Pulsed charging and heating techniques for energy sources

Abstract

Embodiments are disclosed that provide advanced charging of energy source arrangements for energy storage applications. The embodiments can be used in energy storage systems having a cascaded arrangement of converter modules. The embodiments can include applying pulses to the energy sources of each module of the system. The pulses can be applied for charging and preheating purposes. Feedback-based pulse control embodiments are also disclosed.

Description

Technical Field

[0001] (Cross - reference to related applications) This application claims the benefit and priority of U.S. Provisional Application No. 63 / 084,352, filed on September 28, 2020, and U.S. Provisional Application No. 63 / 119,504, filed on November 30, 2020, both of which are incorporated herein by reference in their entirety for all purposes.

[0002] (Technical Field) The subject matter described herein generally relates to pulsed charging of an energy source in an energy storage system for both mobile and stationary applications.

Background Art

[0003] Electrical energy storage systems are an important 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 vehicles (e.g., through the use of regenerative braking).

[0004] An electrical energy storage system requires periodic charging to replenish the 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 the long charging time for electric vehicles (EVs) is a major factor limiting their widespread adoption. The use of conventional constant-current charging methods can take several hours to fully charge a battery pack. Such long waiting times cause substantial inconvenience and inefficiency when using an EV for trips outside the range of a single charge. Thus, conventional EVs are most typically used for trips that can be completed without requiring local commuting or recharging of the battery pack. To the extent that there are charging stations that can charge at a higher voltage and in a shorter time, repeated use of such stations can result in a dramatically reduced lifespan of the battery pack. For these and other reasons, there is a need for improved systems, devices, and methods for fast or rapid charging of electrical energy storage systems.

Summary of the Invention

Means for Solving the Problems

[0005] Exemplary embodiments of systems, devices, and methods for fast charging of energy sources, either isolated from or as part of an energy storage system (e.g., battery packs for electric vehicles, stationary systems for driving microgrids, and others), are described herein. Embodiments described herein may include heating the energy source by applying a preheating signal that increases the source temperature and reduces the overall impedance of the energy source, so that accelerated electrochemical reactions are enabled through subsequent charging. Embodiments may include charging the energy source with charging pulses at a frequency that passes through the dual-sheet capacitance of the energy source, reduces the activation impedance of the source, and enables charging of the source at a higher C rate without degradation reactions. Embodiments may also include combinations of a pulsed preheating or pulsed charging stage with a constant-current (or non-pulsed) charging stage at a higher temperature, and some embodiments may include at least one example of all three stages. The embodiments described herein are particularly suitable for application in a cascaded modular energy storage system in which each module includes an energy source and a switch network capable of applying current in a pulsed manner for preheating and / or charging. Embodiments for monitoring the energy source to detect potentially degradable conditions such as non-uniform lithiation and lithium plating are also disclosed.

[0006] Other systems, devices, methods, features, and advantages of the subject matter described herein will be apparent, or will become apparent, to those skilled in the art upon consideration of the following figures and detailed description. All such additional systems, methods, features, and advantages are included in this description, within the scope of the subject matter described herein, and are intended to be protected by the accompanying claims. Features of exemplary embodiments should not be construed as limiting the accompanying claims in any way unless those features are explicitly described in the claims. This specification also provides, for example, the following: (Item 1) A method for charging an energy source, wherein the method is The method involves applying a preheating signal to a lithium-ion battery module comprising multiple cells, the preheating signal comprising a sequence of alternating charge and discharge energy pulses of equal duration, thereby inducing localized heating to increase the temperature of the lithium-ion module, wherein the frequency of the preheating signal is greater than 1 kilohertz, and the application of the preheating signal occurs in such a way as to avoid electrochemical charge transfer of the main storage reaction and side reactions of the lithium-ion battery module. Next, a charging signal is applied to the lithium-ion battery so that the charge of the lithium-ion battery increases. Includes, A method wherein a preheating signal is applied until the lithium-ion battery reaches a first temperature, and a charging signal is applied after the lithium-ion battery has reached the first temperature. (Item 2) The method according to item 1, wherein the electrochemical charge transfer is avoided by the interfacial capacitance of the electrodes of the lithium-ion battery module with respect to the electrolyte of the energy source. (Item 3) The method according to item 1, wherein the charging signal comprises a plurality of charging pulses having a pulse duration of 10 milliseconds or less. (Item 4) The lithium-ion battery module has an open-circuit voltage and an upper cutoff voltage, and the plurality of charging pulses are in a voltage between the open-circuit voltage and the upper cutoff voltage, according to item 3. (Item 5) The charging signal is a first charging signal comprising a plurality of pulses, and the method is The method further includes applying a second charging signal to the lithium-ion battery module after applying the first charging signal, The method described in item 1, wherein the second charging signal is a constant current charging signal. (Item 6) The method according to item 5, wherein the preheating signal is applied until the lithium-ion battery module reaches a first temperature, the first charging signal is applied until the lithium-ion battery module reaches a second temperature, and the second charging signal is applied after the lithium-ion battery module has reached the second temperature. (Item 7) The method according to item 6, wherein the first temperature is 25 degrees Celsius or higher, and the second temperature is 45 degrees Celsius or higher. (Item 8) The method according to item 5, wherein the first charging signal is applied until the lithium-ion battery module reaches a first charging state, and the second charging signal is applied after the lithium-ion battery module has reached the first charging state. (Item 9) The method according to item 8, wherein the second charging signal is applied until the lithium-ion battery module reaches a charge state of 95% or more. (Item 10) The method according to item 5, wherein when the activation impedance of the electrodes of the lithium-ion battery module is 50% or less of the total impedance of the electrodes, the application of the first charging signal is stopped and the application of the second charging signal is started. (Item 11) The method according to item 1, further comprising monitoring the lithium-ion battery module with respect to lithium plating. (Item 12) The method according to item 1, further comprising monitoring the impedance of the lithium-ion battery module with respect to degradation indicators. (Item 13) The method according to item 12, further comprising adjusting the application of the charging signal in response to the monitored impedance. (Item 14) The method of item 13, wherein monitoring the impedance of the lithium-ion battery module is performed intermittently during the charging phase of the lithium-ion battery module when the charging signal is applied. (Item 15) The method according to item 1, wherein the charging signal comprises a plurality of charging pulses, and when the Warburg impedance of the electrodes of the lithium-ion battery module is 20% or less of the total impedance of the electrodes, the application of the preheating signal is stopped and the application of the charging signal is started. (Item 16) The method according to item 1, wherein the pulse preheating signal is applied at a voltage greater than the upper cutoff voltage and lower cutoff voltage of the lithium-ion battery module. (Item 17) The method according to item 1, wherein the charging signal comprises a plurality of charging pulses at a peak voltage greater than the cutoff voltage of the lithium-ion battery module. (Item 18) A system configured to charge an energy source, the system comprising a control system, the control system (a) Controlling a switch network to apply a preheating signal to an energy source such that the temperature of the energy source increases until a certain condition is met, wherein the preheating signal comprises a sequence of alternating charge and discharge energy pulses. (b) Controlling the switch network to apply a charging signal to the energy source after the energy source has satisfied the conditions. A system configured to perform the following actions. (Item 19) A method for charging multiple energy sources in an energy storage system, wherein the energy storage system comprises multiple converter modules connected together in a cascaded manner, each of the multiple converter modules comprises an energy source and a switch network, each of the multiple converter modules is independently controllable by a control system to output a module voltage, and the energy storage system is configured to generate AC power with superposition of module output voltages generated by the multiple converter modules, and the method is: The switching network of each module applies a preheating signal to the energy source of each module, comprising a sequence of alternating charge and discharge energy pulses of equal duration, thereby inducing ohmic heating to increase the temperature of the energy source of each module, wherein the frequency of the preheating signal is greater than 1 kilohertz, and the application of the preheating signal occurs in such a way as to avoid electrochemical charge transfer of the main storage reaction and side reactions of the energy source. Next, the switch network of each module applies a charging signal to the energy source of each module. Methods that include... (Item 20) The method according to item 19, wherein the module transitions from applying the preheating signal to applying the charging signal at different times based on when each module reaches a temperature threshold. (Item 21) The method according to item 19, wherein the charging signal comprises a plurality of charging pulses having a pulse duration of 10 milliseconds or less. (Item 22) The method according to item 21, wherein the energy source has an open-circuit voltage and an upper cutoff voltage, and the plurality of charging pulses are in a voltage between the open-circuit voltage and the upper cutoff voltage. (Item 23) The charging signal is a first charging signal comprising a plurality of pulses, and the method is The method further includes applying a second charging signal to the energy source after applying the first charging signal, The method described in item 19, wherein the second charging signal is a constant current charging signal. (Item 24) The method according to item 23, wherein the preheating signal is applied until the energy source reaches a first temperature, the first charging signal is applied until the energy source reaches a second temperature, and the second charging signal is applied after the energy source has reached the second temperature. (Item 25) The method according to item 24, wherein the first temperature is 25 degrees Celsius or higher, and the second temperature is 45 degrees Celsius or higher. (Item 26) The method according to item 24, wherein the first charging signal is applied until the energy source reaches a first charging state, and the second charging signal is applied after the energy source has reached the first charging state. (Item 27) The method according to item 26, wherein the second charging signal is applied until the energy source reaches a charge state of 95% or more. (Item 28) The method according to item 24, wherein when the activation impedance of the electrode of the energy source is 50% or less of the total impedance of the electrode, the application of the first charging signal is stopped and the application of the second charging signal is started. (Item 29) The method according to item 19, further comprising monitoring the energy source with respect to lithium plating. (Item 30) The method of item 19, further comprising monitoring the impedance of the energy source with respect to degradation indications. (Item 31) The method according to item 30, further comprising adjusting the application of the charging signal in response to the monitored impedance. (Item 32) The method according to item 31, wherein monitoring the impedance of the energy source is performed intermittently during the charging phase of the energy source when the charging signal is applied. (Item 33) The method according to item 19, wherein the charging signal comprises a plurality of charging pulses, and when the Warburg impedance of the electrodes of the energy source is 20% or less of the total impedance of the electrodes, the application of the preheating signal is stopped and the application of the charging signal is started. (Item 34) The method according to item 19, wherein the pulse preheating signal is applied at a voltage greater than the upper cutoff voltage and the lower cutoff voltage of the energy source. (Item 35) The method according to item 19, wherein the charging signal comprises a plurality of charging pulses at a peak voltage greater than the cutoff voltage of the energy source. (Item 36) An energy storage system, wherein the energy storage system is The energy storage system comprises multiple modules connected together in a cascaded manner, each of which comprises an energy source and a switching network, and the energy storage system is configured to generate AC power with respect to the superposition of output signals generated by the multiple modules, and with respect to each module, (a) Controlling the switch network to apply a preheating signal to the energy source so that the temperature of the energy source increases until the energy source reaches a first temperature, wherein the preheating signal comprises a sequence of alternating charge and discharge energy pulses, (b) When the energy source is at or above the first temperature, the switch network is controlled to apply a charging signal to the energy source. An energy storage system configured to perform the following actions. (Item 37) A method for charging an energy source, wherein the method is This includes applying a preheating signal to the energy source, which comprises a sequence of alternating charge and discharge energy pulses that increase the temperature of the energy source. The method wherein the preheating signal is at a frequency that passes through the double-layer capacitance of the energy source. (Item 38) The method according to item 37, wherein the double-layer capacitance comprises the double-layer capacitance of the anode of the energy source and the double-layer capacitance of the cathode of the energy source. (Item 39) The method according to item 37, wherein the preheating signal does not substantially charge the energy source. (Item 40) The method according to item 37, wherein the preheating signal is applied for a first duration so that the energy source is heated without being substantially charged, and then the preheating signal is applied for a second duration so that the energy source is heated and charged. (Item 41) The method according to item 40, wherein the duration of the charging energy pulse is gradually increased with respect to the discharge energy pulse during the second duration. (Item 42) The method according to item 37, wherein the preheating signal is applied until the energy source reaches a first temperature, and the charging signal is applied after the energy source has reached the first temperature. (Item 43) The method according to item 37, wherein the preheating signal is applied over a first duration, and the charging signal is applied after the first duration. (Item 44) The method according to item 37, wherein the preheating signal has a frequency such that no electrochemical storage reaction or side reaction occurs in the energy source. [Brief explanation of the drawing]

