Pulsed charging for the energy sources of connected modules

Abstract

Embodiments are disclosed that provide advanced charging of an energy source arrangement for energy storage applications. The embodiments can be used in an energy storage system having a cascaded arrangement of converter modules. The embodiments can include applying pulses to the energy source of each module of the system. The pulses can be applied for charging and pre-heating purposes. Control techniques can be used to distribute a charging signal from a charging source to multiple modules of the energy storage system.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit (under 35 U.S.C. §119(e)) of and priority to U.S. Provisional Patent Application No. 63 / 332,529, filed April 19, 2022, which is incorporated by reference herein in its entirety for all purposes.

[0002] The subject matter described herein relates generally to pulsed charging of energy sources in energy storage systems used in mobile or stationary applications, or both. [Background technology]

[0003] Electrical energy storage systems are a key aspect in the global transition to cleaner forms of energy. Electrical energy storage systems are found in many stationary and mobile applications. Electrical energy storage systems in the form of battery packs or racks can be used to power hybrid and fully electric vehicles, and electrical energy storage systems can be used to store electrical power generated by the vehicle (e.g., through the use of regenerative braking).

[0004] Electrical energy storage systems require periodic charging to replenish discharged power. Several deficiencies and problems associated with existing charging methods have been identified, such as heat loss, degradation, and slow charging rates. For example, it is well known that long charging times for electric vehicles (EVs) are a major factor limiting their widespread adoption. Using conventional constant current charging methods can take several hours to fully charge a battery pack. Such long standby times create substantial inconvenience and inefficiency when using an EV for travel outside the range of a single charge for the EV. Thus, conventional EVs are most typically used for local commuting or travel that can be completed without requiring recharging of the battery pack. To the extent that charging stations exist that allow charging at higher voltages and for shorter times, repeated use of such stations can result in a dramatically reduced lifespan of the battery pack. Summary of the Invention [Means for solving the problem]

[0005] Exemplary embodiments of systems, devices, and methods for fast charging of an energy source separate from or as part of an energy storage system (e.g., battery packs of electric vehicles, stationary systems for powering microgrids, and others) are described herein. The embodiments described herein can include heating the energy source through application of a preheat signal that raises the source temperature and lowers the overall impedance of the energy source so that accelerated electrochemical reactions are possible through subsequent charging. The embodiments can include charging the energy source with charge pulses at a frequency that passes through the double sheet capacitance of the energy source, reduces the activation impedance of the source, and allows charging of the source at a higher C-rate without degradation reactions. The C-rate is a measure of the rate at which a battery is charged or discharged. The embodiments can also include a combination of a pulse preheat phase or a pulse charging phase with a constant current (or non-pulsed) charging phase at a higher temperature, and some embodiments can include at least one instance of all three phases. The embodiments described herein are particularly suitable for application within cascaded modular energy storage systems, where each module includes an energy source and a switching network capable of applying current in a pulsed manner for preheating and / or charging. Also disclosed are embodiments for monitoring the energy source to detect potentially degrading conditions such as uneven lithiation and lithium plating.

[0006] Embodiments may include controlling the charge pulses provided to each module such that a maximum amount of current can be applied from the charge source to each module and / or such that the current and / or voltage output by the charge source is constant, e.g., within a threshold tolerance. The control methodologies described herein may include distributing the charge pulses to the energy sources of the modules and / or groups of modules in an interleaving manner such that the total current drawn by the energy sources of the modules is constant and each module's energy source receives a designated frequency of charge pulses. The duty cycle of the charge pulses may be adjusted for some or all of the modules to account for bypass modules, unbalanced charging, and / or module operating characteristics.

[0007] Other systems, devices, methods, features, and advantages of the subject matter described herein will be apparent to one of ordinary skill in the art upon review of the following figures and detailed description. All such additional systems, methods, features, and advantages are intended to be included herein and within the scope of the subject matter described herein. Features of the exemplary embodiments are not to 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]

[0008] Details of the subject matter described herein, both as to its structure and operation, are illustrated in the accompanying drawings, where 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.

[0009] [Figure 1A] FIG. 1 is a block diagram illustrating an exemplary embodiment of a modular energy system. [Figure 1B] Same as above. [Figure 1C] Same as above. [Figure 1D] FIG. 1 is a block diagram illustrating an example embodiment of a control device for an energy system. [Figure 1E] Same as above. [Figure 1F] FIG. 1 is a block diagram illustrating an example embodiment of a modular energy system coupled to a load and a charging source. [Figure 1G] Same as above. [Figure 2A] FIG. 1 is a block diagram illustrating an example embodiment of a module and a control system within an energy system. [Figure 2B] Same as above. [Figure 2C] FIG. 2 is a block diagram illustrating an exemplary embodiment of a physical configuration of modules. [Figure 2D] FIG. 1 is a block diagram illustrating an example embodiment of a physical configuration of a modular energy system. [Figure 3A] 1A-1C are block diagrams illustrating exemplary embodiments of modules having various electrical configurations. [Figure 3B] Same as above. [Figure 3C] Same as above. [Figure 4A] FIG. 2 is a schematic diagram illustrating an exemplary embodiment of an energy source. [Figure 4B] Same as above. [Figure 4C] Same as above. [Figure 4D] Same as above. [Figure 4E] Same as above. [Figure 4F] Same as above. [Figure 5A] FIG. 2 is a schematic diagram illustrating an exemplary embodiment of an energy buffer. [Figure 5B] Same as above. [Figure 5C] Same as above. [Figure 6A] FIG. 1 is a schematic diagram illustrating an exemplary embodiment of a converter. [Figure 6B] Same as above. [Figure 6C] Same as above. [Figure 7A] 1A-1D are block diagrams illustrating example embodiments of modular energy systems having various topologies. [Figure 7B] Same as above. [Figure 7C] Same as above. [Figure 7D] Same as above. [Figure 7E] Same as above. [Figure 8A] 1 is a plot illustrating an example output voltage of a module. [Figure 8B] 1 is a plot illustrating an example multi-level output voltage of a module array. [Figure 8C] 1 is a plot illustrating exemplary reference and carrier signals that can be used in a pulse width modulation control technique. [Figure 8D] 1 is a plot illustrating exemplary reference and carrier signals that can be used in a pulse width modulation control technique. [Figure 8E] 4 is a plot illustrating an example switch signal generated in accordance with a pulse width modulation control technique. [Figure 8F] 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. [Figure 9A] FIG. 2 is a block diagram illustrating an example embodiment of a controller for a modular energy system. [Figure 9B] Same as above. [Figure 10A] FIG. 1 is a block diagram illustrating an example embodiment of a multi-phase modular energy system having interconnected modules. [Figure 10B] FIG. 10B is a schematic diagram illustrating an exemplary embodiment of an interconnection module in the multi-phase embodiment of FIG. 10A. [Figure 10C] FIG. 1 is a block diagram illustrating an example embodiment of a modular energy system having two subsystems connected together by an interconnection module. [Figure 10D]FIG. 1 is a block diagram illustrating an example embodiment of a three-phase modular energy system having interconnected modules supplying auxiliary loads. [Figure 10E] FIG. 10E is a schematic diagram illustrating an exemplary embodiment of an interconnection module in the multi-phase embodiment of FIG. 10D. [Figure 10F] FIG. 2 is a block diagram illustrating another exemplary embodiment of a three-phase modular energy system having interconnected modules supplying auxiliary loads. [Figure 11A] 1 is a plot illustrating a framework for explaining several example embodiments of a fast charging protocol. [Figure 11B] Same as above. [Figure 11C] 11A-11C are current versus time graphs illustrating exemplary embodiments of a preheat pulse train with and without a time gap, respectively. [Figure 11D] Same as above. [Figure 11E] 11 is a current versus time graph illustrating an exemplary embodiment of a preheat signal applied during multiple sub-stages. [Figure 11F] 4 is a current versus time graph illustrating an exemplary embodiment of a pulse charge signal for use in a pulse charge phase. [Figure 12A] FIG. 1 is a cross-sectional view of a generalized lithium-ion battery cell. [Figure 12B] FIG. 1 is an explanatory diagram depicting an expanded anode and cathode illustration and listing examples of degradation modes that can occur within a typical lithium ion battery cell. [Figure 12C] 1 is an electrical circuit diagram model of a battery cell. [Figure 12D] 1 is a plot illustrating an exemplary voltage response to a charge pulse applied to a lithium-ion cell. [Figure 12E] 1 is a graph showing an example voltage on a lithium-ion cell over a range of states of charge. [Figure 12F] 1 is a plot illustrating an example impedance response of a lithium-ion cell. [Figure 13A]4 is a graph showing example levels for a constant current charging signal during a constant current charging phase. [Figure 13B] 11 is a graph illustrating another example embodiment of a fast charging protocol with a constant current signal at a decreasing magnitude. [Figure 14] 1 is a series of plots illustrating an exemplary embodiment of monitoring for indications that lithium plating is occurring. [Figure 15A] 1A-1C are plots of absolute and normalized capacity retention comparing experimental data for an exemplary embodiment of constant current charging and pulse charging, respectively, performed on a pair of lithium ion battery cells rated for use in power applications. [Figure 15B] Same as above. [Figure 16A] 1A-1C are plots of absolute and normalized capacity retention comparing experimental data for an exemplary embodiment of constant current charging and fast charging protocols, respectively, performed on a pair of lithium ion battery cells rated for use in power applications. [Figure 16B] Same as above. [Figure 16C] FIG. 16C is a graph of capacity versus time and FIG. 16D is a graph of voltage versus time, both showing data collected from performing an exemplary cycle of a fast charging protocol on a battery cell. [Figure 16D] Same as above. [Figure 17A] 1 is a voltage versus capacity plot comparing experimental data for exemplary embodiments of constant current charging and pulse charging, respectively, performed on a pair of lithium ion battery cells rated for use in power applications. [Figure 17B] Same as above. [Figure 18A] 1 is a plot of the imaginary and real impedance components for a constant current charged cell and a pulse charged cell at end of life. [Figure 18B] 1 is a plot of cell voltage versus time showing experimental data collected on a lithium-ion cell exposed to constant current charging and pulse charging with different pulse durations. [Figure 19A] FIG. 1 is a block diagram illustrating an example embodiment of a fast charging protocol implementation for various battery types. [Figure 19B] Same as above. [Figure 19C] Same as above. [Figure 19D] Same as above. [Figure 19E] Same as above. [Figure 19F] Same as above. [Figure 19G] Same as above. [Figure 20] FIG. 1 is a block diagram illustrating an example embodiment of an application that may be configured to apply the fast charging protocol described herein. [Figure 21] FIG. 1 is a block diagram illustrating an example embodiment of a modular energy system coupled with a charging source. [Figure 22A] 13 illustrates an example plot of a charging signal for a module's pulse charging energy source. [Figure 22B] Same as above. [Figure 22C] Same as above. [Figure 22D] Same as above. [Figure 23] 1 is a flow chart illustrating an exemplary embodiment of a method for pulse charging energy sources for multiple connected modules. [Figure 24A] 4 shows exemplary plots of voltage and current levels during stages of a charging protocol. [Figure 24B] Same as above. [Figure 24C] Same as above. [Diagram 25] 1 is a flow chart illustrating an exemplary embodiment of a method for pulse charging energy sources for multiple connected modules. [Figure 26] 1 is a flow chart illustrating an exemplary embodiment of a method for pulse charging energy sources for multiple connected modules. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Before the present subject matter is described in detail, it is to be understood that this disclosure is not limited to particular embodiments described, which may, of course, vary. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, as the scope of the present disclosure will be limited only by the appended claims.

[0011] Before describing exemplary embodiments relating to charging and discharging modular energy systems, 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 a modular energy system may be implemented, embodiments of a control system or device for the modular energy system, configuration of embodiments of a modular energy system relative to charging sources and loads, embodiments of individual modules, embodiments of topologies for placement of modules in a system, embodiments of control methodologies, embodiments for balancing operational characteristics of modules in a system, and embodiments of the use of interconnected modules. EXAMPLES

[0012] 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 alternative location when not in use. The module-based energy system resides in a static location while providing 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, but are not limited to, 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 mobile applications described below (e.g., charging sources or charging stations), and systems that convert solar power, wind power, 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 a storage or non-storage role.

[0013] 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.

[0014] 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 do not 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 can be used in both mobile and stationary applications. Although certain configurations may be more suitable for some applications than others, all exemplary embodiments disclosed herein can be used in both mobile and stationary applications unless otherwise specified.

[0015] 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 to each other 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.

[0016] The system 100 is configured to provide 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 depicting an exemplary embodiment of the system 100 with a power input interface 151 for receiving power from a charging source 150 (e.g., a utility grid, a microgrid, a local renewable energy source, etc.) 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 having 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 local renewable energy sources (e.g., solar)).

[0017] 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 the LCDs 114 and the modules 108.

[0018] 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.

[0019] The control system 102 may be configured as a single device for the entire system 100 (e.g., FIG. 1A), may be distributed across multiple devices (e.g., FIGS. 1B-1C), or may be 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.

[0020] The control system 102 can be configured to perform the control using software (instructions stored in 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.

[0021] The control system 102 may have a communication interface for communicating with devices 104 external to the system 100 via communication links or paths 105. For example, the control system 102 (e.g., the MCD 112) may output data or information related to the system 100 to another control device 104 (e.g., a vehicle's Electronic Control Unit (ECU) or Motor Control Unit (MCU) in a mobile application, a grid controller in a stationary application, etc.).

[0022] The communication paths or links 105, 106, 115, 116, 118 (FIG. 2B), and 2105 (FIG. 21) 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 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.

[0023] The control system 102 is configured to control one or more of the modules 108 based on status information received from the same or different one or more of the 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.

[0024] Status information for all modules 108 in the system 100 can be communicated to the control system 102, which can control all modules 108-1...108-N independent of the status information. Other variations are possible. For example, a particular module 108 (or a subset of modules 108) can be controlled based on status information for that particular module 108 (or subset), based on status information for a different module 108 that is not that particular module 108 (or subset), based on status information for all modules 108 other than that particular module 108 (or subset), based on status information for that particular module 108 (or subset) and status information for at least one other module 108 that is not that particular module 108 (or subset), or based on status information for all modules 108 in the system 100.

[0025] The status information may be information regarding one or more aspects, characteristics, or parameters of each module 108. Types of status information may include, but are not limited to, the following aspects of a module 108 or one or more of its components (e.g., energy sources, energy buffers, converters, monitoring circuits): the state of charge (SOC) of one or more energy sources of the module (e.g., the level of charge of an energy source relative to its capacity, such as a fraction or percentage); the state of health (SOH) of one or more energy sources of the module (e.g., a figure of merit of the condition of an energy source compared to its ideal condition); 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; and / or the presence or absence of a fault in any one or more of the components of the module.

[0026] The LCD 114 can be configured to receive status information from each module 108 or determine status information 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 status information based on the raw data. The MCD 112 can then use the module 108 status information to make control decisions accordingly. The decisions can take the form of instructions, commands, or other information (such as the modulation index described herein) that can be utilized by the LCD 114 to maintain or adjust the operation of each module 108.

[0027] For example, the MCD 112 may receive status information 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 conditions, 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 reduce or increase (depending on the condition) 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 reduced to cause the associated parameter (e.g., SOC or temperature) of that module 108 to converge toward the parameters of one or more other modules 108.

[0028] The decision to adjust the operation of a particular module 108 can be made by comparing the status information to a predefined threshold, limit, or condition, without necessarily comparing it to the status of other modules 108. The predefined threshold, limit, or condition can 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 can be a dynamic threshold, limit, or condition that may or may not change during use. For example, the MCD 112 can adjust the operation of a module 108 if the status information 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 can adjust the operation of a module 108 if the status information 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 stopped entirely.

[0029] The MCD 112 may control the modules 108 in the system 100 to achieve or converge toward 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 predetermined thresholds, limits, or conditions. This process may also be referred to as balancing or seeking to achieve balance in the operation or operating characteristics of the modules 108. The term "balance," as used herein, does not require absolute equality between the modules 108 or their components, but rather is used broadly to convey that operation of the system 100 may be used to actively reduce disparities in operation between the modules 108 that would otherwise exist.

[0030] 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 modulated 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.

[0031] 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 (system or subsystem), the control of the system 100 may be implemented in any desired manner, such as one or more software applications executed by 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.).

[0032] 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 an LCD 114 via a path 115, and 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 the 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 separate integrated circuit (IC) chips or packages contained therein.

[0033] In FIG. 1E, the external control device 104 functions as a common control device 132, with the main control functions 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. The external control device 104 can manage communication with the LCD 114 via interface 141 and other devices via interface 144. In various embodiments, the 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.

[0034] 1D and 1E, the primary control functions of the system 102 are shared in the common device 132, although other divisions of the shared control are permitted. For example, some of the primary control functions may be distributed between the common device 132 and the dedicated MCD 112. In another example, both the primary control functions and at least some of the local control functions may be implemented in the common device 132 (e.g., with the remaining local control functions 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 functions are implemented in a device that is shared with another component of each module 108, such as a Battery Management System (BMS).

[0035] 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 or 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.

[0036] Converter 202 may also (or alternatively) be configured to perform AC-DC conversion (e.g., a rectifier), DC-DC conversion, and / or AC-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.

[0037] 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 power supply devices. The fuel cell can be a single fuel cell, multiple fuel cells connected in series or parallel, or a fuel cell module. Two or more energy sources can be included within each module, where the two or more sources can include two batteries of the same or different types, two capacitors of the same or different types, two fuel cells of the same or different types, one or more batteries combined with one or more capacitors and / or fuel cells, and one or more capacitors combined with one or more fuel cells.

[0038] 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 are schematic diagrams illustrating example embodiments of the energy source 206 configured as a single battery cell 402 (Figure 4A), a battery module having a series connection of four cells 402 (Figure 4B), a battery module having a parallel connection of single cells 402 (Figure 4C), and a battery module having a parallel connection with legs each having two cells 402 (Figure 4D). Examples of battery types are described elsewhere herein.

[0039] 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).

[0040] The energy source 206 may also be a fuel cell. Examples of fuel cells 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 others. Similar to the batteries described with respect to Figures 4A-4D, the energy source 206 may 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 batteries, capacitors, and fuel cells are not intended to form an exhaustive list, and one of ordinary skill in the art will recognize other variations that fall within the scope of the present subject matter.

[0041] 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 or other transient responses of converter 202. These fluctuations may be absorbed by buffer 204 instead of being passed to source 206 or ports IO3 and IO4 of converter 202.

[0042] 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).

[0043] 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 separate 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.

[0044] 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 status information (or that may be used, for example, to determine the status information by the LCD 114). The primary function of the status information is to describe the state of one or more energy sources 206 of the module 108 to facilitate a decision on how much to utilize the energy source relative to other sources in the system 100, although status information 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 component 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. Discrete circuitry is not required to monitor each type of status information because one or more types of status information may be monitored in a single circuit or device, or may otherwise be determined algorithmically without the need for additional circuitry.

[0045] The LCD 114 can receive status information (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 from the module components. For example, the LCD 114 can cause the status information to be transmitted via paths 116, 118 by directly requesting the status information or by applying a stimulus (e.g., a voltage) to generate the status information, possibly in combination with a switch signal that places the converter 202 in a particular state.

[0046] 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, the buffer 204, and the source 206, are housed along with other optional components, such as an integrated LCD 114. In other embodiments, the various components can be separated in separate housings that are fastened together. FIG. 2C is a block diagram illustrating an exemplary embodiment of a module 108 having a first housing 220 that holds the module's energy source 206 and 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 for the module 108. Electrical connections between the various module components can travel through the housings 220, 222, 224 and can be exposed to the exterior of either of the housings for connection with other modules 108 or other devices, such as the MCD 112.

[0047] 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 fixed 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.

[0048] 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.

[0049] 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.

[0050] The energy source 206 can be configured as any of the energy source types described herein (e.g., a cell, 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 of the energy buffer 204, respectively. 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 LEB1 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

[0051] 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.

[0052] 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 a relatively high switching frequency, 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 mode.

[0053] 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 DCLBy 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). DCL To 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.

