources 206 can be of the same class (e.g., each can be a battery, each can be a HED capacitor, or each can be a fuel cell), or can be of different classes (e.g., a first source can be a battery and a second source can be a HED capacitor or a fuel cell, or a first source can be a HED capacitor and a second source can be a fuel cell).

[0109] 3B is a block diagram illustrating an exemplary embodiment of a module 108B in a dual energy source configuration having a primary energy source 206A and a secondary energy source 206B. The ports IO1 and IO2 of the primary source 202A can be connected to the ports IO1 and IO2 of the energy buffer 204. The module 108B includes a converter 202B with an additional IO port. The ports IO3 and IO4 of the buffer 204 can be the connection ports IO1 and IO2 of the converter 202B, respectively. The ports IO1 and IO2 of the secondary source 206B can be connected to the ports IO5 and IO2 of the converter 202B, respectively (and can also be connected to the port IO4 of the buffer 204).

[0110] In this exemplary embodiment of module 108B, the primary energy source 202A, along with the other modules 108 of the system 100, supplies the average power required by the load. The secondary source 202B may function to assist the energy source 202 by providing additional power at load power peaks, or by absorbing excess power, or in other ways.

[0111] As mentioned above, both the primary source 206A and the secondary source 206B can be utilized at the same time or at different times depending on the switch state of the converter 202B. At the same time, the electrolytic capacitor and / or the film capacitor (C ES ) can be placed in parallel with source 206B as shown in FIG. 4E to act as an energy buffer for source 206B, or energy source 206B can be configured to utilize a HED capacitor in parallel with another energy source (e.g., a battery or fuel cell) as shown in FIG. 4F.

[0112] 6B and 6C are schematic diagrams illustrating example embodiments of converters 202B and 202C, respectively. Converter 202B includes switch circuit portions 601 and 602A. Portion 601 includes switches S3-S6 configured as a full bridge in a manner similar to converter 202A and configured to selectively couple IO1 and IO2 to either IO3 or IO4, thereby varying the output voltage of module 108B. Portion 602A includes switches S1 and S2 configured as a half bridge and coupled between ports IO1 and IO2. A coupled inductor L C is connected between port IO5 and node 1, which exists between switch S1 and switch S2, so that switch portion 602A is a bidirectional converter that can regulate (boost or buck) voltage (or reverse current). Switch portion 602A ... DCL2Two different voltages, 0 and 1, can be generated at node 1. The current drawn from or input to the energy source 202B can be controlled by the coupled inductor L, for example, using a pulse width modulation technique or a hysteretic control method to commutate the switches S1 and S2. C This can be controlled by adjusting the voltage on the MOSFET. Other techniques can also be used.

[0113] Converter 202C differs from that of 202B because switch portion 602B includes switches S1 and S2 configured as a half-bridge and coupled between ports IO5 and IO2. C is connected between port IO1 and a node 1 that exists between switch S1 and switch S2 such that switch portion 602B is configured to regulate the voltage.

[0114] The control system 102 or the LCD 114 can independently control each switch of the converters 202B and 202C via the control input lines 118-3 to each gate. In these embodiments and the embodiment of FIG. 6A, the LCD 114 (not the MCD 112) generates the switching signals for the converter switches. Alternatively, the MCD 112 can generate switching signals that can be communicated directly to the switches or relayed by the LCD 114. In some embodiments, driver circuitry for generating the switching signals can be present in or associated with the MCD 112 and / or the LCD 114.

[0115] The aforementioned zero voltage configuration of converter 202 (S3 and S5 on with S4 and S6 off, or S4 and S6 on with S3 and S5 off) can also be referred to as a bypass state for a given module. This bypass state can be entered when a fault is detected in a given module, or when a system fault is detected that justifies shutting off multiple (or all) modules in an array or system. The module fault can be detected by LCD 114, and a control switching signal for converter 202 can be set to engage the bypass state without intervention by MCD 112. Alternatively, the fault information for a given module can be communicated by LCD 114 to MCD 112, which can then decide whether to engage the bypass state, and if so, can communicate a command to engage the bypass state to the LCD 114 associated with the faulty module, at which point LCD 114 can output a switching signal to cause engagement of the bypass state.

[0116] In embodiments in which the module 108 includes more than two energy sources 206, the converters 202B and 202C can be scaled accordingly such that each additional energy source 206B is coupled to an additional IO port that leads to an additional switch circuit portion 602A or 602B, depending on the needs of the particular source. For example, the dual source converter 202 can include both switch portions 202A and 202B.

[0117] A module 108 with multiple energy sources 206 can perform additional functions such as energy sharing between the energy sources 206, energy harvesting from within the application (e.g., regenerative braking), charging a primary source with a secondary source even while the entire system is in a discharging state, and active filtering of the module output. The active filtering function can also be performed by a module with a typical electrolytic capacitor instead of a secondary energy source. Examples of these functions are described in more detail in International Application No. PCT / US20 / 25366, filed March 27, 2020, and entitled Module-Based Energy Systems Capable of Cascaded and Interconnected Configurations, and Methods Related Thereto, and International Application No. 2019 / 183553, filed March 22, 2019, and entitled Systems and Methods for Power Management and Control, both of which are incorporated herein by reference in their entirety for all purposes.

[0118] Each module 108 can be configured to supply its one or more energy sources 206 to one or more auxiliary loads. An auxiliary load is a load that requires a lower voltage than the primary load 101. An example of an auxiliary load can be, for example, an on-board electrical network of an electric vehicle, or an HVAC system of an electric vehicle. A load of the system 100 can be, for example, an electric vehicle motor or one of the phases of an electric grid. This embodiment can allow for a complete decoupling between the electrical characteristics of the energy source (terminal voltage and current) and the electrical characteristics of the load.

[0119] FIG. 3C is a block diagram illustrating an exemplary embodiment of a module 108C configured to power a first auxiliary load 301 and a second auxiliary load 302, the module 108C including an energy source 206, an energy buffer 204, and a converter 202B coupled together in a manner similar to FIG. 3B. The first auxiliary load 301 requires a voltage equal to the voltage provided by the source 206. The load 301 is coupled to IO ports 3 and 4 of the module 108C, which are in turn coupled to ports IO1 and IO2 of the source 206. The source 206 can output power to both the power connection 110 and the load 301. The second auxiliary load 302 requires a constant voltage lower than the voltage of the source 206. The load 302 is coupled to IO ports 5 and 6 of the module 108C, which are coupled to ports IO5 and IO2 of the converter 202B, respectively. The converter 202B is coupled to a coupled inductor L coupled to port IO5. C (FIG. 6B). The energy provided by the source 206 can be delivered to the load 302 through the switch portion 602 of the converter 202B. It is assumed that the load 302 has an input capacitor (if not, a capacitor can be added to the module 108C), so that the switches S1 and S2 are commutated to couple the coupled inductor L C 206 to a lower magnitude voltage required by the load 302.

[0120] Thus, module 108C can be configured to supply one or more first auxiliary loads in the manner described with respect to load 301, with one or more first loads coupled to IO ports 3 and 4. Module 108C can also be configured to supply one or more second auxiliary loads in the manner described with respect to load 302. If there are multiple second auxiliary loads 302, then for each additional load 302, module 108C can be scaled with additional dedicated module output ports (such as 5 and 6), additional dedicated switch sections 602, and additional converter IO ports coupled to the additional sections 602. You can do this.

[0121] Thus, energy source 206 can supply power to any number of auxiliary loads (e.g., 301 and 302), as well as a corresponding portion of the system output power required by primary load 101. Power flow from source 206 to the various loads can be adjusted as desired.

[0122] The module 108 can be configured with two or more energy sources 206 (FIG. 3B) as needed to supply a first and / or second auxiliary load (FIG. 3C) by adding a switch portion 602 and converter port IO5 for each additional energy source 206B or second auxiliary load 302. Additional module IO ports (e.g., 3, 4, 5, 6) can be added as needed. The module 108 can also be configured as an interconnect module to exchange energy between two or more arrays, two or more packs, or two or more systems 100 (e.g., for balancing), as described further herein. This interconnect function can be combined with multiple source and / or multiple auxiliary load supply functions as well.

[0123] The control system 102 may perform a variety of functions with respect to the components of the modules 108A, 108B, and 108C. These functions may include managing the utilization of each energy source 206, protecting the energy buffer 204 from overcurrent, overvoltage, and high temperature conditions, and controlling and protecting the converter 202.

[0124] For example, the LCD 114 may receive one or more monitored voltages, temperatures, and currents from each energy source 206 (or monitoring circuitry) to manage (e.g., adjust by increasing, decreasing, or maintaining) the utilization of each energy source 206. The monitored voltages may be at least one, and preferably all, of the voltages of each basic component independent of other components of the source 206 (e.g., each individual battery cell, HED capacitor, and / or fuel cell), or the voltages of the group of basic components as a whole (e.g., the voltages of the battery array, HED capacitor array, and / or fuel cell array). Similarly, the monitored temperatures and currents may be at least one, and preferably all, of the temperatures and currents of each basic component independent of other components of the source 206, or the temperatures and currents of the group of basic components as a whole, or any combination thereof. The monitored signals may be status information 160 that enables the LCD 114 to perform one or more of the following: calculate or determine an actual capacity, an actual State of Charge (SOC) and / or State of Health (SOH) of a base component or group of base components, set or output a warning or alarm indication based on the monitored and / or calculated status information 160, and / or transmit the status information 160 to the MCD 112. The LCD 114 may receive control information (e.g., modulation index, synchronization signals) from the MCD 112 and use this control information to generate switch signals for the converter 202 that manage the utilization of the source 206.

[0125] To protect the energy buffer 204, the LCD 114 can receive one or more monitored voltages, temperatures, and currents from the energy buffer 204 (or a monitoring circuit). The monitored voltages are measured by each basic component (e.g., C EB , C EB1 , C EB2 , L EB1 , L EB2 , D EB ) or the voltage of a group of basic components or buffer 204 as a whole (e.g., between IO1 and IO2, or between IO3 and IO4). Similarly, the monitored temperatures and currents may be at least one of the temperatures and currents of each basic component of buffer 204 independent of other components, or the temperatures and currents of the group of basic components or buffer 204 as a whole, or any combination thereof. The monitored signals may be one or more of the following: status information 160 that enables the LCD 114 to set or output a warning or alarm indication, communicate the status information 160 to the MCD 112, or control converter 202 to adjust (increase or decrease) utilization of the source 206 and module 108 as a whole for buffer protection.

[0126] To control and protect the converter 202, the LCD 114 can receive control information (e.g., a modulated reference signal, or a reference signal and a modulation index) from the MCD 112, which can be used in conjunction with PWM techniques in the LCD 114 to generate control signals for each switch (e.g., S1-S6). The LCD 114 can receive current feedback signals from current sensors in the converter 202, which can be used for overcurrent protection along with one or more fault status signals from the converter switch driver circuits (not shown), which can carry information regarding the fault status (e.g., short circuit or open circuit fault modes) of all switches in the converter 202. Based on this data, the LCD 114 can determine which combination of switching signals to apply to manage the utilization of the module 108, and potentially to bypass or disconnect the converter 202 (and the entire module 108) from the system 100.

[0127] When controlling module 108C supplying a second auxiliary load 302, LCD 114 displays one or more monitored voltages (e.g., the voltage between IO port 5 and IO port 6) and one or more monitored currents (e.g., the current of load 302, the coupled inductor L C Based on these signals, the LCD 114 can adjust the switching cycles of S1 and S2 (e.g., by adjusting the modulation index or reference waveform) to control (and stabilize) the voltage on the load 302.

[0128] Example of a cascaded energy system topology Two or more modules 108 can be coupled together in a cascaded array that outputs a voltage signal formed by the superposition of the discrete voltages generated by each module 108 in the array. FIG. 7A is a block diagram illustrating an example embodiment of a topology for the system 100 in which N modules 108-1, 108-2...108-N are coupled together in series to form a series array 700. In this embodiment and all embodiments described herein, N can be any integer greater than 1. The array 700 includes a first system IO port SIO1 and a second system IO port SIO2 at which the array output voltage is generated. The array 700 can be used as a DC or single-phase AC energy source for DC or AC single-phase loads that can be connected to SIO1 and SIO2 of the array 700. FIG. 8A is a voltage versus time plot illustrating an example output signal generated by a single module 108 having a 48 volt energy source. FIG. 8B is a voltage versus time plot illustrating an example single-phase AC output signal generated by an array 700 having six 48V modules 108 coupled in series.

[0129] The system 100 can be arranged in a wide variety of different topologies to meet the various needs of an application. The system 100 can supply polyphase power (e.g., 2-phase, 3-phase, 4-phase, 5-phase, 6-phase, etc.) to a load through the use of multiple arrays 700, each of which can generate an AC output signal having a different phase angle.

[0130] 7B is a block diagram showing the system 100 with two arrays 700-PA and 700-PB coupled together. Each array 700 is one-dimensional, formed by a series connection of N modules 108. The two arrays 700-PA and 700-PB can each generate a single-phase AC signal, with the two AC signals having different phase angles PA and PB (e.g., 180 degrees apart). The IO port 1 of the module 108-1 of each array 700-PA and 700-PB can form or be connected to system IO ports SIO1 and SIO2, respectively, which can then serve as the first output of each array that can supply two-phase power to a load (not shown). Or, alternatively, the ports SIO1 and SIO2 can be connected to supply single-phase power from the two parallel arrays. IO port 2 of module 108-N of each array 700-PA and 700-PB can serve as a second output for each array 700-PA and 700-PB at the opposite end of the array from system IO ports SIO1 and SIO2, which can be tied together at a common node and optionally used for an additional system IO port SIO3 that can function as neutral, if desired. This common node can be referred to as a rail, and IO port 2 of module 108-N of each array 700 can be referred to as being on the rail side of the array.

[0131] FIG. 7C is a block diagram illustrating a system 100 having three arrays 700-PA, 700-PB, and 700-PC coupled together. Each array 700 is one-dimensional, formed by a series connection of N modules 108. The three arrays 700-1 and 700-2 can each generate a single-phase AC signal, with the three AC signals having different phase angles PA, PB, PC (e.g., 120 degrees apart). IO port 1 of modules 108-1 of each array 700-PA, 700-PB, and 700-PC can form or connect to system IO ports SIO1, SIO2, and SIO3, respectively, which can then supply three-phase power to a load (not shown). IO port 2 of modules 108-N of each array 700-PA, 700-PB, and 700-PC can be coupled together at a common node, which can optionally be used for an additional system IO port SIO4 that can function as a neutral, if desired.

[0132] 7B and 7C can be extended to systems 100 that generate more phases of power. For example, a non-exhaustive list of additional examples includes a system 100 having four arrays 700, each of which is configured to generate a single-phase AC signal having a different phase angle (e.g., 90 degrees apart), a system 100 having five arrays 700, each of which is configured to generate a single-phase AC signal having a different phase angle (e.g., 72 degrees apart), and a system 100 having six arrays 700, each of which is configured to generate a single-phase AC signal having a different phase angle (e.g., 60 degrees apart).

[0133] The system 100 can be configured such that the arrays 700 are interconnected at electrical nodes between the modules 108 in each array. Figure 7D is a block diagram illustrating the system 100 having three arrays 700-PA, 700-PB, and 700-PC coupled together in a combined series and delta arrangement. Each array 700 includes a first series connection of M modules 108, where M is 2 or more, coupled with a second series connection of N modules 108, where N is 2 or more. The delta configuration is formed by the interconnections between the arrays, which can be located in any desired location. In this embodiment, IO port 2 of module 108-(M+N) of array 700-PC is coupled to IO port 2 of module 108-M and IO port 1 of module 108-(M+1) of array 700-PA, IO port 2 of module 108-(M+N) of array 700-PB is coupled to IO port 2 of module 108-M and IO port 1 of module 108-(M+1) of array 700-PC, and IO port 2 of module 108-(M+N) of array 700-PA is coupled to IO port 2 of module 108-M and IO port 1 of module 108-(M+1) of array 700-PB.

[0134] FIG. 7E is a block diagram illustrating a system 100 having three arrays 700-PA, 700-PB, and 700-PC coupled together in a combined series and delta arrangement. This embodiment is similar to that of FIG. 7D, except that it has a different cross-connection. In this embodiment, IO port 2 of module 108-M of array 700-PC is coupled to IO port 1 of module 108-1 of array 700-PA, IO port 2 of module 108-M of array 700-PB is coupled to IO port 1 of module 108-1 of array 700-PC, and IO port 2 of module 108-M of array 700-PA is coupled to IO port 1 of module 108-1 of array 700-PB. The arrangements of FIG. 7D and FIG. 7E can be implemented with as few as two modules in each array 700. The combined delta and series configuration allows for efficient energy exchange between all modules 108 of the system (inter-phase balancing) and the phases of the power grid or load, and also allows for a reduction in the total number of modules 108 in the array 700 to obtain a desired output voltage.

[0135] In the embodiments described herein, it is advantageous for the number of modules 108 to be the same for each array 700 in the system 100, but such is not required and different arrays 700 may have different numbers of modules 108. Furthermore, each array 700 may have modules 108 that are all of the same configuration (e.g., all modules are 108A, all modules are 108B, all modules are 108C, or the like) or different configurations (e.g., one or more modules are 108A, one or more are 108B, one or more are 108C, or the like). Thus, the range of topologies of the system 100 covered herein is broad.

[0136] Control method examples As mentioned, the control of the system 100 can be performed according to various methods, such as hysteresis or PWM. Some examples of PWM include space vector modulation and sinusoidal pulse width modulation, where the switching signals for the converter 202 are generated with a phase shifted carrier technique that continuously rotates the utilization of each module 108 to equally distribute the power between them.

[0137] 8C-8F are plots illustrating an exemplary embodiment of a phase-shifted PWM control method that can generate multi-level output PWM waveforms using incrementally shifted two-level waveforms. An X-level PWM waveform can be created by the sum of (X-1) / 2 two-level PWM waveforms. These two-level waveforms can be generated by comparing a reference waveform Vref to a carrier shifted by 360° / (X-1). The carrier is triangular, but the embodiment is not limited to such. A nine-level example (using four modules 108) is shown in FIG. 8C. The carrier is incrementally shifted by 360° / (9-1)=45° and compared to Vref. The resulting two-level PWM waveform is shown in FIG. 8E. These two-level waveforms can be used as switching signals for the semiconductor switches (e.g., S1-S6) of the converter 202. 8E, for a one-dimensional array 700 including four modules 108 each having a converter 202, the 0° signal is for control of S3 of the first module 108-1, the 180° signal is for S6 of the first module 108-1, the 45° signal is for S3 of the second module 108-2, the 225° signal is for S6 of the second module 108-2, the 90 signal is for S3 of the third module 108-3, the 270 signal is for S6 of the third module 108-3, the 135 signal is for S3 of the fourth module 108-4, and the 315 signal is for S6 of the fourth module 108-4. The signal for S3 is complementary to S4, and the signal for S5 is complementary to S6 with sufficient dead time to avoid shoot-through of each half-bridge. FIG. 8F illustrates an exemplary single-phase AC waveform produced by the superposition (addition) of the output voltages from four modules 108.

[0138] An alternative is to utilize both positive and negative reference signals on the first (n-1) / 2 carriers. A nine-level example is shown in FIG. 8D. In this example, the 0° to 135° switching signal (FIG. 8E) is generated by comparing +Vref with the 0° to 135° carrier of FIG. 8D, and the 180° to 315° switching signal is generated by comparing -Vref with the 0° to 135° carrier of FIG. 8D. However, the logic of comparison in the latter case is reversed. Other techniques, such as state machine decoders, may also be used to generate the gate signals for the switches of the converter 202.

[0139] In embodiments of a multi-phase system, the same carrier can be used for each phase, or the set of carriers can be shifted as a whole for each phase. For example, in a three-phase system with a single reference voltage (Vref), each array 700 can use the same number of carriers with the same relative offset, as shown in Figures 8C and 8D, but the carrier of the second phase is shifted 120 degrees compared to the carrier of the first phase, and the carrier of the third phase is shifted 240 degrees compared to the carrier of the first phase. If different reference voltages are available for each phase, then the phase information can be carried in the reference voltage and the same carrier can be used for each phase. Often the carrier frequency is fixed, but in some exemplary embodiments the carrier frequency can be adjusted, which can help reduce losses in the EV motor under high current conditions.

[0140] An appropriate switching signal can be provided to each module by the control system 102. For example, the MCD 112 can provide Vref and an appropriate carrier signal to each LCD 114 depending on the module or modules 108 that the LCD 114 controls, and the LCD 114 can then generate the switching signal. Or, all carrier signals can be provided to all LCDs 114 in the array, and the LCD can select the appropriate carrier signal. In another example, the LCD 114 can generate the carrier signal using a PWM controller, for example, as described below with reference to Figures 11A and 11B.

[0141] The relative utilization of each module 108 may be adjusted to perform balancing or based on one or more parameter status information 160 as described herein. Parameter balancing may involve adjusting utilization to minimize parameter variance over time compared to a system in which individual module utilization adjustments are not performed. Utilization may be the relative amount of time a module 108 is discharging when the system 100 is in a discharging state, or the relative amount of time a module 108 is charging when the system 100 is in a charging state.

[0142] As described herein, modules 108 may be balanced relative to other modules in an array 700, which may be referred to as intra-array or intraphase balancing, and different arrays 700 may be balanced relative to each other, which may be referred to as interarray or interphase balancing. Arrays 700 of different subsystems may also be balanced relative to each other. The control system 102 may simultaneously perform any combination of intra-phase balancing, inter-phase balancing, utilization of multiple energy sources within a module, active filtering, and auxiliary load supply.

[0143] 9A is a block diagram illustrating an example embodiment of an array controller 900 of a control system 102 for a single-phase AC or DC array. The array controller 900 can include a peak detector 902, a divider 904, and an intra-phase (or intra-array) balance controller 906. The array controller 900 can receive as inputs a reference voltage waveform (Vr) and status information 160 (e.g., state of charge (SOCi), temperature (Ti), capacity (Qi), and voltage (Vi)) for each of the N modules 108 in the array, and generate as outputs a normalized reference signal, e.g., a voltage waveform (Vrn), and a modulation index (Mi). The peak detector 902 detects the peak (Vpk) of Vr, which can be specific to the phase the controller 900 is operating on and / or balancing. The divider 904 generates Vrn by dividing Vr by its detected Vpk. The intra-phase balance controller 906 uses Vpk along with the status information 160 (eg, SOCi, Ti, Qi, Vi, etc.) to generate a modulation index Mi for each module 108 in the array 700 being controlled.