[0007] Details of the subject matter described herein, both in terms of its structure and operation, may be evident from the accompanying diagrams, where similar reference numbers point to similar parts. Components in the diagrams are not necessarily to scale, but rather the emphasis is on illustrating the principles of the subject matter. Furthermore, all illustrations are intended to convey concepts where relative size, shape, and other detailed attributes can be illustrated graphically, rather than literally or precisely.

[0008] [Figure 1-1] Figure 1A-1C is a block diagram illustrating an exemplary embodiment of a modular energy system. [Figure 1-2] Figure 1A-1C is a block diagram illustrating an exemplary embodiment of a modular energy system.

[0009] [Figure 1-3] Figure 1D-1E is a block diagram illustrating an exemplary embodiment of a control device for an energy system.

[0010] [Figure 1-4] Figure 1F-1G is a block diagram illustrating an exemplary embodiment of a modular energy system coupled with loads and charge sources.

[0011] [Figure 2A] Figures 2A-2B are block diagrams illustrating exemplary embodiments of modules and control systems within an energy system. [Figure 2B] Figures 2A-2B are block diagrams illustrating exemplary embodiments of modules and control systems within an energy system.

[0012] [Figure 2C] Figure 2C is a block diagram illustrating an exemplary embodiment of the physical configuration of the module.

[0013] [Figure 2D]Figure 2D is a block diagram illustrating an exemplary embodiment of the physical configuration of a modular energy system.

[0014] [Figure 3-1] Figures 3A-3C are block diagrams illustrating exemplary embodiments of modules having various electrical configurations. [Figure 3-2] Figures 3A-3C are block diagrams illustrating exemplary embodiments of modules having various electrical configurations.

[0015] [Figure 4] Figures 4A-4F are schematic diagrams illustrating exemplary embodiments of the energy source.

[0016] [Figure 5] Figures 5A-5C are schematic diagrams illustrating exemplary embodiments of the energy buffer.

[0017] [Figure 6-1] Figures 6A-6C are schematic diagrams illustrating exemplary embodiments of the converter. [Figure 6-2] Figures 6A-6C are schematic diagrams illustrating exemplary embodiments of the converter.

[0018] [Figure 7-1] Figures 7A-7E are block diagrams illustrating exemplary embodiments of modular energy systems with various topologies. [Figure 7-2] Figures 7A-7E are block diagrams illustrating exemplary embodiments of modular energy systems with various topologies.

[0019] [Figure 8A] Figure 8A is a plot illustrating the exemplary output voltage of the module.

[0020] [Figure 8B] Figure 8B is a plot illustrating the exemplary multilevel output voltage of the module array.

[0021] [Figure 8C] Figure 8C is a plot illustrating exemplary reference and carrier signals usable in pulse width modulation control techniques.

[0022] [Figure 8D] Figure 8D is a plot illustrating exemplary reference and carrier signals usable in pulse width modulation control techniques.

[0023] [Figure 8E] Figure 8E is a plot illustrating an exemplary switch signal generated according to pulse width modulation control techniques.

[0024] [Figure 8F] Figure 8F is a plot illustrating exemplary multilevel output voltages generated by superimposing output voltages from a module array under pulse width modulation control techniques.

[0025] [Figure 9] Figures 9A-9B are block diagrams illustrating exemplary embodiments of a controller for a modular energy system.

[0026] [Figure 10A] Figure 10A is a block diagram illustrating an exemplary embodiment of a multiphase modular energy system having interconnection modules.

[0027] [Figure 10B] Figure 10B is a schematic diagram illustrating an exemplary embodiment of the interconnection module in the multiphase embodiment of Figure 10A.

[0028] [Figure 10C] Figure 10C is a block diagram illustrating an exemplary embodiment of a modular energy system having two subsystems connected together by an interconnection module.

[0029] [Figure 10D] Figure 10D is a block diagram illustrating an exemplary embodiment of a three-phase modular energy system having interconnection modules that supply auxiliary loads.

[0030] [Figure 10E] Figure 10E is a schematic diagram illustrating an exemplary embodiment of the interconnection module in the multiphase embodiment shown in Figure 10D.

[0031] [Figure 10F] Figure 10F is a block diagram illustrating another exemplary embodiment of a three-phase modular energy system having interconnection modules that supply auxiliary loads.

[0032] [Figure 11A] Figures 11A-11B are plots illustrating a framework for describing several exemplary embodiments of the fast charging protocol. [Figure 11B] Figures 11A-11B are plots illustrating a framework for describing several exemplary embodiments of the fast charging protocol.

[0033] [Figure 11C] Figures 11C-11D are current-versus-time graphs illustrating exemplary embodiments of preheating pulse trains with and without a time gap, respectively. [Figure 11D] Figures 11C-11D are current-versus-time graphs illustrating exemplary embodiments of preheating pulse trains with and without a time gap, respectively.

[0034] [Figure 11E] Figure 11E is a current-versus-time graph illustrating an exemplary embodiment of the preheating signal applied between multiple sub-stages.

[0035] [Figure 11F]Figure 11F is a current-versus-time graph illustrating an exemplary embodiment of a pulsed charging signal for use in the pulsed charging phase.

[0036] [Figure 12A] Figure 12A is a cross-sectional view of a typical lithium-ion battery.

[0037] [Figure 12B] Figure 12B is an explanatory diagram illustrating enlarged anodes and cathodes and listing examples of degradation modes that can occur in a typical lithium-ion battery.

[0038] [Figure 12C] Figure 12C is an electrical circuit diagram model of a battery.

[0039] [Figure 12D] Figure 12D is a plot illustrating the exemplary voltage response to a charging pulse applied to a lithium-ion battery.

[0040] [Figure 12E] Figure 12E is a graph illustrating exemplary voltages on a lithium-ion battery across a range of charge states.

[0041] [Figure 12F] Figure 12F is a plot illustrating the exemplary impedance response of a lithium-ion battery.

[0042] [Figure 13A] Figure 13A is a graph illustrating exemplary levels of the constant current charging signal during the constant current charging phase.

[0043] [Figure 13B] Figure 13B is a graph illustrating another exemplary embodiment of a fast charging protocol with a constant current signal of gradually decreasing magnitude.

[0044] [Figure 14] Figure 14 is a series of plots illustrating an exemplary embodiment of monitoring for indications where lithium plating is occurring.

[0045] [Figure 15] Figures 15A and 15B are absolute capacity retention and normalized capacity retention plots comparing experimental data for exemplary embodiments of constant current charging and pulse charging performed on pairs of lithium-ion batteries rated and determined for use in power applications, respectively.

[0046] [Figure 16-1] Figures 16A and 16B are absolute capacity retention and normalized capacity retention plots comparing experimental data for exemplary embodiments of constant-current and fast-charging protocols performed on pairs of lithium-ion batteries rated and determined for use in power applications, respectively.

[0047] [Figure 16-2] Figure 16C is a capacity-versus-time graph, and Figure 16D is a voltage-versus-time graph, both showing data collected from an exemplary cycle of a fast charging protocol for a battery.

[0048] [Figure 17] Figures 17A and 17B are voltage-versus-capacity plots comparing experimental data from exemplary embodiments of constant-current charging and pulsed charging performed on pairs of lithium-ion batteries rated and determined for use in power applications, respectively.

[0049] [Figure 18A] Figure 18A plots the imaginary and real impedance components for constant-current and pulse-charged batteries at the end of their lifespan.

[0050] [Figure 18B]Figure 18B is a battery voltage versus time plot illustrating experimental data collected for lithium-ion batteries exposed to constant current charging and pulsed charging with different pulse durations.

[0051] [Figure 19-1] Figures 19A-19G are block diagrams illustrating exemplary embodiments of fast charging protocol implementations for various battery types. [Figure 19-2] Figures 19A-19G are block diagrams illustrating exemplary embodiments of fast charging protocol implementations for various battery types.

[0052] [Figure 20] Figure 20 is a block diagram illustrating an exemplary embodiment of an application that may be configured to apply the fast charging protocol described herein. [Modes for carrying out the invention]

[0053] Before the subject matter is described in detail, it should be understood that this disclosure is not limited to the specific embodiments described and is therefore naturally subject to change. It should also be understood that the terminology used herein is intended to describe only specific embodiments and is not intended to be restrictive, as the scope of this disclosure will be limited only by the appended claims.

[0054] Before describing exemplary embodiments of charge and discharge modular energy systems, it is useful to first describe in more detail the underlying systems. Referring to Figure 1A-10F, the following sections describe various applications in which embodiments of modular energy systems may be implemented, embodiments of control systems or devices for modular energy systems, configurations of modular energy system embodiments relating to charge sources and loads, embodiments of individual modules, embodiments of topologies for the arrangement of modules in the system, embodiments of control methodologies, embodiments of balanced operation characteristics of modules in the system, and embodiments of the use of interconnection modules. (Examples of uses)

[0055] Stationary applications are those in which modular energy systems are located in a fixed location while in use but can be moved to an alternative location when not in use. Modular energy systems, while permanently stationed at their installation site, provide electrical energy for consumption by one or more other entities, or store or buffer energy for later consumption. Examples of stationary applications in which 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 locations; energy systems for use by or within one or more industrial structures or locations; energy systems for use by or within one or more commercial structures or locations; energy systems for use by or within one or more government structures or locations (including both military and non-military uses); energy systems for charging mobile applications as described below (e.g., charging sources or charging stations); and systems that convert solar thermal 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 storage or non-storage roles.