[0054] 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 technique, such as space vector pulse-width modulation (SVPWM) or sinusoidal pulse-width modulation (SPWM), or variations thereof. FIG. 8A is a voltage versus time graph illustrating 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.

[0055] 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 may be of the same type (e.g., each may be a battery) or of different types (e.g., the first source may be a battery and the second source may be a HED capacitor, or the first source may be a battery having a first type (e.g., an NMC) and the second source may be a battery having a second type (e.g., an LFP)).

[0056] 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).

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] The control system 102 or LCD 114 can independently control each switch of converters 202B and 202C via control input lines 118-3 to each gate. In these embodiments and the embodiment of FIG. 6A, the LCD 114 (and 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.

[0062] 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.

[0063] A module 108 having multiple energy sources 206 can perform additional functions such as energy sharing between 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 having 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 Publication No. WO 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 entireties for all purposes.

[0064] 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.

[0065] 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 (FIG. 6B). C The energy provided by the source 206 can be delivered to the load 302 through the switch portion 602 of the converter 202B. The load 302 has an input capacitor (a capacitor can be added to the module 108C if not applicable), and therefore the switches S1 and S2 are connected to the coupled inductor L C It is assumed that the source 206 can be rectified to regulate the voltage on and current through it, thus producing a stable constant voltage for the load 302. This regulation can step down the voltage of the source 206 to a lower magnitude voltage required by the load 302.

[0066] 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 portions 602, and additional converter IO ports coupled to the additional portions 602.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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 temperature and current of each basic component independent of other components of the source 206, or the temperature and current of the group of basic components as a whole, or any combination thereof. The monitored signals may be status information 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 a 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, and / or send status information to the MCD 112. The LCD 114 may receive control information (e.g., modulation index, synchronization signal) 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.

[0071] 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 for 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 of the buffer 204 as a whole (e.g., between IO1 and IO2 or between IO3 and IO4). Similarly, the monitored temperatures and currents can be at least one, preferably all, of the temperature and current of each basic component of the buffer 204 independent of the other components, or the temperature and current of a group of basic components or the buffer 204 as a whole, or any combination thereof. The monitored signal can be status information that enables the LCD 114 to do one or more of: set or output a warning or alarm indication, communicate status information to the MCD 112, or control the converter 202 to adjust (increase or decrease) the utilization of the source 206 and the module 108 as a whole for buffer protection.

[0072] 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.

[0073] 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, 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 load 302.

[0074] 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 separate 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 of an output signal 801 generated by a single module 108 with a 48 volt energy source. FIG. 8B is a plot of voltage versus time illustrating an exemplary single-phase AC output signal 802 produced by an array 700 having six 48V modules 108 coupled in series.

[0075] The system 100 can be arranged in a wide variety of different topologies to meet various application needs. 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.

[0076] 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 on the opposite end of the array from system IO ports SIO1 and SIO2, which can be tied together at a common node and can optionally be 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.

[0077] 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.

[0078] 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).

[0079] 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.

[0080] 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 with 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 FIGS. 7D and 7E can be implemented with as few as two modules in each array 700. The combined delta and series configuration facilitates 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.

[0081] 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.

[0082] Exemplary embodiments of the control methodology As mentioned, the control of the system 100 can be performed according to various methodologies, 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.

[0083] 8C-8F are plots illustrating an exemplary embodiment of a phase-shifted PWM control methodology that may generate a multi-level output PWM waveform using incrementally shifted two-level waveforms. An X-level PWM waveform may be created by the sum of (X-1) / 2 two-level PWM waveforms. These two-level waveforms may 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 may 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.

[0084] 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.

[0085] 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 for the second phase is shifted 120 degrees compared to the carrier for the first phase, and the carrier for the third phase is shifted 240 degrees compared to the carrier for the first phase. If different reference voltages are available for each phase, 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.

[0086] 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, which can then generate the switching signal, depending on which module or modules 108 the LCD 114 controls, or all carrier signals can be provided to all LCDs 114 in the array, and the LCD can select the appropriate carrier signal.

[0087] The relative utilization of each module 108 can be adjusted to perform balancing or based on status information of one or more parameters as described herein. Parameter balancing can involve adjusting utilization to minimize parameter divergence over time compared to a system in which individual module utilization adjustments are not performed. Utilization can 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.

[0088] 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 intra-phase balancing, and different arrays 700 may be balanced relative to one another, which may be referred to as inter-array or inter-phase balancing. Arrays 700 of different subsystems may also be balanced relative to one another. 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.

[0089] 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 (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 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 on which the controller 900 is operating with and / or without balancing. The divider 904 generates Vrn by dividing Vr by its detected Vpk. The intra-phase balance controller 906 uses Vpk along with status information (eg, SOCi, Ti, Qi, Vi, etc.) to generate a modulation index Mi for each module 108 in the array 700 being controlled.

[0090] 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 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 circuitry (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 signals 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.

[0091] The controller 906 can use any type or combination of types of status information 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 can have a relatively high Mi. If the SOC is relatively low or T is relatively high, the module 108 can have a relatively low Mi, resulting in a lower utilization than other modules 108 in the array 700. The controller 906 can determine Mi such that the sum of the module voltages does not exceed Vpk. For example, Vpk can 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 indices, and therefore respective voltage contributions by the modules, may be used, but the total generated voltage should remain the same.

[0092] The controller 900 can control the operation of the energy sources in each module 108 to balance or converge to a balanced state if not balanced, and / or the temperature of the energy sources or other components (e.g., energy buffers) in each module to balance or converge to a balanced state if not balanced, to the extent that it does not prevent 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 can be adjusted so that capacitance differences between sources do not cause SOC deviations. Balancing SOC and temperature can indirectly cause SOH balancing. Voltage and current can be directly balanced if desired, but in many embodiments, the primary objective of the system is to balance SOC and temperature, and balancing SOC can result in voltage and current balancing in a highly symmetrical system where modules have similar capacitance and impedance.

[0093] Since it may not be possible to balance all parameters simultaneously (e.g., balancing one parameter cannot further balance 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 over the other depending on the requirements of the application. Balancing priority may be given to SOC over the 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 imbalance state outside of thresholds.

[0094] 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 an intra-Ω-phase balance controller 906-PA...906-PΩ for phases PA-PΩ, as well as a peak detector 902 and a divider 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.

[0095] 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 separate controllers independent of the MCD 112 and the LCD 114.

[0096] Exemplary embodiments 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 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.).

[0097] 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 or equal to 2. 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 Ω IO ports for connection to IO port 2 of each module 108 through N of arrays 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).

[0098] 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.

[0099] 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 ICmay be selectively coupled to respective module I / O ports 1-Ω. The control system 102 may 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 may receive monitoring data or status information from monitoring circuitry of the module 108 IC. This monitoring data and / or other status information derived from this monitoring data may be output to the MCD 112 for use in system control as described herein. The LCD 114 may 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).

[0100] 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.

[0101] For example, in some exemplary embodiments applying PWM, the LCD 114 may be configured to receive (from the MCD 112) a normalized voltage reference signal (Vrn) 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 from the MCD 112 modulation indices MiPA-MiPΩ for the switch units 604-PA-604-PΩ for each array 700, respectively. 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 .

[0102] 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.

[0103] Based on collected status information 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.

[0104] 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.

[0105] When an imbalance occurs between the arrays 700, the modulation index of the system 100 can be adjusted to converge toward a balanced state 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 indexes for the other switch units 604 supplying the other higher arrays relatively unchanged (or decreased).

[0106] 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 Ω switch portions 604 coupled to Ω different arrays 700 may be combined with a second module 108IC having one switch portion 604 coupled to one array 700, such that the two modules are combined to service a system 100 having Ω+1 arrays 700. Any number of modules 108IC may be combined in this manner, each coupled to one or more arrays 700 of the system 100.

[0107] 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.

[0108] 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.

[0109] 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, for balancing between subsystems 1000 (e.g., pack-to-pack 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 described herein as compensating 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.

[0110] 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.

[0111] 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.

[0112] 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 having 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 does not actively inject voltage or current into any array 700 of system 100. In this embodiment, module 108IC-3 can 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. Accordingly, 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 the charge of source 206A of modules 108IC-1 and 108IC-2 via the parallel connection with source 206 of module 108IC-3.

[0113] 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 the same rate relatively as the other modules.

[0114] Example of the second life energy source The energy source 206 described herein can be used in the system 100 described herein in both first-life and second-life applications. A first-life source 206 is the original application in which the source 206 is used. For example, a first-life application is a first implementation in which the source 206 is used by a first customer of the source 206 after their original manufacture (not refurbishment). A user of the source 206 in the first life of the source 206 would typically have received the source 206 from a manufacturer, distributor, or original equipment manufacturer (OEM). Batteries 206 used in a first-life application would typically have the same electrochemistry (e.g., the same variant of lithium-ion electrochemistry (e.g., LFP, NMC)), the same nominal voltage, and have a capacity variation that is minimal (e.g., 5% or less) across the pack or system. Use of the energy storage system with the battery 206 in a first life application results in the battery 206 having a longer lifespan 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.

[0115] As used herein, a "second life" application refers to any application or implementation after the first life application (e.g., second implementation, third implementation, fourth implementation, etc.) of a source 206. A second life energy source refers to any energy source (e.g., a battery or HED capacitor) implemented in the second life application of that source.

[0116] 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 refurbished and tested, and then implemented in 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, hydro), energy buffering, etc.) 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 application or a mobile application.

[0117] Sources 206 may be selected and / or utilized by system 100 to minimize (or at least reduce) any differences in initial capacity and nominal voltage for the second life application. For example, sources 206 having a capacity difference of 5% or more may be included in system 100 and operated to provide energy to a load. In another example, an operator or an automated system may select sources 206 for system 100 that have a capacity difference within a threshold amount, for example, to reduce the initial capacity difference between sources of system 206. If a module 108 is compatible with both the first and second life applications (e.g., with or without reconfiguration), the module 108 may be selected for the second life application based on the capacity difference of the sources 206 of the module 108.

[0118] The system 100 can individually adjust the utilization of each source 206 such that the sources 206 in the system 100 or the packs of the system 100 are relatively balanced in terms of SOC or total charge (SOC time capacity) when the packs or system 100 are discharged, even though the sources 206 in the system 100 can have widely varying capacities. Similarly, the system 100 can maintain balance when the packs or system 100 are 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), etc. Thus, the system 100 can be used such that every module 206 in the system 100 or each pack of the system 100 is a second life energy source (or a combination of first life energy sources and second life energy sources are used) with various combinations of different characteristics.

[0119] In one example, the system 100 can include a second life energy source 206 (and optionally one or more first life energy sources 206) having 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%.

[0120] In another example, the system 100 can include a second energy life source 206 (and optionally one or more first energy life sources 206) having an energy capacity variation per mass density 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%.

[0121] In another example, the system 100 may include a second Rife energy source 206 (and optionally one or more first Rife energy sources 206) having a peak power variation per mass density 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%.

[0122] In another example, the system 100 may include a second Rife energy source 206 (and optionally one or more first Rife 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%.

[0123] In another example, the system 100 may include a second Rife energy source 206 (and optionally one or more first Rife energy sources 206) having 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%.

[0124] 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 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%.

[0125] 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 specified 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%.

[0126] A variation of X% (e.g., 5% or more, or 5-30%) can be met by the variation between the module 108 having the highest value for that parameter and the module 108 having the lowest value for that parameter in the system 100. For example, if the module 108 having the lowest capacity source 206 has a capacity that is 95% or less than the capacity of the module 108 having the highest capacity source 206, a variation of 5% or more in capacity can be met by the system 100. For each and every embodiment and parameter disclosed herein, the time at which the 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 commissioning of the system 100, after replacing one source 206 with another source 206, after 10 hours or more operation of the system 100, after 100 hours or more operation of the system 100, and / or after 10,000 hours or more operation of the system 100. For example, even if no capacity variations were present during commissioning, capacity variations of 5% or more may occur after 1000 hours of operation of system 100. This reflects the ability of embodiments of system 100 to continue to operate with and account for increasing capacity differences between sources 206 over time of operation.

[0127] In another example, the system 100 may include a second LiFe energy source 206 (and optionally one or more of the first LiFe energy sources 206) that has variations in electrochemical type (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).

[0128] The system 100 may include a second life energy source 206 (and optionally one or more of the first life energy sources 206) having any combination of characteristics provided in the foregoing examples.

[0129] fast charging Exemplary embodiments will now be described herein with respect to fast charging techniques for energy sources using pulse preheat and / or pulse charging techniques. Although the embodiments will be described primarily in the context of an energy source 206 that is a battery, the embodiments are applicable to other energy source types as well (e.g., high energy density capacitors and fuel cells). The embodiments can be applied to charge batteries having a single cell, batteries having multiple cells (e.g., connected in series, parallel, or combinations thereof, sometimes referred to as a battery module), and systems having multiple battery modules (e.g., connected in series, parallel, or combinations thereof, sometimes referred to as a battery pack).

[0130] Examples of battery types suitable for use with the present subject matter include solid-state batteries, liquid electrolytic type based batteries, liquid phase batteries, and flow batteries, such as lithium (Li) metal batteries, Li-ion batteries, Li-air batteries, sodium-ion batteries, potassium-ion batteries, magnesium-ion batteries, alkaline batteries, nickel-metal hydride batteries, nickel sulfate batteries, lead acid batteries, zinc-air batteries, and others. Some examples of Li-ion battery types include Li cobalt oxide (LCO), Li manganese oxide (LMO), Li nickel manganese cobalt oxide (NMC), Li iron phosphate (LFP), Li nickel cobalt aluminum oxide (NCA), and Li titanate (LTO).

[0131] Although not required to be used with any particular configuration of the energy storage system, the embodiments of the system 100 described herein can particularly benefit from use with the present fast charging embodiment. When used with an embodiment of the system 100 to charge the energy source 206 therein, the converter 202 of each module 108 is independently controlled to apply a positive, zero, or negative pulse from the power connection 110 to the source 206. The AC or DC signal applied to the power connection 110 can be fed back to the source 206 in a manner that reverses the process described herein to generate a superposition of all output pulses from all modules 108. Each converter 202 can be switched at a frequency of greater than 100 Hz to apply pulses of 5 milliseconds (ms) or less at a 50% duty cycle, for example. Longer or shorter pulse durations with different duty cycles can also be used. This pulsing capability allows the energy source to be charged and / or heated as will be described herein.

[0132] The converter 202 can be controlled using a control system that applies pulse width modulation techniques, hysteresis techniques, or another technique that seeks to utilize all modules equally over time. Each module 108 can monitor the status of its energy source 206 (e.g., state of charge (SOC), temperature, voltage, current, etc.) and feed this monitoring information back to the control system 102, which can adjust the charge utilization of each module 108 individually to maintain balance or converge toward a selected parameter or parameters to be balanced (e.g., SOC and / or temperature).

[0133] The cascaded topology of the system 100 allows the charging voltage or charging current from the charging source to be split between the energy sources as needed to implement charging schemes of various sophistication. For example, the voltage (or current) can be applied in a pulsed manner, with some sources 206 generally charging at some times and others not, provided that the total voltage applied to the sources 206 (and other charging sinks in the system) is generally equal to the DC or AC voltage supplied to the system 100 by the charging sources at that moment in time. The voltage and duration of the applied pulses (and the duration of the rest time between pulses) can be varied and timed based on the state of those sources 206 as monitored by each module 108 (e.g., the monitor circuitry 208 and the LCD 114). Thus, the division of the voltage between the modules 108 allows both charging and resting of the sources 206 of the modules 108 as needed.

[0134] This embodiment can be used to charge the source 206 with various levels of granularity. For example, a battery module can be pulsed as a whole, e.g., one pulse can be applied for all of the cells that make up that battery module. Alternatively, additional switching circuitry (e.g., in addition to the configuration shown for the converter 202) can be included for each individual cell, such that each cell of the battery module can be pulsed independently. For example, a system 100 having N battery modules, each having M cells, can be configured with NM (N multiplied by M) converters or switch circuits. Other levels of granularity are also possible, such as the ability to pulse charge groups of cells within each battery module (e.g., the cells are divided into two groups, each of which can be controlled independently such that the system has 2N converters or switch circuits). Control of the switch circuitry for the various battery modules and / or cells can be implemented by a control system 102 communicatively coupled to the system module 108 (e.g., the MCD 112 communicatively coupled to the LCD 114).

[0135] Exemplary embodiments of fast charging techniques Exemplary embodiments related to fast or rapid charging of energy sources at improved rates are provided herein. Exemplary embodiments relate to applying voltage or current pulses to a battery to raise the temperature of that battery through localized heating, applying voltage or current pulses to a battery to charge the battery, applying a constant (non-pulsed) voltage or constant current to a battery to charge the battery at higher temperatures, monitoring the battery for degradation conditions during charging, and any combination thereof. The embodiments described herein can help stationary and mobile energy storage systems to be charged at a wide range of C-rates, provided that certain voltage and temperature constraints on the battery cells are not exceeded. For example, the present embodiments can enable an EV with 100 kilowatt-hour (kWh) storage capacity to be charged from zero to 80% capacity in 10 minutes (or less) without substantial capacity degradation over the rated life of the battery pack.

[0136] FIG. 11A is a plot depicting a framework for describing several exemplary embodiments of a fast charging protocol 1100 for charging a battery source 206 from a relatively low state of charge (SOC) to a substantial SOC in a short time frame of less than 15 minutes. FIG. 11B is a plot of an embodiment of the protocol 1100 with exemplary values ​​applied. The fast charging protocol 1100 described with respect to FIGS. 11A-11B (and elsewhere herein) can be applied to a battery having only a single cell or a battery module having two or more cells (e.g., 2-100 cells) and can be implemented by a charging and switching network near the external charging source. For example, the charger can sense the temperature (e.g., surface) and voltage response of the battery device as a whole and adjust the application of preheat and charging signals accordingly. Although such an approach is possible for charging a single cell, a battery module with multiple cells, or even the system as a whole (e.g., a battery pack), the approach does not allow for granular control of the preheat and charging process as applied to individual cells within a battery module and / or individual battery modules within a system.

[0137] To provide more granular control, the protocol 1100 can also be applied within a cascaded modular energy storage system 100 such as those described herein, where each module 108 includes a battery 206 that may be only a single cell or may include more than one cell (e.g., 2-100 cells), and the number of modules 108 may be two or more (e.g., 2-1,000 modules 108). The converters 202 of each module 108 can be independently controlled as described herein such that the protocol 1100 can be independently controlled by each module 108 of the system 100. For example, considering a battery pack having 12 modules 108, each having a battery 206 including 12 cells, the protocol 1100 can be independently applied by each module 108 to charge each battery 206 having 12 cells in 15 minutes or less, thus charging the entire battery pack in the same or similar time. Because the conditions of the batteries 206 in the system 100 vary, and because embodiments can adjust the charging rate based on feedback from each battery 206, the charging time for each battery 206 can vary. At the start of a charging cycle, some batteries 206 may be at 2-3% SOC, while others are at or near 0% SOC, or some percentage in between. Some batteries 206 may have higher capacity than others and will require longer to reach the desired SOC. Some batteries 206 may exhibit signs of degradation or other characteristics during charging that require the charging process to be slowed down.

[0138] To enable discussion of protocol 1100 in more detail, Figures 12A-12F will be discussed to provide context for battery cell properties and structure. Figure 12A is a cross-sectional view of a generalized lithium-ion battery cell 1200. The cell 1200 includes a repeating layered structure, with each layer including an anode 1201 and a cathode 1202 with a separator 1203 therebetween. Each anode 1201 includes an anode material 1204 having a current collector 1205 interspersed with electrolyte 1208 and positioned within the anode material 1204. Similarly, each cathode 1202 includes a cathode material 1206 having a current collector 1207 interspersed with electrolyte 1209 and positioned within it.

[0139] 12B is an explanatory diagram depicting an expanded view of the anode 1201 and cathode 1202 and listing examples of degradation modes that may occur within a typical lithium-ion battery cell. Each of the degradation modes listed here can be caused, directly or indirectly, by application of excessive voltages to the anode and cathode, and by charging at excessive temperatures. Exemplary embodiments described herein seek to limit the application of excessive voltages and operation at excessive temperatures, and thus limit these degradation modes.