[0144] The modulation index and Vrn can be used to generate a switching signal for each converter 202. The modulation index can be a number between zero and one, inclusive. For a particular module 108, the normalized reference signal Vrn can be modulated or scaled by Mi, and this modulated reference signal (Vrnm) can be used as Vref (or -Vref) according to the PWM technique described with respect to Figs. 8C-8F, or according to other techniques. In this manner, the modulation index can be used to control the PWM switching signals provided to the converter switching circuits (e.g., S3-S6 or S1-S6), and thus regulate the operation of each module 108. For example, a module 108 controlled to maintain normal or full operation may receive a Mi of 1, a module 108 controlled to operate less than normal or full operation may receive a Mi less than 1, and a module 108 controlled to stop power output may receive a Mi of 0. This operation can be performed in a variety of ways by the control system 102, such as by the MCD 112 outputting Vrn and Mi to the appropriate LCD 114 for modulation and switch signal generation, by the MCD 112 performing modulation and outputting modulated Vrnm to the appropriate LCD 114 for switch signal generation, or by the MCD 112 performing modulation and switch signal generation to output the switch signal directly to the LCD or converter 202 of each module 108. Vrn can be transmitted continuously with Mi transmitted at regular intervals, such as once every period of Vrn or once every minute.

[0145] The controller 906 may use any type or combination of types of status information 160 described herein (e.g., SOC, temperature (T), Q, SOH, voltage, current) to generate Mi for each module 108. For example, using SOC and T, if the SOC is relatively high and the temperature is relatively low compared to other modules 108 in the array 700, the module 108 may have a relatively high Mi. If the SOC is relatively low or T is relatively high, the module 108 may have a relatively low Mi, resulting in a lower utilization than other modules 108 in the array 700. The controller 906 may determine Mi such that the sum of the module voltages does not exceed Vpk. For example, Vpk may be the sum of the products of the voltages of the sources 206 of each module and Mi for that module (e.g., Vpk=M1V1+M2V2+M3V3...+M N V N etc.) Different combinations of modulation indexes, and therefore respective voltage contributions by the modules, may be used, but the total generated voltage should remain the same.

[0146] The controller 900 may be configured to control the SOC of the energy sources in each module 108 to be balanced or to converge to a balanced state if unbalanced. The operation of the modules may be controlled to balance the power supply voltage and / or temperature of the energy sources or other components (e.g., energy buffers) in each module to remain balanced or converge to a balanced state if not balanced, without preventing the system from achieving its power output requirements at any time (e.g., during maximum acceleration of the EV). Power flow into and out of the modules may be adjusted so that capacitance differences between sources do not cause SOC deviations. Balancing SOC and temperature may indirectly cause SOH balancing. While voltage and current may be directly balanced if desired, in many embodiments the primary objective of the system is to balance SOC and temperature, and balancing SOC may result in voltage and current balancing in a highly symmetrical system where modules have similar capacitance and impedance.

[0147] Since it may not be possible to balance all parameters simultaneously (e.g., balancing one parameter cannot be further balanced by another parameter), a combination of balancing any two or more parameters (SOC, T, Q, SOH, V, I) may be applied with priority given to one or the other depending on the requirements of the application. Balancing priority may be given to SOC over other parameters (T, Q, SOH, V, I), with an exception being made if one of the other parameters (T, Q, SOH, V, I) reaches a severe out-of-threshold imbalance state.

[0148] Balancing between arrays 700 of different phases (or arrays of the same phase, e.g., if parallel arrays are used) can be performed simultaneously with intra-phase balancing. FIG. 9B illustrates an exemplary embodiment of an Ω-phase (or Ω-array) controller 950 configured for operation in an Ω-phase system 100 having at least an Ω-array 700, where Ω is any integer greater than 1. The controller 950 can include one inter-phase (or inter-array) controller 910 and intra-Ω-phase balance controllers 906-PA...906-PΩ for phases PA-PΩ, as well as peak detectors 902 and dividers 904 (FIG. 9A) for generating normalized references VrnPA-VrnPΩ from each phase-specific reference VrPA-VrPΩ. The intra-phase controller 906 can generate Mi for each module 108 of each array 700, as described with respect to FIG. 9A. The inter-phase balance controller 910 is configured or programmed to balance aspects of the modules 108 across the multi-dimensional system, for example, between arrays of different phases. This may be accomplished by injecting a common mode into the phases (e.g., neutral point shifting), or by the use of interconnection modules (as described herein), or both. Common mode injection involves introducing phase and amplitude shifts into the reference signals VrPA-VrPΩ to compensate for imbalances in one or more arrays to generate normalized waveforms VrnPA-VrnPΩ, as further described in International Application No. PCT / US20 / 25366, which is incorporated herein.

[0149] The controllers 900 and 950 (as well as the balance controllers 906 and 910) may be implemented in hardware, software, or a combination thereof within the control system 102. The controllers 900 and 950 may be implemented within the MCD 112, may be partially or fully distributed among the LCD 114, or may be implemented as discrete controllers separate from the MCD 112 and the LCD 114.

[0150] Example of an Interconnect (IC) Module Modules 108 may be connected between modules of different arrays 700 for the purpose of exchanging energy between arrays or for the purpose of acting as a source for auxiliary loads, or both. Such modules are referred to herein as interconnect (IC) modules 108IC. The IC modules 108IC may be implemented in any of the module configurations (108A, 108B, 108C) previously described, as well as other configurations described herein. The IC modules 108IC may include any number of one or more energy sources, optional energy buffers, switch circuits for providing energy to one or more arrays and / or for providing power to one or more auxiliary loads, control circuits (e.g., local control devices), and monitoring circuits for collecting status information 160 regarding the IC module itself or its various loads (e.g., SOC of the energy source, temperature of the energy source or energy buffer, capacity of the energy source, SOH of the energy source, voltage and / or current measurements associated with the IC module, voltage and / or current measurements associated with the auxiliary loads, etc.).

[0151] FIG. 10A is a block diagram illustrating an exemplary embodiment of a system 100 capable of generating Ω-phase power with Ω arrays 700-PA through 700-PΩ, where Ω can be any integer greater than 1. In this and other embodiments, IC module 108IC can be located on the rail side of array 700 such that the array 700 to which module 108IC is connected (in this embodiment, arrays 700-PA through 700-PΩ) is electrically connected between module 108IC and the output to the load (e.g., SIO1 through SIOΩ). Here, module 108IC has an ΩIO port for connection to IO port 2 of each module 108-N of array 700-PA through 700-PΩ. In the configuration shown here, module 108IC can perform phase-to-phase balancing by selectively connecting one or more energy sources of module 108IC to one or more of arrays 700-PA through 700-PΩ (or to none or equally to all outputs if phase-to-phase balancing is not required). The system 100 can be controlled by a control system 102 (not shown, see FIG. 1A).

[0152] FIG. 10B is a schematic diagram illustrating an exemplary embodiment of the module 108IC. In this embodiment, the module 108IC includes an energy source 206 connected to an energy buffer 204, which is connected to a switch circuit 603. The switch circuit 603 can include switch circuit units 604-PA to 604-PΩ for independently connecting the energy source 206 to each of the arrays 700-PA to 700-PΩ. Various switch configurations can be used for each unit 604, which in this embodiment is configured as a half-bridge with two semiconductor switches S7 and S8. Each half-bridge is controlled by a control line 118-3 from the LCD 114. This configuration is similar to the module 108A described with respect to FIG. 3A. As described with respect to the converter 202, the switch circuit 603 can be configured in any arrangement and with any switch type (e.g., MOSFET, IGBT, silicon, GaN, etc.) suitable for the requirements of the application.

[0153] The switch circuit unit 604 is coupled between the positive and negative terminals of the energy source 206 and has an output connected to an IO port of the module 108 IC. The units 604-PA to 604-PΩ are controlled by the control system 102 to switch the voltage +V IC or -V ICcan be selectively coupled to respective module I / O ports 1-Ω. The control system 102 can control the switch circuit 603 according to any desired control technique, including the PWM and hysteresis techniques described herein. Here, the control circuit 102 is implemented as an LCD 114 and an MCD 112 (not shown). The LCD 114 can receive monitoring data or status information 160 from the monitoring circuitry of the module 108 IC. This monitoring data and / or other status information 160 derived from this monitoring data can be output to the MCD 112 for use in system control as described herein. The LCD 114 can also receive timing information (not shown) for purposes of synchronizing the modules 108 of the system 100 with one or more carrier signals (not shown), such as sawtooth signals used in the PWM (FIGS. 8C-8D).

[0154] In the case of inter-phase balancing, proportionally more energy from the source 206 can be delivered to any one or more of the arrays 700-PA through 700-PΩ that are relatively low charged compared to the other arrays 700. The delivery of this supplemental energy to a particular array 700 allows the energy output of those cascaded modules 108-1 through 108-N within that array 700 to be reduced relative to the un-fed phase arrays.

[0155] For example, in some exemplary embodiments applying PWM, the LCD 114 may be configured to receive a normalized voltage reference signal (Vrn) (from the MCD 112) for each of the one or more arrays 700 to which the module 108 IC is coupled, e.g., VrnPA-VrnPΩ. The LCD 114 may also receive modulation indexes MiPA-MiPΩ for the switch units 604-PA-604-PΩ for each array 700, respectively, from the MCD 112. The LCD 114 may modulate (e.g., multiply) each Vrn with a modulation index for the switch section directly coupled to that array (e.g., multiply VrnA by MiA) and then utilize a carrier signal to generate a control signal for each switch unit 604. In other embodiments, the MCD 112 may perform the modulation and output a modulated voltage reference waveform for each unit 604 directly to the LCD 114 of the module 108 IC. In yet other embodiments, all processing and modulation may occur by a single control entity that may output control signals directly to each unit 604 .

[0156] This switching can be modulated so that power from the energy source 206 is provided at appropriate intervals and durations to the array 700. Such a method can be implemented in a variety of ways.

[0157] Based on collected status information 160 for the system 100, such as the current capacity (Q) and SOC of each energy source in each array, the MCD 112 can determine an aggregate charge for each array 700 (e.g., the aggregate charge for an array can be determined as the sum of the capacity vs. SOC for each module in that array). The MCD 112 can determine whether a balanced or unbalanced condition exists (e.g., by use of relative difference thresholds and other metrics described herein) and generate modulation indices MiPA through MiPΩ for each switch unit 604-PA through 604-PΩ accordingly.

[0158] During balanced operation, Mi for each switch unit 604 can be set to a value that causes each array 700 to be supplied with the same or similar amount of net energy over time by the energy source 206 and / or energy buffer 204. For example, Mi for each switch unit 604 can be the same or similar and can be set to a level or value that causes the module 108IC to perform a net or time-averaged discharge of energy to one or more arrays 700-PA to 700-PΩ during balanced operation, such that the module 108IC discharges at the same rate as other modules 108 in the system 100. In some embodiments, Mi for each unit 604 can be set to a level or value that causes no net or time-averaged discharge of energy (zero net energy discharge) during balanced operation. This can be useful when the module 108IC has a lower aggregate charge than other modules in the system.

[0159] When an unbalanced condition occurs between the arrays 700, the modulation index of the system 100 can be adjusted to converge toward a balanced condition or to minimize further divergence. For example, the control system 102 can cause a module 108 to discharge more into the array 700 at a lower charge than others, and cause the modules 108-1 to 108-N of the lower array 700 to discharge relatively less (e.g., on a time-averaged basis). The relative net energy contributed by the module 108 increases compared to the modules 108-1 to 108-N of the supported array 700, and compared to the amount of net energy module 108 contributing to other arrays. This can be achieved by increasing Mi for the switch unit 604 supplying that lower array 700, and by decreasing the modulation index of the modules 108-1 to 108-N of the lower array 700 in a manner that maintains Vout for that lower array at an appropriate or required level, while keeping the modulation index for the other switch units 604 supplying the other higher arrays relatively unchanged (or decreased).

[0160] 10A-10B may be used alone to provide inter-phase or inter-array balancing for a single system, or may be used in combination with one or more other modules 108IC, each having an energy source and one or more switch portions 604 coupled to one or more arrays. For example, a module 108IC having an Ω switch portion 604 coupled to an Ω different array 700 may be combined with a second module 108IC having one switch portion 604 coupled to an array 700, such that the two modules are combined to service a system 100 having an Ω+1 array 700. Any number of modules 108IC may be combined in this manner, each coupled to one or more arrays 700 of the system 100.

[0161] Additionally, the IC module may be configured to exchange energy between two or more subsystems of the system 100. FIG. 10C is a block diagram illustrating an example embodiment of the system 100 having a first subsystem 1000-1 and a second subsystem 1000-2 interconnected by an IC module. Specifically, the subsystem 1000-1 is configured to supply three-phase power PA, PB, and PC to a first load (not shown) via system I / O ports SIO1, SIO2, and SIO3, and the subsystem 1000-2 is configured to supply three-phase power PD, PE, and PF to a second load (not shown) via system I / O ports SIO4, SIO5, and SIO06, respectively. For example, the subsystems 1000-1 and 1000-2 may be configured as different packs that power different motors of an EV or as different racks that power different microgrids.

[0162] In this embodiment, each module 108IC is coupled to the first array of the subsystem 1000-1 (via IO port 1) and the first array of the subsystem 1000-2 (via IO port 2), and each module 108IC can be electrically connected to the other modules 108IC via I / O ports 3 and 4, which are coupled to the energy source 206 of each module 108IC as described with respect to the module 108C in FIG. 3C. This connection places the sources 206 of the modules 108IC-1, 108IC-2, and 108IC-3 in parallel, and thus the energy stored and supplied by the modules 108IC is pooled together by this parallel arrangement. Other arrangements, such as deep connections, can also be used. The modules 108IC are housed in a common enclosure of the subsystem 1000-1, but the interconnection module can be outside the common enclosure and physically located as an independent entity between the common enclosures of both subsystems 1000.

[0163] Each module 108IC has a switch unit 604-1 coupled to IO port 1 and a switch unit 604-2 coupled to I / O port 2, as described with respect to FIG. 10B. Thus, in the case of balancing between subsystems 1000 (e.g., pack-to-pack balancing or rack-to-rack balancing), a particular module 108IC can supply relatively more energy to one or both of the two arrays to which it is connected (e.g., module 108IC-1 can supply array 700-PA and / or array 700-PD). The control circuitry can monitor the relative parameters (e.g., SOC and temperature) of the arrays of the different subsystems and adjust the energy output of the IC modules to compensate for imbalances between arrays or phases of the different subsystems in the same manner as described herein to compensate for imbalances between two arrays of the same rack or pack. Because all three modules 108IC are in parallel, energy can be efficiently exchanged between any and all arrays of the system 100. In this embodiment, each module 108 IC supplies two arrays 700, although other configurations can be used including a single IC module for all arrays in system 100 and one dedicated IC module for each array 700 (e.g., six IC modules for six arrays with each IC module having one switch unit 604). In all cases with multiple IC modules, the energy sources can be coupled in parallel to share energy as described herein.

[0164] In systems with inter-phase IC modules, inter-phase balancing can also be performed with neutral point shifting (or common mode injection), as described above. Such a combination allows for more robust and flexible balancing under a wider range of operating conditions. System 100 can determine the appropriate circumstances to perform inter-phase balancing with a combination of only neutral point shifting, only inter-phase energy injection, or both simultaneously.

[0165] The IC module can also be configured to supply power to one or more auxiliary loads 301 (at the same voltage as source 206) and / or one or more auxiliary loads 302 (at a stepped-down voltage from source 302). FIG. 10D is a block diagram illustrating an example embodiment of a three-phase system 100A having two modules 108IC connected to perform phase-to-phase balancing and supply auxiliary loads 301 and 302. FIG. 10E is a schematic diagram illustrating this example embodiment of the system 100 with emphasis on modules 108IC-1 and 108IC-2. Here, the control circuit 102 is again implemented as an LCD 114 and MCD 112 (not shown). The LCD 114 can receive monitoring data from the modules 108IC (e.g., SOC of ES1, temperature of ES1, Q of ES1, voltages of auxiliary loads 301 and 302, etc.) and can output this and / or other monitoring data to the MCD 112 for use in system control as described herein. Each module 108IC may include a switch portion 602A (or 602B as described with respect to FIG. 6C) for each load 302 being supplied by that module, and each switch portion 602 may be controlled independently or based on a control input from the MCD 112 to maintain a required voltage level for the load 302 through the LCD 114. In this embodiment, each module 108IC includes switch portions 602A connected together to supply one load 302, although such is not required.

[0166] FIG. 10F is a block diagram illustrating another exemplary embodiment of a three-phase system configured to power one or more auxiliary loads 301 and 302 with modules 108IC-1, 108IC-2, and 108IC-3. In this embodiment, modules 108IC-1 and 108IC-2 are configured in the same manner as described with respect to FIGS. 10D-10E. Module 108IC-3 is configured in a purely auxiliary role and is not included in system 1. 3B, does not actively inject voltage or current into any of the arrays 700 of 108IC-3. In this embodiment, module 108IC-3 may be configured like module 108C of FIG. 3B, having converters 202B,C (FIGS. 6B-6C) with one or more auxiliary switch portions 602A, but omitting switch portion 601. Thus, one or more energy sources 206 of module 108IC-3 are interconnected in parallel with those of modules 108IC-1 and 108IC-2, and thus this embodiment of system 100 is configured with additional energy to supply auxiliary loads 301 and 302, as well as to maintain charge on sources 206A of modules 108IC-1 and 108IC-2 via their parallel connection with sources 206 of module 108IC-3.

[0167] The energy source 206 of each IC module can be, but is not required to be, the same voltage and capacity as the energy sources 206 of the other modules 108-1 through 108-N in the system. For example, a relatively high capacity may be desirable in an embodiment where one module 108 IC applies energy to multiple arrays 700 (FIG. 10A) to allow the IC module to discharge at the same rate as the modules in the phased array itself. If the module 108 IC is also supplying an auxiliary load, an even larger capacity may be desirable to allow the IC module to supply the auxiliary load and discharge at relatively the same rate as the other modules.

[0168] Examples of Second Life Energy Sources The energy sources 206 described herein can be used in the system 100 described herein in both first-life and second-life applications. The first-life of a source 206 is the original application in which the source 206 is used. For example, a first-life application is the first implementation in which the sources 206 are used by the first customer of the source 206 after their original manufacture (and not refurbished). The user of the source 206 in their first life would typically receive the source 206 from a manufacturer, distributor, or original equipment manufacturer (OEM). The batteries 206 used in first-life applications would typically have the same electrochemistry (e.g., the same lithium-ion electrochemistry variant (e.g., LFP, NMC)), the same nominal voltage, and have minimal (e.g., 5% or less) capacity variation across the pack or system. Use of the energy storage system with the battery 206 in those first-life applications will result in the battery 206 having a longer life in that first-life application, and upon removal from that first-life application, the battery 206 will be more similar in terms of capacity degradation than a battery from a first-life application that does not use the energy storage system.

[0169] As used herein, a "second-life" application refers to any application or implementation (e.g., a second implementation, a third implementation, a fourth implementation, etc.) after the first-life application of the source 206. A second-life energy source refers to any energy source (e.g., a battery or HED capacitor) implemented within the second-life application of the source.

[0170] An example of a first-life application for the battery 206 is in an energy storage system for an EV. Then, at the end of its life (e.g., after 100,000 miles of driving or after a threshold amount of degradation of the batteries in that battery pack), the battery 206 can be removed from the battery pack, optionally reconditioned and tested, and then implemented into a second-life application that can be used, for example, in a stationary energy storage system (e.g., residential, commercial, or industrial energy buffering, EV charging station energy buffering, renewable sources (e.g., wind, solar, hydroelectric), energy buffering, and the like) or another mobile energy storage system (e.g., a battery pack for an electric vehicle, bus, train, or truck). Similarly, the first-life application can be a first stationary application, and the second-life application can be a stationary or mobile application.

[0171] For second-life applications, sources 206 can be selected and / or utilized by system 100 to minimize (or at least reduce) any differences in initial capacity and nominal voltage. For example, sources 206 having a capacity difference of 5% or more can be included and operated within system 100 to provide energy for a load. In another example, an operator or automated system can select sources 206 for system 100 having a capacity difference within a threshold amount, e.g., to reduce the initial capacity difference between the sources of system 206. If a module 108 is compatible with both first and second-life applications (e.g., with or without reconfiguration), the module 108 can be selected for second-life applications based on the capacity difference of the sources 206 of the module 108.

[0172] The system 100 can individually adjust the utilization of each source 206 so that the sources 206 in the system 100 or packs of the system 100 are relatively balanced in terms of SOC or total charge (the product of SOC and capacity) when the pack or system 100 is discharged, even though the sources 206 in the system 100 may have widely varying capacities. Similarly, the system 100 can maintain balance when the pack or system 100 is charged. The sources 206 can vary not only in terms of capacity, but also in nominal voltage, power rating, electrochemical type (e.g., a combination of LFP and NMC batteries), and the like. Thus, the system 100 can be used such that all modules 206 in the system 100 or each pack of the system 100 are second-life energy sources (or a combination of first-life and second-life energy sources are used) and have various combinations of different characteristics.

[0173] As an example, the system 100 may include a second-life energy source 206 (and optionally one or more first-life energy sources 206) that has an energy capacity variation of 2% or more, 5% or more, 10% or more, 15% or more, 20% or more, or 25% or more, 30% or more, 5-30%, 10-30%, and / or 20-30%.

[0174] In another example, the system 100 may include a second-life energy source 206 (and optionally one or more first-life energy sources 206) that has an energy capacity per mass density variation of 2% or more, 5% or more, 10% or more, 15% or more, 20% or more, or 25% or more, 30% or more, 5-30%, 10-30%, and / or 20-30%.

[0175] In another example, the system 100 may include a second-life energy source 206 (and optionally one or more first-life energy sources 206) that has a peak power per mass density variation of 2% or more, 5% or more, 10% or more, 15% or more, 20% or more, or 25% or more, 30% or more, 5-30%, 10-30%, and / or 20-30%.

[0176] In another example, the system 100 may include a second-life energy source 206 (and optionally one or more first-life energy sources 206) having a nominal voltage variation of 2% or more, 5% or more, 10% or more, 15% or more, 20% or more, or 25% or more, 30% or more, 5-30%, 10-30%, and / or 20-30%.

[0177] In another example, the system 100 may include a second-life energy source 206 (and optionally one or more first-life energy sources 206) that has an operating voltage range variation of 2% or more, 5% or more, 10% or more, 15% or more, 20% or more, or 25% or more, 30% or more, 5-30%, 10-30%, and / or 20-30%.

[0178] In another example, the system 100 may include a second-life energy source 206 (and optionally one or more first-life energy sources 206) that has a maximum specified current rise time variation of 2% or more, 5% or more, 10% or more, 15% or more, 20% or more, or 25% or more, 30% or more, 5-30%, 10-30%, and / or 20-30%.