[0056] Mobility applications, sometimes also referred to as towing applications, generally involve a modular energy system located on or within an entity that stores and provides electrical energy for conversion into motor-driven power, thereby moving or assisting in the movement of that entity. Examples of mobile entities in which the embodiments disclosed herein may be used include, but are not limited to, electric and / or hybrid entities that move on land or underground, at sea or in the ocean, above land or sea without contact with it (e.g., flying or hovering in the air), or through outer space. Examples of mobile entities in which the embodiments disclosed herein may be used include, but are not limited to, vehicles, trains, trams, ships, vessels, aircraft, and spacecraft. Examples of mobile vehicles in which the embodiments disclosed herein may be used include, but are not limited to, those having only one wheel or track, those having only two wheels or tracks, those having only three wheels or tracks, those having only four wheels or tracks, and those having five or more wheels or tracks. Examples of mobile entities in which the embodiments disclosed herein may be used together include, but are not limited to, automobiles, buses, trucks, motorcycles, scooters, industrial vehicles, mining vehicles, aircraft (e.g., airplanes, helicopters, drones, etc.), vessels (e.g., commercial transport ships, ships, yachts, boats, or other watercraft), submarines, locomotives or rail-based vehicles (e.g., trains, trams, etc.), military vehicles, spacecraft, and satellites.

[0057] In describing embodiments of this specification, specific stationary applications (e.g., grids, microgrids, data centers, cloud computing environments) or mobile applications (e.g., electric vehicles) may be referenced. Such references are made for the sake of clarity and do not imply that a particular embodiment is limited to that specific mobile or stationary application for use only. Embodiments of systems that provide power to a motor can be used in both mobile and stationary applications. While some configurations may be more suitable for certain applications than others, all exemplary embodiments disclosed herein are usable in both mobile and stationary applications unless otherwise described. (Example of a modular energy system)

[0058] Figure 1A is a block diagram illustrating an exemplary embodiment of a module-based energy system 100, where the system 100 includes a control system 102 that is communicatively coupled to N converter source modules 108-1 to 108-N, each via a communication path or links 106-1 to 106-N. Each module 108 is configured to store energy and, if necessary, output energy to a load 101 (or other module 108). In these embodiments, any number of two or more modules 108 can be used (e.g., N is 2 or more). The modules 108 can be connected to each other in various ways, as will be described in more detail with respect to Figures 7A-7E. For ease of illustration, in Figures 1A-1C, the modules 108 are shown connected in series or as a one-dimensional array, with the Nth module coupled to the load 101.

[0059] System 100 is configured to supply power to a load 101. The load 101 may be any type of load, such as a motor or a grid. System 100 is also configured to store power received from a power source. Figure 1F is a block diagram depicting an exemplary embodiment of System 100 with a power input interface 151 for receiving power from a power source 150 (e.g., a public 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, System 100 can output power via interface 152 and simultaneously receive and store power via interface 151. Figure 1G is a block diagram depicting another exemplary embodiment of System 100 with a switchable interface 154. In this embodiment, System 100 can choose between receiving power from the power source 150 and outputting power to the load 101, or can be commanded to choose between the two. The system 100 can be configured to supply power to multiple loads 101, including both primary and auxiliary loads, and / or to receive power from multiple charging sources 150 (e.g., a public power grid and local renewable energy sources (e.g., solar thermal)).

[0060] Figure 1B depicts another exemplary embodiment of system 100. Here, the control system 102 is implemented as a master control device (MCD) 112, each communicatively coupled to N different local control devices (LCDs) 114-1 to 114-N via communication paths or links 115-1 to 115-N. Each LCD 114-1 to 114-N is communicatively coupled to one module 108-1 to 108-N via a communication path or links 116-1 to 116-N, such that a one-to-one relationship exists between the LCD 114 and module 108.

[0061] Figure 1C depicts another exemplary embodiment of system 100. Here, each MCD112 is communicably coupled to M different LCDs 114-1 to 114-M via a communication path or links 115-1 to 115-M. Each LCD 114 can be coupled to and controlled by two or more modules 108. In the example shown here, each LCD 114 is communicably coupled to two modules 108 such that M LCDs 114-1 to 114-M are each coupled to 2M modules 108-1 to 108-2M via a communication path or links 116-1 to 116-2M.

[0062] The control system 102 can be configured as a single device for the entire system 100 (e.g., Figure 1A), distributed across multiple devices, or implemented as multiple devices (e.g., Figures 1B-1C). In some embodiments, the control system 102 can be distributed among the LCDs 114 associated with module 108, thereby allowing any MCD 112 to be omitted from system 100 if unnecessary.

[0063] The control system 102 can be configured to perform control using software (instructions stored in memory executable by the processing network), hardware, or a combination thereof. Each of one or more devices of the control system 102 may include the processing network 120 and the memory 122, as shown herein. Exemplary implementations of the processing network and memory are described further below.

[0064] The control system 102 may have a communication interface for communicating with external devices 104 of the system 100 via a communication link or path 105. For example, the control system 102 (e.g., MCD112) may output data or information about the system 100 to another control device 104 (e.g., an electronic control unit (ECU) or motor control unit (MCU) of a vehicle in a mobile application, or a grid controller in a stationary application).

[0065] Each of the communication paths or links 105, 106, 115, 116, and 118 (Figure 2B) may be a wired (e.g., electrical, optical) or wireless communication path for communicating data or information bidirectionally, in parallel or series. Data may be communicated in a standardized (e.g., IEEE, ANSI) or custom (e.g., proprietary) format. In automotive applications, communication path 115 may be configured to communicate according to the FlexRay or CAN protocol. Communication paths 106, 115, 116, and 118 also provide wired power and can directly supply operating power for the system 102 from one or more modules 108. For example, the operating power for each LCD 114 may be supplied by only one or more modules 108 to which that LCD 114 is connected, while the operating power for the MCD 112 may be supplied indirectly from one or more of the modules 108 (e.g., through the automotive power network).

[0066] The control system 102 is configured to control one or more modules 108 based on status information received from one or more of the same or different modules 108. 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.

[0067] Status information for all modules 108 in system 100 can be communicated to control system 102, and system 102 can control all modules 108-1...108-N independently of the status information. Other variations are also possible. For example, a particular module 108 (or part of module 108) can be controlled based on the status information of that particular module 108 (or part of module 108); based on the status information of a different module 108 that is not that particular module 108 (or part of module 108); based on the status information of all modules 108 other than that particular module 108 (or part of module 108); based on the status information of that particular module 108 (or part of module 108) and the status information of at least one other module 108 that is not that particular module 108 (or part of module 108); or based on the status information of all modules 108 in system 100.

[0068] Status information may be information about one or more aspects, characteristics, or parameters of each module 108. The type of status information is not limited to, but may include the following aspects of module 108 or one or more components (e.g., energy sources, energy buffers, converters, monitoring networks): the state of charge (SOC) of one or more energy sources of the module (e.g., the level of charge of the 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., the figure of performance of the energy source conditions compared to its ideal conditions); 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.

[0069] The LCD 114 can be configured to receive status information from each module 108, or to determine status information from monitoring signals or data received from or within each module 108, and to communicate that information to the MCD 112. In some embodiments, each LCD 114 can communicate raw acquired data to the MCD 112, which then algorithmically determines the status information based on that raw data. The MCD 112 can then use the status information of the module 108 to make control decisions as appropriate. The decisions may take the form of instructions, commands, or other information (such as modulation indices as described herein) that can be used by the LCD 114 to either maintain or adjust the operation of each module 108.

[0070] For example, the MCD112 may receive status information, assess that information, and 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 MCD112 may determine that a particular module 108 is operating with 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 capacitance, 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 MCD112 may output control information that causes the relevant aspects of that particular module 108 (e.g., output voltage, current, power, temperature) to be reduced or increased (depending on the conditions). In this way, the use of outlier modules 108 (e.g., operating with relatively low SOC or high temperature) can be reduced, causing the relevant parameters (e.g., SOC or temperature) of that module 108 to converge towards those of one or more other modules 108.

[0071] The decision of whether to adjust the operation of a particular module 108 may not necessarily be made by comparing its status information with a predetermined threshold, limit, or condition, but rather by comparing it with the status of other modules 108. The predetermined threshold, limit, or condition may be a static threshold, limit, or condition set by the manufacturer that does not change during use. The predetermined threshold, limit, or condition may be a dynamic threshold, limit, or condition that is made possible to change or changes during use. For example, the MCD 112 may adjust the operation of module 108 if its status information indicates that module 108 is in violation of a predetermined threshold or limit (e.g., above or below it) or is operating outside a predetermined range of acceptable operating conditions. Similarly, the MCD 112 may adjust the operation of module 108 if its status information indicates the presence of an actual or potential fault (e.g., an alarm or warning), or the absence or removal of an actual or potential fault. Examples of failures include, but are not limited to, actual component failures, potential component failures, short circuits or other excessive current conditions, open circuits, excessive voltage conditions, poor communication reception, and reception of corrupted data. Depending on the type and severity of the failure, the use of the faulty module may be reduced to avoid damaging the module, or the use of the module may be stopped entirely.

[0072] The MCD 112 can control the modules 108 in system 100 to achieve or converge toward a desired target. The target may be, for example, that the operation of all modules 108 is at the same or similar level relative to one another, or within a predetermined threshold, limit, or condition. This process is also referred to as equilibrium in the operation or operating characteristics of the modules 108, or the search for equilibrium. The term “equilibrium,” as used herein, is used broadly to convey that it does not require absolute equivalence between modules 108 or their components, but rather that the operation of system 100 may be used to actively reduce any differences in the operation between modules 108 that would otherwise exist.

[0073] The MCD112 can communicate control information to the LCD114 for the purpose of controlling a module 108 associated with the LCD114. The control information may be, for example, a modulation index and reference signal, a modulation reference signal, or something else as described herein. Each LCD114 can use (e.g., receive and process) the control information and generate switch signals that control the operation of one or more components (e.g., a converter) within the associated module 108. In some embodiments, the MCD112 directly generates switch signals and outputs them to the LCD114, which then relays the switch signals to the intended module components.

[0074] All or part of the control system 102 can be combined with an external system control device 104 that controls one or more other aspects of mobile or stationary applications. When integrated within this shared or common control device (system or subsystem), control of system 100 can be implemented in any desired manner, such as one or more software applications performed by the processing network of the shared device, the hardware of the shared device, or a combination thereof. Non-inclusive examples of the external control device 104 include: an on-board ECU or MCU with control capabilities for one or more other on-board functions (e.g., motor control, driver interface control, traction force control, etc.); a grid or microgrid controller involved in one or more other power management functions (e.g., load interface, load power requirement prediction, transmission and switching, interface with charge sources (e.g., diesel, solar, wind), charge source power prediction, backup source monitoring, asset dispatch, etc.); and a data center control subsystem (e.g., environmental control, network control, backup control, etc.).