[0140] FIG. 12C is an electrical schematic model of a battery cell 1200. The anode has an ohmic component (V ohmic ) and the electrochemical interface components (V EC INTERFACE ) and indicates the voltage drop. V ohmic is the ohmic resistance of the anode (R ohmic ) is determined by the magnitude of V EC INTERFACE is the anode double layer sheet capacitance (C DL ) and the activation impedance (R CT ) and the diffusion base impedance (R Warburg ) is determined by V A is R CT is the activation-based voltage drop across the Nernst is RWarburg The total impedance of the anode is R ohmic , R CT , and R Warburg The cathode is modeled similarly, but with its own characteristic values. The electrolyte also has an ohmic resistance (R ohmic electrolyte ) is determined by the voltage (V ohmic electrolyte ) indicates a descent.

[0141] FIG. 12D is a plot depicting an example voltage response 1212 to a charge pulse 1214 applied to a lithium-ion cell. The resistance (V ohmic ), activation base (V A ), and diffusion base (V Nernst ) can be determined by analysis of the response after the end of the charge pulse 1214. FIG. 12E is a graph depicting an example voltage on a lithium-ion cell traversing a range of SOC, showing the components of the voltage due to the cathode, anode, and the cell itself. Voltage response analysis can be used to determine the magnitude of the overvoltage on the anode and cathode, and the magnitude and frequency of the charge pulse can be maintained, increased, or decreased accordingly to stay within acceptable limits. The available overvoltage range for the anode and cathode decreases as the state of charge on the cell increases. The embodiments herein can be applied such that the current is reduced as the cell is charged in any of the stages 1110, 1120, 1130 (FIGS. 11A-11B).

[0142] 12F is a plot depicting an example impedance response 1210 of a lithium-ion cell. As the frequency of the charge pulse increases, the impedance response becomes pure R of real impedance with a low imaginary component. ohmic Pulsing at a higher frequency can reduce the activation component of the voltage response.

[0143] 11A-11B, the protocol 1100 can have three phases: a preheat phase 1110, a first charging phase 1120, and a second charging phase 1130. Energy for the preheat and charging signals applied to the battery 206 can be provided from a charging source external to the system (e.g., the grid or a charging station) or, in some cases, internally, such as through a second source 206B. Here, the pulse preheat phase 1110 can continue for a set duration (time_0-time_1) or until a first temperature threshold is reached (temp_1). In FIG. 11B, the preheat phase 1110 is applied until the battery reaches 30° C., which occurs after about 1 minute.

[0144] The preheat phase 1110 involves application of a preheat pulse signal 1112 as a train or series of pulses, each pulse alternating from a charge pulse (negative current) to a discharge pulse (positive current) of equal or substantially equal duration (optionally with a time gap between application of the charge and discharge pulse pairs). Figures 11C-11D are current versus time graphs depicting an exemplary embodiment of a preheat pulse train 1112 with and without a time gap, respectively, in which the preheat pulse train 1112 oscillates between a positive preheat current (+Iph) and an equal but opposite negative preheat current (-Iph).

[0145] The preheat stage 1110 can achieve localized heating by increasing the temperature of the anode current collector 1205, the cathode current collector 1207, and the electrolyte 1209 (FIG. 12A) without activating an electrochemical reaction. In many embodiments, the frequency (F preheat ) follows the formula (1) below. (1)F preheat >>1 / (R CT ×C DL )

[0146] The preheat signal 1112 may be a signal at a single frequency, with each pulse having a rectangular or substantially rectangular shape (as visualized in the time domain). In other embodiments, the preheat signal 1112 may be implemented in a more complex manner with multiple frequency components, such as a primary pulse train and a secondary pulse, in a frequency domain from 1 Hertz (Hz) up to 1 Megahertz (Mhz). In various embodiments, the preheat signal 1112 has a frequency range of 100 Hz to 100 kilohertz (kHz). The frequency of the preheat signal 1112 causes a voltage drop to occur, primarily due to the effects of electrolyte impedance and current collector impedance, and thus the voltage of the preheat signal 1112 may lead to cathode and anode voltages exceeding their relative cutoff overvoltages at both relatively low and relatively high states of charge.

[0147] The pre-heating stage 1110 induces a temperature increase in a localized area within the battery cell by targeting the ohmic impedance to heat the active materials while avoiding the activation of electrochemical reactions such as side reactions (e.g., electrolyte decomposition, active decomposition, lithium plating) or the main electrochemical reaction (e.g., lithiation). These reactions are preferably avoided so that they do not substantially occur (within reasonable tolerances as identified by a person skilled in the art that allow for long functional operation in the respective commercial, research, or industrial applications). Stage 1110 warms the cell until the activation impedance and total impedance are small enough so that overvoltage on the anode promotes electrochemical reactions and does not promote lithium plating. Stage 1110 thus allows rapid heating of the electrochemical interface and bulk material temperature control, allowing subsequent charging without causing side reactions due to rapid degradation (e.g., lithiation or delithiation) of the anode and cathode materials or damage due to material stress.

[0148] The preheating phase 1110 can be applied until all cells of the source 206 reach a minimum temperature threshold, provided that no cell exceeds the maximum temperature threshold. If a cell reaches the maximum threshold, the preheating phase 1110 can be slowed down or stopped, or the protocol 1100 can transition to the next phase (first or second charging phase 1120, 1130) as described herein. Cell temperatures can be measured directly using a temperature sensor (e.g., infrared) or indirectly (e.g., temperature at or adjacent to a subgroup of cells). Alternatively, or in combination with direct sensing, temperatures for one or more cells (including all cells) can be measured using a single sensor (e.g., infrared image of multiple cells). Temperature can also be inferred based on data collected from previously characterized cells, optionally by use of models or lookup tables that reference other indirect metrics (e.g., voltage, current, impedance). The temperature thresholds for this and other stages are preferably correlated to the internal temperature of the cell in which the electrolyte and active materials are located. Thus, if the battery cell surface temperature is measured (e.g., with a thermistor or optical device), the thresholds are set for the surface temperatures that correlate to the desired internal cell temperatures based on estimates, look-up tables, or models.

[0149] The preheating stage 1110 raises the temperature of the battery 206 to a first temperature threshold, which in the example of FIG. 11B is 30 degrees Celsius (° C.) measured on the cell surface. The temperature threshold may depend on the battery type, and may be, for example, 25-70° C. inclusive, for a lithium-ion battery. In other embodiments, the preheating stage 1110 may last for a predetermined duration (time_0-time_1), such as less than 1 minute, 1 minute, 2 minutes, 3 minutes, 5 minutes, or the like. The duration of the stage 1110 may vary based on the starting temperature, with lower starting temperatures requiring relatively more time. When the preheating signal 1112 includes charge and discharge pulses of equal or substantially equal duration, the net charge of the battery 206 remains substantially unchanged during this stage and remains at or near the initial SOC. Furthermore, the applied frequency configuration of the pulse train is preferably selected so as not to initiate electrochemical reactions of storage reactions or side reactions. The preferred frequency range is 100hz to 100kHz for the preheat pulse signal 1112.

[0150] The C-rate of the pulse applied during the preheat phase 1110 can vary widely and depends primarily on the ohmic characteristics of the cell, the applied voltage, and the thermal behavior during this phase. C-rates up to 30C and higher can be applied in phase 1110. Additionally, while phase 1110 can be applied such that no net charging or discharging occurs, in other embodiments, the length of the charge pulse can be slightly longer (e.g., 1-15%) than the length of the discharge pulse to begin charging the cell at a relatively lower rate compared to the subsequent phases. This can occur, for example, toward the transition from the preheat phase 1110 to the first charging phase 1120 when the battery 206 is heating toward a transition threshold temperature or time. Thus, phase 1110 can be divided into a first sub-phase 1114 where no charging occurs, and a second subsequent sub-phase 1116 after reaching a higher temperature where the charge pulse length is longer than the discharge pulse length to begin charging, but at a slower rate than the second phase of the pulsed charge described below. An example embodiment of a preheat signal 1112 applied during both sub-phases 1114 and 1116 is depicted in Figure 11E. The second sub-phase 1116 can introduce charge at a fixed rate (e.g., a 5% longer charge pulse) or can begin charging by gradually increasing amounts over a duration until transitioning to the first charge phase 1120 (e.g., a 1% longer charge pulse for 30 seconds, followed by a 2% longer charge pulse for 30 seconds, etc.).

[0151] The transition from phase 1110 to the first charging phase 1120, or alternatively, the transition from the first sub-phase 1114 to the second sub-phase 1116, can occur under conditions where pulse charging can occur at high C rates for fast charging without causing significant side reactions such as lithium plating. In some embodiments, this condition occurs when the average current times the Warburg impedance (R Warburg ) may be such that it does not result in a voltage exceeding the overpotential range for either electrode. In other embodiments, the condition that may govern the transition to pulse charging is R WarburgFor embodiments in which the preheating stage 1110 transitions directly to the constant current charging stage 1130 (without the pulse charging stage 1120), the transition condition may in some examples be when the activation impedance drops to 50%, 40%, 30%, 20%, or 10% of the total impedance for each electrode.

[0152] The first charging stage 1120 is a pulse charging stage in which a pulse charging signal is applied to the battery 206. Stage 1120 allows for fast charging at high C-rates with reduced activation overvoltage and reduced occurrence of side reactions, as described in more detail herein. FIG. 11F is a current versus time graph depicting an exemplary embodiment of a pulse charging signal 1122 for use in stage 1120. The signal 1122 oscillates between zero and +Ipc, and in this embodiment, the +Ipc pulse is in the form of a square wave with duration 1124 and a 50% duty cycle. During stage 1120, the magnitude of the signal 1122 can be controlled to maintain a constant temperature of the battery 206, or can be further increased to accelerate the kinetics of the storage reaction to further reduce the overvoltage on the electrochemical interface. Although current controlled pulses are described with respect to the preheat signal 1112 and the pulse charging signal 1122, voltage controlled pulses can be used as well.

[0153] The pulse applied in step 1110 can have a voltage that exceeds the cutoff voltage (upper and lower) of the energy source 206. In some embodiments, the amount that the step 1110 pulse can exceed the cutoff voltage is limited by the breakdown voltage of the electrolyte. The pulse applied in step 1120 can also have a voltage that exceeds the cutoff voltage (upper and lower) of the energy source 206. In some embodiments, the amount that the step 1120 pulse can exceed the cutoff voltage is less than or equal to the pulse charging current times the activation impedance for the electrode.

[0154] The optimal frequency and duration 1124 of the applied pulses depends on the battery type. In many embodiments, the frequency (F pulse ) follows the formula (2) below. (2)F pulse >1 / (R CT ×C DL )

[0155] F is more than twice that of Eq. (2). pulse The value substantially eliminates activation impedance and activation overvoltage (e.g., V in FIG. 12C). A and R CTcomponents) and allows for faster charging without exceeding the maximum overvoltage at the EC interface. For certain embodiments of lithium-ion batteries with graphite anode and nickel-cobalt cathode chemistry, it has been found that a charge pulse duration 1124 of 2 milliseconds (ms) (e.g., 250 Hz at 50% duty cycle) can be utilized in the protocol 1100 to charge the battery 206 at a fast rate (e.g., 0-75% charge in less than 15 minutes) without substantial capacity degradation over time (e.g., over the course of multiple charge cycles in which the battery 206 is cycled from low or no charge to a nominal SOC level) compared to a constant current charge signal at a similar amperage. Charge pulse durations 1124 of 5 ms or less can charge the battery 206 at a fast rate with significant improvement in capacity retention over time compared to a constant current charge signal at a similar amperage. The exemplary embodiments described herein can be applied at any charge pulse duration 1124 that is operable for the battery type. Embodiments include charge pulse durations for lithium ion batteries that are 5 ms or less, 4 ms or less, 3 ms or less, 2 ms or less, 1.5 ms or less, or 0.5 ms or less. The duration can be as short as 0.05 ms, or 0.1 ms (e.g., 0.05 ms to 5 ms, 0.05 ms to 1.0 ms, 0.1 ms to 2 ms, etc.). The data was collected at a 50% duty cycle, but the pulses can be applied at a variety of different duty cycles, such as 10-90%, 25-75%, 40-60%, and 45-55% (referring to the portion of the pulse that applies the charge, or the "on" duration). In some embodiments, pulses are applied at a pulse C-rate of 10.67C to charge 80% in 9 minutes, which gives a time-average C-rate of 5.33C for the second stage given a 50% duty cycle (10.67C / 2).

[0156] Depending on the duty cycle, the time-averaged C-rate can be greater or less to meet the desired target (e.g., 80% SOC within about 9 minutes). The magnitude of the C-rate itself is not a constraint, as long as the applied C-rate does not exceed the voltage and temperature constraints described herein or the chemical and physical constraints of the battery cell and the electrical and physical constraints of the system being charged and the charger. Thus, the time-averaged C-rate for the second phase can vary significantly across embodiments. In one example, the time-averaged C-rate for the pulse charging phase 1120 is 4C to 8C, although the subject matter is not so limited. With respect to protocol 1100, time-averaged C-rates of 30C and higher are within the scope of the subject matter.

[0157] The pulse signal 1122 can be applied at a current magnitude such that each battery cell exhibits a voltage response above the open circuit voltage of the cell but below the upper cutoff voltage of the electrochemical interface voltage (excluding ohmic overvoltage) on the anode and cathode electrodes. In various embodiments, the pulses are applied such that each cell does not exceed the anode only overvoltage range, the cathode only overvoltage range, or the anode and cathode combined overvoltage range. Pulse charging can drive cell voltages to higher voltages than constant current charging at the same (lower) temperature range as a result of the reduced activation overvoltage.

[0158] The optimal duration of stage 1120 depends on the battery type, and longer pulse charging stages can be used for chemistries with more activation or activation that lasts at higher temperatures. Pulse charging stage 1120 can continue until the activation impedance is reduced to 50% or less of the full initial impedance (e.g., at the start of stage 1120). In other embodiments, stage 1120 can continue until the activation impedance is reduced to 40% or less, 30% or less, 20% or less, or 10% or less of the full impedance. Other constraints, such as cell temperature and cutoff voltage, can also determine when stage 1120 ends.

[0159] 11A and 11B, the first charging stage 1120 may continue for a predetermined duration (e.g., time_1 to time_2), until a SOC or capacity threshold is reached (e.g., SOC_1), until a temperature threshold is reached (e.g., temp_2), or any combination thereof (e.g., terminating when any of the time, SOC, or temperature thresholds are reached). Stage 1120 is intended for charging at relatively low temperatures where the benefits of pulsing prevail, but is not so limited. For example, stage 1120 may be designed to further increase the temperature to one suitable for transitioning to a second charging stage 1130 to apply a constant current charge to charge to a higher state of charge.

[0160] In the embodiment of FIG. 11B, stage 1120 ends when the temperature of battery 206 is about 50° C. In other embodiments, for example, the temperature threshold (temp_2) may be greater than 30° C., such as 30-60° C. or 40-55° C. Thresholds outside these ranges are also possible, based on battery chemistry. In the embodiment of FIG. 11B, the temperature threshold for ending stage 1120 is reached when the battery SOC reaches about 55%. In embodiments using an SOC threshold, the threshold may be 30%-80%, 40%-70%, or 50-60%. In the embodiment of FIG. 11B, the second stage ends after a duration of about 5 minutes. In other embodiments, for example, the duration may be greater than 1 minute, such as 1-9 minutes, 2-8 minutes, 3-7 minutes, or 5-7 minutes.

[0161] The second charging stage 1130 is a constant current charging stage in which the constant current signal is applied to the battery 206 without being pulsed. Stage 1130 is a constant current charging stage in which the impedance of the activation and diffusion base is reduced (e.g., V A , R CT , V Nernst , and R WarburgThe relatively high temperatures at the component (electrochemical) interfaces are contemplated, and thus the benefits of pulse charging are reduced. The reduced activation and diffusion impedance facilitates constant current charging at higher rates and higher SOC without exceeding the maximum overpotential. Phase 1130 can be initiated after completion of the first charging phase 1120 and can continue until the battery 206 is fully charged or substantially charged (>50%). As the open circuit voltage of each cell rises, the magnitude of the charge pulse is preferably controlled so as not to exceed the upper cutoff voltage of each cell.

[0162] A constant current can be applied at a relatively high time-average C-rate, such as 4C to 8C (or higher). With a constant current, generally there will not be any difference between the time-average C-rate and the actual C-rate when the current is applied, but in some cases, slight fluctuations in the current can make the time-average C-rate a more relevant metric.

[0163] In some embodiments, during the second charging phase 1130, the magnitude of the constant current charging signal can be varied as the charging process progresses. For example, in some embodiments, the magnitude of the constant current charging signal 1132 can begin phase 1130 at a relatively high C-rate and then gradually transition to lower C-rate values ​​as the charging process progresses to avoid exceeding the over-voltage range as the SOC increases (see FIG. 12E). A relatively short pause or rest period can occur during constant current charging to allow the battery voltage to stabilize. FIG. 13A is a graph depicting example levels for a constant current charging signal 1132 in phase 1130, where during a first sub-phase 1133, the signal 1132 is applied at a first C-rate (e.g., 6C-8C) for a first duration T1 (e.g., 60-120 seconds), followed by a relatively short pause period (e.g., 5-15 seconds) during which no signal is applied, and then during a second sub-phase 1134, the signal 1132 is applied at a second relatively lower C-rate (e.g., 4C-6C) for a second duration T2 (e.g., 90-150 seconds), again during which no signal is applied. Then during a third sub-phase 1135, the signal 1132 is applied at a third still lower C-rate (e.g., 2C-4C) for a third duration T3 (e.g., 90-150 seconds), followed by a relatively short pause period (e.g., 5-15 seconds) during which no signal is applied, and then during a fourth sub-phase 1136, the signal 1132 is applied at a fourth still lower C-rate (e.g., 1C-2C) for a fourth duration T4 (e.g., 4-8 minutes), completing the charging protocol embodiment 1100. The duration T1-T4 during which the signal 1132 is applied during each sub-phase 1133-1136 may be constant or may be variable, with the signal 1132 being stopped when the battery (or cell) voltage reaches a threshold selected to avoid entering an over-voltage condition. The exemplary C-rates and durations provided herein are by way of example only and are not limiting as embodiments may be practiced outside of these ranges.Step 1130 can be implemented using a single constant current rate, or any number of two or more sub-steps (eg, 1133-1136) in which the constant current rate is iteratively decreased.

[0164] Figure 13B is a graph of another example embodiment of the protocol 1100 in which a second charging phase 1130 is applied with a constant current signal at a decreasing magnitude such as that described with respect to Figure 13A. Each of the sub-phases 1133-1136 can be terminated and transitioned to a next sub-phase upon the occurrence of a time threshold, a temperature threshold, a SOC threshold, a voltage threshold, and / or any combination thereof.

[0165] Protocol 1100 is not required to execute all three stages 1110, 1120, and 1130. In some embodiments, the first charging stage 1120 can be omitted and protocol 1100 can proceed immediately from the pulse preheating stage 1110 to the constant current charging stage 1130. In other embodiments, the second charging stage 1130 can be omitted and protocol 1100 can proceed immediately from the pulse preheating stage 1110 to the first charging stage 1120 and subsequently terminate. In still other embodiments, the pulse preheating stage 1110 can be omitted, for example, if battery 206 is already sufficiently heated. Exemplary embodiments with these and other variations to protocol 1100 are described with respect to FIGS. 19B-19G.