[0179] In another example, the system 100 may include a second-life energy source 206 (and optionally one or more first-life energy sources 206) that has a defined peak current variation of 2% or more, 5% or more, 10% or more, 15% or more, 20% or more, or 25% or more, 30% or more, 5-30%, 10-30%, and / or 20-30%.

[0180] An X% variation (e.g., 5% or more, or 5-30%) can be met by the variation between the module 108 in the system 100 having the highest value for that parameter and the module 108 having the lowest value for that parameter. For example, a 5% or more variation in capacity can be met by a system 100 in which the module 108 with the lowest capacity source 206 has a capacity that is 95% or less of that of the module 108 with the highest capacity source 206. For each and every embodiment and parameter disclosed herein, the time at which a system 100 having one or more second-life sources meets the X% variation condition in that parameter can be upon installation of the system 100, upon start-up of the system 100, after replacing one source 206 with another source 206, after the system 100 has operated for 10 hours or more, after the system 100 has operated for 100 hours or more, after the system 100 has operated for 1,000 hours or more, and / or after the system 100 has operated for 10,000 hours or more. For example, a capacity variation of 5% or more may occur after system 100 has been in operation for 1,000 hours, even if capacity variation was not present at the start of operation. This reflects the ability of embodiments of system 100 to continue to operate while accounting for capacity differences between sources 206 that increase with time of operation.

[0181] In another example, the system 100 may include a second-life energy source 206 (and optionally one or more first-life energy sources 206) having a variety of electrochemical types (e.g., a lithium-ion battery with a non-lithium-ion battery or a different lithium-ion battery (e.g., any combination of NMC, LFP, LTO, or other lithium-ion battery types)).

[0182] The system 100 can include a second-life energy source 206 (and optionally one or more first-life energy sources 206) having any combination of the characteristics provided in the preceding examples.

[0183] Examples of communication interfaces and control technologies in cascaded energy systems 11A-11B are block diagrams illustrating an example embodiment of modular energy system 100 having a communication path 115 connecting MCD 112 to LCD 114 of a module 108 (e.g., modules 108-1 through 108-N of arrays 700-PA through 700-PC). In general, MCD 112 sends control information to LCD 114 via communication path 115. As described in more detail below, MCD 112 and LCD 114 may include communication interfaces that enable MCD 112 and LCD 114 to communicate via communication path 115. For example, MCD 112 includes a control interface 1120 for communicating control information to LCD 114 via communication paths 115-1 to 115-3, an information interface 1130 for communicating information, such as status information 160, to LCD 114 via communication path 108, and a synchronization interface 1140 for transmitting synchronization signals to LCD 114 via communication paths or links 1141-1 to 1141-3.

[0184] The LCD 114 uses (e.g., receives and processes) the control information to generate switch signals that control the operation of one or more components (e.g., power converter 202) within the module 108. Although the LCD 114 is shown in FIG. 11B as being part of the module 108, each LCD 114 may be communicatively coupled to one or more modules 108, as described above. In this example, the modules 108 are arranged in three arrays 700-PA, 700-PB, and 700-PC of cascaded modules 108. The arrays 700-PA, 700-PB, and 700-PC may each generate a single-phase AC signal, with the three AC signals having different phase angles PA, PB, PC for phases A, B, and C (e.g., 120 degrees apart for a three-phase AC output). For example, array 700-PA may generate a single-phase AC signal for phase A, array 700-PB may generate a single-phase AC signal for phase B, and array 700-PC may generate a single-phase signal for phase C. Each array 700-PA, 700-PB, and 700-PC includes "N" modules 108, which may be the same or different for arrays 700-PA, 700-PB, and 700-PC.

[0185] The MCD 112 includes a controller 950. The controller 950 may include an inter-phase (or inter-array) controller 910 (FIG. 9B) and an intra-phase balance controller 906 (FIG. 9B) for each of the phases A, B, and C, as well as a peak detector 902 and a divider 904 (FIG. 9A). The controller 950 is configured to receive one or more reference signals 1105, such as reference voltages (e.g., Va, Vb, and Vc) for each phase and / or reference currents (e.g., Ia, Ib, and Ic) for each phase, and status information 160. The controller 150 is also configured to generate normalized reference signals VrnPA-VrnP from each phase-specific reference VrPA-VrPC based on the reference signals 1105 and the status information 160. Each intra-phase controller 906 of the controller 150 may also generate a modulation index Mi for each module 108 of the array 700 of the system 100 based on the reference signals 1105 and the status information 160. For example, the intra-phase controller 906-PA can generate MiPA1-MiPAn for modules 108-1 to 108-n of the array 700-PA, the intra-phase controller 906-PB can generate MiPB1-MiPBn for modules 108-1 to 108-n of the array 700-PA, and the intra-phase controller 906-PC can generate MiPC1-MiPCn for modules 108-1 to 108-n of the array 700-PC.

[0186] Although shown as reference voltage waveforms, the normalized reference signals VrnPA, VrnPB, and VrnPC output by the controller 950 include either a reference current or a reference voltage, e.g., a reference current waveform or a reference voltage waveform, for each of the three phases depending on the operating mode of the system 100. For example, when the system 100 is in a grid-connected mode such that the converters 202 of the modules 108 of the system 100 are connected to the grid and function like a current source, the converters 202 of the system 100 generate an output AC signal having the same voltage level, frequency, and phase of the grid. In the grid-connected mode, the reference signal 1105 can include data representing characteristics (e.g., phase, frequency, magnitude, etc.) of a reference current or current waveform based on the current waveform of the grid. When the system 100 is in a grid-independent (e.g., grid islanding) mode, the system 100 can function as a voltage source and the converters 202 of the system 110 can generate an output AC signal having a voltage level, frequency, and phase that was last known on the grid before the grid was disconnected. In a grid independent mode, the reference signal 1105 can include a reference voltage based on these characteristics. Each normalized reference signal VrnPA, VrnPB, and VrnPC represents a reference voltage or current waveform, respectively, that would mimic the AC output signal generated by the arrays 700-PA, 700-PB, and 700-PC, including the modules 108, but at a higher voltage or current level, for example.

[0187] As mentioned above, the modules 108 can use the reference signal as Vref (or -Vref) according to the PWM technique described with respect to Figures 8C-8F or according to other techniques. The controller 950 can generate a normalized reference signal for each array 700 and a modulation index Mi for each module 108 of each array 700. In this example, when the system 100 is used for multi-phase operation (e.g., split phase, three-phase, etc.), the controller 950 is configured to perform inter-phase balancing (e.g., in addition to intra-phase balancing) by independently scaling (e.g., scaling up or down) the normalized reference signal for each phase. In a single-phase implementation where the system includes a single array 700, the controller 900 can be used to generate the normalized reference signal for the array 700 using the peak detector 902 and divider 904, as described above, and generate the modulation index Mi for each module in the array 700 using the intra-phase balancing controller 906.

[0188] For each phase A, B, and C, the MCD 112 transmits the same normalized reference signal to the LCD 114 of each module 108 in the array 700 for that phase. That is, the MCD 112 can transmit a normalized reference signal VrnPA to the LCD 114 of the modules 108 in array 700-PA, the MCD 112 can transmit a normalized reference signal VrnPB to the LCD 114 of the modules 108 of array 700-PB, and the MCD 112 can transmit a normalized reference signal VrnPC to the LCD 114 of the modules 108 of array 700-PC.

[0189] In some implementations, for each phase A, B, and C, the MCD 112 also transmits a modulation index Mi for each module 108 in the array 700 for that phase to the LCD 114 of each module 108 in the array 700 for that phase. That is, the MCD 112 can transmit a modulation index MiPA1 for module 108-1 of the array 700-PA to the LCD 114 for modules 108-1 to 108-N of the array 700-PA, the MCD 112 can transmit a modulation index MiPA2 for module 108-2 of the array 700-PA to the LCD 114 for modules 108-1 to 108-N of the array 700-PA, and the MCD 112 can transmit a modulation index MiPA1 for module 108-N of the array 700-PA to the LCD 114 for modules 108-1 to 108-N of the array 700-PA.

[0190] The system 100 may include separate communication paths 115-1, 115-2, and 115-3 for each array 700-PA, 700-PB, and 700-PC, respectively. The MCD 112 may use the control interface 1120 to transmit control information including the normalized reference signal Vrn and the modulation index Mi to the modules 108 of the array 700 via the communication path 115 for the array 700. For example, the MCD 112 may transmit control information including the normalized reference signal VrnPA and the modulation index MiPA1 (for module 108-1), MiPA2 (for module 108-2), ~MiPAn (for module 108-N) to each LCD 114 of each module 108-1 ~ 108-N of the array 700-PA via separate communication paths 115-1 ~ 115-n connecting the MCD 112 to the LCD 114 of these modules 108.

[0191] In some implementations, each communication path 115 is a serial or parallel path configured to provide unidirectional communication from the MCD 112 to the LCD 114 of each module 108 in the array, e.g., array 700-PA, 700-PB, or 700-PC. In some implementations, each communication path 115 is a serial or parallel bidirectional path that allows bidirectional communication between the MCD 112 and the LCD 114 of each module 108 in the array, e.g., array 700-PA, 700-PB, or 700-PC. In some implementations, the communication paths 115 can be connected in a daisy chain, star network topology, mesh topology, or another suitable configuration.

[0192] The communication path 115 may include an RS-485 physical layer, and the control interface 1120 of the MCD 112 and the corresponding control interface 1742 of the LCD 114 (FIG. 17) may include a differential half-duplex serial synchronous interface. In this example, the communication path 115 may include twisted pair wiring that connects to the control interface 1120 of the MCD 112 and controls the interface 1742 of the LCD 114 of each array 700-PA, 700-PB, and 700-PC. The communication path 115 may be a unidirectional, time-deterministic communication path with a data sample time that is a multiple of the carrier frequency of the PWM signal of each module. Other suitable paths may also be used. Time-deterministic means that the control information data elements transmitted over the communication path 115 are transmitted according to a defined time period. That is, the data sample time is constant, and the time between successive communication data elements may also be constant, such that each LCD 114 has access to the time at which each control information data element will arrive.

[0193] Each module 108 can be assigned an identifier, for example. The identifier for the module 108 allows the MCD 112 to distinguish each module 108 from each other module 108 and to define which modulation index is for which module 108. Each module 108 in an array, for example, array 700-PA, 700-PB, or 700-PC, can have an identifier that is unique to the module 108 relative to other modules in the array. For example, the identifiers for the modules 108 of array 700-PA can all be unique within a particular implemented system such that they are different from one another.

[0194] In some implementations, the MCD 112 transmits control information to the modules 108 of the array, e.g., arrays 700-PA, 700-PB, or 700-PC, in the form of data elements that include, e.g., encode, the control information. These control information data elements can be in the form of one or more data packets per control information data element or a data frame for each control information data element. Each control information data element for the array 700 of modules 108 can include a normalized reference signal Vrn for the modules 108 (e.g., all modules 108) of the array 700, a modulation index Mi for one of the modules 108 of the array 700, and an identifier for one module 108 of the array 700. In other examples, the control information data element can include a modulation index Mi and an identifier for multiple modules 108 in the array 700. However, the MCD 112 can transmit updated reference signals to the modules 108 in the array 700 more quickly if less data (e.g., fewer modulation indexes and identifiers) is transmitted in each control information data element.

[0195] The MCD 112 may periodically, e.g., based on a defined time period, transmit control information data elements to the LCDs 114 of the modules 108 of the array, e.g., arrays 700-PA, 700-PB, or 700-PC, according to a sequence defining the order of the modules 108, in which updated modulation indexes are transmitted to the modules 108. For example, if the sequence for array 700-PA is module 108-1, module 108-2, etc. through 108-N, the MCD 112 may transmit a first control information data element to all modules 108-1 through 108-N of array 700-PA, including a normalized reference signal VrnPA for all modules 108-1 through 108-N in array 700-PA, a modulation index MiPA1 for module 108-1, and an identifier for module 108-1. Next, MCD 112 can transmit a second control information data element to all modules 108-1 to 108-N of array 700-PA, including normalized reference signals VrnPA for all modules 108-1 to 108-N in array 700-PA, modulation index MiPA2 for module 108-2, and an identifier for module 108-2. After reaching module 108-N in the sequence and transmitting a control information data element including normalized reference signals VrnPA for all modules 108-1 to 108-N in array 700-PA, modulation index MiPAn for module 108-N, and an identifier for module 108-N, MCD 112 can start over by transmitting an updated control information data element for module 108-1. MCD 112 can transmit control information data elements to each other's arrays 700-PB and 700-PC in a similar manner.

[0196] The MCD 112 can transmit each control information data element using a defined data protocol. The control information data element can be in the form of one or more data packets. Each data packet can include one or more data segments. Each control information data element includes multiple portions. The multiple portions can include a first portion with two or more bits assigned to represent, e.g., encode, an identifier for the module 108. The multiple portions can include a second portion with two or more bits assigned to represent a modulation index Mi for the module 108 identified by the identifier. The multiple portions can include a third portion with two or more bits assigned to represent a normalized reference signal Vrn for the module 108 in the array 700 that includes the module 108. The first, second, and third portions can be arranged in any pre-determined order within the control information data element. The control information data element can also optionally include one or more bits for error detection, e.g., Cyclic Redundancy Check (CRC). The various portions can be assigned specific bit positions within each byte of the control information data element such that their location within the data element does not vary. Each portion may extend across different bytes of the control information data element depending on the length of the portion.

[0197] In addition to the communication path or link 115 for transmitting control information to the LCD 114, the system 100 may include another communication path or link 1108 for exchanging data between the MCD 112 and each LCD 114. For example, the communication path 1108 may be used to transmit status information 160 from each module 108 to the MCD 112. The communication path 1108 may be a serial or parallel bidirectional path connecting the MCD 112 to the LCD 114 of each module 108 in the array, e.g., arrays 700-PA, 700-PB, or 700-PC. Each array 700-PA, 700-PB, and 700-PC may have a separate communication path 1108, or all of the arrays 700-PA, 700-PB, and 700-PC may share a common communication path 1108. In some implementations, the communication path 1108 is both bidirectional (MCD 112 to LCD 114 and LCD 114 to MCD 112) and is not time critical. The communication path 1108 may be implemented as a CAN bus to couple the MCD 112 to each LCD 114 for communication using the CAN protocol. In this example, the information interface 1130 may be a CAN interface. Other suitable types of communication paths may be used in place of CAN.

[0198] Using a combination of a unidirectional serial time-deterministic path for controlling the converter 202 and a bidirectional non-time-deterministic path for other data exchange can provide performance advantages, especially for applications with limited bandwidth, such as those where communication is performed over twisted pair. For example, this allows faster communication of the normalized reference signal from the MCD 112 to the LCD 114, while also ensuring timely updates to the modulation index and allowing error correction using CRC bits. Packing one modulation index into each control information data element can ensure that the normalized reference signals for all modules 108 are updated every frame (e.g., every time a control information data element is transmitted), while the modulation index for each module 108 is updated 1 / N times per frame (where N is the number of modules 108 in the array, e.g., arrays 700-PA, 700-PB, or 700-PC).

[0199] Each module 108 includes its LCD 114, a converter 202 including a switch circuit, and an energy source 206, e.g., one or more batteries. In general, the LCD 114 decodes control information data elements received from the MCD 112 and uses the decoded control information to control the switch circuit of the converter 202.

[0200] In this embodiment, each LCD 114 includes a combiner unit 1121 and a PWM controller 1123. The combiner unit 1121, which can be implemented in hardware and / or software, is configured to modulate or scale a normalized reference signal Vrn of the control information using a modulation index Mi of the control information. In some embodiments, the combiner unit 1121 is a software module of the LCD 114. The combiner unit 1121 outputs the modulated reference signal to the PWM controller 1123.

[0201] The PWM controller 1123, which may be implemented in hardware and / or software, generates switching signals for the switches of the converter 202 using PWM techniques such as those described above. The PWM controller 1123 may be configured to generate carrier signals using PWM counters. The PWM controller 1123 may use the PWM counters to provide an appropriate phase shift between the carrier signals for the switches of the converter 202.

[0202] The LCD 114 decodes the control information data element to obtain the normalized reference signal Vrn, the modulation index Mi, and the identifier. The combiner unit 1121 modulates or scales the normalized reference signal Vrn using the assigned modulation index Mi, e.g., the modulation index Mi received in the control information data element that includes the identifier for the module 108 that includes (or is communicatively coupled to) the LCD 114. When the LCD 114 receives the control information data element, the LCD 114 can determine whether the identifier included in the control information data element matches the identifier for that module 108. If there is a match, the combiner unit 1121 scales the normalized reference signal Vrn of the received control information data element using the modulation index Mi. If not, the combiner unit 1121 scales the normalized reference signal Vrn of the received control information data element using the most recently received modulation index Mi for the module 108 that includes (or is communicatively coupled to) the LCD 114.

[0203] For example, when the LCD 114-1 of the module 108 of the array 700-PA receives a control information data element including an identifier identifying the module 108-1 of the array 700-PA, the control information data element includes a normalized reference signal VrnPA for the array 700-PA and a modulation index MiPA1 for the module 108-1 of the array 700-PA. In this example, the LCD 114-1 of the module 108 of the array 700-PA uses this modulation index MiPA1 to scale the normalized reference signal VrnPA. The next control information data element can include an identifier identifying the module 108-2 of the array 700-PA, and the control information data element includes a normalized reference signal VrnPA for the array 700-PA and a modulation index MiPA2 for the module 108-2 of the array 700-PA. Instead of using the modulation index MiPA2 to scale the normalized reference signal VrnPA, module 108-1 of array 700-PA scales the newly received normalized reference signal VrnPA using the modulation index MiPA1 from the previously received control information data element.

[0204] When the LCD 114 receives a control information data element including an identifier for its module 108 and a modulation index Mi, the LCD 114 can store the modulation index Mi for scaling each received reference signal received by the LCD 114 until the next modulation index Mi for the LCD 114 is received. For example, the LCD 114-1 of the module 108 of the array 700-PA can receive a control information data element with a normalized reference signal VrnA and a modulation index MiPA1. The combiner unit 1121 can scale the normalized reference signal VrnA using the modulation index MiPA1, and the PWM controller 1123 can use the scaled reference signal to control the switch circuit of the module 108-1 of the array 700-P. The LCD 114-1 of the module 108 of the array 700-PA can also store the modulation index MiPA1. The next control information data element received by the LCD 114-1 of the module 108 of the array 700-PA may contain the updated normalized reference signal VrnA for the module 108-2 of the array 700-PA and the modulation index MiPA1, but not the modulation index MiPA1 for the module 108-1 of the array 700-PA. The combiner unit 1121 of the module 108-1 of the array 700-PA may scale the reference signal VrnPA using the previously received and stored modulation index MiPA1. The combiner unit 1121 of the module 108-1 of the array 700-PA may continue to do this until another modulation index MiPA1 is received in a control information data element containing an identifier for the module 108-1 of the array 700-PA.

[0205] The combiner unit 1121 of each LCD 114 can use its modulation index Mi to scale the normalized reference signal Vrn, for example, by determining the product of the normalized reference signal Vrn and its modulation index MiPA1. The PWM controller 1123 of each LCD 114 can then operate the switch circuit of its converter 202 (e.g., generate a control signal for each switch) using PWM or hysteresis techniques based on the scaled reference signal, as described in detail above. In this manner, the modulation index Mi can control the PWM switching signal provided to the power converter switching circuit, and thus regulate the operation of the module 108, using a modulation index Mi similar to that described above. The outputs of each converter 202 can be connected together to provide an accumulated output signal, for example, to a load for stationary or mobile applications.

[0206] For example, as described above with reference to Figures 8C and 8D, the carrier signal for each module 108 in the array 700 is phase shifted to generate a multi-level output voltage. To ensure proper phase shifting of the carrier signal between modules 108, the PWM counters of the PWM controllers 1123 of the modules 108 can be synchronized using the synchronization techniques described herein. In general, when a PWM synchronization event is detected, the PWM controller 1123 can reset its PWM counters and restart the carrier signal generated by the PWM controller 1123.

[0207] In some embodiments, the PWM controller 1123 is synchronized using a synchronization signal transmitted from the MCD 112 via paths 1141-1 through 1141-3. In such embodiments, the MCD 112 includes a synchronization interface 1140 configured to generate the synchronization signal. In some embodiments, the PWM controller 1123 is synchronized using a data absent event, as described in more detail below. In such embodiments, the MCD 112 may or may not include a synchronization interface 1140.

[0208] The communication paths 1141-1-1141-3 may traverse the desired unidirectional or bidirectional physical layer, which may be, for example, an RS-485 or Ethernet physical layer. The synchronous interface 1140 of the MCD 112 and the corresponding synchronous interface 1743 of the LCD 114 (FIG. 17) may each include a corresponding interface, such as a differential half-duplex serial synchronous interface for an RS-485 or Ethernet transceiver. The communication paths 1141-1-1141-3 may include twisted pair wiring connecting the synchronous interface 1140 of the MCD 112 to the synchronous interface 1743 of the LCD 114 of each of the arrays 700-PA, 700-PB, and 700-PC. In other embodiments, the cabling may be optical fiber other than twisted pair or a different conductive arrangement.

[0209] The paths and links 105, 106, 115, 116, 118, 1108, 1141, 1213 (FIG. 12), and 2501-2508 (FIG. 25A) discussed herein may be single conduit or multiple conduit paths or links, and different paths or links (e.g., 115 and 1141) between the same entities (e.g., MCD 112 and LCD 114) may be consolidated or combined onto a single path. To the extent the present embodiments are described with reference to the RS-485 standard, that is for ease of explanation and the embodiments are not limited to use only with RS-485, but are also applicable to other forms of communication, whether standardized or non-standardized.

[0210] The synchronization signal can be used for multiple purposes, for example, the synchronization signal can be used to synchronize the PWM controller 1123, to synchronize the receipt of control information data packets, and / or to wake the LCD 114 when it is in a sleep mode.

[0211] In general, the synchronization signal may be a modulated signal, e.g., a modulated square wave signal. MCD 112 may adjust the pulse width of a sequence of pulses in the synchronization signal and / or the frequency of the synchronization signal to trigger a synchronization event. MCD 112 may be configured to use different types of modulation based, for example, on the physical layer used for paths 1141-1-1141-3 and / or the type of isolation used to isolate interfaces 1140 and 1743 from paths 1141-1-1141-3. Exemplary synchronization techniques are described in further detail below.

[0212] 12 is a block diagram illustrating an example embodiment of a single-phase energy system 100. The system 100 includes an external control device 104, an MCD 112, and an array 700 of cascaded modules 108 (108-1 through 108-5). The example array 700 includes five modules 108, although other suitable numbers of modules 108 may be used.