[0075] Figures 1D and 1E are block diagrams depicting exemplary embodiments of a shared or common control device (or system) 132 in which a control system 102 may be implemented. In Figure 1D, the common control device 132 includes a master control device 112 and an external control device 104. The master control device 112 includes an interface 141 for communication with the LCD 114 via 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 for the overall 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, and devices 112 and 104 may be implemented as separate integrated circuit (IC) chips or packages contained therein.

[0076] In Figure 1E, the external control device 104 functions as a common control device 132, and the master control functionality is implemented as a component within device 104. This component 112 may be or contain software or other program instructions, stored in the memory of device 104 and / or hardcoded and executed by its processing network. The component may also include dedicated hardware. The component may be a self-contained module or core, and one or more internal hardware and / or software interfaces (e.g., application programming interfaces (APIs)) are 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 communication with other devices via interface 144. In various embodiments, devices 104 / 132 may be integrated as a single IC chip, integrated in multiple IC chips within a single package, or integrated as multiple semiconductor packages within a common enclosure.

[0077] In the embodiments of Figures 1D and 1E, the master control functionality of system 102 is shared within the common device 132; however, other divisions of the shared control are also possible. For example, a portion of the master control functionality can be distributed between the common device 132 and the dedicated MCD 112. In another example, both the master control functionality and at least a portion of the local control functionality can be implemented within the common device 132 (for example, the remaining local control functionality is implemented within the LCD 114). In some embodiments, the entire control system 102 is implemented within the common device (or subsystem) 132. In some embodiments, the local control functionality is implemented within a device shared with other components of each module 108, such as a battery management system (BMS). (Example of a module in a cascade energy system)

[0078] Module 108 may include one or more energy sources, a power electronics converter, and, optionally, an energy buffer. Figures 2A-2B are block diagrams depicting an additional exemplary embodiment of system 100 with module 108 having 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. Embodiments are described herein with reference to a voltage converter, but embodiments are not limited thereto. The converter 202 may be configured to convert a direct current (DC) signal from the energy source 204 into 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 204 with either polarity in a sustained 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 a switch, and the converter (and the module as a whole) does not include a transformer.

[0079] The converter 202 may also be configured to perform AC / DC conversion (e.g., a rectifier), DC / DC conversion, and / or AC / AC conversion (e.g., in combination with an AC / DC converter), such as for charging a DC energy source from an AC source. In some embodiments, such as for performing AC / AC conversion, the 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 those where weight and cost are important factors, the converter 202 may be configured to perform the conversion without a transformer, using only a power switch, power diode, or other semiconductor device.

[0080] The energy source 206 is preferably a robust energy storage device capable of outputting DC and having an energy density suitable for energy storage applications for electric devices. The fuel cell may be a single fuel cell, multiple fuel cells connected in series or parallel, or a fuel cell module. Two or more energy sources may be included within each module, and the two or more sources may 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.

[0081] The energy source 206 may be an electrochemical battery, such as a single battery, multiple battery cells connected together in a battery module or array, or any combination thereof. Figures 4A–4D are schematic diagrams illustrating exemplary embodiments of the energy source 206, which are configured as a single battery cell 402 (Figure 4A), a battery module with four batteries 402 connected in series (Figure 4B), a battery module with single batteries 402 connected in parallel (Figure 4C), and a battery module with parallel connections to legs, each having two batteries 402 (Figure 4D). Examples of battery types are described elsewhere in this specification.

[0082] Energy source 206 may also be a high-energy-density (HED) capacitor, such as an ultracapacitor or supercapacitor. In contrast to typical solid-dielectric electrolytic capacitors, HED capacitors can be configured as double-layer capacitors (electrostatic charge storage devices), pseudocapacitors (electrochemical charge storage devices), hybrid capacitors (electrostatic and electrochemical), or others. In addition to higher capacitance, HED capacitors can have an energy density 10 to 100 times (or higher) that of electrolytic capacitors. For example, an HED capacitor can have a specific energy greater than 1.0 watt-hour / kilogram (Wh / kg) and a capacitance greater than 10 to 100 farads (F). Similar to the battery described with respect to Figures 4A-4D, energy source 206 can be configured as a single HED capacitor or as multiple HED capacitors connected together in an array (e.g., in series, parallel, or a combination thereof).

[0083] 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, energy source 206 can be configured as a single fuel cell or as 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 those skilled in the art will recognize other variations that fall within the scope of this subject.

[0084] Energy buffer 204 is connected to a DC line or link (for example, +V as described below). DCL and -V DCLThe buffer 204 can attenuate or filter current fluctuations across the source 206, helping to maintain stability in the DC link voltage. These fluctuations may be relatively low (e.g., kilohertz) or high (e.g., megahertz) frequency fluctuations or harmonics caused by switching or other transients of the converter 202. These fluctuations can be absorbed by the buffer 204 instead of being passed through ports IO3 and IO4 of the source 206 or converter 202.

[0085] The power connection 110 is a connection for transferring energy or power to, and through, module 108. Module 108 can output energy from energy source 206 to power connection 110, and the energy can be transferred to other modules or loads in the system. Module 108 can also receive energy from other modules 108 or charging sources (DC charger, single-phase charger, multi-phase charger). Signals can also be routed through module 108, bypassing energy source 206. Routing of energy or power into and out of module 108 is carried out by converter 202 under the control of LCD 114 (or another entity in system 102).

[0086] In the embodiment shown in Figure 2A, the LCD 114 is implemented as a separate component from module 108 (e.g., not in a shared module housing) and is connected to and capable of communicating with converter 202 via communication path 116. In the embodiment shown in Figure 2B, the LCD 114 is included as a component of module 108 and is connected to and capable of communicating with converter 202 via internal communication path 118 (e.g., a shared bus or separate connection). The LCD 114 may also receive signals from energy buffer 204 and / or energy source 206, and transmit signals to them, via path 116 or 118.

[0087] Module 108 may also include a monitoring network 208, which is configured to monitor (e.g., collect, sense, measure, and / or determine) one or more aspects of Module 108 and / or its components, such as voltage, current, temperature, or other operating parameters, which constitute status information (or can be used, for example, by the LCD 114, to determine the status information). The primary function of the status information is to describe the state of one or more energy sources 206 of Module 108, enabling a decision on how much of the energy sources should be utilized compared to other sources in System 100. However, status information describing the state of other components (e.g., voltage, temperature, and / or presence of faults in Buffer 204, temperature and / or presence of faults in Converter 202, presence of faults elsewhere in Module 108, etc.) can also be used in utilization decisions. The monitoring network 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 network 208 may be separate from the various components 202, 204, and 206, or it may be integrated with each component 202, 204, and 206 (as shown in Figures 2A-2B), or it may be any combination thereof. In some embodiments, the monitoring network 208 may be part of or shared with a battery management system (BMS) for the battery energy source 204. Since two or more types of status information are monitored using a single circuit or device without the need for additional circuitry, or otherwise can be determined algorithmically, separate networks are not required to monitor each type of status information.

[0088] The LCD 114 can receive status information (or raw data) about module components via communication paths 116 and 118. The LCD 114 can also transmit information to module components via paths 116 and 118. Paths 116 and 118 may include diagnostic, measurement, protection, and control signal lines. The transmitted information may be control signals for one or more module components. The control signals may be switch signals for converter 202 and / or one or more signals requesting status information from the module components. For example, the LCD 114 may transmit status information via paths 116 and 118 by directly requesting the status information, or, in some cases, by applying a stimulus (e.g., voltage) that causes the status information to be generated, in combination with a switch signal that places converter 202 into a specific state.

[0089] The physical configuration or layout of module 108 can take various forms. In some embodiments, module 108 may include a common housing in which all module components, such as the converter 202, buffer 204, and source 206, are housed together with other optional components, such as an integrated LCD 114. In other embodiments, the various components may be separated in separate housings that are fixed together. Figure 2C is a block diagram depicting an exemplary embodiment of module 108, which comprises a first housing 220 that houses the module's energy source 206 and ancillary electronics such as a monitoring network; a second housing 222 that houses module electronics such as the converter 202, energy buffer 204, and other ancillary electronics such as a monitoring network; and a third housing 224 that houses the LCD 114 for module 108. Electrical connections between the various module components can run through housings 220, 222, and 224 and may be exposed on any of the outside of the housings for connection to other modules 108 or other devices such as an MCD 112.

[0090] The modules 108 of 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 system 100 provides power for a microgrid, the modules 108 can be installed in one or more racks or other frameworks. Such a configuration may also be suitable for larger mobile applications such as marine vessels. Alternatively, the modules 108 can be fixed together and located in a common housing referred to as a pack. The rack or pack may have its own dedicated cooling system shared across all modules. The pack configuration is useful for smaller mobile applications such as electric vehicles. System 100 can be implemented using one or more racks (e.g., for parallel supply to a microgrid), or one or more packs (e.g., supplying different motors in a vehicle), or a combination thereof. Figure 2D is a block diagram depicting an exemplary embodiment of system 100 configured as a pack in which nine modules 108 are electrically and physically coupled together in a common housing 230.

[0091] Examples of these and further configurations are described in International Application PCT / US20 / 25366, filed on 27 March 2020, entitled "Module-Based Energy Systems Capable of Cascaded and Interconnected Configurations, and Methods Related Thereto" (which, for all purposes, is incorporated herein by reference in its entirety).

[0092] Figures 3A-3C are block diagrams depicting exemplary embodiments of module 108 having various electrical configurations. These embodiments are described as having one LCD 114 per module 108, the LCD 114 being housed within the associated module, but they can be configured otherwise as described herein. Figure 3A depicts a first exemplary configuration of module 108A in 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) to which power can be input and / or output, referred herein as an IO port. Such ports may also be referred to as input ports or output ports, depending on the context.

[0093] The energy source 206 can be configured as any of the energy source types described herein (e.g., a battery, HED capacitor, fuel cell, or others, as described with respect to Figures 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 waves arriving at the buffer 204 through the converter 202, which would otherwise degrade the performance of module 108. The topology and components for the buffer 204 are selected to accommodate the maximum allowable amplitude of these high frequency voltage waves. Several (non-exclusive) exemplary embodiments of the energy buffer 204 are depicted in schematic diagrams of Figures 5A–5C. In Figure 5A, the buffer 204 is connected to an electrolytic and / or film capacitor C EB In Figure 5B, buffer 204 consists of two inductors L EB1 and L EB2 and two electrolytic and / or film capacitors C EB1 and C EB2 The Z-source network 710 is formed by the following, and in Figure 5C, the buffer 204 consists of two inductors LEB1 and L EB2 and two electrolytic and / or film capacitors C EB1 and C EB2 and a diode D EB which forms a quasi-Z-source network 720.