[0166] Protocol 1100 also includes monitoring each battery 206 for indications of a potentially degrading condition. This monitoring, which may be performed during any and all of steps 1110, 1120, and 1130, may include voltage and / or impedance response analysis, and / or monitoring for indications that lithium plating has occurred. For example, the voltage and impedance of each battery 206 may be monitored using voltage and impedance response analysis to detect indications of accelerated or decelerated side reactions (see, e.g., FIG. 12F). Detection of a side reaction may be used to modify characteristics of the charging signal, e.g., the voltage of the charging signal may be reduced to slow down the side reaction, the duration of the charging pulse may be reduced to slow down the side reaction, the frequency of application of the charging pulse may be reduced to slow down the side reaction, or the reverse may be performed if the rate of the side reaction is determined to be sufficiently low to allow faster charging. Voltage and impedance analysis can be performed during all three phases (1110, 1120, 1130), only during the preheat phase 1110, only during the first charging phase 1120, only during the second charging phase 1130, or any combination thereof.

[0167] 14 is a series of plots depicting an example embodiment 1400 of monitoring for an indication that lithium plating is occurring. In this embodiment, a signal 1402 is applied to the battery 206, which includes a charge pulse, as shown at the top in plot 1401, immediately followed by a discharge pulse of equal or substantially equal duration. There may be a small time gap between the application of the pulses. Here, a first charge pulse 1404 and a subsequent discharge pulse 1405 are shown with respect to example 1408, where no lithium plating is occurring, and a second charge pulse 1406 and a second discharge pulse 1407 are shown with respect to example 1409, where lithium plating is occurring.

[0168] The voltage response of the battery 206 to the signal 1402 can be monitored as shown in the intermediate plot 1410. A normal voltage response 1412 is shown on the left for an example where no lithium plating is occurring, and a voltage response 1414 indicating that lithium plating is occurring, specifically an indication that the plated lithium has been stripped, is shown on the right. If a lithium plating event is occurring, it will be evident in a portion of the voltage response 1414 to the discharge pulse 1406, typically a relatively rapid transition in the response 1414 from one voltage to another while the discharge pulse is applied at a substantially constant magnitude. This rapid transition in the voltage response 1414 indicates that the plated lithium is continuing to be stripped. Thus, the response is caused by lithium stripping, and thus indicates that lithium plating is occurring prior to application of the discharge pulse 1407.

[0169] Plating can be detected directly from the voltage response or from the derivative 1422 of the voltage response as depicted below in plot 1420. The derivative of the voltage response produces transitions (e.g., either positive or negative peaks or spikes) at times when the voltage response undergoes relatively significant non-linear transitions (such as when the current pulse begins and ends 1424 and when a lithium stripping event occurs as shown by 1426). In some embodiments, only the voltage response to the discharge pulse or its derivative is monitored. If lithium plating is detected, the characteristics of the charging signal can be modified as described with respect to impedance monitoring above. Lithium plating detection 1400 can be performed intermittently during all three phases, only during the preheat phase 1110, only during the first charging phase 1120, only during the second charging phase 1130, or any combination thereof. For example, monitoring routine 1400 can be performed once every 5 seconds, 10 seconds, 20 seconds, or any other desired interval. Routine 1400 can include application of one pair of pulses (e.g., 1404 and 1405) or multiple pairs. Pulse lengths can range from 0.1 ms to 10 s, preferably about 100 ms or less, so as to have little effect on the charge time of routine 1400.

[0170] FIG. 15A is a plot of experimental data comparing the effects of pulse charging and constant current charging on a pair of lithium ion battery cells rated for use in power applications such as in a conventional EV car battery pack. Data 1502 shows results from a cell charged with a constant current at a 1C rate, and data 1504 shows results from a cell pulse charged in a manner similar to that described with respect to the pulse charging phase 1120. FIG. 15A compares capacity in milliamp hours (mAh) with cycle time, which is a measure of the cumulative time the cell was tested in repeated cycles. A constant current charging cycle was formed by application of a 1C constant current to charge to approximately 2.5Ah of the full rated capacity of 2.95Ah, followed by discharge to zero at a 1C rate, and then the cycle was repeated. A pulse cycle was formed by application of a 1C pulse with a duration of 2 ms at a 50% duty cycle for 1 hour, followed by discharge at a 1C rate for 1 hour, and then the cycle was repeated. The experimental data was collected at 25° C. and the cycles were performed for approximately 280 hours. Figure 15A shows that the pulse-charged cell achieved an average of 10% more capacity than the constant-current charged cell on each cycle, and the cycle life for both degraded at approximately the same rate.

[0171] FIG. 15B shows the same data as FIG. 15A in normalized form, with capacity shown as a percentage of the initial capacity achieved. This again shows nearly the same reduction in cycle life for the pulse charged cell data 1514 compared to the constant current data 1512. Thus, the data in FIGS. 15A-15B show that pulse charging has not caused an increased cycle life degradation compared to the constant current cell. Pulse charging can reduce activation impedance, resulting in improved capacity. If conditions are adjusted to pulse charge the cell to the same lower capacity that the constant current cell would have achieved, the cycle life for the pulse charged cell will be improved compared to the constant current charged cell.

[0172] FIG. 16A is a plot of experimental data comparing the effect of fast charging protocol 1100 with constant current charging on a pair of lithium ion battery cells rated for use in power applications (such as in a conventional EV car battery pack). Protocol 1100 was implemented with a preheat phase 1110, a first charging phase 1120, and a second charging phase 1130, then cooled and discharged to form one cycle. This cycle was repeated consecutively and independently on two battery cells. FIG. 16C is a graph of capacity versus time, and FIG. 16D is a graph of voltage versus time, both showing data collected from implementation of an exemplary cycle of protocol 1100 on the battery cells. This exemplary embodiment of protocol 1100 included a net zero charge pulse preheat phase 1110, which raised the cell temperature from about 20° C. to about 35° C. This was followed by a pulse charging phase 1120 for 3 minutes, where 2 ms pulses at 5C and 50% duty cycle were applied. This was followed in turn by a constant current charging phase 1130 having a 10 second rest period, a first sub-phase 1133 with a 7C rate for 90 seconds, a 10 second rest period, a 5C rate for 120 seconds, a third sub-phase 1135 with a 3.3C rate for 120 seconds, and a fourth sub-phase 1136 with a 1.8C rate for 6 minutes. The pulse charging phase 1120 and sub-phases 1133-1136 were also subject to cell voltage limitations (4.25V for phase 1120, 4.2V for sub-phases 1133-1136). This example of protocol 1100 achieved over 75% nominal capacity in under 13 minutes. After charging, a relatively long rest period of approximately 60 seconds was performed to allow the battery cell to cool, after which the cell was discharged at a rate that achieved zero capacity one hour after the start of protocol 1100.

[0173] Referring again to FIG. 16A, data 1602 shows results from a cell charged using a constant current at a 3.2C rate, and data 1604 shows results from a cell charged using protocol 1100 as described with respect to FIGS. 16B-16C. FIG. 16A compares capacity (mAh) with cycle time, which is a measure of the cumulative time the cell was tested in repeated cycles. The constant current charge cycle for data 1602 was formed by application of a 3.2C constant current for 13 minutes, followed by discharge at a rate that achieved full discharge 1 hour after initiation, whereby the full constant current cycle lasted 1 hour, and then the cycle was continuously repeated. The cycle was carried out for approximately 200 hours. FIG. 16B shows the same data as FIG. 16A in normalized form, with capacity shown as a percentage of the initial capacity achieved.

[0174] 16A-16B show that rapid capacity loss occurs with standard constant current fast charging data 1602. This rapid capacity loss is caused by high impedance growth induced in the cell by constant current charging. Conversely, fast charging protocol 1100 avoids this impedance growth and substantially improves capacity retention (similar to the 1C baseline rate of FIGS. 15A-15B) while achieving 75% of nominal capacity in under 13 minutes. Still further refinement of the parameters of protocol 1100 can lead to even faster charging times of 10 minutes or less to reach the same or similar capacity.

[0175] The battery cells used to collect the data in Figures 15A-15B were subjected to a slow charge cycle characterization analysis, and the results are presented in the voltage vs. capacity plots of Figures 17A-17B. Figure 17A depicts data for a 1C constant current charged cell, where characterization curve 1702 was taken at the beginning of life (BOL) before the testing described with respect to Figures 15A-15B, and characterization curve 1704 was taken at the end of life (EOL) after the testing was completed. Comparison of curves 1702 and 1704 shows that the constant current cell underwent an irreversible capacity loss of about 15%. Figure 17B depicts data for a 1C pulse charged cell, where characterization curve 1712 was taken at the beginning of life (BOL) before the testing described with respect to Figures 15A-15B, and characterization curve 1714 was taken at the end of life (EOL) after the testing was completed. Comparison of curves 1712 and 1714 shows that the pulse charged cell also underwent an irreversible capacity loss of about 15%. Thus, at EOL, the pulse charged cell had similar irreversible capacity loss to the constant current cell compared to (BOL). Cycle life was also comparable. Pulse charging therefore does not significantly degrade the cell nor does it cause rapid impedance growth.

[0176] 18A is a plot of the imaginary and real impedance components for a constant current charging cell and a pulse charging cell at EOL. Data 1802 corresponds to the constant current charging cell and data 1804 corresponds to the pulse charging cell. Both cell pairs show substantially the same impedance characteristics, with the pulse charging cells only showing a slightly higher ohmic and activation component to their impedance. This is likely due to SEI layer buildup and resulting impedance growth due to higher than optimal temperatures, which can be mitigated through further refinement of the parameters of protocol 1100 to allow for more temperature control.

[0177] FIG. 18B is a plot of cell voltage versus time depicting experimental data collected for a lithium-ion cell subjected to constant current charging (1812), pulse charging with a 10 ms pulse duration (1814), and pulse charging with a 2 ms pulse duration (1816). Charging at either constant current or pulse charging, followed by a pause, allows for rapid measurement of ohmic / activation versus diffusion contributions. The measurements are summarized in Table 1 below. These findings indicate that pulse charging 1816 reduces the activation impedance and activation overpotential, but maintains a similar diffusion overpotential. [Table 1]

[0178] 19A-G are block diagrams depicting exemplary embodiments of implementations of fast charging protocol 1100 for various battery types. In these figures, cell temperature generally increases with time. FIG. 19A depicts protocol 1100-1 implemented according to the embodiment of FIGS. 11A-11B, where a pulse preheat phase 1110 is performed first, followed by a pulse charging phase 1120, and culminating with a relatively high temperature constant current (CC) charging phase 1130. Protocol 1100-1 can be used, for example, with NMC or NCA battery cells.

[0179] 19B depicts protocol 1100-2 in which the pulse preheat phase 1110 is performed first, followed by the pulse charging phase 1120, and the constant current charging phase 1130 is omitted. By way of example, this embodiment may be suitable for battery types having chemistries with relatively high activation but relatively low diffusion at acceptable charging temperatures as compared to NMC or NCA battery cells.

[0180] 19C depicts a protocol 1100-3 having only the pulse charging phase 1120, and omitting the preheating phase 1110 and the constant current charging phase 1130. By way of example, this embodiment may be suitable for battery types having chemistries with relatively high activation at acceptable charging temperatures compared to NMC or NCA battery cells.

[0181] 19D depicts a protocol 1100-4 having a pulse charging phase 1120 followed by a constant current charging phase 1130, but omitting the preheat phase 1110. By way of example, this embodiment may be suitable for battery types having chemistries with relatively low activation at their high states of charge that facilitate constant current charging at their high states of charge, as compared to NMC or NCA battery cells.

[0182] 19E depicts protocol 1100-5 having a pulse preheat phase 1110 immediately followed by a constant current charging phase 1130. The pulse charging phase 1120 is omitted. By way of example, this embodiment may be suitable for battery types having chemistries with relatively low activation at acceptable charging temperatures compared to NMC or NCA battery cells.

[0183] 19F depicts a protocol 1100-6 similar to 1100-5 with a first preheat phase 1110-1 and a constant current phase 1130-1, but protocol 1100-6 repeats this regime with a second pulse preheat phase 1110-2 and a second constant current charging phase 1130-2. By way of example, this embodiment may be suitable for battery types having chemistries with relatively low activation at acceptable charging temperatures compared to NMC or NCA battery cells, and is implemented across two distinct temperature regimes.

[0184] FIG 19G depicts a protocol 1100-7 having a pulse preheat stage 1110, immediately followed by a first constant current charging stage 1130-1, then followed by a pulse charging stage 1120 and a second constant current charging stage 1130-2. By way of example, this embodiment may be suitable for battery types having chemistries with relatively high activation in the mid-range state of charge compared to NMC or NCA battery cells. Any other combination of the stages of FIG 19A-19G is also possible unless otherwise stated or logically plausible.

[0185] The protocol embodiments described with respect to Figures 19A-19G and elsewhere herein can be implemented independently for each energy source in the system being charged. Information about the condition of each source (e.g., SOC, temperature, voltage response, impedance response, lithium plating indication, etc.) can be collected for each source and communicated to a control system (e.g., 102) to facilitate coordinated system-wide management of application of protocol 1100 and distribution of power at each module or power connection (e.g., 110) to the source. For example, a modular energy system 100 having an array of N different modules 108, each having an energy source 206, can implement protocol 1100-1 of Figure 19A independently in each of the N modules 108. A determination of when each source 206 has reached a transition condition (e.g., from stage 1110, 1120 to stage 1120, 1130, or between sub-stages 1114, 1116, 1133-1136) can be made by the control system 102 (e.g., MCD 112) and appropriate instructions can be issued for each source 206 therein to transition that module 108 to the next stage (e.g., by MCD 112 instructing LCD 114 to modify the switching signal to converter 202 to generate a charging pulse (or constant current) as opposed to a preheat pulse train). A first group of one or more modules 108 may meet the condition (e.g., at a minimum temperature, etc.) to transition from the pulse preheat stage 1110 to the pulse charging stage 1120, while a second group of one or more different modules 108 may not yet meet the condition. Thus, the system 100 can control and partition the application of power using the control system 102 (e.g., at the direction of the MCD 112) such that a first group of one or more modules 108 is in the pulse charge phase 1120 while a second group of one or more different modules 108 remains in the pulse pre-heat phase 1110. Once each module 108 in the second group independently reaches a transition condition, that module 108 can enter the pulse pre-heat phase along with the first group of modules 108.Similarly, each module 108 in the pulse charging stage 1120 can independently transition from stage 1120 to stage 1130 as conditions for transitioning to the constant current charging stage 1130 are reached. In some examples, the different stages 1110, 1120, and 1130 can all be executed simultaneously on different energy sources in the same system. The same applies to the execution of the protocol sub-stages (e.g., 1114, 1116, and 1133-1136) on sources in a system, such that different sub-stages can be executed simultaneously on different sources.

[0186] FIG. 20 is a block diagram depicting an exemplary embodiment of an application that may be configured to apply the protocol 1100 described herein. Here, charging sources 150 are shown in the bottom row and the energy source configurations to be charged are shown in the top row. In the exemplary configuration 2010, charging source 150-1 is configured as a DC charger with a switching network to allow the DC charging voltage to be pulsed for performing pulse preheating. Charging source 150-1 is used to charge a conventional electric powertrain 2012, such as a series-connected pack of a conventional electric vehicle. In the exemplary configuration 2020, charging source 150-2 is configured as a DC charger and used to charge a conventional powertrain 2014, which is configured with a switching network to allow the received DC charging voltage to be pulsed for preheating and / or charging prior to input to a battery energy storage device. In example configuration 2030, charging source 150-3 is configured according to the embodiment of system 100 described with respect to FIGS. 1A-10F and supplies a pulsed DC or AC voltage to conventional powertrain 2012. In example configuration 2040, charging source 150-4 is configured as a DC charger used to supply a DC charging voltage to energy system 100 configured according to the embodiment described with respect to FIGS. 1A-10F. In example configuration 2050, charging source 150-5 is configured as an AC charger used to supply an AC charging voltage to energy system 100 configured according to the embodiment described with respect to FIGS. 1A-10F. In example configuration 2060, charging source 150-3 (such as that of configuration 2030) is used to supply a DC or AC voltage to energy system 100 configured according to the embodiment described with respect to FIGS. 1A-10F, in which case either the charging source or system 100 can provide pulse capability.

[0187] Although not so limited, configurations 2010, 2020, and 2030 may be particularly suitable for relatively low voltage applications (e.g., 10 watt-hours to 20 kilowatt-hours (kWh)), while configurations 2040 and 2050 may be particularly suitable for relatively high (medium) voltage applications (e.g., 20 kWh to 100 kWh), and configuration 2060 may be particularly suitable for relatively high voltage applications (e.g., 100 kWh and above).

[0188] Example of Charging Multiple Connected Modules In many applications, the modules 108 are connected, for example, in one or more arrays 700 to provide power to one or more loads 101. The pulse charging and pre-heating techniques described herein can be used to synchronously charge the energy sources 108 of multiple connected modules 108, for example, using a common charging source 150. For example, the control system 102 can be configured to provide coordinated system-wide charging of the modules 108 in one or more packs. The multi-module pulse charging technique is configured to increase the charging rate of the energy source 206 without incurring significant ohmic losses in the energy source 206. For example, increasing the amplitude of the charging DC current causes an increase in ohmic losses in the battery 206 due to the parasitic resistance of the battery 206. The increased ohmic losses in the battery 206 are converted to additional heat in the battery 206, which increases the temperature of the cells inside the battery 206 and, consequently, shortens the life of the battery 206. Thus, the described multi-module pulse charging technique is particularly useful for charging an energy storage system having a large number of batteries 206, such as a battery pack of an EV. As mentioned above, the present embodiment will be described primarily in the context of the energy source 206 being a battery, however the present embodiment is applicable to other energy source types as well (e.g., high energy density capacitors and fuel cells).

[0189] 21 is a block diagram illustrating another exemplary embodiment of a modular energy system 100 coupled with a charging source 150. The system 100 includes a number "N" of modules 108 connected together, for example, in one or more arrays 700 (see FIGS. 7A-7E), where N is an integer greater than or equal to 2. The modules 108 are illustrated as including a battery and a full-bridge converter 202, although any of the configurations of modules 108 and converters 202 described herein may be used with this embodiment of the system 100.

[0190] The modules 108 can be connected such that when in a charging mode of operation, all of the modules 108 are connected in series between the system I / O ports SIO1 and SIO2 of the system 100, e.g., the power connections 110 of the modules 108 are connected in series. For example, the converters 202 of the modules 108 can be connected such that the illustrated converter 202 switches can be operated to place the batteries 206 of the modules 108 in series during charging. However, the converter 202 switches can be operated such that some batteries 206 are bypassed by a charge signal at times during charging, as described below. The modules 108 can be placed in a pack, e.g., an EV or a pack in a stationary application. The modules 108 can also be placed in two, three, four, or more packs of EVs, such as via an interconnect module 108-IC connected between the packs. Thus, the embodiments described herein can be used to simultaneously charge one or more packs of EVs. Alternatively, the embodiments described herein can be used to charge two or more packs at different times, as needed.

[0191] In the illustrated embodiment, control system 102 includes a single MCD 112 and multiple LCDs 114, with one LCD 114 per module 108. However, as discussed above, LCD 114 may alternatively be configured to control multiple modules 108. MCD 112 may be coupled to one or more external control devices 104 via communication paths or links 105, and may be coupled to control device 155 of charging source 150 via communication paths or links 2105.

[0192] The control device 155 is configured to control the charging circuit 157 to output a supply charging signal to the module 108 of the system 100. In some embodiments, the control device 155 is configured to control the charging circuit 157 to output a DC charging signal having a regulated voltage or a regulated current. For example, the control device 155 can be configured to adjust the voltage level of the supply charging signal in a voltage control mode or adjust the current level of the supply charging signal in a current control mode. The control device 155 can be configured to adjust the voltage level of the current level based on a set value received from the MCD 112, and the voltage level can remain constant during one or more stages of a charging cycle or can vary between and / or within stages, as described in more detail herein.

[0193] In general, the control device 155 can control the charging signal 157 such that it follows or tracks a set value received from the MCD 112, which can remain constant for a duration and can change during a charging cycle. While the set value is constant, the control device 155 can control the charging signal 157 such that it also remains constant within a defined tolerance.