[0213] Each module 108 includes an LCD 114, a converter 202, batteries 206-1 and 206-2, and an internal communication path 118. Although two batteries 206-1 are shown, the module 108 may include other numbers of batteries 206. The internal communication paths include a communication path 118-1 that communicatively couples the converter 202 and the battery 206-1, and a communication path 118-2 that communicatively couples the batteries 206-1 and 206-2. The communication path 118-1, which may be an RS-485 physical layer or another suitable path, allows the LCD 114 to obtain status information for the battery. Although a battery 206 is shown in this example, other energy sources may be used as described above.

[0214] As described above, the LCD 114 can scale the normalized reference signal Vrn using the modulation index Mi and operate the circuitry of the converter 202 using PWM techniques based on the scaled reference signal. Each converter 202 can be configured to convert the DC signals from the batteries 206-1 and 206-2 to an AC signal. The combined AC signal of the modules 108-1 through 108-5 outputs to a load interface 1260, which can be electrically connected to a load. In some implementations, the load interface 1260 is a terminal block to which conductors can be connected.

[0215] The external control device 104 allows an operator to monitor and control the operation of one or more loads, including the loads connected to the load interface 1260. This can include controlling when and how much power is provided to the loads. The external control device 104 can provide an interactive interface, for example, a graphical user interface (GUI), that allows an operator to monitor and control the power to the loads.

[0216] The external control device 104 is communicatively coupled to the MCD 112 via a communication path or link 105. In some implementations, this communication path 105 may be implemented using a Modbus protocol, a Profibus protocol, or another suitable communication protocol. The external control device 104 may provide power control information to the MCD 112 via the communication path 105. This power control information may include, for example, a target voltage level, a target current level, a target AC frequency, a target phase, and / or other suitable characteristics of a target AC voltage waveform for the load.

[0217] The MCD 112 controls the modules 108-1-108-5 and generates an output AC waveform to the load interface 1260 based on power control information received from the external control device 104, status information 160 for the modules 108-1-108-5, and characteristics of the AC waveform output by the modules 108-1-108-5 received from the coupling module 1212. Because the system 100 includes a single array 700 for a single phase, the MCD 112 will balance the modules 1221 using intra-phase balancing but will not use inter-array balancing. As described above, the MCD 1210 can generate normalized reference signals Vrn and modulation indexes Mi for the modules 108-1-108-5 using the information and balancing techniques.

[0218] The system 100 includes a communication path 115 communicatively coupling the MCD 112 to the LCD 114 of each module 108. The MCD 112 can transmit control information data elements to the LCD 114 via the communication path 115. As described above, the control information data elements can include a normalized reference signal, a modulation index Mi for the module 108, and an identifier for the module 108. As described above, the communication path 115 can be a serial communication path coupled to individual communication interfaces of the MCD 112 and LCD 114 of each module 108-1 through 108-5 in the array 700.

[0219] The MCD 112 and LCD 114 of each module 108-1-108-5 may also communicate via a bidirectional communication path 1108 that communicatively couples the MCD 112 to the LCD 114 of each module 108. As described above, the communication path 1108 allows the MCD 112 and LCD 114 to exchange information, such as status information 160 for each module 108-1-108-5.

[0220] The system 100 also includes a communication path 1141 that communicatively couples the MCD 112 to the LCD 114 of each module 108. As described above, the MCD 112 can transmit a synchronization signal to the LCD 114 via the communication path 1141.

[0221] Each embodiment of the system 100 described herein can include one or more combining modules 1212. Each system embodiment can have a single combining module. The combining module 1212 connects in series with the output of the converter 202 such that the combining module 1212 can measure characteristics of the AC waveform output by the module 1221. These characteristics can include, for example, the voltage and current levels of the AC waveform. An exemplary combining module is shown in Figures 16A-16B and described below.

[0222] The coupling module 1212 is communicatively coupled to the MCD 112 using a communication path or link 1213. The coupling module 1212 provides the measured characteristics to the MCD 112 via the communication path 1213. In some implementations, the communication path 1213 is a High-Speed ​​Serial Interface (HSSI). The HSSI can include parallel data lines or differential pairs enabling data transfer rates of 1 to 2+ Gigabits per second (Gbps).

[0223] Figure 13 is a block diagram illustrating an example embodiment of a split-phase energy system 100. System 100 differs from system 100 of Figure 12 by having two arrays 700-PA and 700-PB, each including "N" modules 108 (108-1 through 108-N), to provide a three-wire split-phase AC output to a load interface 1260 that can be connected to a load. Load interface 1260 can include terminals that make a first AC system output (L1), a second AC system output (L2), and a neutral system output (N) electrically available to a load.

[0224] Each module 108 may include an LCD 114, a converter 202, batteries 206-1 and 206-2, and internal communication paths as described above. The AC outputs of arrays 700-PA and 700-PB may be the same voltage (e.g., 120V), but the AC output of array 700-PA may be 180 degrees out of phase with the AC output of array 700-N. This may produce an AC output signal measured between system output L1 and system output L2 that is twice the magnitude of the AC output signal from each array (e.g., between L1 and N) taken individually. All of the embodiment systems 100 described herein may be optionally implemented in a split-phase topology.

[0225] The system 100 includes a combining module 1212 (e.g., combining modules 1212-1 and 1212-2). The MCD 112 controls the modules 108 and generates and outputs a split-phase AC waveform to the load interface 1260 based on power control information received from the external control device 104, status information 160 for the modules 108, and characteristics of the AC voltage waveform output by the modules 108 received from the combining modules 1212-1 and 1212-2. Because the system 100 includes multiple arrays 700-PA and 700-PB for split-phase power conversion, the MCD 112 can be configured to balance the modules 108 using intra-phase balancing and / or inter-phase balancing. As described above, the MCD 112 can generate a normalized reference signal Vrn and a modulation index Mi for the modules 108 using the information and balancing techniques.

[0226] The system includes communication paths 115, e.g., communication paths 115-1 and 115-2. Communication path 115-1 communicatively couples the MCD 112 to the LCD 114 of each module 108 in array 700-PA. Similarly, communication path 115-2 communicatively couples the MCD 112 to the LCD 114 of each module 108 in array 700-PB.

[0227] The MCD 112 can transmit control information data elements to the LCD 114 of the module 108 of the array 700-PA via communication path 115-1. Similarly, the MCD 112 can transmit control information data elements to the LCD 114 of the module 108 of the array 700-PB via communication path 115-2. As described above, the control information data elements can include a normalized reference signal Vrn, a modulation index Mi for the module 108, and an identifier for the module 108. As described above, the communication path 115 can be a serial communication path coupled to the MCD 112 and the LCD 114 of each module 108.

[0228] By using two different communication paths 115-1 and 115-2, the MCD 112 can transmit a single normalized reference signal to each module 108 of the array 700-PA via communication path 115-1, and a single normalized reference signal to each module 108 of the array 700-PB via communication path 115-2. Because the normalized reference signals for different arrays may differ, for example, by at least having different phase angles, this can reduce the amount of data transmitted along each communication path 115-1 and 115-2 and increase the rate at which updated normalized reference signals are transmitted to each module 108. For example, the MCD 112 does not need to include both normalized reference signals in the same data frame because if the MCD 112 were to alternate between the two reference signals, this would increase the size of the data frame or reduce the rate at which control information is transmitted to the modules 108.

[0229] The MCD 112 and LCD 114 of each module 108 may also communicate via a bidirectional communication path that communicatively couples the MCD 112 to the LCD 114 of each module 108. Similar to the communication path 1108 of FIGS. 11A-11B, this bidirectional communication path allows the MCD 112 to exchange information, such as status information 160 for each module 108. Both arrays 700-PA and 700-PB may share a common bidirectional communication path or may have separate bidirectional communication paths, for example, one that communicatively couples the LCD 114 of the modules 108 of array 700-PA to the MCD 112 and one that communicatively couples the LCD 114 of the modules 108 of array 700-PB to the MCD 112.

[0230] System 100 may also include a communication path 1141-1 that communicatively couples MCD 112 to the LCD 114 of each module 108 of array 700-PA. Similarly, system 100 may also include a communication path 1141-2 that communicatively couples MCD 112 to each module 108 of array 700-PB. As described above, MCD 112 may transmit a synchronization signal to LCD 114 via communication path 1141.

[0231] The coupling module 1212-1 connects in series with the outputs of the converters 202 of the modules 108 of the array 700-PA such that the coupling module 1212-1 can measure characteristics of the AC waveform output by the modules 108 of the array 700-PA. These characteristics can include, for example, the voltage and current levels of the AC waveform. The coupling module 1212-1 communicatively couples to the MCD 112 using a communication path 1213. The coupling module 1212-1 provides the monitored characteristics to the MCD 112 via the communication path 1213.

[0232] The combining module 1212-1 connects in series with the outputs of the converters 202 of the array 700-PB of modules 108 such that the combining module 1212-2 can measure characteristics of the AC waveform output by the modules 108 of the array 700-PB. These characteristics can include, for example, the voltage and current levels of the AC waveform. Although not shown, the combining module 1212-2 can be connected to the MCD 112 in the same manner as the combining module 1212-1, for example, using the communication path 1213.

[0233] The embodiments of the system 100 described herein may include a single combining module 1212 electrically connected to both arrays 700-PA and 700-PB, or may include multiple discrete combining modules 1212, one for each array 700-A and 700-B. In this example, both of the outputs of the converters 202 of each array 700-PA and 700-PB may be separately connected in series with the combining module 1212 such that the combining module 1212 may measure characteristics of the AC waveform output by each array 700-PA and 700-PB and provide the measured characteristics to the MCD 112.

[0234] Figure 14 is a block diagram illustrating an example embodiment of a three-phase energy system 100. System 100 differs from systems 100 of Figures 12 and 13 by having three arrays 700-PA, 700-PB, and 700-PC, each including "N" modules 108 (108-1 through 108-N), to provide a four-wire, three-phase AC output to a load interface 1260 that can connect to a load.

[0235] Each module 108 may include an LCD 114, a converter 202, batteries 206-1 and 206-2, and an internal interface as described above. The AC output of each array may be 120 degrees out of phase with each other array.

[0236] The system 100 includes a combining module 1212 (e.g., combining modules 1212-1, 1212-2, and 1212-3). The MCD 112 controls the modules 108 to generate and output a three-phase AC waveform to a load interface 1260 based on power control information received from the external control device 104, status information 160 for the modules 108, and characteristics of the AC voltage waveform output by the modules 108 received from the combining modules 1212-1, 1212-2, and 1212-3. Because the system 100 includes multiple arrays 700-PA, 700-PB, and 700-PC for three-phase power conversion, the MCD 112 can be configured to balance the modules 108 using intra-phase balancing and / or inter-phase balancing. As described above, the MCD 112 can use information and balancing techniques to generate a normalized reference signal Vrn and a modulation index Mi for the module 108.

[0237] System 100 includes communication paths 115, e.g., communication paths 115-1, 115-2, and 115-3. Communication path 115-1 communicatively couples MCD 112 to the LCD 114 of each module 108 in array 700-PA. Similarly, communication path 115-2 communicatively couples MCD 112 to the LCD 114 of each module 108 in array 700-PB, and communication path 115-3 communicatively couples MCD 112 to the LCD 114 of each module 108 in array 700-PC.

[0238] The MCD 112 can transmit control information data elements to the LCD 114 of the module 108 of the array 700-PA via communication path 115-1. Similarly, the MCD 112 can transmit control information data elements to the LCD 114 of the module 108 of the array 700-PB via communication path 115-2, and transmit control information data elements to the LCD 114 of the module 108 of the array 700-PC via communication path 115-3. As described above, the control information data elements can include a normalized reference signal Vrn, a modulation index Mi for the module 108, and an identifier for the module 108. As described above, the communication path 115 can be a serial interface coupled to the MCD 112 and the LCD 114 of each module 108.

[0239] The MCD 112 and the LCD 114 of each module 108 may also communicate via a bidirectional communication path that communicatively couples the MCD 112 to the LCD 114 of each module 108. Similar to the communication path 1108 of FIGS. 11A-11B, this bidirectional communication path allows the MCD 112 and the LCD 114 to exchange information, such as status information 160 for each module 1421. All three arrays 700-PA, 700-PB, and 700-PC may share a common bidirectional communication path or may have separate bidirectional communication paths, e.g., one that communicatively couples the LCD 114 of the modules 108 of array 700-PA to the MCD 112, one that communicatively couples the LCD 114 of the modules 108 of array 700-PB to the MCD 112, and one that communicatively couples the LCD 114 of the modules 108 of array 700-PC to the MCD 112.

[0240] System 100 also includes a communication path 1141-1 that communicatively couples MCD 112 to the LCD 114 of each module 108 in array 700-PA. Similarly, system 100 includes a communication path 1141-2 that communicatively couples MCD 112 to each module 108 in array 700-PB, and a communication path 1141-3 that communicatively couples MCD 112 to each module 108 in array 700-PC. As described above, MCD 112 can transmit a synchronization signal to LCD 114 via communication path 1141.

[0241] The coupling module 1212-1 connects in series with the outputs of the converters 202 of the modules 108 of the array 700-PA such that the coupling module 1212-1 can measure characteristics of the AC waveform output by the modules 108 of the array 700-PA. These characteristics can include, for example, the voltage and current levels of the AC waveform. The coupling module 1212-1 communicatively couples to the MCD 112 using a communication path 1213. The coupling module 1212-1 provides the monitored characteristics to the MCD 112 via the communication path 1213.

[0242] The combining module 1212-2 connects in series with the outputs of the converters 202 of the modules 108 of the array 700-PB such that the combining module 1212-2 can measure characteristics of the AC waveform output by the modules 108 of the array 700-PB. These characteristics can include, for example, the voltage and current levels of the AC waveform. Although not shown, the combining module 1212-2 can be connected to the MCD 112 in the same manner as the combining module 1212-1, for example, using the communication path 1213.

[0243] The combining module 1212-3 connects in series with the outputs of the converters 202 of the modules 108 of the array 700-PC such that the combining module 1212-3 can measure characteristics of the AC waveform output by the modules 108 of the array 700-PC. These characteristics can include, for example, the voltage and current levels of the AC waveform. Although not shown, the combining module 1212-3 can be connected to the MCD 112 in the same manner as the combining module 1212-1, for example, using the communication path 1213.

[0244] In some implementations, the three-phase energy system 100 may include a single combining module 1212 for all three arrays 700-PA, 700-PB, and 700-PC. In this example, the outputs of the converters 202 of each array 700-PA, 700-PB, and 700-PC may each be separately connected in series with the combining module 1212 such that the combining module 1212 may measure characteristics of the AC waveform output by each array 700-PA, 700-PB, and 700-PC and provide the measured characteristics to the MCD 112.

[0245] Figure 15 is a block diagram illustrating interfaces of an exemplary embodiment of MCD 112. MCD 112 may be used to implement the MCD of any of systems 100 described herein. MCD 112 also includes components not shown in Figure 15, such as controller 900, controller 950, and / or other components as described above. Certain types of interfaces are shown in Figure 15 and described below, although other types of suitable interfaces may be used.

[0246] The MCD 112 includes a control interface 1510 that includes an external control device interface 1511 (e.g., a High Level Control System (HLCS) transceiver), a local computer interface 1512 (e.g., a USB-COM transceiver), and an internet interface 1513 (e.g., an Ethernet transceiver). The external control device interface 1511 can be configured to communicate with the external control device 104 over path 105. As an example, the external control device interface 1511 can be implemented as an RS-485 serial interface for coupling to a bus coupled to a site controller. Other suitable interfaces can also be used. The external control device 104 can provide power control information to the MCD 112 through the external control device interface 1511.

[0247] The local computer interface 1512 can be configured to communicate with one or more computers, for example, via a USB cable. The Internet interface 1513 is configured to connect the MCD 112 to a remote system, for example, via the Internet or another network. The MCD 112 can use the Ethernet transceiver to get firmware updates, retrieve log information, etc. from the remote system.

[0248] The MCD 112 includes discrete inputs 1520. The discrete inputs 1520 receive feedback from the coupling module 1212. In this example, the discrete inputs 1520 include a ground fault status input for receiving an indication of a ground fault (at GND_SAFE) or another type of fault, such as a power failure (at +24V_SAFE). In the event of a fault, the MCD 112 can instruct or cause the system 100 to terminate operation and shut down. The discrete inputs can also include a coupling module status input to indicate whether a grid contactor connecting the system 100 to the grid is closed and whether a load contactor connecting the system 100 to a load is closed.

[0249] The MCD 112 includes discrete outputs 1530. The discrete outputs 1530 include one or more outputs to a grid contactor to control a grid contactor switch (e.g., an electromechanical relay) that selectively connects and disconnects the grid, and one or more outputs to a load contactor to control a load contactor switch (e.g., an electromechanical relay) that selectively connects and disconnects the load. The grid contactor switches and the load contactor switches can be located within the system 100, such as within the coupling module 1212, as desired.

[0250] The MCD 112 includes a serial interface 1540, e.g., an HSSI, configured to provide a high-speed interface for receiving signals from the combining module 1212. For example, the combining module 1212 can digitize analog signals and transmit them to the MCD 112 via a serial bus coupled to the HSSI 1540.

[0251] The MCD 112 includes an analog input 1550 configured to receive as an analog input the analog output from the combining module 1212. The analog input may include sensed voltage and current measurements output by each array 700 for the various phases.

[0252] As described above, the combining module 1212 can measure characteristics of the AC waveform output by the module 108. These characteristics can include, for example, the voltage and current levels of the AC waveform. The combining module 1212 can provide the characteristics for each phase in analog form to a corresponding analog input and / or digitally to the serial interface 1540, which can be implemented as an HSSI, as described above.

[0253] The MCD 112 includes a digital interface 1560 for communicating with the LCD 114 of the module 108. The digital interface 1560 can be bidirectional and / or unidirectional, and can communicate information according to various standardized or custom protocols. Here, the interface 1560 includes a bidirectional CAN protocol transceiver 1562 (e.g., for each phase of the output AC signal) for each array 700 of the cascaded module 108. For example, the digital interface 1560 includes a CAN transceiver A 1562-1 for the array 700-PA, a CAN transceiver B 1562-2 for the array 700-PB, and a CAN transceiver C 1562-3 for the array 700-PC. The CAN transceivers 1562 are configured to communicate over a CAN bus that couples the CAN transceivers 1562 to the CAN transceivers of the LCD.

[0254] The CAN transceiver 1562 allows for bidirectional data exchange directly between the MCD 12 and the LCD 114 and between the LCDs 114. For example, the LCD 114 can send status information 160 to the MCD 112 via the CAN bus. If a module 108 detects a fault, the LCD 114 can notify the MCD 112, and the MCD 112 can instruct the faulty module to terminate operation. The CAN interface also allows communication between any LCD 114 and any other LCD 114. This can be useful when one of the LCDs 114 detects a fault but there is also a fault within the MCD 112 such that the MCD 112 is unable to take action in response to the fault. In this case, a fault command sent from the faulty LCD 114 is received by the other operational LCDs 114, which can take a safety action, for example, disconnecting the converter 202 from the AC line. Using a CAN interface or other protocol with similar capabilities allows the MCD 112 to be bypassed and the LCD 114 to instruct the other LCDs 114 in the array 700 to, for example, shut down. Although the MCD 112 includes a CAN transceiver for each array, the MCD 112 can communicate with the LCDs 114 of multiple arrays using a single CAN transceiver via a single CAN bus coupled to the MCDs 112 and each LCD 114 in the multiple arrays. The number of CAN buses can vary based on, for example, the bandwidth of the interface and the data being transmitted across the interface.

[0255] The digital interface 1560 also includes a serial transceiver 1564, e.g., an RS-485 transceiver, configured to be coupled to a serial bus, e.g., a twisted pair cable. The serial transceiver 1564 may be implemented, for example, as an RS-485 transceiver and / or an Ethernet transceiver.

[0256] The MCD 112 transmits control information to the LCD 114 using a serial transceiver 1564. As described above, the control information may include a normalized reference signal, a modulation index, and an identifier for the module. The MCD 112 includes a serial transceiver 1564 for each array of cascaded modules (e.g., for each phase of the output AC signal). In particular, the MCD 112 includes a serial transceiver A 1564-1 for transmitting control information to the LCD 114 of the module 108 in array A, a serial transceiver B 1564-2 for transmitting control information to the LCD 114 of the module 108 in array B, and a serial transceiver C 1564-3 for transmitting control information to the LCD 114 of the module 108 in array C.

[0257] The digital interface 1560 also includes a wake interface 1565. The wake interface 1565 can be used to send a wake signal to the LCDs 114 to wake them from a sleep mode of operation. For example, the MCD 112 can send a command to instruct the LCDs 114 to enter a sleep mode of operation via the interface 1565. To wake the LCDs 114 from a sleep mode of operation, the MCD 112 can send a wake signal to each LCD 114 using the wake interface 1565.

[0258] The MCD 112 includes an analog to digital converter (ADC) that converts analog signals to digital signals. The MCD 112 includes light-emitting diode (LED) indicators 1572 that indicate information about the MCD 112 and / or the system 110 that includes the MCD 112, such as status information, fault information, etc. The MCD 112 also includes a display 1573 that displays information about the MCD 112 and / or the system 110 and / or allows a user to provide information or commands to the MCD 112. For example, the display 1573 may include a touch screen or other input device that allows a user to interact with the MCD 112.

[0259] The MCD 112 includes volatile memory 1574 (e.g., DRAM) and non-volatile memory (e.g., flash memory, hard drive, etc.) 1575. The volatile memory 1574 can be used in the execution of instructions and to store data currently being used, while the non-volatile memory 1575 can be used to store energy independent information, such as logs.

[0260] MCD 112 includes a control device 1576, which may be in the form of a processor, a microcontroller, a Field Programmable Gate Array (FPGA), or other suitable type of control device. Control device 1576 may execute software that performs various functions of MCD 112 as described herein. For example, control device 1576 may implement controller 900 and / or controller 950.

[0261] The MCD 112 includes a programming interface 1577. The programming interface 1577 allows a user to program and / or debug the MCD 112. In some implementations, the programming interface 1577 includes a Joint Test Action Group (JTAG) interface.

[0262] The MCD 112 includes one or more power supplies 1578 for powering the various hardware components of the MCD 112. The MCD 112 also includes an internal bus 1590 that communicatively couples the various hardware components of the MCD 112.

[0263] 16A-16B are block diagrams illustrating example components of the combining module 1212. The combining module 1212 can be used to implement the combining modules described herein.

[0264] 16A, the combining module 1212 includes a voltage and current detector 1605 for each of the one or more phases. In this example, the combining module 1212 includes a phase A voltage and current detector 1605-1, a phase B voltage and current detector 1605-2, and a phase C voltage and current detector 1605-3. Each voltage and current detector 1605 may include a voltage sensor and a current sensor to measure the voltage and current of the AC waveform generated by the converter 202 for that phase.