[0094] Ports IO3 and IO4 of the energy buffer 204 can be connected to ports IO1 and IO2 of the converter 202A respectively, and the converter 202A can be configured as any of the power converter types described herein. FIG. 6A is a schematic diagram depicting an exemplary embodiment of a converter 202A configured as a DC-AC converter that can receive a DC voltage at ports IO1 and IO2 and switch to generate a pulse at ports IO3 and IO4. The converter 202A can include a plurality of switches, here 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.

[0095] The switches can be of any suitable switch type such as a power semiconductor such as a metal oxide semiconductor field effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), or a gallium nitride (GaN) transistor shown herein. The semiconductor switches operate at a relatively high switching frequency, thereby enabling the converter 202 to be operated in pulse width modulation (PWM) mode if desired and respond to control commands within a relatively short time interval. This can provide a high tolerance for output voltage regulation and fast dynamic behavior in the transient mode.

[0096] In this embodiment, a DC line voltage V<9000013>can be applied to the converter 202 between ports IO1 and IO2. Different combinations of the switches S3, S4, S5, S6 result in V DCLBy connecting to ports IO3 and IO4, the converter 202 provides three different voltage outputs, namely +V DCL , 0, and -V DCL This can be generated on ports IO3 and IO4. The switch signals provided to each switch control whether the switch is turned on (closed) or off (open). +V DCL To obtain this, switches S3 and S6 are turned on, while S4 and S5 are turned off, -V DCL The voltages can be obtained by turning switches S4 and S5 on and S3 and S6 off. The output voltages can be set to zero (including near zero) or a reference voltage by turning S4 and S6 off with S3 and S5 on, or by turning S3 and S5 off with S4 and S6 on. These voltages can be output from module 108 via power connection 110. Ports IO3 and IO4 of converter 202 can be connected to (or from) module IO ports 1 and 2 of power connection 110 to generate output voltages for use with output voltages from other modules 108.

[0097] The control or switch signals for embodiments of the converter 202 described herein can be generated in different ways depending on the control technique used by the system 100 to generate the output voltage of the converter 202. In some embodiments, the control technique is a PWM technique such as spatial vector pulse width modulation (SVPWM) or sinusoidal pulse width modulation (SPWM) or its variations. Figure 8A is a voltage-versus-time graph illustrating an example of the output voltage waveform 802 of the converter 202. For ease of explanation, embodiments herein will be described in the context of PWM control techniques, but embodiments are not limited thereto. Other classes of techniques may also be used. One alternative class is based on hysteresis, examples of which are described in International Publications WO2018 / 231810A1, WO2018 / 232403A1, and WO2019 / 183553A1 (which are incorporated herein by reference for all purposes).

[0098] Each module 108 can be configured with multiple energy sources 206 (e.g., two, three, four, or more). Each energy source 206 of module 108 may 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 may simultaneously output power to the connection 110 (or be charged), or only one (or some) of the sources 206 may supply power (or be charged) at any given time. In some embodiments, the sources 206 of the module can exchange energy with each other, for example, one source 206 may charge another source 206. Each of the sources 206 may 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 (for example, each may be a battery) or of different types (for example, the first source may be a battery and the second source may be an HED capacitor, or the first source may be a battery of the first type (for example, an NMC) and the second source may be a battery of the second type (for example, an LFP)).

[0099] Figure 3B is a block diagram illustrating an exemplary embodiment of module 108B in a dual energy source configuration with a primary energy source 206A and a secondary energy source 206B. Ports IO1 and IO2 of the primary source 202A can be connected to ports IO1 and IO2 of the energy buffer 204. Module 108B includes a converter 202B having additional IO ports. Ports IO3 and IO4 of the buffer 204 can be connected to ports IO1 and IO2 of the converter 202B, respectively. Ports IO1 and IO2 of the secondary source 206B can be connected to ports IO5 and IO2 of the converter 202B (and also to port IO4 of the buffer 204), respectively.

[0100] In this exemplary embodiment of module 108B, the primary energy source 202A, together with the other modules 108 of system 100, supplies the average power required by the load. The secondary source 202B can function as an auxiliary energy source 202 by providing additional power at load power peaks, absorbing excess power, or otherwise.

[0101] As stated, both the primary source 206A and the secondary source 206B can be used simultaneously or at separate times, depending on the switching state of the converter 202B. If used simultaneously, electrolytic and / or film capacitors (C ES The HED capacitor may be installed in parallel with the source 206B, as depicted in Figure 4E, and function as an energy buffer for the source 206B, or the energy source 206B may be configured to utilize the HED capacitor in parallel with another energy source (e.g., a battery or fuel cell), as depicted in Figure 4F.

[0102] Figures 6B and 6C are schematic diagrams illustrating exemplary embodiments of converters 202B and 202C, respectively. Converter 202B includes switch network sections 601 and 602A. Section 601 includes switches S3-S6 configured as a full bridge in a manner similar to converter 202A, configured to selectively couple IO1 and IO2 to either IO3 or IO4, thereby changing the output voltage of module 108B. Section 602A includes switches S1 and S2 configured as a half bridge, coupled between ports IO1 and IO2. Coupling inductor L C However, the switch section 602A is connected between port IO5 and node 1, which is located between switches S1 and S2, so that it is a bidirectional converter capable of adjusting the (boost or buck) voltage (or conversely, current). The switch section 602A is referenced to port IO2, which may be at virtually zero potential, +V DCL2Two different voltages, and 0, can be generated at node 1. The current drawn from or input to the energy source 202B is used, for example, to rectify switches S1 and S2 using pulse width modulation techniques or hysteresis control methods to connect the coupled inductor L C It can be controlled by adjusting the voltage above. Other techniques can also be used.

[0103] Converter 202C differs from that of 202B in that the switching section 602B is configured as a half-bridge and includes switches S1 and S2 coupled between ports IO5 and IO2. Coupling inductor L C However, the switch section 602B is configured to adjust the voltage, and is connected between port IO1 and node 1, which is located between switches S1 and S2.

[0104] The control system 102 or LCD 114 can independently control the switches of converters 202B and 202C via control input lines 118-3 to each gate. In these embodiments and in Figure 6A, LCD 114 (but not MCD 112) generates the switching signals for the converter switches. Alternatively, MCD 112 can also generate switching signals, which can be communicated directly to the switches or relayed by LCD 114.

[0105] In embodiments where module 108 includes three or more energy sources 206, converters 202B and 202C can be scaled as appropriate so that each additional energy source 206B is coupled to an additional I / O port leading to an additional switch network section 602A or 602B, depending on the needs of a particular source. For example, a dual-source converter 202 may include both switch sections 202A and 202B.

[0106] Module 108 with multiple energy sources 206 can perform additional functions such as energy sharing among the sources 206, energy capture from within the application (e.g., regenerative braking), charging of the primary source by the secondary source even while the overall system is in a discharge 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 detail in International Application PCT / US20 / 25366, filed on 27 March 2020, titled "Module-Based Energy Systems Capable of Cascaded and Interconnected Configurations, and Methods Related Thereto," and International Publication WO2019 / 183553, filed on 22 March 2019, titled "Systems and Methods for Power Management and Control" (both of which are incorporated herein by reference in their entirety for all purposes).

[0107] Each module 108 can be configured to supply one or more auxiliary loads using its one or more energy sources 206. The auxiliary loads are loads that require a lower voltage than the primary load 101. Examples of auxiliary loads may be, for example, the onboard electrical network of an electric vehicle or the HVAC system of an electric vehicle. The loads of system 100 may be, for example, an electric vehicle motor or one of the phases of a power distribution network. This embodiment allows for complete isolation between the electrical characteristics (terminal voltage and current) of the energy source and the electrical characteristics of the load.

[0108] Figure 3C is a block diagram depicting an exemplary embodiment of module 108C configured to supply power to 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 that of Figure 3B. The first auxiliary load 301 requires a voltage equivalent to that supplied by the source 206. The load 301 is coupled to IO ports 3 and 4 of 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 that of the source 206. The load 302 is coupled to IO ports 5 and 6 of module 108C, which are, in turn, coupled to ports IO5 and IO2 of the converter 202B. Converter 202B is coupled to port IO5 (Figure 6B) with a coupling inductor L C The converter 202B may include a switch section 602 having a coupling inductor L. The energy supplied by the power source 206 can be supplied to the load 302 through the switch section 602 of the converter 202B. The load 302 has an input capacitor (a capacitor may be added to module 108C if not applicable), and thus switches S1 and S2 have a coupling inductor L. C It is assumed that the voltage above and the current passing through it are rectified to adjust and thus produce a stable constant voltage for the load 302. This adjustment can reduce the voltage of source 206 to a lower magnitude voltage required by the load 302.

[0109] Module 108C can therefore 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, module 108C can be scaled with respect to each additional load 302 with additional dedicated module output ports (such as 5 and 6), additional dedicated switch sections 602, and additional converter IO ports coupled to the additional sections 602.

[0110] The energy source 206 can therefore supply power for any number of auxiliary loads (e.g., 301 and 302) and the corresponding portion of the system output power required by the primary load 101. The power flow from the source 206 to the various loads can be adjusted as desired.

[0111] Module 108 may optionally consist of two or more energy sources 206 (Figure 3B), which can be configured to supply the first and / or second auxiliary load (Figure 3C) with respect to each additional source 206B or second auxiliary load 302 through the addition of a switch section 602 and converter port IO5. Additional module IO ports (e.g., 3, 4, 5, 6) may be added as needed. Module 108 may also be configured as an interconnection module that can exchange energy between two or more arrays, two or more packs, or two or more systems 100 as described further herein (e.g., for equilibrium). This interconnection functionality can also be combined with the ability to supply multiple sources and / or multiple auxiliary loads.

[0112] The control system 102 can perform various functions related to the components of modules 108A, 108B, and 108C. These functions may include managing the utilization (amount used) of each energy source 206, protecting the energy buffer 204 from overcurrent, overvoltage, and high-temperature conditions, and controlling and protecting the converter 202.

[0113] For example, in order to manage the utilization of each energy source 206 (e.g., by adjusting it by increasing, decreasing, or maintaining it), the LCD 114 may receive one or more monitoring voltages, temperatures, and currents from each energy source 206 (or monitoring network). The monitoring voltages may be at least one, preferably all, of the voltages of each basic component independent of other components of the source 206 (e.g., each individual battery, HED capacitor, and / or fuel cell), or the voltage 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 monitoring temperatures and currents may be at least one, preferably all, of the temperatures and currents of each basic component independent of other components of the source 206, or the temperature and currents of the group of basic components as a whole, or any combination thereof. The monitoring signal may be status information, which the LCD114 may use to perform one or more of the following: calculation or determination of the actual capacity, actual state of charge (SOC), and / or state of health (SOH) of a basic component or group of basic components; setting or outputting a warning or alarm indication based on the monitored and / or calculated status information; and / or transmission of the status information to the MCD112. The LCD114 may receive control information (e.g., modulation index, synchronization signal) from the MCD112 and use this control information to generate a switch signal for the converter 202 that manages the utilization of the source 206.