[0194] In the voltage control mode, the control system 102, e.g., the MCD 112, can provide a voltage setpoint for controlling the device 155 via a communication path or link 2105. The control device 155 can also control the voltage (V pack The control device 155 may receive voltage measurements from a voltage sensor that measures the setpoint provided by the MCD 112 and the measured voltage V pack and control the charging circuit 157 based on the difference, e.g., to reduce or even minimize the difference. For example, the control device 155 may include a closed-loop voltage controller, e.g., a proportional-integral (PI), proportional-integral-derivative (PID), or other suitable controller, that adjusts the voltage level based on a voltage setpoint and a voltage measurement.

[0195] In the current control mode, the control system 102, e.g., the MCD 112, can provide a current setpoint to control the device 155 via a communication path or link 2105. The control device 155 also controls the supply charging current (I) flowing from the charging source 150 to a module 108 of the system 100, e.g., to a system I / O port SIO1 or from a system I / O port SIO2 of the system 100. pack ), the control device 155 can monitor the difference between the set point received from the MCD 112 and the measured current and control the charging circuit 157 based on the difference, e.g., to reduce or even minimize the difference. For example, the control device 155 can include a closed loop current controller, e.g., a PI, PID, or other suitable controller, that adjusts the current level based on the current set point and the current measurement.

[0196] The control system 102 may also be configured to instruct the control device 155 to switch between voltage and current control modes, for example, by providing control instructions over the communication path or link 2105. For example, the control system 102 may be configured to execute a charge control protocol for a control cycle that includes multiple stages, such as preheat, pulse charging, constant current (non-pulsed) charging, and / or constant voltage (non-pulsed) charging.

[0197] During constant current charging and some pulse charging and / or pulse preheating phases, the control device 155 may operate in a current control mode to adjust the supplied charging current based on a current set point received from the MCD 112. In general, the amplitude of the current may remain constant (within a tolerance range) over a duration based on the constant current set point, but may also vary in response to set point changes or temporary deviations from the set point. Similarly, during constant voltage charging and some pulse charging and / or pulse preheating phases, the control device 155 may operate in a voltage control mode to adjust the supplied charging voltage based on a voltage set point received from the MCD 112. In general, the amplitude of the voltage may remain constant (within a tolerance range) over a duration based on the constant voltage set point, but may also vary in response to set point changes or temporary deviations from the set point.

[0198] For example, as described below, the control system 102 can instruct the control device 155 to operate in a voltage control mode during the pulse charging phase. The control system 102 can also increase the voltage set point, for example, continuously or periodically, during the pulse charging phase based on the voltage level of the module 108. In this example, the voltage amplitude can remain constant between periodic updates of the set point or can increase continuously with the increase to the voltage set point.

[0199] The control system 102 may transition between stages based on the occurrence of an event or condition being met. For example, the control system 102 may transition from a preheat stage to a pulse charge stage when each module 108 reaches a minimum or aggregate temperature (e.g., an average of central tendency or other measure) of the modules 108 in the system 100. When transitioning between stages that require a different control mode of the control device 155, the control system 102 may provide control instructions to the control device 155 via the communication path or link 2105. For example, when transitioning from a current control mode to a voltage control mode, the control system 102 may provide instructions to operate in a voltage control mode along with a voltage set point for use during voltage control mode operation. The control system 102 may also adjust set points during any of the modes or stages of the charge cycle and provide the adjusted set points to the control device 155 via the communication path or link 2105.

[0200] The control circuit 157 may include or be coupled to an RLC circuit 158 ​​including one or more resistors, one or more inductors, and / or one or more capacitors. For example, the RLC circuit 158 ​​may include an inductor coupled along a positive output path 159A of the charging circuit 157. In another example, the RLC circuit 158 ​​may include an inductor coupled along a positive output path 159A of the charging circuit 157 and a capacitor coupled between the positive output path 159A of the charging circuit 157 and the negative output path 159B of the charging circuit 157. The RLC circuit 158 ​​may be disposed at an output of the charging circuit 157 such that, for example, output terminals of the RLC circuit 158 ​​are coupled to the system I / O ports SIO1 and SIO2 of the system 100.

[0201] The voltage and / or current in the RLC circuit 158 ​​is proportional to the voltage V of the supply charging signal provided to the system 100. pack and current I pack The control device 155 can be different from the voltage V pack and current I packThe RLC circuit 158 ​​may be configured to adjust the voltage and / or current such that follows a set value provided by the MCD 112.

[0202] The system 100 may include an inductor L1 coupled to an output of the charging circuit 157. For example, the system 100 may include the inductor L1 in implementations in which the control device 155 is configured to operate in a voltage control mode. The inclusion of the inductor L1 facilitates the ability of the control system 102 to control the current provided to the battery 206 of the module 108. The inductor L1 may be located within the pack housing the module 108 or outside the pack.

[0203] In some embodiments, the external control device 104 can initiate a pre-heating and / or charging cycle. For example, if the system 100 is implemented in an EV, the external control device 104 can be a vehicle ECU or MCU that can initiate a pre-heating phase prior to charging. In a particular example, a user (e.g., a driver or passenger) can interact with a user interface (e.g., a knob, button, switch, or graphical user interface (GUI)) to indicate that the user will soon be charging the EV. The external control device 104 can be coupled to the user interface via a communication path or link to receive the instruction. In response to receiving the instruction, the external control device 104 can send a control signal to the MCD 112 via the communication path or link 105 to initiate the pre-heating phase.

[0204] In another example, the external control device 104 can be configured to initiate a pre-heating phase based on data related to the system 100 or the EV in which the system 100 is implemented. For example, the external control device 104 can monitor the aggregate SOC of the system 100 (e.g., the sum of the individual SOCs of the modules 108) and initiate a pre-heating phase when the aggregate SOC is below a threshold. The external control device 104 can use a trained machine learning model or other artificial intelligence to determine when to initiate a pre-heating phase based on, for example, the aggregate SOC of the modules 108 in the system 100 and / or other data, such as the location of the EV relative to a charging station. In an alternative EV embodiment, the vehicle ECU or MCU can be integrated with the MCD 112 as a single controller, in which case this function is performed by the same single device or chipset.

[0205] As mentioned above, the pre-heating phase 1110 (FIGS. 11A-11B) of the module 108 may include application of a pre-heating pulse signal, e.g., pre-heating pulse signal 1112 (FIGS. 11C-11E), from the charging source 150 or the second source 206B (FIG. 3B) of the module 108 to the battery 206. If the charging source 150 is not yet connected to the system 100, e.g., the EV in which the system 100 is implemented has not yet reached the charging source 150, the pre-heating phase may be implemented using the second source 206B (if present in the module).

[0206] In another example, the pre-heat phase may be implemented using one or more modules 108 of the system 100. In this example, the MCD 112 may control one or more modules to output energy to a group of modules 108 that are being charged. For example, the MCD 112 may control the converters 102 of one or more modules 108 to output energy and may also control the converters 202 of the modules 202 that are being charged to apply a pre-heat pulse signal to the batteries 206 of those modules 108 using the energy output by the one or more modules 108.

[0207] In another example, the pre-heating step can include passing a thermal management fluid in proximity to the module 108, for example, through a conduit section of a pack that houses the module 108. The thermal management fluid can be a coolant that is heated to pre-heat the module 108. An example of a system including structures for passing a coolant is described in International Application No. PCT / US21 / 27159, filed April 13, 2021, and entitled Modular Cascaded Energy Systems with a Cooling Apparatus and with Replaceable Energy Source Capability, which is incorporated by reference in its entirety for all purposes.

[0208] During the pulse preheat and pulse charging phases, the control system 102 can control the modules 108 to apply a positive, zero, or negative pulse from the supplied charging signal to the battery 206. For example, the control system 102 can control the converter 202 of each module 108 to apply a positive, zero, or negative pulse from the supplied charging signal to its battery 206. The control system 102 can control the converter 202 of each module 108 to apply a charging signal that includes charging pulses (e.g., positive and / or negative charging pulses) according to a particular frequency (or duration) and duty cycle, as described elsewhere herein. The designated frequency for the battery 206 can be selected to reduce or even minimize activation impedance, as described elsewhere herein.

[0209] The control system 102 determines the current I flowing through the module 108 from the charging source 150. pack and / or the total voltage V across all modules 108 packThe control system 102 may control the converters 202 of the modules 108 to divide the delivered charge between the batteries 206 of the modules 108 such that the setpoint remains at or near the target setpoint, e.g., within a specified tolerance. In many cases, the setpoint is generally constant over time, but may also vary, such as to compensate for different levels of battery SOC or other operating characteristics (e.g., temperature, SOH, etc.) of the modules 108 of the system 100. To divide the delivered charge, the control system 102 may control the duty cycle of the converters 202 of the modules 108 and / or the phase shift (e.g., time shift) of the charge pulses provided to the batteries 206 of the modules 108. The control system 102 may also divide the delivered charge to generate a current I pack and / or V pack The frequency and / or amplitude of the charging pulses can be controlled to regulate

[0210] The MCD 112 can determine the duty cycle, phase shift, frequency, and / or amplitude of the charge pulse in one or more ways. The MCD 112 can determine these parameters at the beginning of a charge cycle and / or adjust the parameters during the charge cycle. For example, the MCD 112 can monitor the operating characteristics of the modules 108 of the system 100 during the charge cycle and adjust the parameters based on the operating characteristics. The MCD 112 can adjust the frequency and amplitude of the charge pulse for multiple modules 108 (e.g., all modules 108) of the system 100 being charged. The MCD 112 can also adjust the duty cycle and / or phase of multiple modules 108 (e.g., all modules) of the system 100 or individual modules 108. For example, the MCD 112 can adjust the duty cycle and / or phase of the current I while simultaneously adjusting the duty cycle and / or phase of individual modules 108 to balance the operating characteristics of the modules 108. pack or voltage V pack It is also possible to divide the delivered charge so that V follows a corresponding set value.

[0211] In one example, the MCD 112 can determine the duty cycle of the charge pulse based on the number of modules 108 in the system 100 being charged. This number can vary based on, for example, whether one or more modules 108 are bypassed. In a particular example, the duty cycle can be determined based on:

number

number

[0212] In another example, the MCD 112 can set the duty cycle of each charging pulse to 50%. In this way, the voltage V across all modules 108 pack The battery 206 of the module 108 in the system 100

number

[0213] In both of the previous examples, the MCD 112 can phase shift the charge pulses for each module 108 such that the total amount of charge current drawn by the modules 108 being charged at any given time during charging is equal to a current setpoint, e.g., a current setpoint provided to the control device 155. For example, if the current setpoint remains constant over a duration during a charging cycle, the MCD 112 can phase shift the charge pulses for each module 108 such that the total amount of charge current drawn by the modules 108 being charged at any given time during this duration is equal to the supplied charge current I pack The charge pulses can be phase shifted for each module 108 to be equal to a constant value of . Exemplary plots illustrating this phase shift are shown in Figures 22A-22D and described below.

[0214] In another example, the MCD 112 groups the modules 108 into M clusters and alternately provides charging pulses to each cluster with a duty cycle based on the number of clusters, M. For example, the duty cycle may be

number

[0215] The MCD 112 can repeat this process to charge the batteries 206 of clusters #2 and #3 by providing a charge pulse with a duty cycle to the module 108 of one of the clusters while turning off the other cluster so that no charge signal is provided to the battery 206 of the other cluster. The MCD 112 can cycle through clusters #1-#3 repeatedly during the pulse charging phase. In each of these cycles, the MCD 112 can control the converter 202 to apply one or more charge pulses to each module 108 of each cluster according to the determined duty cycle and phase shift. Alternatively, the reverse process can be applied where two of the clusters can be simultaneously charged with a 66% duty cycle while the remaining cluster is turned off, and where one cluster that is turned off cycles through all three clusters.

[0216] The MCD 112 can assign modules 108 to a particular cluster based on the physical location of the modules 108 within a system, pack, or multiple packs. For example, across all arrays 700, the modules 108 of a first cluster can be all of the modules of a particular array 700-1, the modules 108 of a second cluster can be all of the modules of a different array 700-2, etc. Alternatively, the modules 108 of a first cluster can be one or more modules 108 from each array 700, and the modules 108 of a second cluster can be one or more different modules 108 from each array 700, such that at least one module from each array 700 is in each cluster. The MCD 112 can be programmed such that each module 108 has a predetermined cluster assignment, or the cluster assignment can be determined in real time by the MCD 112.

[0217] The MCD 112 can select modules 108 for a particular cluster based on similarity of operating characteristics of the modules 108, such as SOC or temperature. For example, the modules 108 for a first cluster can be modules 108 with SOC values ​​that are equal to or greater than the central tendency SOC value (e.g., average or median) of the system or pack, while the modules 108 for a second cluster can be modules 108 with SOC values ​​that are equal to or less than the central tendency SOC value. The duty cycle of the pulse charging can then be adjusted to apply more energy to the cluster of modules 108 with a relatively lower SOC than the cluster of modules 108 with a relatively higher SOC, such as, for example, a duty cycle of 50.1-60% for the first cluster with a balance (49.9-40%) for the second cluster, with the duty cycle chosen to result in both clusters having relatively balanced SOC values ​​at the end of the pulse charging phase. A similar approach can be used for more than two clusters.

[0218] As another example, the modules 108 for a first cluster may be modules 108 having a temperature value (e.g., battery module temperature, average battery cell temperature, overall module temperature, etc.) that is equal to or greater than a central tendency temperature value (e.g., average or median) of the system or pack, while the modules 108 for a second cluster may be modules 108 having a SOC value that is equal to or less than the central tendency temperature value. The duty cycle of the pulse charging can then be adjusted to apply more energy to the cluster of modules 108 having a relatively lower temperature than the cluster of modules 108 having a relatively higher temperature, such as, for example, a duty cycle of 50.1-60% for the first cluster having a balance (49.9-40%) for the second cluster, with the duty cycle chosen to result in both clusters having relatively balanced temperature values ​​at the end of the pulse charging phase. A similar approach can be used for more than two clusters.

[0219] In some embodiments, a cluster may be bypassed, for example, if the temperature of the modules 108 in the cluster or the aggregate temperature of the modules 108 in the cluster meets a threshold, or if one or more modules 108. In such cases, the MCD 112 may adjust the duty cycle and phase of the charge pulses provided to other clusters based on the number of clusters being charged, for example, as described above.

[0220] In some embodiments, some modules 108 of the system 100 may be in a different charge cycle stage than other modules 108 of the system 100. For example, the MCD 112 may transition a first cluster into a pulse charge stage based on one or more factors for the modules 108 in the first cluster (as described herein, e.g., with reference to FIGS. 23 and 25), while a second cluster remains in a preheat stage based on one or more factors for the modules 108 in the second cluster. FIGS. 22A-22D show example plots of a charging signal for a pulse charge battery 206 of a module 108. Plot 2210 of FIG. 22A shows a DC supply charging voltage V pack and the supply charging current I pack is supplied to the module 108 of the system 100 by the charging source 150 while the system 100 is charging at a generally constant rate, and thus V pack and I pack 22B shows that there is minimal variation in the magnitude of the charge pulses applied to different batteries 206 of modules 108 of the system 100 (or alternatively different clusters of modules 108), where the pulse trains can be current or voltage pulses and are stacked on top of each other to more easily visualize their relationship in time (all pulses would be applied at the same or similar current or voltage). In this example, the system 100 includes ten modules 108.

[0221] FIG. 22C illustrates an example plot 2230 using current regulation and current pulsing, in which the pulses applied to the energy source of the module 108 reduce the total charging current drawn by the battery 206 of the module 108 to a constant (or nearly constant) supplied charging current I packAt each point during charging, the same number of batteries 206 are being charged due to the duty cycle and phase shift of the charge pulses, resulting in a constant current being drawn from the charge source 150. The voltage regulated source and voltage pulses applied to the system 100 result in a depiction similar to FIG. 22C, but instead with a pulse offset resulting in a constant or near constant pack voltage V pack will be achieved.

[0222] The individual currents 2232 shown in plot 2230 represent the pulsed charging currents of the ten modules 108. For clarity, plot 2240 in FIG. 22D shows the charging currents of three batteries 206 of the ten modules 108. The charging currents are shifted in time according to the shifting of the charging pulses for the modules 108.

[0223] 21, the MCD 112 may be configured to adjust the duty cycle, phase shift, frequency, and / or amplitude of the charging signal applied to a module 108 based on various factors. For example, if a module 108 is bypassed, e.g., due to a fault or overheating, the MCD 112 may adjust the duty cycle and phase shift of the charging signals applied to the other modules 108 such that the total charging current remains at or near a target setpoint, e.g., such that the setpoint remains constant or remains constant as it increases or decreases with a corresponding increase or decrease to the target setpoint. In a particular example, the MCD 112 may increase the duty cycle of each module 108 being charged and reduce the phase shift between the charging signals to account for the modules 108 being bypassed.

[0224] The MCD 112 may also adjust the duty cycle and / or phase shift of the charge pulses applied to the individual modules 108 during charging based on, for example, one or more operational characteristics of the modules 108 that are also measured or monitored during the charging process. These operational characteristics may include, for example, SOC, SOH, temperature, capacity, voltage, and / or current. The operational characteristics for the modules 108 may also include the impedance of the module's battery 206, the aging of the battery 206 (e.g., actual age, estimated aging based on usage), and / or other characteristics of the battery 206.

[0225] In some embodiments, the MCD 112 can adjust the duty cycle and / or phase of the charge pulses applied to a module 108 to balance one or more operating characteristics of the module 108. For example, the MCD 112 can increase the duty cycle of a module 108 that has a lower SOC than other modules 108 in the system 100. The MCD 110 can reduce the duty cycle of one or more modules 108, e.g., the module 108 with the highest SOC, in a corresponding manner such that the total current (applied to the battery 206 of the module 108 remains at or near the target setpoint.

[0226] In some embodiments, the MCD 112, LCD 114, or BMS of the battery 206 can determine a charge rate for the battery 206 based on one or more operating characteristics. If determined by the LCD 114 or BMS, the LCD 114 can provide the charge rate to the MCD 112 via the communication path or link 115.

[0227] The MCD 112 can adjust the duty cycle, phase, frequency, and / or amplitude of the charge pulses applied to one or more modules 108 based on the charge rate for the module 108. For example, an older battery 206, or a battery 206 with a high temperature, may have a slow charge rate. In this example, the MCD 112 can reduce the duty cycle of the charge pulses applied to the module 108 with the battery 206 with a slow charge rate. The MCD 112 can also increase the duty cycle and / or adjust the phase shift of the charge pulses of one or more other modules 108 such that the total current drawn by the module 108 remains at or near a target setpoint. In another example, the MCD 112 can reduce the frequency and / or amplitude of the charge pulses for multiple modules 108 (e.g., all modules 108) of the system 100 based on one or more modules 108 having a high temperature (e.g., a temperature above a temperature threshold).

[0228] In some embodiments, the MCD 112 may limit the adjustment of the duty cycle for each individual module 108 to a specified range, for example, 1% of the duty cycle determined for all modules, 2% of this duty cycle, 5% of this duty cycle, or another range.

[0229] 23 is a flow chart illustrating an example embodiment of a method 2300 of a pulse charging energy source for multiple connected modules. Method 2300 may be performed by any embodiment of system 100 described herein unless otherwise stated or logically reasonable. In this example embodiment, charging source 150 is configured to operate in a current control mode to provide a supply charge signal to modules 108 of system 100 based on a target current set point. MCD 112 may hold the set point constant for some duration during process 2300 and / or adjust the current set point, for example, periodically or continuously.

[0230] In step 2310, the MCD 112 determines the duty cycle and / or phase shift (e.g., phase angle or shift in time) for the modules 108 of the system 100. The MCD 112 may determine the duty cycle and phase shift for each module 108 based on the number modules 108 in the system 100. If any module 108 is bypassed, the MCD 112 may determine the duty cycle and / or phase shift based on the number of non-bypassed modules 108 in the system 108. The MCD 112 may also determine the frequency and amplitude of the charging pulses provided to the modules 108. In some embodiments, this step may be omitted if either non-variable or pre-programmed duty cycles, phase shifts, frequencies, and amplitudes are used.