[0265] Each voltage and current detector 1605 can provide its voltage and current measurements to the MCD 112 via communication path 1213. The communication path 1212 can include a digital signal path and / or an analog signal path. When the communication path 1212 is a digital signal path, the combining module 1212 can include an ADC to convert the analog measurements to digital signals. The combining module 1212 can provide the digital signals to the serial interface 1540 (FIG. 15) via the communication path 1213.

[0266] When the communication path 1213 includes an analog signal path, the communication path 1213 can include a separate conductor for each measurement. The combining module 1212 can provide the analog measurements to the analog inputs 1550 (FIG. 15) via the communication paths 1213.

[0267] The coupling module 1211 includes a grid controller 1670 and a grid status module 1675. The grid controller 1670 can operate a grid switch that selectively connects the system 100 to a grid. The grid status module 1675 can receive a status signal that indicates whether the grid switch is open or closed. For example, the grid status module 1675 can be coupled to a contactor of the grid switch that opens or closes with the grid switch.

[0268] The coupling module 1211 includes a load controller 1680 and a load status module 1685. The load controller 1680 can operate a load switch that selectively connects the system 100 to a load. The load status module 1685 can receive a status signal indicating whether the load switch is open or closed. For example, the load status module 1685 can be coupled to a contactor of the load switch that opens or closes with the load switch.

[0269] FIG. 16B provides additional details of the internal components of the example combining module 1212. The combining module 1212 includes a sensor 1611 for each phase of a three-phase AC signal. The sensors 1611-1 to 1611-3 can be part of the detectors 1605-1 to 1605-3, respectively. Each set of sensors 1611-1 to 1611-3 can include a voltage sensor that measures the voltage of that phase and a current sensor that measures the current of that phase and provides the measured values ​​to a separate interface 1612-1 to 1612-3, which can include a shielded RJ-45 jack. The interfaces 1612-1 to 1612-3 can be coupled to separate cables that connect the combining module 1212 to a network that is also coupled to the MCD 1212. In this manner, the combining module 1212 can provide the measured voltage and current to the MCD 1212. In some implementations, the combining module 1212 provides the measured signals to the MCD 1212 as differential analog signals. In some implementations, the coupling module 1212 uses HSSI to provide the measured signal to the MCD 1212. Other suitable communication interfaces may also be used.

[0270] The coupling module 1212 includes a grid contactor status switch 1676 that is part of or implements a grid status module 1675. When the grid switch is closed, the grid contactor status switch 1676 may also be closed to indicate that the grid switch is closed. The coupling module 1212 also includes a load contactor status switch 1686 that is part of or implements a load status module 1685. When the load switch is closed, the load contactor status switch 1686 may also be closed to indicate that the load switch is closed.

[0271] The coupling module 1212 also includes a grid relay 1671 that is part of or implements a grid controller 1670. The coupling module 1212 can close the grid relay 1671, energize the coil of the grid switch, and close the grid switch. The coupling module 1211 can open the grid relay 1671, de-energize the coil of the grid switch, and open the grid switch.

[0272] The coupling module 1212 also includes a load relay 1681 that is part of or implements a load controller 1680. The coupling module 1212 can close the load relay 1681, energize the coil of the load switch, and close the load switch. The coupling module 1211 can open the load relay 1681, de-energize the coil of the load switch, and open the load switch.

[0273] The coupling module 1212 also includes a connector 1660 for connecting to conductors of the coupling module 1212, and a ground fault interrupter (GFI) 1690 for detecting ground faults.

[0274] The MCD 1212 can send commands to the coupling module 1212 to close the grid relay 1671 or the load relay 1681 to minimize overcurrent in the energy storage system (ESS) due to unsynchronized AC line and ESS voltages. The MCD 1212 can send commands to open the grid relay 1671 and the load relay 1681 due to islanding detection or other fault detection signals such as overvoltage, undervoltage, overcurrent, overtemperature, etc.

[0275] 17 is a block diagram illustrating an example embodiment of an LCD 114. The LCD 114 can be used to implement the LCD 114 described herein. As mentioned above, the LCD 114 can be part of a module 108 that includes, in addition to the LCD 114, an energy source 206 (e.g., one or more batteries) and a converter 202. A particular type of interface is shown in FIG. 17 and described below, although other types of suitable interfaces can be used.

[0276] The LCD 114 includes a BMS interface 1711 configured to communicate with a BMS 1710, which manages and / or monitors one or more batteries of the module's energy source. In some implementations, the BMS interface 1711 includes a CAN controller coupled to a CAN bus, which is also coupled to the BMS 1710. The BMS interface 1711 can receive battery status information 160 from the BMS 1710 via the CAN bus. The battery status information can include, for example, voltage, current, temperature, SOC, SOH, and depth of discharge (DOD).

[0277] The LCD 114 includes a battery module controller 1713 configured to perform functions to protect the batteries. For example, the battery module controller 1713 can be configured to receive battery status information and perform balancing among the batteries 206 of the modules 108, and provide over-voltage, under-voltage, over-current, and under-current protection for the batteries 206 of the modules 108.

[0278] The LCD 114 includes a ConBatt interface 1721 configured to communicate with a ConBatt converter 1720. The Combatt interface 1721 can include an ADC controller, a PWM controller, and a GPIO controller, each configured to communicate with the ConBatt converter 1720, e.g., a serial interface converter. The ADC controller can receive analog data from the Combatt converter 1720, convert the analog data to a digital format, and send the digital data to the memory 122. The ConBatt converter 1720 can also be a power converter, similar to the converters of FIGS. 6A-6C, and can include a power switch gate drive and a DC link circuit.

[0279] The LCD 114 includes a human machine interface (HMI) interface 1731 configured to communicate with an HMI 1730 of the module 108. The HMI 1730 can provide a user interface, including interactive controls, that displays status information 160 for the module 108 and allows an operator to locally control the module 108.

[0280] The LCD 114 includes a CAN interface 1741 and a control interface 1742 configured to communicate with the MCD 112. The CAN interface 1741 can transmit status information 160 for the modules 108 to the MCD 112, for example, via a CAN bus coupled to the CAN interface 1742 and the MCD 112. The CAN controller 1741 can obtain the status information 160 from the memory 122 and transmit the status information 160 to the MCD 112 via the CAN bus.

[0281] The control interface 1742 can receive control information, for example, in the form of control information data elements, from the MCD 112 via a serial interface, including a serial bus coupled to the control interface 1742 and the MCD 112. The control interface 1742 can receive the control information data elements and transmit the control information data elements to the memory 122 for storage. The control interface 1742 can be connected to a control information communication device configured to decode the control information data elements received from the MCD 112.

[0282] The LCD 114 also includes a synchronization interface 1743 configured to receive a synchronization signal from the MCD 112, and a wake interface 1744. As described in more detail below, the synchronization signal can be used to receive control information data packets and wake the LCD 114 from a sleep mode of operation. While in the sleep mode of operation, the LCD 114 can be configured to monitor the wake interface 1744 for a wake signal, e.g., in the form of a synchronization signal. If a wake signal is detected, the LCD 114 can activate other components of the LCD 114 (e.g., each interface) and transition to an active mode of operation.

[0283] The LCD 114 also includes a control device 1760, which may be in the form of a processor, microcontroller, FPGA, or other suitable type of control device. For example, the control device 1760 may include the processing circuitry 120. The control device 1760 may execute software that performs various functions of the LCD 114 as described herein.

[0284] The LCD 114 also includes a memory 122, which may include volatile and / or non-volatile memory. The LCD 114 also includes an internal bus 1590 that communicatively couples the various hardware components of the LCD 114.

[0285] 18 is a flow diagram illustrating an example embodiment of a method 1800 for transmitting control information data elements to a local control device and outputting a voltage waveform based on the control information data elements. The method 1800 can be performed by an energy system including an MCD 112 and one or more arrays 700 of cascaded modules 108. For example, the method 1800 can be performed by any one of the systems 100 having an MCD 112 and an LCD 114 described herein. As described above, each module 108 can include an energy source 206, a converter 202 including a switch circuit, and an LCD 114. Each module 108 in the array 700 can also have an identifier that identifies the module 108 and is unique within the array 700.

[0286] In step 1810, the MCD 112 receives input signals, including feedback signals and status information 160. The feedback signals for each array 700 may include voltage and current measurements (and / or other characteristics) made by a combining module 1212 that connects in series with the outputs of the converters 202 of the array 700 of modules 108. As described above, the combining module 1212 may measure the voltage and current of each phase and provide data indicative of the voltage and current of each phase to the MCD 112.

[0287] The status information 160 may include status information 160 for each module 108 in the array 700 of cascaded modules 108. As discussed above, the status information 160 may include information regarding one or more aspects, characteristics, or parameters of each module 108, such as the SOC of one or more energy sources of the module 108, the SOH of one or more energy sources 206 of the module 108, the temperature of one or more energy sources 206 or other components of the module 108, the capacity of one or more energy sources 206 of the module 108, the voltage of one or more energy sources 206 and / or other components of the module 108, the current of one or more energy sources 206 and / or other components of the module 108, the SOP, SOE, and / or the presence or absence of a fault in any one or more of the components of the module 108.

[0288] The input signals may also include set points received by the MCD 112 from the external control device 104. These set points may include target voltages and / or target currents, e.g., target voltage and / or target current waveforms to be output by each array 700. The set points may include other characteristics of the target output AC waveform, such as phase and / or frequency.

[0289] The MCD 112 is configured to receive the status information 160 via a bidirectional communication path between the MCD 112 and the LCD 114 of each module 108. For example, the bidirectional path may include a CAN bus or another suitable communication path.

[0290] In step 1820, the MCD 112 generates a normalized reference signal Vrn for the array 700 of cascaded modules 108 for each phase. As described above, the MCD 112 can include a controller 950 configured to generate the normalized reference signal Vrn based on a feedback signal. In some implementations, the MCD 112 can determine a difference between a set point and the feedback signal as a regulation error. The MCD 112 can generate the normalized reference signal Vrn to compensate for the error. For example, the MCD 112 can adjust the normalized reference signal based on the error using a controller, such as a proportional-integral (PI), proportional-integral-derivative (PID), or other suitable controller.

[0291] In step 1830, the MCD 112 generates a modulation index Mi for the module 108 of the array 700 based on the status information 160. Step 1830 can be performed after, before, or in parallel with step 1820. As described above, the module 108 can be balanced relative to other modules 108 in the array 700 (intra-phase balancing), and different arrays 700 can be balanced relative to each other (inter-phase balancing). The modulation index Mi for the modules 108 in the array 700 can be different. For example, if one of the modules 108 has a higher temperature than the others, the MCD 112 can decrease the output voltage level of that module 108 by decreasing the modulation index Mi for that module 108. To ensure that the voltage level to the load remains at its target, the MCD 112 can also increase the modulation index Mi for one or more of the other modules 108, increasing the output voltage level of the module 108. Thus, the modulation index Mi for at least one module 108 in the array 700 may be different from the modulation index Mi for at least one other module 108 in the array 700.

[0292] In step 1840, the MCD 112 transmits a control information data element to the module 108. The MCD 112 can transmit a different control information data element to each array 700 of cascaded modules 108. The control information data element for the array 700 can include a normalized reference signal Vrn for all modules 108 of the array 700, a single identifier for a single module 108 of the array 700, and a modulation index Mi for the single module 108. As described above, the MCD 112 can cycle through the modules 108 in the array 700 in a sequence such that once every cycle, the MCD 112 provides a modulation index Mi for each module 108 in the array 700. During this cycle, the MCD 112 selects an identifier for one of the modules 108 and can include the modulation index Mi and the identifier for the selected module 108 in the control information data element. An exemplary process for transmitting a control information data element to the LCD 114 is shown in FIG. 19 and described below. As mentioned above, the MCD 112 can transmit control information data elements to the LCD 114 via a serial communication path.

[0293] In step 1850, each LCD 114 scales the normalized reference signal Vrn using the modulation index Mi. The LCD 114 is configured to receive the control information data element and decode the data element to obtain the normalized reference signal Vrn, the modulation index Mi for one of the modules 108, and an identifier for the one module 108 encoded in the control information data element.

[0294] The LCD 114 is also configured to determine whether the identifier of the control information data element matches the identifier of the module that includes the LCD 114, for example, by comparing the identifiers. If they match, the LCD 114 can scale the normalized reference signal Vrn of the control information data element using the modulation index Mi of the control information data element. If they do not match, the LCD 114 can scale the normalized reference signal Vrn of the control information data element using the modulation index Mi of the most recently received control information data element that includes the identifier for the module 108 that includes the LCD 114. As described above, scaling the normalized reference signal Vrn using the modulation index Mi can include multiplying the normalized reference signal Vrn by the modulation index Mi.

[0295] In step 1860, each LCD 114 uses the scaled reference signal to control the switch circuitry of the converter 202 of the module 108 that contains the LCD 114. The LCD 114 can operate the switch circuitry of its converter 202 (e.g., generate control signals for each switch) using PWM or hysteresis techniques based on the scaled reference signal, as described in detail above. In this manner, the modulation index Mi can be used to control the PWM switching signals provided to the power converter switching circuits and thus regulate the operation of the module 108.

[0296] The MCD 112 and LCD 114 can continuously execute the method 1800 to adjust the AC waveform output to a load connected to the output of the converter 202. For example, the MCD 112 can periodically transmit the control information data element based on a defined time period. In another example, the MCD 112 can transmit the control information data element whenever there is a change in the normalized reference signal Vrn or a change in one of the modulation indexes Mi.

[0297] 19 is a flow diagram illustrating an example embodiment of a method 1900 for transmitting control information data elements to the LCD 114. The method may be performed by the MCD 112.

[0298] In step 1910, the MCD 112 selects a module 108 of the array 700 of cascaded modules 108 to provide the modulation index Mi. As described above, the MCD 112 may select the modules 108 in a prescribed sequence, for example, from a first module 108, to a second module 108, to a third module 108, etc.

[0299] In step 1920, the MCD 112 generates a control information data element including a modulation index Mi and an identifier for the selected module 108. The MCD 112 can encode in the control information data element the normalized reference signal Vrn for all modules 108 in the array 700, the modulation index Mi for the selected module 108, and the identifier for the selected module 108.

[0300] In step 1930, the MCD 112 transmits the control information data element to the modules 108 in the array 700, for example, all modules 108 in the array 700. The MCD 112 then returns to step 1910, where the MCD 112 selects another module 108 in the sequence. If the most recently transmitted control information data element includes a modulation index Mi and an identifier for the last module 108 in the sequence, the MCD 112 can start over with the first module 108 in the sequence.

[0301] The LCD 114 can employ a variety of techniques for receiving the control information data elements over the serial communication path. One technique involves determining when a complete control information data element has been received and whether additional data packets are being received based on the duration of time that has elapsed since the first data packet was received. Another technique involves the MCD 112 sending a synchronization signal to the LCD 114 that indicates when the control information data element will arrive at the LCD 114. An exemplary method corresponding to the first technique is shown in FIG. 20, and an exemplary method corresponding to the second technique is shown in FIG. 22.

[0302] Exemplary Techniques for Receiving Control Information FIG. 20 is a flow diagram illustrating an exemplary embodiment of a method 2000 for receiving control information data elements. The method 2000 can be performed by an LCD 114 of an energy system including an MCD 112 and one or more arrays 700 of cascaded modules 108. For example, the method 2000 can be performed by any one of the systems 100 having an MCD 112 and an LCD 114 described herein. As described above, each module 108 can include an energy source 206, a converter 202 including a switch circuit, and an LCD 114. Each module 108 in the array 700 can also have an identifier that identifies the module 108 and is unique within the array 700. The method 2000 is additionally described with reference to FIG. 21, which is a schematic diagram illustrating an exemplary data stream 2100.

[0303] In step 2010, the LCD 114 detects a first data unit on a communication interface connected to the communication path at least a threshold duration of time since the previous control information data element was received. As described above, the MCD 112 can periodically transmit a control information data element that includes a normalized reference signal Vrn. The control information data element can also include a modulation index Mi and an identifier for the module 108 to which the modulation index Mi corresponds.

[0304] In some embodiments, each control information data element is a data frame that includes one or more data segments. In this example, each data unit may be a data segment of a data frame.

[0305] The MCD 112 may transmit the control information data elements periodically such that there is a period of time between the end of reception of one control information data element and the transmission of the next control information data element. For example, referring to FIG. 21, there is a duration of time between each pair of consecutive data frames 2110, 2120, and 2130. This period of time may be used by the LCD 114 to ensure that the control information data element has been completely received and to determine that a newly received data unit after the period of time is for a new control information data element. The threshold duration of time may be this period of time or may be based on this period of time. For example, if the MCD waits 150 microseconds after transmitting one control information data element before transmitting the next control information data element, the threshold duration of time may be 150 microseconds or a shorter period of time, e.g., 100 microseconds, 50 microseconds, or another suitable duration. In some implementations, the minimum threshold duration of time is, for example, the duration to transmit one byte of data over communication path 115 of FIGS. 11A-11B.

[0306] As mentioned above, each control information data element can have a common data size. In some implementations, the control information data element can have a data size of 4 bytes. Other data sizes less than or greater than 4 bytes can also be used. Each data unit can be one byte, one data packet, or another portion of data that can be transmitted one time across a communication path.

[0307] In step 2020, the LCD 114 determines whether a new control information data element has been received that includes the detected data unit. The LCD 114 can be configured to determine whether a new control information data element has been received based on the duration of time that has elapsed since the first data unit was received and whether additional data units have been received after the data reception time period for the new control information data element. The LCD 114 can use configuration steps 2021-2026 to determine whether a new control information data element has been received.

[0308] The LCD 114 starts a timer in response to detecting the first data unit. The timer can be for a data reception time period that is for a specified duration of time. For example, the timer can be a count-up timer that counts from zero to the end of the specified duration, or a count-down timer that counts from the specified duration to zero. In a particular example, the duration can be 70 microseconds. In this example, the timer counts up from zero to 70 microseconds or counts down from 70 microseconds to zero, depending on the start of the timer.

[0309] The data reception time period may be based on an expected time period for receiving the entire control information data element, which may be based on the data size of each control information data element and the data rate of the communication path over which the control information data elements are transmitted.

[0310] In some implementations, the data reception time period is longer than the expected time period. Because data transmission may be delayed, for example, due to noise on the communication path, using a longer data reception time period can be more certain that the entire control information data element is received. As an example, the data reception time period can be based on the expected time period for the control information data element plus some additional time to receive one or two bytes of data. In another example, the data reception time period can be based on the expected time period for the control information data element plus an additional defined duration of time. Referring to FIG. 21, an exemplary data reception time period 2111 extends past the time required to receive a data frame 2110 including a control information data element.

[0311] In step 2022, the LCD 114 receives additional data units during the data reception time period. The LCD 114 may locally store each data unit as it is received.

[0312] In step 2023, the LCD 114 determines whether the data reception time period has elapsed (2023). For example, the LCD 114 can determine whether the counter has finished counting up or down based on the data reception time period.

[0313] If the data reception time period has not elapsed, the LCD 114 returns to step 2022 to continue receiving additional data units. If the data reception time period has elapsed, the LCD 114 starts a timer for the post-reception time period in step 2024. The post-reception time period can immediately follow the data reception time period and can have the same duration as the data reception time period, a longer duration, or a shorter duration. The timer for the post-reception time period, like the timer for the data reception time period, can be a count-up timer or a count-down timer. Referring to FIG. 2100, an exemplary post-reception time period 2112 immediately follows the data reception time period 2111.

[0314] In some implementations, a single timer may be used for the data element receive time period, e.g., without a post-receive time period, In this example, one time period may have a longer duration than the expected duration to receive the full control information data element.

[0315] In step 2025, the LCD 114 determines whether additional data units have been received during the post-reception time period. The LCD 114 may monitor for additional data units until the post-reception time period has elapsed. If additional data units have been received during the post-reception time period, the LCD 114 may determine that the entire control information data element has not been received and may return to step 2022 to receive additional data units. Once the data reception time period has elapsed, the LCD 114 may restart the post-reception time period for each additional data unit received during the post-reception time period until no additional data units have been received during the post-reception time period.

[0316] If no additional data units are received during the post-reception time period, the LCD 114 determines that a control information data element has been received, in step 2026. In response, the LCD 114 may process the control information data element, in step 2030. This processing may include decoding the control information, scaling a normalized reference signal Vrn in the control information using the modulation index Mi, and using the scaled reference signal to operate a switch circuit of the converter 202.

[0317] Before processing the control information data element, the LCD 114 can check for erroneous and / or correct data in the control information data element using the CRC bits. If the data cannot be corrected, the LCD 114 cannot use the control information in the control information data element to operate the switch circuit. Instead, the LCD 114 can use previously received control information of a previously received control information data element to operate the switch circuit. This ensures that there is no interruption in the operation of the module 108 due to corrupted data.

[0318] 22 is a flow diagram illustrating an exemplary embodiment of a method 2200 for receiving control information data elements using a synchronization signal. The method 2200 can be performed by an energy system including an MCD 112 and one or more arrays 700 of cascaded modules 108. For example, the method 2200 can be performed by any one of the systems 100 described herein. As described above, each module 108 can include an energy source 206, a converter 202 including a switch circuit, and an LCD 114. Each module 108 in the array 700 can also have an identifier that identifies the module 108 and is unique within the array 700. The method 2200 is additionally described with reference to FIG. 23, which is a schematic diagram illustrating an exemplary data stream 2300.

[0319] The MCD 112 may be communicatively coupled to each LCD 114 via multiple data communication paths. For example, the MCD 112 may be communicatively coupled to each LCD 114 using a unidirectional serial communication path along which the MCD 112 transmits control information data elements, as described above. The MCD 112 may also be communicatively coupled to each LCD 114 using a synchronization signal bus. In some implementations, the synchronization signal bus is implemented as a unidirectional serial communication path along which the MCD 112 transmits synchronization signals to the LCD 114. For example, the synchronization signal bus may be implemented as a twisted pair cable that connects the MCD 112 to each LCD 114 in the array 700 of cascaded modules 108. Other protocols and buses, such as digital communication paths, may also be used for the synchronization signals. For simplicity, the method 2200 is described in terms of differential signals that may be transmitted over a twisted pair bus or other suitable communication path.

[0320] In step 2210, the MCD 112 sends a synchronization signal to the LCD 114 of a module 108 in the array 700 of cascaded modules 108. The synchronization signal indicates the start of a transmission of control information data to the LCD 114. In some implementations, the differential signal can have a high voltage difference, e.g., above a first threshold, to indicate the start of a transmission, or a low voltage difference, e.g., below a second threshold, which is less than the first threshold, to indicate the end of a transmission. To indicate that a transmission has started, the MCD 112 can send the synchronization signal to the LCD 114 by increasing the voltage difference of the differential signal above the first threshold.