[0114] To protect the energy buffer 204, the LCD 114 can receive one or more monitoring voltages, temperatures, and currents from the energy buffer 204 (or monitoring network). The monitoring voltages are independent of other components of each basic component of the buffer 204 (e.g., C EB , C EB1 , C EB2 , L EB1 , L EB2 , D EB The monitoring temperature and current may be at least one, preferably all, of the voltages of the basic components of buffer 204, or the voltages of the group of basic components of buffer 204 as a whole (for example, between IO1 and IO2 or between IO3 and IO4). Similarly, the monitoring temperature and current may be at least one, preferably all, of the temperature and current of each basic component of buffer 204 independent of other components, or the temperature and current of the group of basic components of buffer 204 as a whole, or any combination thereof. The monitoring signal may be status information, which LCD 114 may use to perform one or more of the following: setting or outputting a warning or alarm indication; communicating the status information to MCD 112; or the control converter 202 may adjust (increase or decrease) the utilization of the source 206 and module 108 as a whole for buffer protection.

[0115] 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 modulation index) from the MCD 112, which can be used within the LCD 114 using PWM techniques to generate control signals for each switch (e.g., S1-S6). The LCD 114 can receive current feedback signals from the current sensor of the converter 202, which can be used for overcurrent protection along with one or more fault status signals from the driver circuit (not shown) of the converter switches, which may carry information about the fault status (e.g., short circuit or open circuit fault mode) of all switches in the converter 202. Based on this data, the LCD 114 can manage the utilization of module 108 and potentially make decisions regarding combinations of switching signals to be applied to bypass or disconnect the converter 202 (and the entire module 108) from system 100.

[0116] When controlling module 108C which supplies power to the second auxiliary load 302, LCD 114 displays one or more monitored voltages within module 108C (e.g., voltages between IO ports 5 and 6) and one or more monitored currents (e.g., the current of the coupled inductor L, which is the current of load 302). C The LCD114 can receive the internal current and other signals. Based on these signals, the LCD114 can adjust the switching cycle of S1 and S2 and control (and stabilize) the voltage for the load 302 (for example, by adjusting the modulation index or reference waveform). (Example of a cascade energy system topology)

[0117] Two or more modules 108 can be coupled together in a cascaded array, which outputs a voltage signal formed by the superposition of separate voltages generated by each module 108 in the array. Figure 7A is a block diagram depicting an exemplary embodiment of the topology for system 100, where 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 or equal to 2. The array 700 includes a first system I / O port SIO1 and a second system I / O port SIO2, through 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 single-phase AC loads that can be connected to SIO1 and SIO2 of the array 700. Figure 8A is a voltage-versus-time plot depicting an exemplary output signal 801 produced by a single module 108 having a 48-volt energy source. Figure 8B is a voltage-versus-time plot illustrating an exemplary single-phase AC output signal 802 generated by an array 700 having six 48V modules 108 coupled in series.

[0118] System 100 can be arranged in a wide variety of different topologies to meet the diverse needs of its applications. By using multiple arrays 700, System 100 can provide multiphase power (e.g., 2-phase, 3-phase, 4-phase, 5-phase, 6-phase, etc.) to a load, and each array can generate AC output signals with different phase angles.

[0119] Figure 7B is a block diagram depicting system 100 with two arrays 700-PA and 700-PB joined together. Each array 700 is one-dimensional and formed by a series connection of N modules 108. Each of the two arrays 700-PA and 700-PB can generate a single-phase AC signal, and the two AC signals have different phase angles PA and PB (e.g., 180 degrees apart). The IO port 1 of 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 outputs of each array capable of providing two-phase power to a load (not shown). Alternatively, ports SIO1 and SIO2 can be connected to provide single-phase power from two parallel arrays. The 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, located on the opposite end from the array system IO ports SIO1 and SIO2. The IO port 2 of module 108-N of each array 700-PA and 700-PB can be coupled together at a common node and optionally used for an additional system IO port SIO3 if desired, and it can serve as a neutral. This common node may be referred to as a rail, and the IO port 2 of module 108-N of each array 700 may be referred to as being on the rail side of the array.

[0120] Figure 7C is a block diagram depicting system 100 with three arrays 700-PA, 700-PB, and 700-PC coupled together. Each array 700 is one-dimensional and formed by a series connection of N modules 108. Each of the three arrays 700-1 and 700-2 can generate a single-phase AC signal, and the three AC signals have different phase angles PA, PB, and PC (e.g., 120 degrees apart). The IO port 1 of module 108-1 of each array 700-PA, 700-PB, and 700-PC can form or be connected to system IO ports SIO1, SIO2, and SIO3, respectively, and system IO ports SIO1, SIO2, and SIO3 can then provide three-phase power to a load (not shown). The IO port 2 of module 108-N of each array 700-PA, 700-PB, and 700-PC can be coupled together at a common node and can optionally be used for an additional system IO port SIO4 if desired, which can serve a neutral role.

[0121] The concepts described with respect to the two-phase and three-phase embodiments in Figures 7B and 7C can be extended to systems 100 that generate power with even more phases. For example, a non-inclusive list of additional examples includes a system 100 having four arrays 700 configured to generate single-phase AC signals, each having a different phase angle (e.g., 90 degrees apart); a system 100 having five arrays 700 configured to generate single-phase AC signals, each having a different phase angle (e.g., 72 degrees apart); and a system 100 having six arrays 700 configured to generate single-phase AC signals, each having a different phase angle (e.g., 60 degrees apart).

[0122] System 100 can be configured such that arrays 700 are interconnected at electrical nodes between modules 108 within each array. Figure 7D is a block diagram depicting System 100 with three arrays 700-PA, 700-PB, and 700-PC coupled together in combined series and delta configurations. Each array 700 includes a first series connection of M modules 108 (where M is 2 or greater), and this first series connection is coupled with a second series connection of N modules 108 (where N is 2 or greater). A delta configuration is formed by interconnections between arrays, and these interconnections can be placed at any desired location. In this embodiment, the IO port 2 of module 108-(M+N) of array 700-PC is coupled with the IO port 2 of module 108-M and the IO port 1 of module 108-(M+1) of array 700-PA, the IO port 2 of module 108-(M+N) of array 700-PB is coupled with the IO port 2 of module 108-M and the IO port 1 of module 108-(M+1) of array 700-PC, and the IO port 2 of module 108-(M+N) of array 700-PA is coupled with the IO port 2 of module 108-M and the IO port 1 of module 108-(M+1) of array 700-PB.

[0123] Figure 7E is a block diagram depicting system 100 with three arrays 700-PA, 700-PB, and 700-PC coupled together in combined series and delta configurations. This embodiment is similar to that of Figure 7D but involves different cross-connections. 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 configurations in Figures 7D and 7E can be implemented with fewer modules, such as two within each array 700. The combined delta and series configurations enable effective energy exchange (interphase equilibrium) between all modules 108 of the system and effective phase exchange of the grid or load, reducing the total number of modules 108 in the array 700 and also allowing the acquisition of a desired output voltage.

[0124] In the embodiments described herein, it is advantageous, but not required, that the number of modules 108 be the same in each array 700 within the system 100, and different arrays 700 may have different numbers of modules 108. Furthermore, each array 700 may have modules 108 that are all identical (e.g., all modules are 108A, all modules are 108B, all modules are 108C, or otherwise) or different (e.g., one or more modules are 108A, one or more modules are 108B, one or more modules are 108C, or otherwise). Thus, the range of system 100 topologies covered herein is extensive. (Exemplary embodiment of control methodology)

[0125] As described, control of system 100 can be carried out according to various methodologies such as hysteresis or PWM. Some examples of PWM include spatial vector modulation and sinusoidal pulse width modulation, and the switching signals for converter 202 are generated using a phase-shift carrier technique that continuously rotates the utilization of each module 108 and distributes the power equally among them.

[0126] Figures 8C–8F are plots illustrating exemplary embodiments of a phase-shifted PWM control methodology that can generate multilevel output PWM waveforms using incrementally shifted two-level waveforms. An X-level PWM waveform can be generated by the sum of two-level PWM waveforms of (X-1) / 2. These two-level waveforms can be generated by comparing a reference waveform Vref with a carrier that has been incrementally shifted by 360° / (X-1). The carrier is triangular, but embodiments are not limited in that way. A 9-level example is shown in Figure 8C (using four modules 108). The carrier is incrementally shifted by 360° / (9-1)=45° and compared with Vref. The resulting two-level PWM waveform is shown in Figure 8E. These two-level waveforms can be used as switching signals for semiconductor switches (e.g., S1–S6) of converter 202. For example, referring to Figure 8E, with respect to a one-dimensional array 700, each containing four modules 108 with converters 202, the 0° signal is for controlling 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 with sufficient dead time to avoid shoot-through of each half-bridge, and the signal for S5 is complementary to S6. Figure 8F depicts an exemplary single-phase AC waveform produced by the superposition (sum) of the output voltages from the four modules 108.

[0127] An alternative is to utilize both positive and negative reference signals along with the first (N-1) / 2 carrier. A 9-level example is shown in Figure 8D. In this example, the 0°~135° switching signal (Figure 8E) is generated by comparing +Vref with the 0°~135° carrier in Figure 8D, and the 180°~315° switching signal is generated by comparing -Vref with the 0°~135° carrier in Figure 8D. However, the logic of the comparison in the latter case is reversed. Other techniques, such as state machine decoders, may also be used to generate gate signals for switching converter 202.

[0128] In a multiphase system embodiment, the same carriers can be used for each phase, or a 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 carriers of the second phase are shifted by 120 degrees compared to the carriers of the first phase, and the carriers of the third phase are shifted by 240 degrees compared to the carriers of the first phase. If different reference voltages are available for each phase, the phase information can be carried within the reference voltage, and the same carriers can be used for each phase. Often the carrier frequency will be fixed, but in some exemplary embodiments, the carrier frequency can be tuned, which can help reduce losses in EV motors under high-current conditions.

[0129] An appropriate switching signal can be provided to each module by the control system 102. For example, the MCD 112 can provide each LCD 114 with Vref and an appropriate carrier signal depending on the module or multiple modules 108 controlled by the LCD 114, and the LCD 114 can then generate a switching signal. Alternatively, all LCD 114 in the array can be provided with all carrier signals, and the LCDs can select the appropriate carrier signal.