[0231] In some embodiments, the MCD 112 may be configured to calculate the current drawn by the module 108 (I pack ) and / or the voltage (V pack ) is constant at any given time (e.g., at all times) during charging. In some embodiments, the MCD 112 can determine the duty cycles and phase shifts for each module 108 such that the duty cycles and phase shifts are such that the same number of modules 108 draw current from the supply charging signal at any given time during charging. In other words, the MCD 112 can determine the duty cycles and phase shifts for the modules 108 such that the charging pulses applied to the batteries 206 of the modules 108 are distributed in time, resulting in the same number of modules 108 drawing current from the supply charging signal at any given time during charging.

[0232] As mentioned above, a number of techniques can be used to determine the duty cycle for the module 108. For example, the duty cycle may be determined by:

number

number

[0233] In embodiments including both a preheat phase and a pulse charging phase, the MCD 112 may determine the duty cycle, phase shift, frequency, and / or amplitude of the signal provided to the module 108 for both the preheat phase and the pulse charging phase. The duty cycle, phase shift, frequency, and / or amplitude of the signal may be the same for both phases or may be different. For example, the amplitude of the charging signal may be lower for the preheat phase relative to the pulse charging phase, or vice versa.

[0234] In embodiments in which the MCD 112 uses the operating characteristics (or charge rates) of the modules 108 to determine individual duty cycles for the individual modules 108, the MCD 112 may obtain the operating characteristics (or charge rates) from or through the LCD 114 or a battery management system (BMS), or otherwise. The MCD 112 may use the obtained information to determine duty cycles for the modules 108. For example, the MCD 112 may reduce the duty cycle for a module 108 that has a slower charge rate, a higher temperature, or a higher SOC than other modules 108 (or relative to the aggregate value of all modules 108 in the system 100) by a specified amount or based on the difference between the value of that module 108 and the aggregate value of all modules 108 in the system 100. Similarly, the MCD 112 may increase the duty cycle for a module 108 that has a higher charge rate, lower temperature, or lower SOC than other modules 108 (or relative to the aggregate value of all modules 108 in the system 100) by a specified amount or based on the difference between the value of that module 108 and the aggregate value of all modules 108 in the system 100.

[0235] Step 2310 may be performed multiple times during a charging cycle, such as during the preheat and / or pulse charging phases. For example, the MCD 112 may continuously or periodically determine the duty cycle and phase for the module 108 during these phases. In this manner, the MCD 112 may adjust for changes in the operating characteristics of the module 108 and / or balance the operating characteristics of the module 108 during charging.

[0236] In step 2320, the MCD 112 controls the module 108 to pre-heat the battery 206 of the module 108. To initiate the pre-heat phase, the MCD 112 can receive, for example, a control signal from the external control device 104 initiating a charging protocol that includes a pre-heat phase or instructing the MCD 112 to initiate a pre-heat phase. In response, the MCD 112 can send a control signal to the control device 155 to instruct the charging source 150 to provide an regulated current signal having a current level that conforms to a target current setpoint. This target setpoint can remain the same throughout all phases of the charging protocol or can vary depending on the current requirements of the system 100. The control device 155 can, for example, provide a supply charge signal having a current level that conforms to the target setpoint within a specified tolerance.

[0237] In some embodiments, the MCD 112 can control the converter 202 of the module 108 to distribute a preheat signal, e.g., preheat signal 1112 (FIGS. 11C-11E), to the battery 206 of the module 108. For each individual module 108, the preheat phase can be the same or similar to the preheat phase 1110 described above. In this embodiment, the MCD 112 can control the converter 202 using the determined duty cycle and phase shift to distribute the preheat signal to the battery 206 such that the total current drawn by the module 108 remains at or near the target setpoint. For example, the MCD 112 can provide a control signal to the LCD 114 that causes the LCD 114 to control the switches of the converter 202 according to the duty cycle and phase shift for the module 108.

[0238] The pre-heat signal may include alternating positive and negative pulses. In some embodiments, pre-heating using the pre-heat signal may also be used to partially charge the batteries 206 of the module 108. For example, the duty cycle of the pre-heat signal may be increased such that a net positive energy is applied to each battery 206 during the pre-heat phase.

[0239] In some embodiments, the MCD 112 can control the passage of thermal management fluid proximate to the module 108 to pre-heat the battery 206 of the module 108. The thermal management fluid can be heated and passed through conduits located proximate to the module 108.

[0240] As described above, the preheat phase causes a temperature increase in a localized area within the battery cells. The MCD 112 can apply preheat to the module 108 until all cells of each battery 206 reach a minimum temperature threshold, provided that no cell exceeds the maximum temperature threshold. If a cell reaches the maximum threshold, the preheat phase can be slowed or stopped, or the MCD 112 can transition to the next phase (pulse charging) as described herein. In another example, the MCD 112 can reduce the duty cycle of the preheat signal applied to the battery 206 having a cell that has reached the maximum threshold while continuing the preheat phase.

[0241] In step 2330, the MCD 112 controls the module 108 to deliver a pulsed charging signal, e.g., the pulsed charging signal 1122, to the battery 206 of the module 108. For each module 108, the pulsed charging phase can be the same or similar to the first charging phase 1120 described above. In this embodiment, the MCD 112 can control the converter 202 using the determined duty cycle and phase shift to deliver the pulsed charging signal 1122 to the battery 206 such that the total current drawn by the module 108 remains at or near the target setpoint. For example, the MCD 112 can provide a control signal to the LCD 114 that causes the LCD 114 to control the switches of the converter 202 according to the duty cycle and phase shift for the module 108.

[0242] The MCD 112 may pulse charge the battery 206 of the module 108 for a predetermined duration, until a SOC or capacity threshold is reached, until a temperature threshold is reached, or any combination thereof (e.g., terminating when any of the time, SOC, or temperature thresholds are reached). In some embodiments, when the temperature threshold is reached, the MCD 112 may terminate the pulse charging phase, regardless of other conditions.

[0243] In step 2340, the MCD 112 controls the modules 108 to continue charging the battery 206 using a constant current (non-pulsed) charging signal. During this charging phase, the MCD 112 may turn on the converters 202 of all modules 108 in the system 100 so that a constant current is injected into the battery 206 of each module 108 in the system 100 without pulsing. This phase may be the same as or similar to the second charging phase 1130 described above.

[0244] In some embodiments, the MCD 112 can balance the operating characteristics of the modules 108 during this constant current charging phase. For example, the MCD 112 can operate the converter 202 using PWM techniques to apply more charge from the constant current charging signal to some modules 108 and less charge from the constant current charging signal to other modules 108 to balance the operating characteristics of one or more of the modules 108. In this example, the duty cycle can be the same for all modules 108 during the preheat and pulse charging phases. In other embodiments, the MCD 112 can adjust both the duty cycle and / or phase shift during the preheat and / or pulse charging phases while balancing during the constant current charging phase.

[0245] The constant current charging phase may be terminated upon the occurrence of a time threshold, a temperature threshold, a SOC threshold, or a voltage threshold, or any combination thereof, to allow for a preheating phase and a pulse charging phase. Although method 2300 includes all three phases, other embodiments of method 2300 may include only one of the phases, or any combination of the three phases. For example, one embodiment of method 2300 may include a preheating phase and a pulse charging phase, but no constant current phase. Similarly, one embodiment of method 2300 may include a pulse charging phase and a constant current phase, but no preheating phase.

[0246] 24A-24C show example plots of voltage and current levels during stages of a charging protocol, e.g., the stages of method 2300 of FIG. 23. FIG. 24A is a plot 2400 of voltage and current levels during a preheat stage, a pulse charge stage, and an example constant stage, which for ease of illustration is a constant current phase, although a constant voltage stage (or both stages) could alternatively be used. Plot 2400 shows voltages 2410 of individual modules 108, total voltage 2412 across all modules 108 of system 100, supplied charging current I pack 2413 , the current drawn by the individual batteries 206 of the module 108 , and the input current 2415 to the charging source 150 .

[0247] During the preheat and pulse charge phases, the output voltage 2410 of the individual modules is in the form of a pulse train corresponding to the pulse charge signal applied during the two phases (see FIGS. 24B and 24C). At reference numeral 2410A, the output voltage of the module 108 pulses between a low voltage level and a high voltage level during the preheat phase. In this example, the low voltage level may be a negative voltage level and the high voltage level may be a positive voltage level during the preheat phase.

[0248] At 2410B, the output voltage of the module 108 pulses between a low voltage level and a high voltage level during the pulse charging phase. In this example, the low voltage level may be a negative or zero voltage level and the high voltage level may be a positive voltage level during the pulse charging phase. During the constant current charging phase, the output voltage 2410 of the individual modules may remain constant (non-pulsed), as shown by 2410C.

[0249] Similar to the individual battery voltages 2410, the individual battery currents are in the form of pulses (see FIGS. 24B and 24C) during the preheat and pulse charge phases, as indicated by reference numerals 2414A and 2414B, respectively. As indicated by reference numeral 2414C, the individual battery currents are constant (non-pulsed) during the constant current charge phase, based on the pulse charge signal applied to the battery 206.

[0250] In this example, the supply charging current I pack After rising during the preheat stage, the supply charging current I remains generally constant throughout all three stages. As mentioned above, pack follows a current setpoint resulting from the distribution of current in the form of a pulsed charging signal to the module 108 according to the duty cycle and phase shift described herein. In another example, the setpoint may be the supply charging current I pack can also be varied for different stages of the charge cycle and / or within a stage of the charge cycle such that the amplitude of V is varied to remain at or near a set value.

[0251] In this example, the charging input current 2415 may vary between stages, but generally remains at a constant DC value during each stage. In this example, more energy is used in the constant current stage versus the pulse charging stage, and more energy is used in the pulse charging stage versus the preheating stage. Thus, the input current 2415 to the charging source 150 increases from the preheating stage to the pulse charging stage and from the pulse charging stage to the constant current stage. Similarly, the total output voltage 2412 of the module increases between stages in a corresponding manner.

[0252] 24B is a plot 2420 of voltage and current levels during the preheat phase. This plot 2420 is an expanded version of the preheat phase portion of plot 2410. Plot 2420 shows pulses of the individual voltages 2410D and 2410E of the modules 108, as well as pulses of the individual battery currents 2414D and 2414E for those modules 108. In this example, the duty cycle of the preheat signal is 50%, and one half of the modules 108 are 180 degrees out of phase with the other half of the modules 108.

[0253] 24C is a plot 2440 of voltage and current levels during the pulse charging phase. This plot 2440 is an expanded version of the pulse charging phase portion of plot 2410. Plot 2440 shows pulses of the individual voltages 2410F-2410I of four modules 108, and pulses of the individual battery currents 2414F-2414I for those four modules 108. In this example, the duty cycle of the pulse charging signal is 25% and the pulses are 90 degrees out of phase with each other.

[0254] 25 is a flow chart illustrating an exemplary embodiment of a method 2500 of pulsing energy source charging of multiple connected modules 108. Method 2500 may be performed by any embodiment of system 100 described herein unless otherwise stated or logically reasonable. In this exemplary embodiment, charging source 150 is configured to operate in a voltage controlled mode of operation to provide a supply charging signal to modules 108 of system 100 based on a target voltage setpoint. That is, charging source 150 regulates a voltage V across all modules 108 of system 100. pack In this mode, the control system 102 is configured to regulate the current I supplied to the modules 108 of the system 100. pack and creating a sequential pattern of charging pulses to the battery 206 of each module 108.

[0255] In step 2510, the MCD 112 determines the duty cycle and / or phase shift (e.g., phase angle or shift in time) for the modules 108 of the system 100. The MCD 112 may also determine the frequency and amplitude of the charging pulses provided to the modules 108. In some embodiments, this step may be omitted if either non-variable or pre-programmed duty cycles, phase shifts, frequencies, and amplitudes are used.

[0256] The MCD 112 may determine a target duty cycle for a module 108 based on, for example, a charge rate, battery characteristics, and / or other factors for the module 108. The MCD 112 may also determine a duty cycle and phase shift for an individual module 108 to adjust the current provided to the battery 206 of the module 108 and / or to balance the characteristics of the module 108. For example, if the temperature of a module 108 is high compared to the other modules 108, the MCD 112 may reduce the duty cycle for that module 108 such that less current is drawn by that module 108. This may reduce the overall current to the modules 108 of the system 100, so the MCD 112 may increase the duty cycle for one or more of the other modules 108 to adjust the current to the module 108 based on, for example, a target current setpoint determined by the MCD 112 or received by the MCD 112 (e.g., from the external control device 104). The MCD 112 may maintain a constant target current set point or adjust the target current set point based on the charging needs and / or operating characteristics of the module 108 .

[0257] In an embodiment that includes both a preheat phase and a pulse charge phase, as in this embodiment, the MCD 112 can determine the duty cycle and / or phase shift for the module 108 for both the preheat phase and the pulse charge phase. The duty cycle and / or phase shift can be the same for both phases or can be different.

[0258] In embodiments in which the MCD 112 uses the operating characteristics (or charge rates) of the modules 108 to determine individual duty cycles for the individual modules 108, the MCD 112 may obtain the operating characteristics (or charge rates) from the LCD 114, the BMS, or otherwise. The MCD 112 may use the obtained information to determine the duty cycles for the modules 108.

[0259] In this embodiment, the LCD 114 can implement a switching technique (e.g., PWM) to control the switches of the converter 202 such that the switching frequency is equal to the pulse charging frequency. For example, if the pulse charging frequency is 1 kilohertz (kHz), the LCD 114 can operate each of the two legs (e.g., a high-side switching leg and a low-side switching leg) at half the pulse charging frequency, e.g., 0.5 kHz, to achieve a total of 1 kHz.

[0260] MCD 112 can also be configured to determine a target voltage set point for charging source 150. In some embodiments, MCD 112 can determine a voltage set point for charging source 150 based on the number of modules 108 being charged, the DC link voltage of the battery 206 of each module 206, and a target duty cycle for the charging signal. MCD 112 can determine a total DC link voltage of the modules 108 and multiply the total DC link voltage by the pulse charging duty cycle to determine a voltage set point for charging source 150. For example, MCD 112 can determine a voltage set point using equation (3): (3) V setpoint =N*V batt *D

[0261] In equation (3), N is the number of modules 108 being charged, and V setpoint is the target voltage setting, and V batt where V is the DC link voltage of the battery 206 of each module 108 being charged (e.g., the voltage across the battery 206), and D is the duty cycle. For example, if there are ten modules 108 in the system 100 with a DC link voltage of 50V and a target pulse charging duty cycle of 50%, then the voltage set point for the charging source 150 would be approximately 250VDC (e.g., 10*50*50%). As described herein, the MCD 112 can update the target voltage set point as the DC link voltage of the battery 206 increases during the charging cycle. An additional compensation loop can also be added to this calculation to improve the accuracy of the generated duty cycle.

[0262] In step 2520, the MCD 112 controls the module 108 to preheat the battery 206 of the module 108. To initiate the preheat phase, the MCD 112 can receive, for example, a control signal from the external control device 104 initiating a charging protocol including a preheat phase or instructing the MCD 112 to initiate a preheat phase. In response, the MCD 112 can send a control signal to the control device 155 to instruct the charging source 150 to provide an regulated voltage signal having a voltage level according to a target voltage setpoint, e.g., a voltage setpoint determined using equation (3). This setpoint can remain the same throughout all phases of the charging protocol or can vary depending on the current requirements of the system 100. The control device 155 can, for example, provide a supply charge signal having a voltage level equal to the target setpoint within a tolerance range.

[0263] In some embodiments, the MCD 112 can control the converter 202 of the module 108 to distribute a preheat signal, e.g., preheat signal 1112 (FIGS. 11C-11E), to the battery 206 of the module 108. For each individual module 108, the preheat stage can be the same or similar to the preheat stage 1110 described above. In this embodiment, the MCD 112 can control the converter 202 using the determined duty cycle and phase shift to distribute the preheat signal to the battery 206 such that the total current drawn by the module 108 remains at or near the target setpoint. For example, the MCD 112 can provide a pulsed charging frequency to the LCD 114 of the module 108, which can control the converter's switches according to that frequency.

[0264] The pre-heat signal may include alternating positive and negative pulses. In some embodiments, pre-heating using the pre-heat signal may also be used to partially charge the batteries 206 of the module 108. For example, the duty cycle of the pre-heat signal may be increased such that a net positive energy is applied to each battery 206 during the pre-heat phase.

[0265] In some embodiments, the MCD 112 can control the passage of thermal management fluid proximate to the module 108 to pre-heat the battery 206 of the module 108. The thermal management fluid can be heated and passed through conduits located proximate to the module 108. Any combination of these aforementioned pre-heating techniques can be used.

[0266] As described above, the preheat phase causes a temperature increase in a localized area within the battery cells. The MCD 112 can apply preheat to the modules 108 until all cells of each battery 206 reach a minimum temperature threshold, provided that no cell exceeds the maximum temperature threshold. If a cell reaches the maximum threshold, the preheat phase for all modules 108 of the system 100 being charged, or the module with the hot cell, can be slowed or stopped, or the MCD 112 can transition to the next phase (pulse charging) as described herein. In another example, the MCD 112 can reduce the duty cycle of the preheat signal applied to the battery 206 with the cell that has reached the maximum threshold while continuing the preheat phase.

[0267] In step 2530, the MCD 112 controls the module 108 to deliver a pulse charging signal, such as the pulse charging signal 1122, to the battery 206 of the module 108. For example, the MCD 112 can provide a pulse charging frequency to the LCD 114 of the module 108, which can control the switches of the converter according to that frequency.

[0268] For each individual module 108, the pre-charging phase may be the same or similar to the first charging phase 1120 described above. In this embodiment, the MCD 112 may control the converter 202 using the determined duty cycle and phase shift to deliver a pulsed charging signal 1122 to the battery 206 such that the total current drawn by the modules 108 remains at or near the target setpoint.

[0269] The MCD 112 may pulse charge the battery 206 of the module 108 for a predetermined duration, until a SOC or capacity threshold is reached, until a temperature threshold is reached, or any combination thereof (e.g., terminating when any of the time, SOC, or temperature thresholds are reached). In some embodiments, when the temperature threshold is reached, the MCD 112 may terminate the pulse charging phase, regardless of other conditions.

[0270] In step 2540, the MCD 112 controls the converters 202 of the modules 108 to continue charging the batteries 206 using a constant voltage (non-pulsed) charging signal. During the charging phase, the MCD 112 can turn on the converters 202 of all modules 108 in the system 100 such that a constant voltage across all modules 108 injects a constant charging current into the batteries 206 of each module 108 in the system 100 without pulsing.

[0271] In some embodiments, the MCD 112 can balance the operating characteristics of the modules 108 during this constant voltage charging phase. For example, the MCD 112 can operate the converter 202 using PWM techniques to apply more charge from the constant voltage charging signal to some modules 108 and less charge from the constant voltage charging signal to other modules 108 to balance the operating characteristics of one or more of the modules 108. In this example, the duty cycle can be the same for all modules 108 during the preheat and pulse charging phases. In other embodiments, the MCD 112 can adjust both the duty cycle and / or phase shift during the preheat and / or pulse charging phases while balancing during the constant current charging phase.

[0272] The constant voltage charging phase may be terminated upon the occurrence of a time threshold, a temperature threshold, a SOC threshold, a voltage threshold, and / or any combination thereof, as may the preheating phase and the pulse charging phase. Although method 2500 includes all three phases, other embodiments may include only one of the phases, or any combination of the three phases. For example, one embodiment may include a preheating phase and a pulse charging phase, but no constant current phase. Similarly, one embodiment may include a pulse charging phase and a constant current phase, but no preheating phase.

[0273] In some embodiments, the MCD 112 can dynamically adjust the voltage output from the charging source 150. For example, the control system 102 can utilize circuitry such as a compensation loop to improve the accuracy and stability of pulse charging based on a constant voltage.

[0274] In some embodiments, the MCD 112 can regulate the current to the module 108 using a closed loop current controller, such as a PI, PID, or other suitable controller. In this example, the MCD 112 regulates the current to the module 108 using a closed loop current controller, such as a PI, PID, or other suitable controller. pack may remain constant during the charging cycle or may vary according to a target current setpoint. pack and a current measurement of the control module 108 can be obtained.