[0321] In step 2220, the MCD 112 transmits the control information data element to the LCD 114 of the module 108 in the array 700. The control information data element may include one or more data packets within a data frame. The MCD 112 may transmit the control information data element after a short delay, for example, a delay in a few microseconds or milliseconds, and simultaneously with a synchronization signal.

[0322] 23, the rising edge of each synchronization signal 2310-1 to 2310-4 aligns with the start of each frame 2320-1 to 2320-4, during which control information is transmitted from the MCD 112 to the LCD 114. As shown in FIG.

[0323] In step 2230, the LCD 114 detects (2230) a synchronization signal. For example, the LCD 114 can detect the synchronization signal based on a voltage difference of the differential signal. In this example, the LCD 114 can compare the voltage level to a first threshold and determine that a synchronization signal is present when the voltage level satisfies the first threshold, for example, by meeting or exceeding the first threshold.

[0324] In step 2240, the LCD 114 of each module 108 in the array 700 captures a control information data element. In response to detecting the synchronization signal, the LCD 114 may begin monitoring the control information, and continue monitoring the control information until the synchronization signal is no longer present, e.g., when the voltage difference of the differential signal is less than a second threshold. The LCD 114 may store the captured control information locally in the LCD's memory.

[0325] When the LCD 114 detects that the synchronization signal is no longer present, it can stop monitoring the control information. After transmitting all of the control information, the MCD 112 can remove the synchronization signal, for example, by reducing the voltage difference of the differential signal below a second threshold.

[0326] 23, the falling edges of synchronization signals 2310-1 through 2310-4 occur after entire frames 2320-1 through 2320-4, respectively, have been transmitted from MCD 112 to LCD 114. In this example, there is a delay from the end of each frame to the falling edge of each synchronization signal. MCD 112 may employ this delay to ensure that all of the data reaches each LCD 114 and is captured before removing the synchronization signal.

[0327] In step 2250, the LCD 114 of each module 108 processes the control information data elements. This processing may include decoding the control information, scaling a normalized reference signal Vrn in the control information using the modulation index Mi, and using the scaled reference signal to operate a switch circuit of the converter 202.

[0328] Before processing a control information data element, LCD 114 may check for erroneous and / or correct data in the control information data element using the CRC bits. If the data cannot be corrected, LCD 114 may not use the control information in the control information data element to operate the switch circuitry. Instead, LCD 114 may use previously received control information of previously received control information data elements to operate the switch circuitry. This ensures that there is no interruption in the operation of the module due to corrupted data.

[0329] The MCD 112 can also use the synchronization signal to "wake" the LCD 114, for example, from a sleep operating mode for the LCD 114. In this way, the synchronization signal can be used for a dual purpose. For example, the LCD 114 can enter a sleep mode in which the LCD 114 conserves power. In a particular example, when the electric vehicle is parked, the peripheral devices of the module, such as the power supply and converter 202, can be switched off, for example, by the MCD 112 and / or the LCD 114, and the LCD 114 can be configured to enter a sleep mode. To wake up the LCD 114 and wake up the peripheral devices, the MCD 112 can provide a trigger pulse on a wake interface, for example, a wake-up pin of the LCD 114. To use the synchronization signal for a dual purpose, the synchronization signal can also be connected to a wake-up pin to wake up the LCD 114 from a sleep mode. In response to the synchronization signal being applied to the wake-up pin, the LCD can wake up the peripheral devices and start monitoring for control information.

[0330] The use of a synchronization signal provides advantages over other approaches. For example, the use of a synchronization signal provides a clear timing window to the LCD 114 when control information is being sent to the LCD 114. Having such a clear boundary can reduce the dead periods between frames, which reduces latency in the system. It also allows for an increase in the number of frames sent over the same period of time, which provides a higher sample rate for the reference signal.

[0331] 24 is a flow diagram illustrating an example embodiment of a method 2400 for waking a local control device. The method 2400 can be performed by an energy system including an MCD 112 and one or more arrays 700 of cascaded modules 108. For example, the method 2400 can be performed by any one of the systems 100 described herein. As described above, each module 108 can include an energy source 206, a converter 202 including a switch circuit, and an LCD 114. Each module 108 in the array 700 can also have an identifier that identifies the module 108 and is unique within the array 700.

[0332] In step 2410, the MCD 112 determines to wake the LCD 114. For example, the MCD of an electric vehicle may be configured to wake each LCD 114 of one or more arrays 700 of modules 108 when a user powers on the vehicle or begins accelerating the vehicle. When the vehicle is off or stationary, the MCD 112 can instruct each LCD to enter a sleep mode of operation. The sleep mode of operation can be a relatively low power mode in which the LCD 114 consumes less power than when in an active or relatively high power mode utilized during normal charging and discharging operations of the system 100.

[0333] In step 2420, the MCD 112 sends a synchronization signal to each awakened LCD 114. The MCD 112 may send the synchronization signal to each LCD via a synchronization path that is used for a dual purpose. For example, the synchronization path may be coupled to both a synchronization interface of the MCD 112 and to a synchronization interface and a wake interface of each LCD 114, e.g., a wake pin of each LCD 114.

[0334] Each LCD 114 can be configured to monitor the wake interface even when the LCD 114 is in a sleep mode of operation. Upon detecting a synchronization signal on the wake interface, the LCD 114 can transition to an active mode of operation in which the LCD 114 monitors all or most of the interfaces, operates at a higher frequency, and / or performs other more power-consuming operations. The LCD 114 can also wake peripheral devices in response to detecting a synchronization signal on the wake interface.

[0335] In step 2430, the MCD 112 transmits control information and synchronization information to each LCD 114. As described above, the MCD 112 may transmit control information, e.g., in the form of a control information data element, to the LCD 114 via a communication interface, e.g., via a control interface. Upon transmitting the control information data element, the MCD 112 transmits a synchronization signal to the LCD 114 via a synchronization path, as described above, to notify the LCD that the control information data element is being transmitted.

[0336] Exemplary Synchronization Techniques As discussed above, various techniques can be used to synchronize the LCD 114 with the transmission of the control information data packets. Synchronization techniques can also be used to synchronize the PWM controllers 1123 of an array 700 or across multiple arrays 700. These techniques can include the use of a synchronization signal or the use of a data absence event similar to method 2000 of FIG. 20. By precisely synchronizing the PWM controllers 1123, the phase shift between the switching signals output by the LCDs 114 and their converter output voltages is more precise and aligned, resulting in superior system performance.

[0337] 25A is a block diagram of an example embodiment of an LCD 114 configured to implement the synchronization techniques described herein. The LCD 114 may be implemented as the LCD 114 in any of the systems described herein.

[0338] The LCD 114 includes a PWM controller 1123. As described above, the PWM controller 1123 is configured to generate switching signals for the switches (e.g., switches S1 to S6) of the converter 202 based on a carrier signal for each switch and the modulated reference signal Vrnm. The PWM controller 1123 includes a switch signal generator 2520 and a carrier generator 2530.

[0339] The carrier generator 2530 is configured to generate carrier signals for the switches of the converter 202 based on the defined phase shifts for the converter 202 and provide the carrier signals for switching the signal generator 2520 via the communication path or link 2502. The phase shifts are different between different converters, and as a result, the switching signals for the switches of each converter 202 are also different. The carrier generator 2530 includes a PWM counter 2532 that is used to control the phase shift between the carrier signals generated by the carrier generator. When the PWM counter 2532 is reset, the carrier generator 2530 resumes the carrier signal generation process. For example, assume that the carrier generator 2530 generates phase shifted carrier signals starting with a first triangular wave with a phase shift of zero at the beginning of the carrier signal generation process. In this example, when the PWM counter 2532 is reset, the carrier generator 2530 resumes the carrier signal generation process by generating a first triangular wave, which then generates triangular waves that are phase shifted from each other in turn according to their phase shifts.

[0340] The switch signal generator 2520 is configured to generate a switching signal for each switch of the converter 202 based on the carrier signal received from the carrier generator 2530 and the modulated reference signal Vrnm received from the combiner unit 1121. The switch signal generator 2520 generates a switching signal based on the carrier signal for the module 108 associated with the LCD 114 that performs PWM processing and the modulated reference signal Vrnm, and outputs the switching signal to the switch of the associated converter 202 to generate a time-varying output signal from that module 108 (the sum of all the time-varying output signals from each module 108 of a phase generates the AC output signal of that phase), which can use, but is not limited to, PWM techniques such as those described herein with reference to Figures 8C-8F.

[0341] The LCD 114 includes a control interface 1742 configured to receive control information, e.g., control information data elements, from the MCD 112 via path or link 115. Similarly, the LCD 114 includes a synchronization interface 1743 configured to receive synchronization signals from the MCD 112. Each interface 1742 and 1743 can include a driver for the interface and an isolation unit.

[0342] The LCD 114 also includes a synchronization unit 2510 communicatively coupled to the synchronization interface 1743. The synchronization unit 2510 is configured to receive synchronization signals from the synchronization interface 1743 via a path or link 2505 and detect a synchronization event based on the synchronization signals. The synchronization unit 2510 can be implemented in the LCD 114 in hardware, software, or a combination thereof. In some embodiments, the synchronization unit 2510 is implemented as a separate component communicatively coupled to the LCD 114 via a path or link.

[0343] The synchronization unit 2510 can be configured to detect PWM synchronization events and / or data capture events based on the synchronization signal. A PWM synchronization event indicates a time to synchronize the PWM controller 1123 of the array 700 or system 100. A data capture event indicates a time to capture control information from a path or link 115. For example, a data capture event may indicate that the MCD 112 transmits a control information data element on a path or link 115. For example, the synchronization unit 2510 is shown in FIG. 26A and described below.

[0344] When a data capture event is detected, the synchronization unit 2510 can output a data capture signal to the data capturer 2510 via a communication path or link 2507. The data capturer 2510, which can be implemented in hardware and / or software, can be configured to capture control information from a path or link 2506 between the control interface 1742 and the data capturer 2510, decode the control information, obtain a normalized reference signal Vrn and a modulation index Mi, and store the control information (e.g., in the memory 122). The data capturer 2510 can also provide the normalized reference signal Vrn and the modulation index Mi to the combiner unit 1121 via a communication path or link 2508. As described above, the combiner unit 1121 is configured to modulate or scale the normalized reference signal Vrn using the modulation index Mi to generate a modulated reference signal Vrnm. The control unit 1121 can output the modulated reference signal Vrnm to the PWM controller 1123 via the communication path or link 2501. In another embodiment, the modulated reference signal Vrnm for each module 108 can be generated by the MCD 112 and transmitted directly to each module 108 as assigned.

[0345] When a PWM synchronization event is detected, the synchronization unit 2510 can be configured to output a reset signal to the PWM controller 1123 via the communication path or link 2503. When the PWM controller 1123 detects the reset signal, the PWM controller 1123 can immediately (e.g., without delay) reset the PWM counter 2532. In some embodiments, the synchronization output of the synchronization unit 2510 couples directly to a dedicated PWM counter reset input of the PWM controller 1123. For example, the counter reset input can be a pin if the PWM controller 1123 is implemented as an integrated circuit. In this way, the reset signal is not delayed by a hardware interrupt of the PWM controller 1123.

[0346] Each of the communication paths or links 2501-2503 and 2506-2508 may be a wired (e.g., electrical, optical) or wireless communication path that communicates data or information in a parallel or serial manner, unidirectional or bidirectional, similar to the communication paths or links 105, 106, 115, 116, and 118.

[0347] FIG. 25B is a schematic diagram illustrating an exemplary embodiment of a communication connection between the MCD 112 and the LCD 114. In this embodiment, an RS-485 physical layer is used for communication between the MCD 112 and the LCDs 114-1-114-N. The MCD 112 includes an RS-485 interface 1564-1 configured to transmit control information to the RS-485 interfaces 1742-1-1742-N of the LCDs 114-1-114-N via the twisted pair cable 115. The MCD 112 also includes an RS-485 interface 1564-2 configured to transmit synchronization signals to the RS-485 interfaces 1743-1-1743-N of the LCDs 114 via the twisted pair cable 1141. Although not shown, the MCD 112 and the LCDs 114 also include other components as described herein.

[0348] Each RS-485 interface 1564, 1742, 1743 includes an RS-485 driver and an isolation unit. In an RS-485 physical layer embodiment, the isolation unit may include a capacitor isolator.

[0349] RS-485 and other equivalent physical layers are also suitable for network topologies, such as the various topologies of the system 100 described herein, and allow for the use of long distance paths or links. These physical layers allow for high baud rates for transmitting control information to the LCD 114, which allows for high speed sampling of the normalized reference signal Vrn and the modulation index Mi by the LCD 114. This increases the overall system performance, especially in terms of harmonics. Some exemplary baud rates include baud rates in the range of 5 megabits per second (Mbit / s) to 10 Mbit / s. For such high baud rates, external synchronization using a synchronization signal allows the LCD 114 to determine the start and end of data packets. This same synchronization signal can also be used to synchronize the PWM controller 1123 of the LCD 114. Using the same synchronization signal for these purposes reduces the amount of wires and corresponding insulation, which reduces the size of the MCD 112, the LCD 114, and the system 100 in which they are implemented, or allows for more components in the same size system 100.

[0350] 25C is a schematic diagram illustrating an exemplary embodiment of a communication connection between the MCD 112 and the LCD 114. In this embodiment, an Ethernet physical layer is used for communication between the MCD 112 and the LCD 114. The MCD 112 includes an Ethernet interface 1513 configured to transmit control information and synchronization signals to the Ethernet interface 1741 of the LCD 114 over a twisted pair cable 1141. Although not shown, the MCD 112 and the LCD 114 may also include other components as described herein, and the MCD 112 may be communicatively coupled to multiple LCDs 112 via the same or similar topology.

[0351] The interface 1513 includes an Ethernet driver and a transformer isolation unit 2581. Similarly, the LCD 114 includes an Ethernet driver 2590 and a transformer isolation unit 2610 (FIG. 26). The isolation units 2581 and 2610 isolate the drivers 2580 and 2590, respectively, and other components of the MCD 112 and LCD 114 from the twisted pair cable 1141.

[0352] The Ethernet interfaces 1513 and 1741 allow for high speed data (e.g., 100 Megabits / sec to 1 Gigabit / sec (GB / sec)). Using an Ethernet interface allows the MCD 112 to send data (e.g., control information) to the LCD 114 using a high speed carrier signal. The MCD 112 may also include a synchronization signal (e.g., in the form of a synchronization pulse) within the carrier signal. This synchronization signal may be implemented using frequency modulation, and the frequency of this synchronization pulse may match that of the PWM frequency of the LCD's converter 202. In such an example, a separate synchronization path 1141 would not be needed, resulting in less wires and insulation, and resulting in a reduced size system 100 or more components within the same size system 100.

[0353] 26A is a block diagram of an exemplary embodiment of a synchronization unit 2510. In this embodiment, the synchronization unit 2510 receives a synchronization signal from a synchronization interface 1743 having an isolation unit 2610. The isolation unit 2610 electrically isolates the LCD 114 from the path or link 1141. The type of isolation unit 2610 can be selected based on the physical layer of the path or link over which the synchronization signal is transmitted from the MCD 112 to the LCD 114. For an RS-485 physical layer, the isolation unit 2610 can include a capacitor-based isolator. For an Ethernet physical layer, the isolation unit 2610 can include a transformer-based isolator. Other suitable isolators may also be used for these or other types of physical layers.

[0354] In this embodiment, the synchronization unit 2510 includes comparators 2620-1 and 2620-2 and a capacitor C1. The comparator 2620-1 is configured to compare the amplitude of the synchronization signal to a first threshold voltage level and output a data capture signal based on the comparison. For example, if the amplitude of the synchronization signal is equal to or greater than the first threshold voltage level, the comparator 2620-1 can output a high data capture signal on the path or link 2507 to instruct the data capturer 2510 to capture information for the control communication path or link 2506. The first threshold can be referred to as a data capture threshold.

[0355] Comparator 2620-2 is configured to compare the voltage level across capacitor C1 to a second threshold voltage level and output a reset signal based on the comparison. For example, if the voltage level across the capacitor is greater than or equal to the second threshold voltage level, comparator 2620-2 can output a low reset signal on path or link 2503 to reset PWM counter 2532. The second threshold can be referred to as a PWM synchronization threshold.

[0356] If the synchronization signal has an alternating amplitude, e.g., a square wave, the capacitor C1 will be charged when the amplitude of the synchronization signal exceeds the voltage level of the capacitor C1. If the amplitude of the synchronization signal remains at a level that charges the capacitor C1 for a sufficient duration, the capacitor C1 will be charged to a level that meets or exceeds the second threshold and trigger the reset signal. When the synchronization signal is at a low level, the capacitor C1 can be discharged through the discharge path.

[0357] To initiate a PWM synchronization event, the MCD 112 can adjust the sequence of pulses of the synchronization signal and / or the frequency of the synchronization signal to drive the voltage level of the capacitor above the second threshold. If the physical layer is RS-485, either technique can be used. For example, the MCD 112 can increase the duty cycle of the synchronization signal such that the synchronization signal remains at a high level for a longer duration relative to the cycle length for one or more cycles, driving the voltage level of the capacitor C1 to a level higher than the regular duty cycle that is not intended to initiate detection of a synchronization event, which may be higher than the second threshold to cause the comparator 2620-2 to output a low reset signal and reset the PWM counter 2532.

[0358] The MCD 112 can also use a frequency modulated synchronization signal to initiate a PWM synchronization event. During normal operation, the MCD 112 can generate a synchronization signal having a first frequency that is used to initiate a data capture event. To initiate a PWM synchronization event, the MCD 112 can adjust the frequency of the synchronization signal. For example, the MCD 112 can decrease the frequency of the synchronization signal such that the synchronization signal remains at high and low levels for a longer duration per period. The longer duration high level can cause the capacitor C1 to charge to a voltage level higher than a second threshold, thereby causing the comparator 2620-2 to output a high reset signal.

[0359] 26B is a schematic diagram of an example embodiment of a comparator 2620. This embodiment may be used within the synchronization unit 2510 for comparators 2620-1, 2620-2, or as a separate comparator to initiate another event or action based on the synchronization signal. For simplicity, the comparator 2620 will be described in terms of outputting a reset signal onto communication path or link 2503, which is also output by comparator 2620-2.

[0360] Comparator 2620 detects a synchronization event based on a synchronization signal and is configured for use in embodiments including capacitor-based isolators and / or transformer-based isolators. Exemplary waveforms of signals associated with a capacitor-based isolator are shown in FIG. 26C and described below. Exemplary waveforms of signals associated with a transformer-based isolator are shown in FIG. 26D and described below.

[0361] As described above, the comparator 2620 can be configured to compare the voltage level of the capacitor C1 with a threshold voltage level. C1 in FIG. 26B can be the same as C1 of the synchronization unit 2510. The comparator 2620 can include a timer circuit 1743 to compare the voltage level of the capacitor C1 with the threshold. The timer circuit 1743 can be implemented as a 555 timer (which is an integrated circuit configured to perform various timer and pulse generation operations), another timer circuit configured to perform a comparison operation, or another type of circuit configured to perform a comparison operation.

[0362] In this embodiment, the timer circuit 1763 includes a VCC input for receiving a positive supply voltage, a discharge output (DIS), a threshold input (THRS), a control voltage input (CV), a ground input (GND) coupled to ground, a trigger input (TRIG), an output (OUT) coupled to path or link 2503, and a reset input (RST).

[0363] The comparator 2620 includes a transistor Q1, which can be implemented as an IGBT, a MOSFET, a GaN transistor, or other type of transistor. The gate of the transistor Q1 is coupled to the synchronization signal and the emitter or source of the transistor Q1 is coupled to the supply voltage through a resistor R1 and a discharge output. When the voltage level of the synchronization signal is at a high level, the capacitor C1 is charged by the supply voltage through the resistor R1.

[0364] When the voltage level of capacitor C1 reaches a threshold voltage level, the internal logic of timer circuit 1763 pulls down the output pin OUT, which creates a short low voltage pulse (e.g., at a potential of 0 VDC or about 0 VDC or GND) on path or link 2503, which initiates a synchronization event. Otherwise, output pin OUT has a high voltage output, e.g., at a potential of 5 VDC or about 5 VDC or a supply voltage coupled to VCC.

[0365] In particular, the internal logic of timer circuit 1743 compares the voltage level at threshold input pin THRS with the control voltage input at pin CV. When the voltage level at threshold input pin THRS exceeds the control voltage input at pin CV, the internal logic of timer circuit 1743 pulls output pin OUT low. When the output is low, the internal logic of timer circuit 1743 causes the discharge output to discharge capacitor C1, causing the output on path or link 2503 to return to a high voltage level.

[0366] 26C is a plot 2630 showing waveforms 2631-2633 of signals associated with the synchronizing unit 2510. These waveforms 2631-2633 may represent waveforms of a synchronizing unit 2510 having or coupled to a capacitor-based isolation unit 2610. Plot 2630 shows a voltage waveform 2631 of the voltage on capacitor C1, a voltage waveform 2632 of an output signal (e.g., a data capture signal on path or link 2507 or a reset signal on path 2503), and a voltage waveform 2633 of a synchronization signal.

[0367] The voltage waveform 2633 of the synchronization signal typically has a normal pulse width 2633-1 for most of the pulses. This causes capacitor C1 to charge to a first level 2631-1, which may be below the threshold for initiating a synchronization event, so that the output waveform remains at a high level 2632-1. To initiate a synchronization event, the synchronization signal can be adjusted to have a longer pulse width 2633-1 at the high level. This causes capacitor C1 to charge to a higher level 2632-2, which in turn causes the output (e.g., the output of the timer circuit 1743) to drop to a low level 2632-2.

[0368] 26D is a plot 2640 showing waveforms 2641-2643 of signals associated with a synchronizing unit 2510. These waveforms 2641-2643 may represent waveforms of a synchronizing unit 2510 that includes or is coupled to a transformer-based isolation unit 2610. The primary difference between waveforms 2631-2633 and waveforms 2641-2643 is the shape of waveforms 2631 and 2641.

[0369] Plot 2640 shows a voltage waveform 2641 of the voltage on capacitor C1, a voltage waveform 2642 of an output signal (eg, the data capture signal on path or link 2507 or the reset signal on path 2503), and a voltage waveform 2643 of a sync signal.

[0370] The voltage waveform 2643 of the synchronization signal typically has a normal pulse width 2643-1 for most of the pulses. This causes the capacitor C1 to charge to a first level 2641-1, which may be below the threshold for initiating a synchronization event, so that the output waveform remains at a high level 2642-1. To initiate a synchronization event, the synchronization signal can be adjusted to have a longer pulse width 2643-1 at the high level. This causes the capacitor C1 to charge to a higher level 2642-2, which in turn causes the output (e.g., the output of the timer circuit 1743) to drop to a low level 2642-2. FIG. 27 is a plot 2700 showing frequency modulated synchronization signals 2710 and 2720 and the voltage level 2730 of the capacitor C1 of the synchronization unit 2510. The MCD 112 can send the frequency modulated synchronization signal 2710 to the LCD 114, which receives the frequency modulated synchronization signal 2720.