[0130] The relative utilization of each module 108 can be adjusted based on status information, as described herein, to perform balancing of one or more parameters. Parameter balancing may involve adjusting utilization and minimizing parameter divergence over time compared to a system in which individual module utilization adjustments are not performed. Utilization may be the relative amount of time that module 108 is discharging when system 100 is in a discharge state, or the relative amount of time that module 108 is charging when system 100 is in a charge state.

[0131] As described herein, module 108 can be balanced with respect to other modules in array 700, which may be referred to as intra-array or intra-phase balance; different arrays 700 can also be balanced with respect to each other, which may be referred to as inter-array or inter-phase balance. Arrays 700 of different subsystems can also be balanced with respect to each other. The control system 102 can simultaneously implement any combination of intra-phase balance, inter-phase balance, utilization of multiple energy sources within a module, active filtering, and auxiliary load supply.

[0132] Figure 9A is a block diagram depicting an exemplary embodiment of an array controller 900 of a control system 102 for a single-phase AC or DC array. The array controller 900 may include a peak detector 902, a divider 904, and an in-phase (or in-array) balancing controller 906. The array controller 900 can receive a reference voltage waveform (Vr) and status information (e.g., charge state (SOCi), temperature (Ti), capacitance (Qi), and voltage (Vi)) for each of the N modules 108 in the array as input and generate a normalized reference voltage waveform (Vrn) and modulation index (Mi) as output. The peak detector 902 detects the peak (Vpk) of Vr, which may be specific to the phase in which the controller 900 is operating and / or maintaining balance. The divider 904 generates Vrn by dividing Vr by its detected Vpk. The phase-to-phase balance controller 906 uses Vpk along with status information (e.g., SOCi, Ti, Qi, Vi, etc.) to generate a modulation index Mi for each module 108 in the controlled array 700.

[0133] 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 (including zero and one). For a particular module 108, a 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 Figures 8C-8F or according to other techniques. Thus, the modulation index can be used to control the PWM switching signal provided to the converter switching network (e.g., S3-S6 or S1-S6) and thus to coordinate the operation of each module 108. For example, a module 108 controlled to maintain normal or full operation may receive a Mi of 1, while a module 108 controlled to normal or less than full operation may receive a Mi of less than 1, and a module 108 controlled to shut off power output may receive a Mi of zero. This operation can be carried out by the control system 102 in various ways (for example, by having the MCD 112 output Vrn and Mi to the appropriate LCD 114 for modulation and switch signal generation, by having the MCD 112 perform modulation for switch signal generation and output the modulated Vrnm to the appropriate LCD 114, or by having the MCD 112 perform modulation and switch signal generation and output the switch signal directly to the LCD or converter 202 of each module 108). Vrn can be transmitted continuously along with Mi, which is transmitted at regular intervals, such as once per Vrn period or once per minute.

[0134] The controller 906 can generate Mi for each module 108 using status information of any type or combination of types described herein (e.g., SOC, temperature (T), Q, SOH, voltage, current). For example, using SOC and T, module 108 may have a relatively high Mi if its SOC is relatively high and its temperature is relatively low compared to other modules 108 in the array 700. If its SOC is relatively low or its T is relatively high, module 108 may have a relatively low Mi and result in less 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 is the sum of the products of the voltages of the source 206 for each module and the Mi for that module (e.g., Vpk = M1V1 + M2V2 + M3V3... + M N V N (and so on) may be used. Different combinations of modulation indices, and therefore the respective voltage contributions of the modules, may be used, but the total generated voltage should remain the same.

[0135] The controller 900 can control its operation at any point in time (e.g., during maximum acceleration of the EV), as long as it does not prevent it from achieving the system's power output requirements, thereby ensuring that the State of Charge (SOC) of the energy sources within each module 108 remains balanced, or converges to a balanced state if they are unbalanced, and / or that the temperatures of the energy sources or other components (e.g., energy buffers) within each module remain balanced, or converges to a balanced state if they are unbalanced. Power flow into and out of the modules can be adjusted so that capacitance differences between sources do not cause SOC deviations. Equilibrium of SOC and temperature can indirectly lead to some degree of equilibrium of SOH. Voltage and current can be directly balanced if desired, but in many embodiments, the primary goal of the system is to maintain equilibrium of SOC and temperature, and equilibrium of SOC can lead to equilibrium of voltage and current in a highly symmetric system (where modules have similar capacitance and impedance).

[0136] Since it is not always possible to maintain equilibrium for all parameters simultaneously (for example, equilibrium for one parameter may further de-equilibrium another), combinations of maintaining equilibrium for any two or more parameters (SOC, T, Q, SOH, V, I) may be applied with a priority given to one of them, depending on the requirements of the application. The priority in equilibrium may be given to SOC compared to the other parameters (T, Q, SOH, V, I), with exceptions allowed if one of the other parameters (T, Q, SOH, V, I) reaches a severe disequilibrium condition outside the threshold.

[0137] Equilibrium between arrays 700 of different phases (or, for example, arrays of the same phase if parallel arrays are used) can be performed simultaneously with intraphase equilibrium. Figure 9B depicts an exemplary embodiment of an Ω-phase (or Ω-array) controller 950 configured for operation within an Ω-phase system 100 having at least Ω arrays 700, where Ω is any integer greater than or equal to 2. The controller 950 may include one interphase (or inter-array) controller 910, Ω intraphase equilibrium controllers 906-PA···906-PΩ for phases PA~PΩ, and peak detectors 902 and dividers 904 (Figure 9A) for generating a normalized reference VrnPA~VrnPΩ from each phase-specific reference VrPA~VrPΩ. The intraphase controller 906 can generate Mi for each module 108 of each array 700, as described with respect to Figure 9A. The interphase balance controller 910 is configured or programmed to maintain balance across the entire multidimensional system, for example, between the sides of module 108 between arrays of different phases. This can be achieved through the injection of common modes into the phase (e.g., neutral point shift), through the use of interconnection modules (as described herein), or both. Common mode injection involves introducing phase and amplitude shifts into a reference signal VrPA~VrPΩ to generate a normalized waveform VrnPA~VrnPΩ to compensate for imbalances in one or more arrays, and is further described in International Application PCT / US20 / 25366 incorporated herein.

[0138] Controllers 900 and 950 (and balanced controllers 906 and 910) can be implemented within the control system 102 in hardware, software, or a combination thereof. Controllers 900 and 950 can be distributed between LCDs 114, either partially or completely, and implemented within the MCD 112, or they can be implemented as separate controllers, independent of the MCD 112 and LCDs 114. (Exemplary embodiment of an interconnect (IC) module)

[0139] Module 108 can be connected between modules of different arrays 700 for the purpose of exchanging energy between arrays, for the purpose of functioning as a source for auxiliary loads, or for both purposes. Such a module is referred herein to as an interconnection (IC) module 108IC. IC module 108IC can be implemented in any of the module configurations already described (108A, 108B, 108C) and others described herein. IC module 108IC may include any number of one or more energy sources, an optional energy buffer, a switching network for supplying energy to one or more arrays and / or power to one or more auxiliary loads, a control network (e.g., a local control device), and a monitoring network for collecting status information about the IC module itself or its various loads (e.g., SOC of the energy sources, temperature of the energy sources or energy buffers, capacity of the energy sources, SOH of the energy sources, voltage and / or current measurements for the IC module, voltage and / or current measurements for the auxiliary loads, etc.).

[0140] Figure 10A is a block diagram illustrating an exemplary embodiment of a system 100 capable of producing Ω phase power using Ω arrays 700-PA to 700-PΩ, where Ω can be any integer greater than or equal to 2. In this embodiment and other embodiments, IC module 108IC can be located on the rail side of array 700, and the array 700 to which module 108IC is connected (in this embodiment, arrays 700-PA to 700-PΩ) is electrically connected between module 108IC and outputs to a load (e.g., SIO1 to SIOΩ). Here, module 108IC has Ω IO ports for connection to IO port 2 of each module 108 to N in array 700-PA to 700-PΩ. In the configuration described herein, module 108IC can achieve interphase balance by selectively connecting one or more of module 108IC's energy sources to one or more of the array 700-PA to 700-PΩ (or to no output or equally to all outputs if interphase balance is not required). System 100 can be controlled by control system 102 (not shown, see Figure 1A).

[0141] Figure 10B is a schematic diagram illustrating an exemplary embodiment of module 108IC. In this embodiment, module 108IC includes an energy source 206 connected to an energy buffer 204, which is then connected to a switch network 603. The switch network 603 may include switch network units 604-PA to 604-PΩ, each 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 control lines 118-3 from LCD 114. This configuration is similar to module 108A described with respect to Figure 3A. As described with respect to converter 202, the switch network 603 can be composed of any switch type (e.g., MOSFET, IGBT, silicon, GaN, etc.) in any arrangement suitable for the requirements of the application.

[0142] The switch network unit 604 is coupled between the positive and negative terminals of the energy source 206 and has an output connected to the I / O port of module 108 IC. Units 604-PA to 604-PΩ are controlled by the control system 102 with a voltage of +V IC or -V ICThese can be controlled to selectively couple to the respective module I / O ports 1~Ω. The control system 102 can control the switch network 603 according to any desired control technique, including the PWM and hysteresis techniques described herein. Here, the control circuit network 102 is implemented as LCD 114 and MCD 112 (not shown). LCD 114 can receive monitoring data or status information from the monitoring network of module 108 IC. This monitoring data and / or other status information derived from this monitoring data can be output to MCD 112 for use in system control, as described herein. LCD 114 can also receive timing information (not shown) for the purpose of synchronizing module 108 of system 100, and one or more carrier signals (not shown), such as sawtooth signals (Figures 8C-8D) used in PWM.

[0143] For interphase equilibrium, proportionally more energy from source 206 can be supplied to one or more of the arrays 700-PA to 700-PΩ, which are in a relatively low-charge state compared to the other arrays 700. This supplemental energy supply to a particular array 700 allows for a reduction in the energy output of those cascaded modules 108-1 to 108-N within that array 700 compared to a phase array that is not supplied.

[0144] For example, in some exemplary embodiments where PWM is applied, The LCD114 can be configured to receive a normalized voltage reference signal (Vrn), e.g., VrnPA to VrnPΩ, for each of the one or more arrays 700 to which the module 108IC is coupled (from the MCD112). The LCD114 can also receive a modulation index MiPA to MiPΩ for the switch units 604-PA to 604-PΩ from the MCD112 for each array 700. The LCD114 can modulate (e.g., multiply) each respective Vrn using the modulation index for the switch divisions directly coupled to its array (e.g., VrnA multiplied by MiA), and then use the carrier signal to generate a control signal for each switch unit 604. In another embodiment, the MCD112 can perform the modulation and output the modulated voltage reference waveform for each unit 604 directly to the LCD114 of the module 108IC. In yet another embodiment, all processing and modulation can be performed by a single control entity that can output the control signal directly to each unit 604.

[0145] This switching can be modulated so that power from energy source 206 can be supplied to array 700 at appropriate intervals and durations. Such methodologies can be implemented in various ways.