[0275] 26 is a flow chart illustrating an example embodiment of a method 2600 of a pulse charging energy source for multiple connected modules 108. Method 2600 may be performed by any embodiment of system 100 described herein unless otherwise stated or logically reasonable. Method 2600 may be performed during a preheat phase or a pulse charging phase of a charging cycle. Some steps of method 2600 may also be performed during a constant voltage and / or constant current charging phase, such as steps 2610 and 2620 associated with controlling the set point of charging source 150.

[0276] In step 2610, MCD 112 selects a target set point for charging source 150. As described herein, the set point can be a voltage set point for operating the charging source in a voltage control mode or a current set point for operating the charging source in a current control mode.

[0277] In the current control mode, the initial current set point may be a specified value based on, for example, the stage of the charging cycle (e.g., preheat, pulse charge, or constant current). For example, different current set points may be used for each stage. The MCD 112 may also adjust the current set point between stages based on one or more operating characteristics of the module 108 (e.g., SOC, SOH, temperature, capacity, voltage, current, impedance, and / or aging). For example, if the temperature of the module 108 or the aggregate (e.g., sum, mean, median, or other measure of central tendency) temperature of the module 108 meets or exceeds a temperature threshold, the MCD 112 may reduce the current set point to reduce the amplitude of the pulse applied to the battery 206 of the module 108. In another example, if the aggregate SOC of the module 108 reaches a threshold, the MCD 112 may adjust the current set point. In a particular example, the MCD 112 may pulse charge the battery 206 of the module 108 using a higher current level until the aggregate SOC meets or exceeds a threshold. At that point, the MCD 112 can reduce the current setpoint for the subsequent pulse charge.

[0278] In the voltage control mode, the MCD 112 may determine a voltage set point based on the number of modules 108 being charged, a target duty cycle of pulses applied to the battery 206 of the module 108 being charged, and / or the voltage of the battery 206 being charged (e.g., the voltage across the battery 206). For example, the MCD 112 may determine the voltage set point using equation (3) above. As the voltage of the battery increases during charging, the MCD 112 may increase the voltage set point to provide charging current to the battery 206, for example, according to equation (3).

[0279] In step 2620, the MCD 112 sends the target setpoint to the control device 155 of the charging source 150 via the communication path or link 2105. The MCD 112 can send an instruction to operate in a current control mode or a voltage control mode along with the corresponding target setpoint.

[0280] In step 2630, the MCD 112 obtains operational characteristics for the modules 108. The operational characteristics may include, for example, SOC, SOH, temperature, capacity, voltage, current, impedance, and / or aging of each module 108. In some embodiments, the LCD 114 may monitor operational characteristics for one or more modules 108 and provide data indicative of the operational characteristics to the MCD 112 via the communication path or link 115. The MCD 112 and / or LCD 114 may also be configured to obtain battery 206-specific operational characteristics from a BMS for the battery 206.

[0281] In step 2640, the MCD 112 determines a duty cycle and / or phase for a pulse signal (e.g., a pulsed charging signal or a preheat signal) for each module 108 being charged. In both voltage and current control modes, the MCD 112 can operate the modules 108 based on a target duty cycle for all modules 108. In some cases, the MCD 112 can operate all modules 108 being charged using a target duty cycle, for example, by providing the target duty cycle to the LCD 114 for each module 108.

[0282] The target duty cycle can be a non-variable or pre-programmed duty cycle. In some embodiments, the MCD 112 can determine the target duty cycle based on the number of modules 108 being charged and / or based on the number of clusters into which the modules 108 being charged are grouped, as described above.

[0283] The MCD 112 may also adjust the duty cycle and / or phase of the pulse signal for an individual module 108 based on, for example, one or more of the operating characteristics for the module 108. For example, if the temperature of a module 108 is high (e.g., greater than a temperature threshold or greater than the average value of the charged modules 108), the MCD 112 may adjust (e.g., reduce) the duty cycle of that module 108 to reduce the amount of energy applied to the module 108.

[0284] The MCD 112 can be configured to adjust the duty cycle of the pulsed signal for the modules 108 to balance one or more operating characteristics of the modules 108. For example, if one module 108 has a higher SOC than the other modules 108, the MCD 112 can adjust (e.g., decrease) the duty cycle of the pulsed signal for the one module 108 and / or adjust (e.g., increase) the duty cycle of the pulsed signal for one or more other modules 108 (e.g., the one or more modules 108 with the lowest SOC).

[0285] In some embodiments, the MCD 112 can be configured to make a corresponding adjustment to the duty cycle of the pulse signal for one or more other modules 108 whenever an adjustment is made to the duty cycle of a module 108. For example, the MCD 112 can adjust the duty cycle for a module 108 such that the aggregate (e.g., average or other measure of central tendency) duty cycle of the modules 108 being charged equals the target duty cycle (e.g., within a defined tolerance). In a particular example, if the target duty cycle is 50% and the MCD 112 adjusts the duty cycle for one module 108 from 50% to 49%, the MCD 112 can adjust the duty cycle of one other module 108 from 50% to 51% to maintain an aggregate duty cycle that matches the target duty cycle. In another example, if the target duty cycle is 50% and the MCD 112 adjusts the duty cycle for one module 108 from 50% to 48%, the MCD 112 may adjust the duty cycle for two modules 108 from 50% to 51% to maintain an aggregate duty cycle that matches the target duty cycle. In some embodiments, the MCD 112 is configured to adjust the duty cycle for one or more modules 108 without making corresponding adjustments of the other modules 108.

[0286] Each time the MCD 112 adjusts the duty cycle of the pulsed signals for one or more modules 108, the MCD 112 may also adjust the phase of the modules 108. For example, the MCD 112 may increase or decrease the phase shift between the pulsed signals such that, given the adjusted duty cycle, the pulsed signals are still applied to the same number of modules 108 at any given time during the preheat or charging phase.

[0287] In step 2650, the modules 108 are controlled according to their duty cycles and phases. The MCD 112 can provide control signals to the LCD 114 to instruct the LCD 114 for each module 108 to control its converter 202 based on the duty cycle and phase of the control signal. The control signal for a module 108 can include the duty cycle and phase for that module 108. The LCD 114 can then use the duty cycle and phase to control the switches of the converter 202 of the module 108, as described elsewhere herein.

[0288] Throughout the charging cycle, or phase of the charging cycle, the MCD 112 may perform steps 2610-2640 to update the target setpoint, duty cycle, and phase of the module 108 to provide a pulsed charging signal to the battery of the module 108 such that the desired charging is performed while ensuring that the voltage and current provided by the charging source 150 is regulated. Additionally, these steps may be performed to balance the operating characteristics of the module 108 during the charging cycle or phase. Although steps 2630 and 2640 are shown as being performed in parallel with steps 2610 and 2620, in other embodiments, these steps may be performed sequentially. Steps 2630 and 2640 may be performed iteratively independent of steps 2610 and 2620.

[0289] For pulse charging using both constant voltage and constant current approaches, the control system 102 can generate multi-level waveforms by shifting the phase angle of the carrier in a manner similar to that described with reference to Figures 8C-8F. In particular, for a system 100 having N battery modules 108, the LCD 114 can control the carrier phase angle to generate up to 2N+1 levels.

[0290] In some embodiments, the LCDs 114 of the modules 108 can continually communicate with the MCD 112 to negotiate the desired amplitude of the pulsed charging current or voltage. For example, an LCD 114 controlling a module 108 with a slower charging rate or higher temperature can communicate with the other LCDs 114 to reduce the amplitude of the pulsed charging current. When all battery modules 108 in the system 100 are connected in series, the amplitude is the same for all battery modules 108.

[0291] As mentioned above, in some embodiments, the duty cycle of the charging signal may vary slightly between modules 108. The deviation may allow factors such as operating characteristics such as SOC, SOH, and temperature to be taken into account, which may vary for each individual module 108. For example, a module 108 experiencing a higher battery temperature than the remaining modules 108 may be allowed to pulse charge at a lower duty cycle resulting in a lower average current than the other modules 108 to prevent overheating. The MCD 112 may actively monitor and manage the duty cycle of the modules 108 based on the operating characteristics of the modules 108 and / or other factors. For example, when the MCD 112 makes a decision to reduce the duty cycle of a module 108 to prevent overheating, the MCD 112 may increase the duty cycle of another module 108 to compensate for the deviation, so that the overall charging rate remains constant.

[0292] In all of the embodiments described herein, the primary energy source of each module of a particular system can have the same voltage (either standard operating voltage or nominal voltage). Such a configuration simplifies the management and construction of the system. The primary and secondary energy sources can also have the same voltage (standard or nominal). Other configurations can be implemented, such as primary energy sources of different modules of the same system having different voltages (standard or nominal) and primary and secondary energy sources of a module having different voltages (standard or nominal). Configurations can also be implemented in which the primary energy sources of modules of the system have primary energy source batteries of different chemistries, or still other configurations can be implemented in which modules of the system have primary energy source batteries of a first chemistry and secondary energy source batteries of a second chemistry. The different modules can be based on their placement in the system (e.g., modules in a phase array are different from IC (interconnect) modules).

[0293] Various aspects of the present subject matter are described below with elaboration and / or supplementation of the previously described embodiments, where emphasis is placed on the interrelationships and compatibility of the following embodiments, in other words, emphasis is placed on the fact that each feature of the embodiments can be combined with each and every other feature, unless otherwise specified or taught otherwise.

[0294] In many embodiments, the energy system includes a plurality of modules connected together, each module including an energy source and a switch circuit, and the energy storage system is configured to generate AC power with a superposition of output signals generated by the plurality of modules. The energy system includes a control system configured to generate a charge signal including a plurality of charge pulses from a supply charge signal received from a charge source, and to control the switch circuit of each module to apply the charge signal to the energy source such that the plurality of charge pulses applied to the energy source of each module are shifted in time relative to the plurality of charge pulses applied to the energy sources of one or more other modules of the energy storage system.

[0295] In many embodiments, an energy storage system includes a plurality of modules connected together, each module comprising an energy source and a switch circuit, and a control system configured to generate a charge signal from a supply charge signal received from a charge source, the charge signal comprising a plurality of charge pulses, and to control each module to apply the charge signal to the energy source such that the plurality of charge pulses applied to the energy source of each module are shifted in time relative to the plurality of charge pulses applied to the energy sources of one or more other modules of the energy storage system.

[0296] In some embodiments, the supply charging signal is a constant current charging signal.

[0297] In some embodiments, the supply charging signal is a constant voltage charging signal.

[0298] In some embodiments, the control system is configured to control the switch circuitry of each module to distribute the supply charging signal among the multiple modules.

[0299] In some embodiments, the charge pulses applied to the energy source of each module are shifted in time relative to the charge pulses applied to the energy sources of every other module in the energy storage system.

[0300] The charge pulses applied to the energy source of each module are shifted in time relative to the charge pulses applied to the energy sources of one or more other modules in the energy storage system such that at any given time during charging, charge pulses are applied to the energy sources of half of the modules.

[0301] In some embodiments, the control system is configured to control the switch circuitry of each module such that the duty cycle of the multiple charge pulses is based on the number of modules in the multiple modules or the number of modules being charged.

[0302] In some embodiments, the duty cycle of the plurality of charge pulses is equal to (100 / N)%, where N is equal to the number of modules in the plurality of modules.

[0303] In some embodiments, at any given time during charging, the voltage across all modules in the plurality of modules is equal to the voltage level of each energy source.

[0304] In some embodiments, the average current delivered to each energy source is equal to the current level of the supply charging signal.

[0305] In some embodiments, the control system is configured to control the switch circuitry of each module such that the duty cycle of the multiple charge pulses is 50%.

[0306] In some embodiments, at any given time during charging, the voltage across all modules in the plurality of modules is based on the number of modules in the plurality of modules.

[0307] In some embodiments, the voltage across all modules in the plurality of modules is equal to N / 2 times the voltage of the supply charging signal, where N is equal to the number of modules in the plurality of modules or the number of modules being charged.

[0308] In some embodiments, the average current delivered to each energy source is equal to half the current level of the supply charging signal.

[0309] In some embodiments, the plurality of modules includes a plurality of groups of modules, and the control system is configured to control the switch circuitry of each module to apply a charge signal including a plurality of charge pulses to an energy source such that the plurality of charge pulses applied to the energy source of each module in each group of modules are shifted in time relative to the plurality of charge pulses applied to the energy source of each module in each other group of modules.

[0310] In some embodiments, the plurality of modules are arranged in two or more arrays of cascade modules, with each group of modules being part of one of the two or more arrays.

[0311] In some embodiments, each array is configured to output a single-phase AC signal in a superposition of output signals generated by the cascaded modules in the array when the energy storage system is providing energy to the load.

[0312] In some embodiments, the control system is configured to control the switch circuitry of each module in each group of modules such that a duty cycle of the multiple charge pulses is based on the number of groups in the multiple groups of modules.

[0313] In some embodiments, the duty cycle of the multiple charge pulses is equal to (100 / N)%, where N is equal to the number of groups in the multiple groups of modules.

[0314] In some embodiments, each module of the plurality of modules is assigned to a respective cluster, and the control system is configured to control the switch circuitry of each module to apply a charge signal comprising a plurality of charge pulses to the energy source such that the plurality of charge pulses applied to the energy source of each module in each cluster of modules are shifted in time relative to the plurality of charge pulses applied to the energy source of each module in each other cluster of modules.

[0315] In some embodiments, modules of the plurality of modules are assigned to particular clusters based on their respective physical locations within the energy storage system or within one or more packs of the energy storage system.

[0316] In some embodiments, the modules of the plurality of modules are arranged in two or more arrays of modules, and each of the modules of a cluster is all of the modules in a corresponding array of modules.

[0317] In some embodiments, the modules of the plurality of modules are arranged in two or more arrays of modules, with at least one module from each array being in each cluster.

[0318] In some embodiments, the array of modules is an array of cascade modules.

[0319] In some embodiments, modules are assigned to clusters according to a pre-defined cluster assignment.

[0320] In some embodiments, modules are assigned to clusters in real time.

[0321] In some embodiments, the control system is programmed to determine the allocation of modules to clusters.

[0322] In some embodiments, the control system is programmed to select modules for a particular cluster based on the similarity of the modules' operational characteristics, such that a cluster is composed of modules that have one or more similar operational characteristics.

[0323] In some embodiments, the similar operating characteristics include similar module temperatures or similar state of charge values.

[0324] In some embodiments, the control system is programmed to select for the first cluster modules having state of charge values ​​that are at or above the central tendency of the state of charge values, and to select for the second cluster modules having state of charge values ​​that are at or below the central tendency of the state of charge values.

[0325] In some embodiments, the duty cycle for charging the first and second clusters is adjusted to apply more energy to the second cluster of the module than to the first cluster of the module, such that both clusters have relatively more balanced state of charge values ​​at the end of charging.

[0326] In some embodiments, the control system is programmed to select for the first cluster modules having temperature values ​​that are at or above the central tendency of the temperature values, and to select for the second cluster modules having temperature values ​​that are at or below the central tendency of the temperature values.

[0327] In some embodiments, the duty cycle for charging the first and second clusters is adjusted to apply more energy to the second cluster of modules than to the first cluster of modules, such that both clusters have relatively more balanced temperature values ​​at the end of charging.

[0328] In some embodiments, the control system is configured to determine a duty cycle for the multiple charge pulses for each module.

[0329] In some embodiments, the control system is configured to determine a duty cycle for the multiple charge pulses for each module based on one or more operating characteristics of the module.

[0330] In some embodiments, the one or more operating characteristics include at least one of temperature, state of charge, impedance, or aging.

[0331] In some embodiments, the control system is configured to determine a charge rate for each module based on one or more operational characteristics of the module.

[0332] In some embodiments, the control system is configured to determine a duty cycle for the multiple charge pulses for each module based on a charge rate for each module.

[0333] In some embodiments, the control system is configured to adjust a duty cycle for the multiple charge pulses for each module in response to one or more modules being placed in a bypass state.

[0334] In some embodiments, the control system is configured to adjust a duty cycle for the multiple charge pulses for each module in response to detecting a specified condition for one or more modules.

[0335] In some embodiments, the specified conditions include high temperature conditions for one or more modules.

[0336] In some embodiments, the control system is configured to adjust a duty cycle for the multiple charge pulses for each module to balance one or more operating characteristics of the multiple modules.

[0337] In some embodiments, the control system is configured to detect state of charge conditions for the plurality of modules and coordinate control of the switch circuitry of each module to charge the energy source of each module using a constant current charging signal provided by the charging source.

[0338] In some embodiments, the state of charge condition includes an aggregate state of charge of multiple modules that meets a threshold state of charge.

[0339] In some embodiments, the control system is configured to send a control signal to a control device of the charging source to instruct the charging source to output a constant current charging signal.

[0340] In some embodiments, the control system is configured to control the switch circuit to selectively pass the constant current charging signal to the plurality of modules to balance one or more operating characteristics of the plurality of modules.

[0341] In some embodiments, the one or more operating characteristics include one or more of a state of charge or a temperature.

[0342] In some embodiments, the control system includes a master control device configured to communicate with the control device of the charging source and with local control devices, each of the local control devices coupled to control one or more switch circuits of each of the plurality of modules.

[0343] In some embodiments, the master control device is configured to send a control signal to a control device of the charging source, the control signal including a charging mode and a set point.

[0344] In some embodiments, the charging mode includes a constant current mode or a constant voltage mode.

[0345] In some embodiments, the set point comprises one of a current set point for the supply charging signal or a voltage set point for the supply charging signal.

[0346] In some embodiments, the master control device is configured to send a modulation index or modulation reference signal to the local control devices to control the switch circuits of the modules.

[0347] In some embodiments, the local control device is configured to generate switch signals for the switch circuits of one or more modules based on the received modulation index or modulation reference signal.

[0348] In some embodiments, the control system is configured to pre-heat each energy source.

[0349] In some embodiments, the control system is configured to pass a thermal management fluid proximate to the module to pre-heat the module.

[0350] In some embodiments, the control system is configured to instruct the control device of the charging source to pre-heat each energy source.

[0351] In some embodiments, the control system is configured to initiate a pre-heat cycle for the energy source in response to a control signal from a vehicle control unit of an electric vehicle driven by the multiple modules.

[0352] In some embodiments, the vehicle control unit is configured to transmit control signals in response to user commands.

[0353] In some embodiments, the plurality of charge pulses comprises a sequence of charge pulses having a frequency.

[0354] In some embodiments, the frequency is selected based on one or more characteristics of the energy source.

[0355] In some embodiments, each module includes a full bridge converter that includes a switch circuit.

[0356] In some embodiments, the control system is configured to control the switch circuitry of each module to control the full bridge converter of each module to generate the charging signal according to a duty cycle.

[0357] In many embodiments, an energy storage system includes a plurality of modules, each module including an energy source, and means for applying a respective charging signal including a sequence of charging pulses to charge each energy source of each module, such that charging pulses applied to the energy source of each module are shifted in time relative to charging pulses applied to the energy sources of one or more other modules of the energy storage system.

[0358] In some embodiments, each charging signal has a common constant current.

[0359] In some embodiments, each charging signal has a common constant voltage.

[0360] In some embodiments, the charge pulse applied to the energy source of each module is shifted in time relative to the charge pulses applied to the energy sources of every other module in the energy storage system.

[0361] In some embodiments, the charge pulse applied to the energy source of each module is shifted in time relative to the charge pulses applied to the energy sources of one or more other modules in the energy storage system, such that at any given time during charging, a charge pulse is applied to the energy sources of half of the modules.

[0362] In some embodiments, the duty cycle of the charge pulse is based on the number of modules in the plurality of modules.

[0363] In some embodiments, the duty cycle of the charging pulse is equal to (100 / N)%, where N is equal to the number of modules in the plurality of modules or the number of modules being charged.

[0364] In some embodiments, at any given time during charging, the voltage across all modules in the plurality of modules is equal to the voltage level of each energy source.

[0365] In some embodiments, the average current delivered to each energy source is equal to the current level of the supply charging signal provided to all of the modules.