[0371] During a first time period (period 1), the frequency of the frequency modulated synchronization signal 2710 remains constant. As a result, the voltage level 2730 of capacitor C1 charges to a first threshold level 2740 (e.g., a data capture threshold) every period of the frequency modulated synchronization signal 2710. Because the frequency is constant, capacitor C1 charges to approximately the same value every period.

[0372] During a second time period (period 2), the MCD 112 reduces the frequency of the frequency modulated synchronization signal 2710 for one period of the frequency modulated synchronization signal 2710. As a result of the synchronization signal 2710 remaining at a high level longer than in the previous period 1 as indicated by reference numeral 2711, the voltage level of the capacitor C1 is charged above a second threshold 2750 (e.g., a PWM synchronization threshold) at reference numeral 2731, which is higher than the first threshold 2740. For example, the first threshold 2740 can be for initiating a data capture event, and the second threshold 2750 can be for initiating a PWM synchronization event. Thus, the frequency of the frequency modulated signal reduced during period 2 can charge the capacitor C1 to a voltage level that initiates a PWM synchronization event. Each time synchronization of the PWM controller 1123 is justified, the MCD 112 can reduce the frequency of the frequency modulated signal to the frequency shown in period 2 and then return the frequency to that of period 1 or period 3, preventing another PWM synchronization event from being detected until another PWM synchronization event is initiated by the MCD 112.

[0373] 28 is a plot 2800 illustrating a frequency modulated synchronization signal 2810 and a reset signal 2820 generated based on the frequency modulated synchronization signal 2810. The MCD 112 can generate and send the frequency modulated signal 2810 to the LCD 114. The synchronization unit 2510 can detect a synchronization event based on the frequency of the frequency modulated synchronization signal 2810. The frequency modulated synchronization signal and periods 1-3 of FIG. 28 can be the same as or similar to the frequency modulated signal 2710 and periods 1-3 of FIG. 27.

[0374] During the first time period (period 1), the frequency of the frequency modulated synchronization signal 2810 remains constant at a high enough frequency that does not allow the capacitor C1 of the synchronization unit 2510 to reach the threshold for detection of a PWM synchronization event. During the second time period (period 2), the MCD 112 decreases the frequency of the frequency modulated synchronization signal 2810, thereby causing the voltage level of C1 to reach the threshold, resulting in a low reset signal 2820 during period 2. The reset signal 2820 remains high during the third period (period 3) as the MCD 112 increases the frequency of the frequency modulated synchronization signal 2810 to its previous level in period 1.

[0375] 29 is a flow diagram illustrating an example embodiment of a method 2900 for synchronizing data capture events and PWM events. The method 2900 may be performed by an energy system including an MCD 112 and one or more arrays 700 of cascaded modules 108. For example, the method 2900 may be performed by any one of the systems 100 described herein.

[0376] In step 2910, the MCD 112 generates and transmits a regular synchronization signal to the LCDs 114 for the modules 108 in one or more arrays 700 of the system 100. In some implementations, the MCD 112 transmits the regular synchronization signal to each LCD 114 in the array 700. For multi-phase embodiments, the MCD 112 can transmit the same or different synchronization signals to the LCDs 114 of the array 700 for each phase.

[0377] The synchronization signal may be a modulated voltage waveform having an alternating amplitude, e.g., a square wave voltage signal. The regular synchronization signal may have a constant (or at least approximately constant within a specified tolerance) amplitude and frequency. The MCD 112 may generate and provide the regular synchronization signal to the LCD 114 to initiate data capture events.

[0378] The MCD 112 can also transmit control information to the LCD 114 based on the regular synchronization signal. For example, the MCD 112 can transmit control information for the communication path or link 115 during the time that the regular synchronization signal is at a particular level (e.g., above a particular voltage level) or in a particular state (e.g., high state). In this manner, the MCD 112 can use the synchronization signal to inform the LCD 114 of where control information is being transmitted to the LCD 114.

[0379] In step 2920, the LCD 114 detects a data capture event based on the synchronization signal. As described above, the LCD 114 can be configured to compare the amplitude of the synchronization signal to a data capture threshold. The LCD 114 can detect a data capture event whenever the amplitude of the synchronization signal satisfies the data capture threshold, for example, by meeting or exceeding the data capture threshold.

[0380] In step 2921, the LCD 114 captures control information for the communication path or link 115. In response to detecting a data capture event, the LCD 114 may capture control information data packets on the communication path or link. The LCD 114 may capture the control information as described elsewhere herein.

[0381] In step 2922, the LCD 114 controls the converter 202 based on the captured control information. As described above, the LCD 114 can be configured to use the modulation index Mi of the control information designated for the LCD 114 to modulate or scale the normalized reference signal Vrn of the control information to generate a modulated reference signal Vrnm. The LCD 114 can use the modulated reference signal Vrnm to control the switch of the converter 202. As described above, the LCD 114 can continue to operate the switch of the converter 202 using the control information designated for the LCD 114 until updated control information designated for the LCD 114 is captured from the path or link 115.

[0382] In step 2911, the MCD 112 determines whether to initiate a synchronization event. For example, the MCD 112 may determine to initiate a PWM synchronization event. The PWM synchronization event synchronizes the PWM controllers of each LCD 114 in the array 700 or in multiple arrays 700 of the system 100.

[0383] The MCD 112 may periodically initiate a PWM synchronization event based on a defined time period. For example, the MCD 112 may restart a timer after each PWM synchronization event is initiated and initiate a new PWM synchronization event when the timer expires. The MCD 112 may also initiate a PWM synchronization event, change the frequency of the PWM, synchronize the data acquisition process between the MCD 112 and the LCD 114, and / or wake the sleeping LCD 114. If the MCD 112 determines not to initiate a PWM synchronization event, the method 2900 returns to step 2910, where the MCD 112 generates and sends a regular synchronization signal to the LCD 114.

[0384] In step 2912, the MCD 112 adjusts the synchronization signal for a period of time in response to determining to initiate a PWM synchronization event and / or other type of synchronization event or action. For example, the MCD 112 may adjust the synchronization signal for a defined duration (e.g., seconds, milliseconds, or microseconds) or a defined number of periods of the synchronization signal (e.g., one, two, five, or another suitable number of periods). The MCD 112 may adjust the synchronization signal to initiate a PWM synchronization event, synchronize a PWM counter of the LCD 114, wake the LCD 114, synchronize a data capture event, and / or initiate another event or action.

[0385] In some embodiments, the synchronization signal is a frequency modulated synchronization signal. In this example, the MCD 112 is configured to adjust the frequency of the synchronization signal. For example, the MCD 112 can decrease the frequency of the synchronization signal, increase the voltage across the capacitor C1 (FIG. 26), and initiate detection of the PWM synchronization event by each LCD 114.

[0386] In some embodiments, the MCD 112 is configured to adjust the duty cycle of the synchronization signal. For example, the MCD 112 can increase the duty cycle of the synchronization signal so that the synchronization signal remains high for a longer duration per period, driving the voltage level of the capacitor C1 (FIG. 26) to a higher level than the regular duty cycle of the regular synchronization signal.

[0387] In some embodiments, the MCD 112 can be configured to adjust the amplitude of the pulses of the synchronization signal. For example, the MCD 112 can increase the amplitude of the pulses of the synchronization signal to drive the voltage level of the capacitor C1 (FIG. 26) to a level higher than the regular amplitude of the regular synchronization signal.

[0388] After the time period has elapsed, the MCD 112 can adjust the synchronization signal back to a regular synchronization signal.

[0389] In step 2923, the LCD 114 detects a PWM synchronization event. As described above, the LCD 114 can be configured to compare the amplitude of the voltage on the capacitor C1 (FIG. 26) to a PWM synchronization threshold. The LCD 114 can detect a PWM synchronization event whenever the amplitude of the capacitor C1 satisfies the PWM synchronization threshold, for example, by meeting or exceeding the PWM synchronization threshold.

[0390] In step 2924, the LCD 114 resets the PWM counter 2532 of the PWM controller 1123. For example, the LCD 114 may send a reset signal to the PWM controller 1123, e.g., a reset pin of the PWM controller integrated circuit. This is an example of a synchronous action that may be performed by the LCD 114 in response to detecting a synchronous event.

[0391] In another example, the LCD 114 detects a data capture event whenever the amplitude of the capacitor C1 meets or exceeds a data capture threshold, and in response, the LCD 114 can begin monitoring control information from the MCD 112, for example, at the control interface 1742.

[0392] Although the exemplary method 2900 includes detecting a data capture event and controlling the converter 202 based on the captured control information in response to detecting the data capture event, these steps may be omitted in some embodiments. For example, in some embodiments, the MCD 112 may initiate a PWM synchronization event by adjusting a synchronization signal in steps 2911-2913, and the LCD 114 may detect the PWM synchronization event and reset PWM counter 2532 and synchronize the capture of the control information without using synchronization steps 2920-2922.

[0393] In some embodiments, the data absent event is used to synchronize capture of control information data elements and / or synchronize the PWM controllers 1123 of the LCDs 114 in one or more arrays 700. For example, the method 2000 of FIG. 20 can be modified to include the additional step of resetting the PWM counter 2532 in response to each determination that a control information data element has been received in step 2026, e.g., before, after, or in parallel with step 2030.

[0394] 30 is a flow diagram illustrating an example embodiment of a method 3000 for synchronizing data capture events and PWM events. Method 3000 is another example in which a data absent event can be used to synchronize capture of control information data elements and / or synchronize PWM controllers 1123 of LCDs 114 in one or more arrays 700. Method 2900 can be performed by an energy system including an MCD 112 and one or more arrays 700 of cascaded modules 108. For example, method 2900 can be performed by any one of the systems 100 described herein.

[0395] In step 3010, LCD 114 detects a first data unit on a communication interface connected to the communication path at least a threshold duration of time since the previous control information data element was received. Step 3010 may be implemented in the same or similar manner as step 2010 of method 2000 of FIG.

[0396] In step 3020, LCD 114 determines whether a new control information data element has been received that includes the detected data unit. LCD 114 can be configured to determine that a new control information data element has been received when data is absent on path or link 115 for a defined duration of time after the last received data unit. LCD 114 can use configuration steps 3021-3024 to determine whether a data absent event has occurred and therefore whether a new control information data element has been received.

[0397] In step 3021, the LCD 114 starts a timer for a defined time period. The time period may be based on an expected duration of time between receipt of consecutive data units (e.g., data segments) of a control information data element (e.g., in the form of a data frame). In some embodiments, the time period may be longer than this expected duration to account for delays in transmission. For example, the time period may be based on the duration of time to receive one data unit, two data units, three data units, or another suitable number of data units. In another example, the time period may be a multiple of the expected duration, e.g., two times the expected duration, three times the expected duration, and / or another suitable multiple.

[0398] In step 3022, LCD 114 determines whether any additional data units have been received before the timer expires. If so, method 3000 returns to step 3021 and the timer is reset. Otherwise, in step 3024, LCD 114 determines that a no data event has occurred. In response to determining that a no data event has occurred, LCD 114 may determine that a control information data element has been received.

[0399] In step 3030, the LCD 114 resets the PWM counter 2532 of the PWM controller 1132. For example, the LCD 1134 can send a reset signal to the PWM controller 1123, e.g., a reset pin of the PWM controller integrated circuit.

[0400] In step 3040, the LCD 114 processes the received control information data element. Step 3040 may be implemented in the same or similar manner as step 2010 of the method 2030 of FIG.

[0401] The synchronization techniques described above utilizing the synchronization signal reduce the amount of jitter that would otherwise be present in the synchronization signal received by the LCD 114 and increase the precision of the synchronization of the PWM controllers 1123 of the multiple modules 108 in one or more arrays 700 of the system 100. Jitter refers to the variation of a signal from an ideal signal, such as an output waveform. Imprecise synchronization between the LCDs 114 can result in jitter being present on the switching signal output by the LCD 114. Jitter can be caused by software and uncontrolled execution time of low level interrupts of the processor and / or controller implementing the control logic. Jitter can include, for example, an increase and / or decrease in the level of the signal for a short period of time during the rising and / or falling edges in the signal.

[0402] For example, resetting the PWM counter 2532 of one LCD 114 in the array 700 before resetting the PWM counter 2532 of another LCD 114 in the array 700 can result in imprecise phase shifts in their carrier signals, resulting in imprecise timing of the switching signals for the converter 202 and distorted output voltage of the system 100. Using synchronization techniques such as those described above, this jitter can be reduced, resulting in closer synchronization and corresponding switching signals, thereby resulting in a better quality output voltage.

[0403] 31 is a plot 3100 illustrating the jitter present on the switching signals output by the LCD 114. The plot 3100 shows the jitter on the rising edges of switching signals 3110-3140 generated by the LCDs 114 of four different modules 108 of the array 700 based on PWM synchronization events. For switching signal 3210, jitter is present during jitter time period 3150. Similar jitter is present on the rising edges of switching signals 3120, 3130, and 3140 during similar time periods.

[0404] 32 is a plot 3200 illustrating the reduced jitter present on a switching signal output by the LCD 114. The plot 3200 can show, on the same time scale as the plot 3100, the reduced jitter resulting from the use of the systems 100, their synchronization units 2510, and / or the synchronization techniques described herein.

[0405] Plot 3200 shows a voltage waveform 3210 of a synchronization signal input to the synchronization unit 2610, a reset signal 3220 output by the synchronization unit 2610, a voltage waveform 3230 of a switching signal output by a first LCD 114 receiving the reset signal output by the synchronization unit 2610, and a switching signal output by a second LCD 114 receiving the reset signal output by the synchronization unit 2610.

[0406] Here, the voltage waveform 3210 of the synchronization signal typically has a normal pulse width 3210-1 for most of the pulses. To initiate a synchronization event, the synchronization signal can be adjusted to have a longer pulse width 3210-2 at the high level. This causes the output voltage 3220 to drop from the high level 3220-1 to the low level 3220-2 for the short pulse, as described above.

[0407] In this example, each LCD 114 uses the rising edge of the sync signal to reset the PWM counter 2532. As described above, once the PWM counter 2532 is reset, the carrier generator 2530 restarts the carrier signal generation process. As shown in Figure 32, the magnitude and duration of the jitter 3231 and 3241 shown on the rising edges of the waveforms 3230 and 3241, respectively, are much less than those in Figure 31.

[0408] Various aspects of the present subject matter are described below in review of and / or to complement the previously described embodiments, with emphasis being placed on the interrelationships and compatibility of the following embodiments, in other words, the fact that each feature of the embodiments can be combined with each and every other feature, unless expressly stated or otherwise taught.

[0409] In many embodiments, the energy system includes an array of cascaded modules configured to output a voltage waveform and / or a current waveform to a load. In these embodiments, each module includes an energy source, a switch circuit, and a local control device, and each module has an identifier. The energy system can include a master control device communicatively coupled to each local control device via a communication path and configured to transmit a control information data element to the local control device via the communication path. Each control information data element can include a normalized reference signal for each module of the array of cascaded modules, a single identifier selected from a set of identifiers including an identifier for each module in the array of cascaded modules, and a modulation index for the module having the single identifier. The local control device of each module can be configured to scale the normalized reference signal of a most recently received control information data element by the modulation index of a most recently received control information data element having the identifier of the module to generate a scaled reference signal, and use the scaled reference signal to control the switch circuit of the module.

[0410] In many embodiments, the master control device periodically transmits control information data elements to the local control devices according to a sequence that defines the ordering of the modules, in which updated modulation indexes are transmitted to the modules using the control information data elements.

[0411] In many embodiments, the local control device of each module is configured to determine whether the selected identifier of each control information data element matches the identifier of the module. When the selected identifier of the control information data element matches the identifier of the module, the local control device of the module can scale the normalized reference signal of the control information data element using the modulation index of the control information data element. When the selected identifier of the control information data element does not match the identifier of the module, the local control device of the module can scale the normalized reference signal of the control information data element using the modulation index of the most recently received control information data element that had the identifier of the module.

[0412] In many embodiments, the master control device includes a controller configured to generate individual modulation indexes for the modules.

[0413] In many embodiments, the modulation index for at least one module in the array of cascaded modules is different from the modulation index for at least one other module in the array of cascaded modules. The energy system can include a bidirectional data path communicatively coupling each local control device to the master control device. Each local control device can be configured to transmit status information for the modules, including the local control device, to the master control device via the bidirectional data path. The controller can generate a modulation index for each module using the status information received from each local control device. The status information for each module can include one or more of a state of charge of the module's energy source, a state of health of the module's energy source, or a temperature of the module's energy source.

[0414] In many embodiments, the communication path includes a serial communication path.

[0415] In many embodiments, a method of controlling a voltage or current delivered to a load includes transmitting, by a master control device and over a communication path, control information data elements to local control devices of an array of cascaded modules configured to output a voltage and / or current waveform to the load. Each module includes an energy source, a switch circuit, a local control device, and an identifier. Each control information data element includes a normalized reference signal for each module of the array of cascaded modules, a single identifier selected from a set of identifiers including an identifier for each module in the array of cascaded modules, and a modulation index for the module having the single identifier. The method may include scaling, by each local control device, the normalized reference signal of a most recently received control information data element by the modulation index of a most recently received control information data element having the identifier of the module to generate a scaled reference signal, and using the scaled reference signal to control the switch circuit of the module.

[0416] In many embodiments, transmitting the control information data element to the local control device of the array of cascaded modules includes the master control device periodically transmitting the control information data element to the local control device according to a sequence defining the ordering of the modules, in which updated modulation indexes are transmitted to the modules using the control information data element.

[0417] In many embodiments, the method includes determining, for each module of the array of cascaded modules, by the module's local control device whether a selected identifier of each control information data element matches an identifier of the module. The method can include scaling, by the module's local control device, a normalized reference signal of the control information data element using a modulation index of the control information data element when the selected identifier of the control information data element matches an identifier of the module. The method can include scaling, by the module's local control device, a normalized reference signal of the control information data element using a modulation index of a most recently received control information data element that had an identifier of the module when the selected identifier of the control information data element does not match an identifier of the module.

[0418] In many embodiments, the method includes generating, by a controller of the master control device, individual modulation indexes for the modules.

[0419] In many embodiments, a modulation index for at least one module in the array of cascaded modules is different from a modulation index for at least one other module in the array of cascaded modules. The method can include transmitting, by each local control device and via a bidirectional data interface communicatively coupling each local control device to the master control device, status information for the modules including the local control device. In many embodiments, the controller generates a modulation index for each module using the status information received from each local control device. In many embodiments, the status information for each module includes one or more of a state of charge of the module's energy source, a state of health of the module's energy source, or a temperature of the module's energy source.

[0420] In many embodiments, the communication path includes a serial communication path.

[0421] In many embodiments, the energy system includes an array of cascaded modules configured to output a voltage waveform and / or a current waveform to a load. Each module includes an energy source, a switch circuit, and a local control device that controls the switch circuit based at least in part on a received normalized reference signal. The energy system can include a master control device communicatively coupled to each local control device via a communication path and configured to transmit a control information data element to the local control device via the communication path. Each control information data element can include a normalized reference signal. Each local control device can be configured to detect a first data unit on the communication path after at least a threshold duration of time since a previous control information data element was received, determine that a new control information data element including the first data unit has been received, and process the new control information data element based on the duration of time that has elapsed since the first data unit was received and whether additional data units have been received after the data reception time period for the new control information data element.

[0422] In many embodiments, determining that a new control information data element has been received includes starting a timer for a data reception time period in response to detecting the first data unit, receiving additional data units during the data element reception time period, determining whether any additional data elements have been received during a post-reception time period, and determining that a new control information data element has been received based on a determination that no additional data units have been received during the elapsed data element reception time period and the post-reception time period.

[0423] In many embodiments, the data reception time period is based on the data size of each control information data element and the data rate for the communication path. The data reception time period can be longer than the expected time period for receiving the control information data element. The data reception time period can include a duration for receiving data having a data size that exceeds the data size of each control information data element by one or two bytes. Processing the new control information data element can include operating the switch circuit using a normalized reference signal and a modulation index for a module that includes the local control device. The local control device is configured to operate the switch circuit using a previously stored normalized reference signal of a previously received control information data element whenever a received control information data element is corrupted or not received completely.

[0424] In many embodiments, a method of controlling a voltage or current delivered to a load includes transmitting, by a master control device and over a communication path, a control information data element to a local control device of an array of cascaded modules configured to output a voltage and / or current waveform to the load. Each module includes an energy source, a switch circuit, and a local control device that controls the switch circuit based at least in part on a received normalized reference signal. The method can include detecting, by the local control device, a first data unit on the communication path at least a threshold duration of time since a previous control information data element was received. The method can include determining, by the local control device, that a new control information data element has been received, including the first data unit, based on the duration of time that has elapsed since the first data unit was received and whether additional data units have been received after a data reception time period for the new control information data element, and processing the new control information data element.

[0425] In many embodiments, determining that a new control information data element has been received includes starting a timer for a data reception time period in response to detecting the first data unit, receiving additional data units during the data element reception time period, determining whether any additional data elements have been received during a post-reception time period, and determining that a new control information data element has been received based on a determination that no additional data units have been received during the elapsed data element reception time period and the post-reception time period.

[0426] In many embodiments, the data reception time period is based on the data size of each control information data element and the data rate for the communication path. The data reception time period can be longer than the expected time period for receiving the control information data element. The data reception time period can include a duration for receiving data having a data size that exceeds the data size of each control information data element by one or two bytes. Processing the new control information data element can include operating the switch circuit using a normalized reference signal and a modulation index for the module including the local control device. The local control device can be configured to operate the switch circuit using a previously stored normalized reference signal of a previously received control information data element each time a received control information data element is corrupted or not received completely.

[0427] In many embodiments, an energy system includes an array of cascaded modules configured to output a voltage waveform and / or a current waveform to a load. Each module can include an energy source, a switch circuit, and a local control device that controls the switch circuit based at least in part on a received normalized reference signal. The energy system can include a master control device that is communicatively coupled to each local control device via a control path and a synchronization path and transmits control information data elements to the local control device via the control path. Each control information data element can include a normalized reference signal for each module of the cascaded modules and a modulation index for scaling the reference signal. The master control device can transmit a synchronization signal to the local control device via the synchronization path. The synchronization signal can indicate when the control information data element is being transmitted to the local control device.

[0428] In many embodiments, the local control device of each module is configured to detect the synchronization signal and to retrieve the control information data element in response to detecting the synchronization signal.

[0429] In many embodiments, the master control device is configured to remove the synchronization signal after transmission of the control information data elements is complete, and the local control device of each module may be configured to stop capturing control information data elements in response to detecting that the synchronization signal has been removed.