[0366] In some embodiments, the duty cycle of the charge pulse is 50%.

[0367] In some embodiments, at any given time during charging, the voltage across all modules in the plurality of modules is based on the number of modules in the plurality of modules or the number of modules being charged.

[0368] In some embodiments, the voltage across all of the modules in the plurality of modules is equal to N / 2 times the supply charging signal voltage of the supply charging signal provided to all of the modules, where N is equal to the number of modules in the plurality of modules or the number of modules being charged.

[0369] In some embodiments, the average current delivered to each energy source is equal to half the current level of the supply charging signal provided to all of the modules.

[0370] In some embodiments, the plurality of modules includes a plurality of groups of modules, and a charge pulse applied to an energy source of each module in each group of modules is shifted in time relative to a charge pulse applied to an energy source of each module in each other group of modules.

[0371] In some embodiments, the plurality of modules are arranged in two or more arrays of cascade modules, with each group of modules being part of one of the two or more arrays.

[0372] In some embodiments, each array is configured to output a single-phase AC signal in a superposition of output signals generated by the cascaded modules in the array when the energy storage system is providing energy to the load.

[0373] In some embodiments, the duty cycle of the charge pulse is based on the number of groups within the multiple groups of modules.

[0374] In some embodiments, the duty cycle of the multiple charge pulses is equal to (100 / N)%, where N is equal to the number of groups in the multiple groups of modules.

[0375] In some embodiments, the duty cycle for the charge pulse for each module is based on one or more operating characteristics of the module.

[0376] In some embodiments, the one or more operating characteristics include at least one of temperature, state of charge, impedance, or aging.

[0377] In some embodiments, the charge rate for each module is based on one or more operational characteristics of the module.

[0378] In some embodiments, the duty cycle for the multiple charge pulses for each module is based on the charge rate for each module.

[0379] In some embodiments, the duty cycle for the charge pulse for each module is adjusted in response to one or more modules being placed in a bypass state.

[0380] In some embodiments, the duty cycle for the charge pulse for each module is adjusted in response to detecting a specified condition for one or more modules.

[0381] In some embodiments, the specified conditions include high temperature conditions for one or more modules.

[0382] In some embodiments, the duty cycle for the charge pulse for each module is adjusted to balance one or more operating characteristics of the multiple modules.

[0383] In some embodiments, each module is charged using a constant current charging signal when a state of charge condition for the module is detected.

[0384] In some embodiments, the state of charge condition includes an aggregate state of charge of multiple modules that meets a threshold state of charge.

[0385] In some embodiments, the constant current charging signal is selectively passed to multiple modules to balance one or more operating characteristics of the multiple modules.

[0386] In some embodiments, the one or more operating characteristics include one or more of a state of charge or a temperature.

[0387] In many embodiments, a method of charging a plurality of modules from a supply charging signal, the plurality of modules being connected together, each module including an energy source, the method including: generating, for each module, a respective pulsed charging signal from the supply charging signal, the respective pulsed charging signal including a plurality of charging pulses; and applying the respective pulsed charging signal to the energy source of the respective module such that the plurality of charging pulses applied to the energy source of each module are shifted in time relative to the plurality of charging pulses applied to the energy source of one or more other modules of the plurality of modules.

[0388] In some embodiments, the supply charging signal is a constant current charging signal.

[0389] In some embodiments, the supply charging signal is a constant voltage charging signal.

[0390] In some embodiments, multiple modules are electrically connected together.

[0391] In some embodiments, each module has a respective switch circuit and the method can include controlling the switch circuit of each module to distribute the supply charging signal in the form of a pulsed charging signal to the multiple modules.

[0392] In some embodiments, the charge pulses applied to the energy source of each module are shifted in time relative to the charge pulses applied to the energy sources of every other module in the plurality of modules.

[0393] The charge pulses applied to the energy source of each module are shifted in time relative to the charge pulses applied to the energy sources of one or more other modules in the energy storage system such that at any given time during charging, charge pulses are applied to the energy sources of half of the modules.

[0394] In some embodiments, the method includes setting a duty cycle of the plurality of charging pulses based on a number of modules in the plurality of modules or a number of modules being charged.

[0395] In some embodiments, the duty cycle of the plurality of charge pulses is equal to (100 / N)%, where N is equal to the number of modules in the plurality of modules.

[0396] In some embodiments, at any given time during charging, the voltage across all modules in the plurality of modules is equal to the voltage level of each energy source.

[0397] In some embodiments, the method includes delivering an average current to each energy source equal to a current level of the supply charging signal.

[0398] In some embodiments, the method includes setting a duty cycle of the multiple charge pulses to 50%.

[0399] In some embodiments, the method includes setting a voltage across all modules in the plurality of modules based on a number of modules in the plurality of modules.

[0400] In some embodiments, the method includes setting a voltage across all modules in the plurality of modules equal to N / 2 times the voltage of the supply charging signal, where N is equal to the number of modules in the plurality of modules or the number of modules being charged.

[0401] In some embodiments, the average current delivered to each energy source is equal to half the current level of the supply charging signal.

[0402] In some embodiments, each module has a respective switch circuit, and the plurality of modules includes a plurality of groups of modules, and the method can include controlling the switch circuit of each module to apply a pulsed charge signal such that a plurality of charge pulses applied to an energy source of each module in each group of modules are shifted in time relative to a plurality of charge pulses applied to an energy source of each module in each other group of modules.

[0403] In some embodiments, the method includes controlling a switch circuit of each module such that a duty cycle of the multiple charge pulses is based on a number of groups within the multiple groups of modules.

[0404] In some embodiments, the duty cycle of the multiple charge pulses is equal to (100 / N)%, where N is equal to the number of groups in the multiple groups of modules.

[0405] In some embodiments, each module of the plurality of modules is assigned to a respective cluster, and the method can include controlling a switch circuit of each module to apply a pulsed charge signal including a plurality of charge pulses to an energy source such that a plurality of charge pulses applied to an energy source of each module in each cluster of modules are shifted in time relative to a plurality of charge pulses applied to an energy source of each module in each other cluster of modules.

[0406] In some embodiments, the method includes assigning modules of the plurality of modules to particular clusters based on their respective physical locations within the energy storage system or within one or more packs of the energy storage system.

[0407] In some embodiments, the modules of the plurality of modules are arranged in two or more arrays of modules, and assigning the modules includes assigning each of the modules of the cluster to be all of the modules in the corresponding array of modules.

[0408] In some embodiments, the modules of the plurality of modules are arranged in two or more arrays of modules, and allocating the modules includes allocating at least one module from each array to be in each cluster.

[0409] In some embodiments, the array of modules is an array of cascade modules.

[0410] In some embodiments, the method includes assigning the modules to clusters according to a predetermined cluster assignment.

[0411] In some embodiments, the method includes assigning modules to clusters in real time.

[0412] In some embodiments, the method includes assigning particular clusters to modules based on similarities in the modules' operational characteristics, such that a cluster is composed of modules that have one or more similar operational characteristics.

[0413] In some embodiments, the similar operating characteristics include similar module temperatures or similar state of charge values.

[0414] In some embodiments, the method includes selecting for the first cluster modules having state of charge values ​​that are at or above the central tendency of the state of charge values, and selecting for the second cluster modules having state of charge values ​​that are at or below the central tendency of the state of charge values.

[0415] In some embodiments, the method includes adjusting a duty cycle for charging the first cluster and the second cluster to apply more energy to the second cluster of the module than to the first cluster of the module, whereby both clusters have relatively more balanced state of charge values ​​at the end of charging.

[0416] In some embodiments, the method includes selecting for the first cluster modules having temperature values ​​that are at or above the central tendency of the temperature values, and selecting for the second cluster modules having temperature values ​​that are at or below the central tendency of the temperature values.

[0417] In some embodiments, the method includes adjusting a duty cycle for charging the first cluster and the second cluster to apply more energy to the second cluster of the module than the first cluster of the module, whereby both clusters have relatively more balanced temperature values ​​at the end of charging.

[0418] In some embodiments, the method includes determining a duty cycle for a number of charge pulses for each module.

[0419] In some embodiments, the method includes determining a duty cycle for the multiple charge pulses for each module based on one or more operational characteristics of the module.

[0420] In some embodiments, the one or more operating characteristics include at least one of temperature, state of charge, impedance, or aging.

[0421] In some embodiments, the method includes determining a charge rate for each module based on one or more operational characteristics of the module.

[0422] In some embodiments, the method includes determining a duty cycle for the multiple charge pulses for each module based on a charge rate for each module.

[0423] In some embodiments, the method includes adjusting a duty cycle for a plurality of charge pulses for each module in response to one or more modules being placed in a bypass state.

[0424] In some embodiments, the method includes adjusting a duty cycle for a plurality of charge pulses for each module in response to detecting a specified condition for one or more modules.

[0425] In some embodiments, the specified conditions include high temperature conditions for one or more modules.

[0426] In some embodiments, adjusting the duty cycle for the multiple charge pulses for each module to balance one or more operating characteristics of the multiple modules.

[0427] In some embodiments, a method includes detecting a state of charge condition for a plurality of modules and coordinating control of a switch circuit of each module to charge an energy source of each module using a constant current charging signal provided by a charging source.

[0428] In some embodiments, the state of charge condition includes an aggregate state of charge of multiple modules that meets a threshold state of charge.

[0429] In some embodiments, the method includes sending a control signal to a control device of the charging source to instruct the charging source to output a constant current charging signal.

[0430] In some embodiments, the method includes selectively passing a constant current charging signal to a plurality of modules to balance one or more operating characteristics of the plurality of modules.

[0431] In some embodiments, the one or more operating characteristics include one or more of a state of charge or a temperature.

[0432] In some embodiments, the method includes sending a control signal to a control device of the charging source, the control signal including a charging mode and a set point.

[0433] In some embodiments, the charging mode includes a constant current mode or a constant voltage mode.

[0434] In some embodiments, the set point comprises one of a current set point for the supply charging signal or a voltage set point for the supply charging signal.

[0435] In some embodiments, the method includes pre-heating each energy source.

[0436] In some embodiments, the method includes passing a thermal management fluid proximate to the module to pre-heat the module.

[0437] In some embodiments, the method includes initiating a pre-heat cycle for an energy source of the plurality of modules in response to a control signal from a vehicle control unit of an electric vehicle powered by the plurality of modules.

[0438] In some embodiments, the plurality of charge pulses comprises a sequence of charge pulses having a frequency.

[0439] In some embodiments, the method includes selecting the frequency based on one or more characteristics of the energy source.

[0440] In many embodiments, a method for charging a plurality of modules, each module including an energy source, includes applying a respective charging signal including a sequence of charging pulses to charge each energy source of each module, such that the charging pulses applied to the energy source of each module are shifted in time relative to the charging pulses applied to the energy sources of one or more other modules of the energy storage system.

[0441] In some embodiments, each charging signal has a common constant current.

[0442] In some embodiments, each charging signal has a common constant voltage.

[0443] In some embodiments, the method includes shifting in time the charge pulse applied to the energy source of each module relative to the charge pulses applied to the energy sources of all other modules in the energy storage system.

[0444] In some embodiments, the method includes shifting a charge pulse applied to the energy source of each module in time relative to a charge pulse applied to an energy source of one or more other modules of the energy storage system such that at any given time during charging, a charge pulse is applied to the energy sources of half of the multiple modules.

[0445] In some embodiments, the method includes setting a duty cycle of the charge pulse over a number of modules in the plurality of modules.

[0446] In some embodiments, the duty cycle of the charging pulse is equal to (100 / N)%, where N is equal to the number of modules in the plurality of modules or the number of modules being charged.

[0447] In some embodiments, the method includes delivering an average current to each energy source equal to a current level of a supply charging signal provided to all of the modules.

[0448] In some embodiments, the method includes setting a duty cycle of the charge pulse to 50%.

[0449] In some embodiments, the method includes setting a voltage across all modules in the plurality of modules based on the number of modules in the plurality of modules or the number of modules being charged at any given time during charging.

[0450] In some embodiments, the voltage across all of the modules in the plurality of modules is equal to N / 2 times the voltage of the supply charging signal provided to all of the modules, where N is equal to the number of modules in the plurality of modules or the number of modules being charged.

[0451] In some embodiments, the method includes delivering an average current to each energy source equal to half the current level of a supply charging signal provided to all of the modules.

[0452] In some embodiments, the plurality of modules includes a plurality of groups of modules, and the method includes applying a charge pulse to an energy source of each module in each group of modules shifted in time relative to a charge pulse applied to an energy source of each module in each other group of modules.

[0453] In some embodiments, the plurality of modules are arranged in two or more arrays of cascade modules, with each group of modules being part of one of the two or more arrays.

[0454] In some embodiments, the method includes setting a duty cycle of the charge pulse based on a number of groups within the plurality of groups of modules.

[0455] In some embodiments, the method includes setting a duty cycle of the plurality of charge pulses equal to (100 / N)%, where N is equal to a number of groups in the plurality of groups of modules.

[0456] In some embodiments, the method includes setting a duty cycle for the charge pulse for each module based on one or more operational characteristics of the module.

[0457] In some embodiments, the one or more operating characteristics include at least one of temperature, state of charge, impedance, or aging.

[0458] In some embodiments, the method includes setting a charge rate for each module based on one or more operational characteristics of the module.

[0459] In some embodiments, the method includes setting a duty cycle for the multiple charge pulses for each module based on a charge rate for each module.

[0460] In some embodiments, the method includes adjusting a duty cycle for a charge pulse for each module in response to one or more modules being placed in a bypass state.

[0461] In some embodiments, the method includes adjusting a duty cycle for a charge pulse for each module in response to detecting a specified condition for one or more modules.

[0462] In some embodiments, the specified conditions include high temperature conditions for one or more modules.

[0463] In some embodiments, the method includes adjusting a duty cycle for a charge pulse for each module to balance one or more operating characteristics of the multiple modules.

[0464] In some embodiments, the method includes detecting a state of charge for the modules, and charging each module using a constant current charging signal when the state of charge for the module is detected.

[0465] In some embodiments, the state of charge condition includes an aggregate state of charge of multiple modules that meets a threshold state of charge.

[0466] In some embodiments, the method includes selectively passing a constant current charging signal to a plurality of modules to balance one or more operating characteristics of the plurality of modules.

[0467] In some embodiments, the one or more operating characteristics include one or more of a state of charge or a temperature.

[0468] 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 can be, but is not required to be, physically removable and replaceable with respect to other modules in the system (e.g., like the wheels of a car, or the blades of an information technology (IT) blade server). For example, a system can 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 can be configured such that each module is removable and replaceable with respect to other modules in any convenient manner without disassembling the system.

[0469] 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.

[0470] The terms "terminal" and "port" are used broadly herein and may be either unidirectional or bidirectional, may be input or output, and do not require a particular physical or mechanical structure such as a female or male configuration.

[0471] The processing circuitry may include one or more processors, microprocessors, controllers, and / or microcontrollers, each of which may be separate or stand-alone 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.

[0472] 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).

[0473] 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.

[0474] The memory can be shared by one or more of the various functional units present, or can be distributed between two or more of them (e.g., as separate memories present in different chips). The memory can also be its own separate chip. The memory can be non-transient and can be volatile (e.g., RAM, etc.) and / or non-volatile memory (e.g., ROM, Flash memory, F-RAM, etc.).

[0475] 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 computer and programming languages, including a non-exhaustive list of examples including Hardware Description Language (HDL), SystemC, C, C++, C#, Objective-C, Matlab®, Simulink, SystemVerilog, SystemVHDL, Handel-C, Python, Java®, JavaScript®, Ruby, HTML, Smalltalk, Transact-SQL, XML, PHP, Golang (Go), the "R" language, and Swift.

[0476] The program instructions may be executed entirely on the user's computing device (e.g., a reader) or partially on the user's computing device. The program instructions may reside partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server, for example, for cases where the identified frequencies are uploaded to a remote location for processing. In the latter scenario, the remote computing device may be connected to the user's computing device through any type of network, or the connection may be made to an external computer.

[0477] 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. If 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.

[0478] To the extent that an embodiment disclosed herein includes or operates in conjunction with a memory, storage, and / or computer readable medium, the memory, storage, and / or computer readable medium is non-transitory. Thus, to the extent that the memory, storage, and / or computer readable medium 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 media 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 any later developed variations thereof.

[0479] 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.

[0480] 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. An energy storage system, wherein the energy storage system is A plurality of modules connected together, each module comprising an energy source and a switch circuit, wherein the energy storage system is configured to generate AC power by superimposing the output signals generated by the plurality of modules, A system comprising: a control system configured to generate a charging signal including a plurality of charging pulses from a supply charging signal received from a charging source, and to control the switch circuit of each module so as to apply the charging signal to the energy source such that the plurality of charging pulses applied to the energy source of each module are temporally shifted relative to the plurality of charging pulses applied to the energy source of one or more other modules of the energy storage system.

2. The system according to claim 1, wherein the control system is configured to control the switch circuit of each module so as to distribute the supply charge signal among the plurality of modules.

3. The system according to claim 1, wherein the plurality of charge pulses applied to the energy source of each module are time-shifted relative to the plurality of charge pulses applied to the energy sources of all other modules of the energy storage system.

4. The system according to claim 1, wherein the plurality of charge pulses applied to the energy source of each module are temporally shifted relative to the plurality of charge pulses applied to the energy source of one or more other modules of the energy storage system, such that at any given point in time during charging, a charge pulse is applied to the energy source of half of the plurality of modules.

5. The system according to claim 1, wherein the control system is configured to control the switch circuit of each module such that the duty cycle of the plurality of charging pulses is based on the number of modules in the plurality of modules or the number of modules being charged.

6. The system according to claim 1, wherein the control system is configured to control the switch circuit of each module such that the duty cycle of the plurality of charging pulses is 50%.

7. The aforementioned multiple modules include multiple groups of modules, The system according to claim 1, wherein the control system is configured to control the switch circuit of each module such that the plurality of charge pulses applied to the energy source of each module in each group of modules are temporally shifted relative to the plurality of charge pulses applied to the energy source of each module in each other group of modules, and the charge signal including the plurality of charge pulses is applied to the energy source.

8. The system according to claim 7, wherein the control system is configured to control the switch circuit of each module within each group of modules such that the duty cycle of the plurality of charging pulses is based on the number of groups within the plurality of groups of modules.

9. Each of the aforementioned modules is assigned to its respective cluster. The system according to claim 1, wherein the control system is configured to control the switch circuit of each module such that the plurality of charge pulses applied to the energy source of each module in each cluster of modules are temporally shifted relative to the plurality of charge pulses applied to the energy source of each module in each other cluster of modules, and the charge signal including the plurality of charge pulses is applied to the energy source.

10. The system according to claim 9, wherein the modules among the plurality of modules are assigned to a specific cluster based on the physical location of each module within the energy storage system or within one or more packs of the energy storage system.

11. The system according to claim 9, wherein the modules among the plurality of modules are arranged in two or more arrays of modules, and each of the modules in the cluster is all of the modules in the corresponding array of modules.

12. The system according to claim 9, wherein the modules among the plurality of modules are arranged in two or more arrays of modules, and at least one module from each array is located in each cluster.

13. The system according to claim 1, wherein the control system is configured to determine the duty cycle for the plurality of charge pulses for each module.

14. The system according to claim 13, wherein the control system is configured to determine a duty cycle for the plurality of charge pulses for each module based on one or more operating characteristics of the modules, the one or more operating characteristics include at least one of temperature, charge state, impedance, or aging.

15. The control system, Based on the one or more operating characteristics of the module, determine the charge rate for each module; based on the charge rate for each module, determine the duty cycle for the plurality of charge pulses for each module; adjust the duty cycle for the plurality of charge pulses for each module in response to one or more modules being placed in a bypass state; adjust the duty cycle for the plurality of charge pulses for each module in order to balance one or more operating characteristics of the plurality of modules; or detect the charge state conditions for the plurality of modules; and The control of the switch circuit of each module is adjusted so that the energy source of each module is charged using a constant current charging signal supplied by the charging source. The system according to claim 1, configured to perform the following:

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