[0430] In many embodiments, transmitting the synchronization signal includes increasing a voltage level on a synchronization signal bus coupled to the master control device and to the local control devices of each module of the array of cascaded modules, and removing the synchronization signal can include decreasing a voltage level on the synchronization signal bus.

[0431] In many embodiments, each local control device is configured to wake the module that contains the local control device from a sleep mode in response to detecting a synchronization signal. The master control device can be configured to transmit a synchronization signal in response to a decision to wake a module of an array of cascaded modules.

[0432] In many embodiments, a method of controlling a voltage or current supplied to a load includes transmitting, by a master control device and via a control path, control information data elements to local control devices of an array of cascaded modules configured to output a voltage waveform and / or a current waveform to the load. Each module can include an energy source, a switch circuit, and a local control device that controls the switch circuit based at least in part on a received normalized reference signal. The master control device can be communicatively coupled to each local control device via the control path and via a synchronization path. Each control information data element can include a normalized reference signal for each module of the cascaded module and a modulation index for scaling the reference signal. The method can include transmitting a synchronization signal to the local control device via the synchronization path. The synchronization signal can indicate when the control information data element is being transmitted to the local control device.

[0433] In many embodiments, the method includes detecting, by a local control device of each module, a synchronization signal; and capturing, by the local control device of each module, a control information data element in response to detecting the synchronization signal.

[0434] In many embodiments, the method includes removing the synchronization signal by the master control device after transmission of the control information data elements is completed. The local control device of each module may be configured to stop capturing the control information data elements in response to detecting that the synchronization signal has been removed.

[0435] In many embodiments, transmitting the synchronization signal includes increasing a voltage level on a synchronization signal bus coupled to the master control device and to the local control devices of each module of the array of cascaded modules, and removing the synchronization signal can include decreasing a voltage level on the synchronization signal bus.

[0436] In many embodiments, each local control device is configured to wake a module that includes the local control device from a sleep mode in response to detecting a synchronization signal. Transmitting the synchronization signal over the synchronization path to the local control device can include transmitting the synchronization signal in response to a determination to wake a module of the array of cascaded modules.

[0437] In many embodiments, an energy system configured to generate split-phase AC power includes first and second arrays of modules. Each module of the first and second arrays can include a converter coupled to an energy source. The first array can be configured to generate a first AC signal between a first output and a second output of the first array, the first AC signal having a first phase angle. The second array can be configured to generate a second AC signal between a first output and a second output of the second array, the second AC signal having a second phase angle that differs from the first phase angle by 180 degrees. The first output of the first array can be connected to a first system output terminal (L1). The first output of the second array can be connected to a second system output terminal (L2). The second outputs of the first and second arrays can be connected to a third system output terminal (N).

[0438] In many embodiments, each module includes a local control device configured to control a switch circuit of the converter of the module based on the normalized reference signal and the modulation index. The energy system can include a master control device configured to transmit a first control information data element to each module of the first array and a second control information data element to each module of the second array. Each first control information data element can include a first normalized reference signal for each module of the array of the first array and a single first identifier selected from a set of first identifiers for modules of the first array. The set of first identifiers can include a first identifier for each module in the first array. Each first control information data element can include a first modulation index for a module of the first array having the single first identifier. Each second control information data element can include a second normalized reference signal for each module of the array of the second array and a single second identifier selected from a set of second identifiers for modules of the second array. The set of second identifiers can include a second identifier for each module in the second array. Each second control information data element may include a second modulation index for a module of the second array having a unique second identifier.

[0439] In many embodiments, the local control device of each module in the first array is configured to scale a first normalized reference signal of a most recently received first control information data element by a first modulation index of a most recently received control information data element having an identifier of the module of the first array to generate a scaled reference signal, and to use the scaled reference signal to control a switch circuit of a converter of the module of the first array.

[0440] In many embodiments, the master control device periodically transmits a first control information data element to each module in the first array according to a sequence defining the order of the modules, in which an updated modulation index is transmitted to the module using the first control information data element.

[0441] In many embodiments, a method for waking up a local control device includes determining, by a master control device communicatively coupled to the local control devices of each module of the array of cascaded modules via a synchronization path, to wake each local control device from a sleep operating mode, and in response to determining to wake each local control device from the sleep operating mode, sending a synchronization signal by the master control device and via the synchronization path to a wake interface of each local control device.

[0442] In many embodiments, the method includes transmitting, by the master control device, a synchronization signal over a synchronization path to each local control device each time the master control device transmits a control information data element to each local control device. The synchronization signal indicates to each local control device that the master control device is transmitting a control information data element. The method can include transmitting, by the master control device, a control information data element to each local control device over a control path communicatively coupling the master control device to each local control device. Each control information data element can include a normalized reference signal for each module of the array and a single identifier selected from a set of identifiers for the modules of the array. The set of identifiers can include an identifier for each module in the array. Each control information data element can include a first modulation index for a module of the first array having the single identifier. The synchronization path can serve a first purpose to indicate to each local control device when a control information data element is being transmitted to each local control device and a second purpose to wake each local control device from a sleep mode of operation.

[0443] In many embodiments, the energy control system includes modules configured to be connected together to output a voltage waveform and / or a current waveform to a load. Each module can include an energy source, a switch circuit, and a local control device. The energy control system can include a master control device configured to send control information to each local control device over a communication path. The control information can include reference signal information, modulated index information, and an identifier that associates the modulated index information with one of the modules.

[0444] In many embodiments, the modules are arranged in a cascaded array.

[0445] In many embodiments, the control information can include control information data elements. Each control information data element can include reference signal information for all modules in the set of modules, modulated index information for one module, and an identifier. The local control device of each module can be configured to scale the reference signal information of the most recently received control information data element by the modulated index information of the most recently received control information data element having the module's identifier to generate a scaled reference signal. The local control device of each module can be configured to use the scaled reference signal to control the switch circuit of the module.

[0446] In many embodiments, the master control device periodically transmits control information to the local control devices according to a sequence that defines the order in which the modules receive updated modulation index information.

[0447] In many embodiments, the local control device of each module is configured to determine whether the identifier matches the module's identifier. When the identifier matches the module's identifier, the module's local control device can scale the reference signal information using the modulation index information. When the identifier does not match the module's identifier, the module's local control device can scale the reference signal information using previously stored modulation information for the module.

[0448] In many embodiments, the master control device includes a controller configured to generate individual modulation index information for the modules.

[0449] In many embodiments, a method of controlling a voltage or current delivered to a load includes transmitting, by a master control device and via a communication path, control information to each local control device of a plurality of modules configured to be connected together to output a voltage waveform and / or a current waveform to the load. Each module of the plurality of modules may include an energy source, a switch circuit, and a local control device. The control information may include reference signal information, modulated index information, and an identifier associating the modulated index information with a module of the plurality of modules.

[0450] In many embodiments, multiple modules are arranged in a cascaded array.

[0451] In many embodiments, the control information includes control information data elements, each of which may include reference signal information for all modules in the set of modules, modulated index information for a module, and an identifier. The method may include scaling, by each local control device, the reference signal information of a most recently received control information data element by the modulated index information of a most recently received control information data element having the identifier of the module to generate a scaled reference signal, and controlling, by each local control device, a switch circuit of the module using the scaled reference signal.

[0452] In many embodiments, the master control device periodically transmits control information to the local control devices according to a sequence that defines the order in which the modules receive updated modulation index information.

[0453] In many embodiments, the method includes determining, by each local controlling device, whether the identifier matches an identifier of the module. The method may include scaling, by the local controlling device, the reference signal information using modulation index information when the identifier matches the identifier of the module. The method may include scaling, by the local controlling device, the reference signal information using previously stored modulation information for the module when the identifier does not match the identifier of the module.

[0454] In many embodiments, the master control device includes a controller configured to generate individual modulation index information for the modules.

[0455] In many embodiments, a method of synchronizing modules of an energy system includes generating a synchronization signal by a master control device communicatively coupled to a local control device of each module. The master control device transmits the synchronization signal to the local control device of each local control device. The master control device adjusts the synchronization signal and initiates a synchronization event. The adjusting includes adjusting at least one of a duty cycle or a frequency of the synchronization signal. Each local control device detects the synchronization event based on the adjusted synchronization signal. Each local control device performs a synchronization action in response to detecting the synchronization event.

[0456] In many embodiments, performing the synchronization action includes resetting a pulse width modulation (PWM) controller of the module, the PWM controller configured to generate a PWM switching signal for a converter of the module.

[0457] In many embodiments, resetting the PWM controller includes resetting a PWM counter of the PWM controller.

[0458] In many embodiments, the PWM controller includes a carrier generator that generates a carrier signal based on the PWM counter for use in generating the PWM switching signal.

[0459] In many embodiments, generating the synchronization signal includes generating a regular synchronization signal having a regular frequency and amplitude.

[0460] In many embodiments, the method includes detecting a data capture event based on a regular synchronization signal.

[0461] In many embodiments, the method includes capturing data from a path or link communicatively coupling the master control device to the local control device in response to detecting a data capture event.

[0462] In many embodiments, detecting a synchronization event includes applying a synchronization signal to a capacitor, comparing a voltage on the capacitor to a threshold voltage level, and detecting a synchronization event when the voltage on the capacitor is greater than or equal to the threshold voltage level.

[0463] In many embodiments, adjusting the synchronization signal includes decreasing the frequency of the synchronization signal.

[0464] In many embodiments, a method of synchronizing modules of an energy system includes detecting, by a local control device, a data absence event on a communication path communicatively coupling the master control device to the local control device. In response to detecting the data absence event, a synchronization action is performed.

[0465] In many embodiments, performing the synchronization action includes resetting a pulse width modulation (PWM) controller of the module. The PWM controller can be configured to generate a PWM switching signal for a converter of the module.

[0466] In many embodiments, resetting the PWM controller includes resetting a PWM counter of the PWM controller.

[0467] In many embodiments, the PWM controller includes a carrier generator that generates a carrier signal based on the PWM counter for use in generating the PWM switching signal.

[0468] In many embodiments, detecting the absence of data event includes detecting a first data unit on the communication path at least a threshold duration of time since a previous data element was received and initiating a timer in response to detecting the first data unit. A absence of data event is detected whenever the timer elapses before a new data unit is detected on the communication path.

[0469] In many embodiments, the method includes resetting the timer each time a new data unit is detected on the communication path before the timer expires.

[0470] In many embodiments, the energy system includes an array of cascaded modules configured to output a voltage waveform and / or a current waveform to a load. Each module includes an energy source, a switch circuit, and a local control device. Each module has an identifier. The energy system includes a master control device communicatively coupled to each local control device via a communication path. The master control device is configured to transmit control information data elements and a synchronization signal to the local control devices via the communication path, and to coordinate the synchronization signal and initiate a synchronization event at each local control device.

[0471] In many embodiments, the master control device is configured to adjust the synchronization signal by adjusting at least one of the duty cycle or frequency of the synchronization signal.

[0472] In many embodiments, the local control device of each module is configured to detect a synchronization event based on the adjusted synchronization signal and to perform a synchronization action in response to detecting the synchronization event.

[0473] In many embodiments, the local control device of each module includes a PWM controller configured to generate PWM switching signals for the switch circuits of the module, and the local control device of each module is configured to perform a synchronization action by resetting the PWM controller of the local control device.

[0474] In many embodiments, resetting the PWM controller includes resetting a PWM counter of the PWM controller.

[0475] In many embodiments, the PWM controller of each local control device includes a carrier generator that generates a carrier signal based on a PWM counter for use in generating the PWM switching signal.

[0476] In many embodiments, each local control device includes a synchronization unit configured to receive a synchronization signal and detect a synchronization event based on the adjusted synchronization signal.

[0477] In many embodiments, the synchronization unit is configured to detect a synchronization event based on a voltage level on a capacitor coupled to the synchronization unit.

[0478] In many embodiments, the master control device is configured to adjust at least one of the duty cycle or frequency of the synchronization signal for one or more periods of the synchronization signal to increase the charge level of the capacitor.

[0479] In many embodiments, the synchronization unit is configured to detect a synchronization event in response to the voltage level on the capacitor meeting or exceeding a threshold voltage level.

[0480] In many embodiments, the synchronization unit includes a comparator configured to compare the voltage level of the capacitor with a threshold voltage level.

[0481] In many embodiments, the energy system includes a plurality of modules, each having an energy source and a converter. The plurality of modules are configured to receive a synchronization signal and generate synchronized output signals. The system is configured to generate an AC signal based on a superposition of the output signals from each module. The plurality of modules are configured to synchronize their output signals based on a change in frequency in the synchronization signal.

[0482] In many embodiments, the multiple modules are configured to perform pulse width modulation to generate the output signal, the synchronization of the pulse width modulation being based on a change in frequency in a synchronization signal.

[0483] In many embodiments, the multiple modules are configured to perform pulse width modulation on a carrier signal and a modulated reference signal having different phases, and the generation of the carrier signal is synchronized between the multiple modules based on a frequency change in a synchronization signal.

[0484] In many embodiments, the multiple modules are configured to determine when to perform a data capture event based on a change in frequency in the synchronization signal.

[0485] In many embodiments, a method of synchronizing modules of an energy system includes receiving, by each module of the plurality of modules, a synchronization signal; generating, by each module of the plurality of modules, a synchronized output signal based on a superposition of output signals from each module to generate an AC signal; and synchronizing, by the plurality of modules, the output signals of the plurality of modules based on a change in frequency in the synchronization signal.

[0486] In many embodiments, generating the synchronized output signal includes performing pulse width modulation, the synchronization of which is based on a change in frequency in the synchronization signal.

[0487] In many embodiments, generating the synchronized output signal includes performing pulse width modulation on a carrier signal and a modulated reference signal having different phases, the generation of the carrier signal being synchronized among the multiple modules based on a change in frequency in a synchronization signal.

[0488] In many embodiments, the method includes determining, by a plurality of modules, when to perform a data capture event based on a change in frequency in the synchronization signal.

[0489] As used herein, the term "module" refers to one of two or more devices or subsystems within a larger system. A module can be configured to operate in combination with other modules of similar size, functionality, and physical arrangement (e.g., location of electrical terminals, connectors, etc.). Modules with the same functionality and energy source can be configured the same (e.g., size and physical arrangement) as all other modules in the same system (e.g., rack or pack), while modules with different functionality or energy sources can differ in size and physical arrangement. Each module may be physically removable and replaceable with respect to other modules of the system (e.g., like the wheels of a car, or the blades of an information technology (IT) blade server), but this is not required. For example, a system may be packaged in a common housing that does not permit removal and replacement of any one module without disassembling the entire system. However, any and all embodiments herein may be configured such that each module is removable and replaceable with respect to other modules in any convenient manner without disassembling the system.

[0490] The term "master control device" is used broadly herein and does not require the implementation of any particular protocol, such as a master and slave relationship between any other device, such as a local control device.

[0491] The term "output" is used broadly herein and does not preclude it from functioning bidirectionally as both an output and an input. Similarly, the term "input" is used broadly herein and does not preclude it from functioning bidirectionally as both an input and an output.

[0492] The terms "terminal" and "port" are used broadly herein and can be either unidirectional or bidirectional, can be input or output, and do not require any physical or mechanical structure such as a specific female or male configuration.

[0493] Various aspects of the present subject matter are described below in review of and / or to complement the previously described embodiments, with emphasis being placed on the interrelationships and compatibility of the following embodiments, in other words, the fact that each feature of the embodiments can be combined with each and every other feature, unless expressly stated or logically justified.

[0494] The processing circuitry may include one or more processors, microprocessors, controllers, and / or microcontrollers, each of which may be separate or standalone chips, or may be distributed among (and portions of) several different chips. Any type of processing circuitry may be implemented, including but not limited to personal computing architectures (such as those used in desktop PCs, laptops, tablets, etc.), programmable gate array architectures, proprietary architectures, custom architectures, etc. The processing circuitry may include digital signal processors, which may be implemented in hardware and / or software. The processing circuitry may execute software instructions stored on memory, which cause the processing circuitry to take many different actions and control other components.

[0495] The processing circuitry may also execute other software and / or hardware routines. For example, the processing circuitry may interface with the communications circuitry and perform analog to digital conversion, encoding and decoding, other digital signal processing, multimedia functions, conversion of data to a format suitable for presentation to the communications circuitry (e.g., in-phase and quadrature), and / or cause the communications circuitry to transmit data (wired or wireless).

[0496] The processing circuitry may also be adapted to execute an operating system and any software applications and to perform other functions thereof not related to processing received and transmitted communications.

[0497] Computer program instructions for performing operations in accordance with the described subject matter may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, Java Script, Smalltalk, C++, C#, Transact-SQL, XML, PHP, and conventional procedural programming languages, such as the "C" programming language or a similar programming language.

[0498] The memory, storage, and / or computer-readable media may be shared by one or more of the various functional units presented, or distributed among two or more of them (e.g., as separate memories residing in different chips). A memory may also reside on its own separate chip.

[0499] To the extent that the embodiments disclosed herein include or operate in conjunction with memory, storage, and / or computer-readable media, the memory, storage, and / or computer-readable media are non-transitory. Thus, to the extent that the memory, storage, and / or computer-readable media is covered by one or more claims, The memory, storage, and / or computer readable medium is only non-transitory. As used herein, the terms "non-transitory" and "tangible" are intended to describe memory, storage, and / or computer readable medium other than propagating electromagnetic signals, but are not intended to limit the type of memory, storage, and / or computer readable medium in terms of permanence of storage or otherwise. For example, "non-transitory" and / or "tangible" memory, storage, and / or computer readable medium encompasses volatile and non-volatile media, such as random access media (e.g., RAM, SRAM, DRAM, FRAM, etc.), read-only media (e.g., ROM, PROM, EPROM, EEPROM, flash, etc.), and combinations thereof (e.g., hybrid RAM and ROM, NVRAM, etc.), and variations thereof.

[0500] It should be noted that all features, elements, components, functions, and steps described with respect to any embodiment provided herein are intended to be freely combinable and replaceable with those from any other embodiment. When a particular feature, element, component, function, or step is described with respect to only one embodiment, it should be understood that the feature, element, component, function, or step can be used with all other embodiments described herein, unless otherwise specified. Thus, this paragraph serves as a prelude and written support for the introduction of claims that combine features, elements, components, functions, and steps from different embodiments, or replace features, elements, components, functions, and steps from one embodiment with features, elements, components, functions, and steps from another embodiment, even if the following description does not specify that such combinations or substitutions are possible in a particular example. It is expressly recognized that an explicit enumeration of all possible combinations and permutations would be unduly burdensome, especially considering that the permissibility of each and every such combination and permutation would be readily recognized by a person skilled in the art.

[0501] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0502] While the embodiments are susceptible to various modifications and alternative forms, specific examples of which have been shown in the drawings and are described in detail herein. It is to be understood, however, that these embodiments are not limited to the particular forms disclosed, but on the contrary, these embodiments are intended to encompass all modifications, equivalents, and alternatives falling within the spirit of the disclosure. Furthermore, any feature, function, step, or element of the embodiments may be recited or added to the claims, as well as any negative limitations that define the scope of the invention in the claims, with any feature, function, step, or element not falling within its scope.

Claims

1. It is an energy system, An array of cascaded modules configured to output voltage waveforms and / or current waveforms to a load, each module comprising an energy source, a switch circuit, and a local control device, and each module having an identifier, A master control device that is communicatively connected to each local control device via a communication path and configured to transmit control information data elements to the local control devices via the communication path, wherein each control information data element is: A normalized reference signal for each module of the array of cascaded modules, A single identifier selected from a set of identifiers including the identifier for each module in the array of the cascaded modules, A modulation index for the module having the single identifier and Includes a master control device and Equipped with, The local control device of each module is The normalized reference signal of the most recently received control information data element is scaled by the modulation index of the most recently received control information data element having the identifier of the module, thereby generating a scaled reference signal. The scaled reference signal is used to control the switch circuit of the module. An energy system configured to perform the following actions.

2. The energy system according to claim 1, wherein the master control device periodically transmits the control information data elements to the local control device in a sequence that defines the order in which modules are transmitted to the modules using the updated modulation index.

3. The local control device of each module is Determining whether the selected identifier of each control information data element matches the identifier of the module, When the selected identifier of the control information data element matches the identifier of the module, the local control device of the module scales the normalized reference signal of the control information data element using the modulation index of the control information data element. When the selected identifier of the control information data element does not match the identifier of the module, the local control device of the module scales the normalized reference signal of the control information data element using the modulation index of the most recently received control information data element that had the identifier of the module. The energy system according to claim 1, configured to perform the following:

4. The energy system according to claim 1, wherein the master control device comprises a controller configured to generate individual modulation indices for the modules.

5. The energy system according to claim 1, wherein the modulation index for at least one module in the array of cascaded modules is different from the modulation index for at least one other module in the array of cascaded modules.

6. The energy system according to claim 5, further comprising a bidirectional data path that connects each local control device to the master control device in a communicative manner, wherein each local control device is configured to transmit status information for the module including the local control device to the master control device via the bidirectional data path.

7. The energy system according to claim 6, wherein the controller generates the modulation index for each module using the status information received from each local control device, or the status information for each module includes one or more of the following: (1) the charge state of the energy source of the module, (2) the health state of the energy source of the module, or (3) the temperature of the energy source of the module.

8. The local control device controls the switch circuit at least in part based on the received normalized reference signal, The energy system according to claim 1, wherein the master control device is further communicably coupled to each local control device via a synchronization path, and transmits a synchronization signal to the local control devices via the synchronization path, the synchronization signal indicating when control information data elements are being transmitted to the local control devices.

9. The energy system according to claim 8, wherein the local control device of each module is configured to detect the synchronization signal and to take in the control information data elements in response to the detection of the synchronization signal.

10. The energy system according to claim 8, wherein the master control device is configured to remove the synchronization signal after the transmission of the control information data elements is completed.

11. The energy system according to claim 10, wherein the local control device of each module is configured to stop taking in the control information data elements in response to detecting that the synchronization signal has been removed.

12. The energy system according to claim 8, wherein transmitting the synchronization signal includes increasing the voltage level on the synchronization signal bus coupled to the master control device and the local control device of each module of the cascaded module array.

13. The energy system according to claim 8, wherein removing the synchronization signal includes reducing the voltage level on the synchronization signal bus.

14. The energy system according to claim 13, wherein the master control device is configured to transmit the synchronization signal in response to a decision to wake the modules of the cascaded module array.

15. (i) The local control device of each module is configured to detect the synchronization event based on the coordinated synchronization signal and to perform a synchronization action in response to the detection of the synchronization event, and / or (ii) The local control device of each module comprises a PWM controller configured to generate PWM switching signals for the switch circuit of the module, The system according to claim 13, wherein the local control device of each module is configured to perform the synchronization action by resetting the PWM controller of the local control device.

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