[0146] Based on the status information collected about the system 100, such as the current capacity (Q) and the SOC of each energy source within each array, the MCD 112 can determine the total charge for each array 700 (for example, the total charge for a given array can be determined as the sum of capacity × SOC for each module in that array). The MCD 112 can determine whether balanced or unbalanced conditions exist (for example, through the use of relative difference thresholds and other metrics described herein) and, as appropriate, generate a modulation index MiPA to MiPΩ for each switch unit 604-PA to 604-PΩ.

[0147] During balanced operation, Mi for each switch unit 604 can be set to a value such that the same or similar amount of net energy is supplied to each array 700 over time by the energy source 206 and / or energy buffer 204. For example, Mi for each switch unit 604 can be set to a level or value such that, during balanced operation, module 108IC performs a net or time-averaged discharge of energy to one or more arrays 700-PA~700-PΩ, which may be the same or similar and drains 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 does not cause a net or time-averaged discharge of energy (causing zero net energy discharge) during balanced operation. This may be useful if module 108IC has a lower total charge than other modules in the system.

[0148] If non-equilibrium conditions occur between arrays 700, the modulation index of system 100 can be adjusted to cause convergence toward equilibrium conditions or to minimize further divergence. For example, the control system 102 can cause module 108IC to discharge more to array 700 with lower charge levels than others, and relatively less to modules 108-1 to 108-N of that lower array 700 (e.g., on a time-averaged basis). The relative net energy given by module 108IC increases compared to modules 108-1 to 108-N of the supported array 700, and also increases compared to the amount of net energy given by module 108IC to the other arrays. This can be accomplished by increasing the Mi of the switch unit 604 supplying the low array 700, and by decreasing the modulation index of modules 108-1 to 108-N of the low array 700 in a manner that maintains the Vout for the low array at an appropriate or required level and keeps the modulation indices of the other switch units 604 supplying the other higher arrays relatively invariant (or decreases them).

[0149] The configuration of module 108IC in Figures 10A-10B can be used alone to provide interphase or interarray balance for a single system, or it can be used in combination with one or more other modules 108IC, each having an energy source and one or more switch parts 604 coupled to one or more arrays. For example, module 108IC with Ω switch parts 604 coupled to Ω different arrays 700 can be combined with a second module 108IC having one switch part 604 coupled to one array 700, thereby the two modules being coupled to supply a system 100 having Ω+1 arrays 700. Any number of modules 108IC can be combined in this manner, each coupled to one or more arrays 700 of system 100.

[0150] Furthermore, the IC module can be configured to exchange energy between two or more subsystems of system 100. Figure 10C is a block diagram depicting an exemplary embodiment of system 100, comprising a first subsystem 1000-1 and a second subsystem 1000-2 interconnected by the IC module. Specifically, subsystem 1000-1 is configured to supply three-phase power PA, PB, and PC to a first load (not shown) using system I / O ports SIO1, SIO2, and SIO3, while subsystem 1000-2 is configured to supply three-phase power PD, PE, and PF to a second load (not shown) using system I / O ports SIO4, SIO5, and SIO06. For example, subsystems 1000-1 and 1000-2 can be configured as different packs supplying power for different motors of an EV, or as different racks supplying power for different microgrids.

[0151] In this embodiment, each module 108IC is coupled to the first array of subsystem 1000-1 (via I / O port 1) and the first array of subsystem 1000-2 (via I / O port 2), and each module 108IC can be electrically connected to each other module 108IC using I / O ports 3 and 4 which are coupled to the energy source 206 of each module 108IC, as described with respect to module 108C in Figure 3C. This connection places the sources 206 of modules 108IC-1, 108IC-2, and 108IC-3 in parallel, and thus the energy stored and supplied by modules 108IC is pooled together by this parallel arrangement. Other arrangements, such as series connections, can also be used. The modules 108IC are housed within a common enclosure of subsystem 1000-1; however, the interconnection modules are outside the common enclosure and can be physically located as independent entities between the common enclosures of both subsystems 1000.

[0152] Each module 108IC has a switch unit 604-1 coupled to I / O port 1 and a switch unit 604-2 coupled to I / O port 2, as described with respect to Figure 10B. Thus, for balance between subsystems 1000 (e.g., between packs or between racks), a particular module 108IC can supply a relatively large amount of energy to one or both of the two arrays to which it is connected (e.g., module 108IC-1 can supply energy to array 700-PA and / or array 700-PD). The control network can monitor the relative parameters (e.g., SOC and temperature) of arrays of different subsystems, adjust the energy output of the IC modules, and compensate for imbalance between arrays or phases of different subsystems, in the same manner as compensating for imbalance between two arrays of the same rack or pack as described herein. Since all three modules 108IC are in parallel, energy can be efficiently exchanged between any arrays of system 100. In this embodiment, each module 108IC supplies two arrays 700, but other configurations can also be used (including a single IC module for all arrays of system 100 and one dedicated IC module for each array 700 (for example, six IC modules for six arrays, each IC module having one switch unit 604)). In all cases involving multiple IC modules, the energy sources can be coupled together in parallel to share energy, as described herein.

[0153] In systems with IC modules between phases, interphase equilibrium can also be achieved by neutral point shift (or common-mode injection), as described above. Such combinations allow for more robust and flexible equilibrium under a wider range of operating conditions. System 100 can determine the appropriate conditions under which interphase equilibrium should be achieved using neutral point shift alone, interphase energy injection alone, or a combination of both simultaneously.

[0154] 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 reduced voltage from source 302). Figure 10D is a block diagram depicting an exemplary embodiment of a three-phase system 100A with two modules 108IC connected to perform inter-phase balancing and supply power to auxiliary loads 301 and 302. Figure 10E is a schematic diagram depicting this exemplary embodiment of system 100 with emphasis on modules 108IC-1 and 108IC-2. Here, the control circuit network 102 is again implemented as LCD 114 and MCD 112 (not shown). LCD114 can receive monitoring data (e.g., SOC of ES1, temperature of ES1, Q of ES1, voltages of auxiliary loads 301 and 302, etc.) from module 108IC and can output this monitoring data and / or other monitoring data to MCD112 for use in system control, as described herein. Each module 108IC may include a switch section 602A (or 602B as described in relation to Figure 6C) for each load 302 supplied by that module, and each switch section 602 may be controlled by LCD114 to maintain essential voltage levels for the loads 302, independently or based on a control input from MCD112. In this embodiment, each module 108IC includes a switch section 602A connected together and supplying one load 302, but is not required to do so.

[0155] Figure 10F is a block diagram depicting another exemplary embodiment of a three-phase system configured to supply power to one or more auxiliary loads 301 and 302 using modules 108IC-1, 108IC-2, and 108IC-3. In this embodiment, modules 108IC-1 and 108IC-2 are configured in the same manner as those described with respect to Figures 10D-10E. Module 108IC-3 is configured purely for auxiliary purposes and does not actively inject voltage or current into any array 700 of the system 100. In this embodiment, module 108IC-3 may have converters 202B, C (Figures 6B-6C) configured as module 108C in Figure 3B, with one or more auxiliary switch portions 602A, but omitting the switch portion 601. Therefore, 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 consists of additional energy to supply auxiliary loads 301 and 302 and to maintain the charge on the sources 206A of modules 108IC-1 and 108IC-2 through the parallel connection with the sources 206 of module 108IC-3.

[0156] The energy source 206 of each IC module may, but is not required to, be the same voltage and capacitance as the sources 206 of the other modules 108-1 to 108-N in the system. For example, a relatively high capacitance may be desirable in embodiments where one module 108IC supplies energy to multiple arrays 700 (Figure 10A) and the IC module discharges at the same rate as the modules of the phase array itself. If module 108IC also supplies an auxiliary load, even greater capacitance may be desired to allow the IC module to both supply the auxiliary load and discharge at a relatively similar rate to the other modules. (fast charging)

[0157] Exemplary embodiments will be described herein relating to fast charging techniques for energy sources that utilize pulsed preheating and / or pulsed charging techniques. While these embodiments will be described primarily in the context of an energy source 206 which is a battery, these embodiments are equally applicable to other types of energy sources (e.g., high energy density capacitors and fuel cells). These embodiments can be applied to charging batteries having a single cell, batteries having multiple cells (e.g., connected in series, parallel, or a combination thereof, and sometimes referred to as battery modules), and systems having multiple battery modules (e.g., connected in series, parallel, or a combination thereof, and sometimes referred to as battery packs).

[0158] Suitable battery types for use with this subject include solid-state batteries, liquid electrotype-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-titanium oxide (LTO).

[0159] Although not required to be used with any particular configuration of an energy storage system, embodiments of the system 100 described herein can, in particular, benefit from use with this fast charging embodiment. When used with an embodiment of the system 100 to charge the energy source among them, 206, the converter 202 of each module 108 is independently controlled to apply positive, zero, or negative pulses 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 opposite to the process described herein for generating the superposition of all output pulses from all modules 108. Each converter 202 can be switched at a frequency greater than 100 Hz, for example, to apply pulses of 5 milliseconds (msec) or less at a 50% duty cycle. Longer or shorter pulse durations with different duty cycles can also be used. This pulsing ability enables the energy source to be charged and / or heated, as will be described herein.

[0160] The converter 202 can be controlled using a control system that applies pulse width modulation techniques, hysteresis techniques, or another technique that attempts to utilize all modules equally over time. Each module 108 can monitor the status of the energy source 206 of that module 108 (e.g., state of charge (SOC), temperature, voltage, current, etc.) and feedback this monitoring information to the control system 102, and the control system 102 can maintain the balance of a selected parameter or parameters (e.g., SOC and / or temperature) that should be kept in balance, or converge towards that balance condition, and can individually adjust the charging utilization of each module 108.

[0161] The cascaded topology of system 100 allows the charging voltage or charging current from a charging source to be divided among energy sources as needed to implement charging schemes of varying complexity. For example, the voltage (or current) may be applied in a pulsed manner, and some sources 206 may be charged at some time, while others are not, on the condition that the total voltage applied to sources 206 (and other charging sinks in the system) is generally equal to the DC or AC voltage supplied to system 100 by the charging source at that moment in time. The voltage and duration of the applied pulses (and the duration of the pauses between pulses) can be varied and timed based on the state of those sources 206, such that they are monitored by each module 108 (e.g., the monitoring network 208 and LCD 114). Thus, the voltage division among modules 108 allows for both charging and pausing of the sources 206 of module 108 as needed.

[0162] This embodiment can be used to charge the source 206 at various levels of granularity. For example, a battery module as a whole can be pulsed, and for example, one pulse can be applied to all the batteries constituting that battery module. Alternatively, an additional switching network (e.g., in addition to the configuration shown with respect to converter 202) can be included for each individual battery so that each battery in a battery module can be pulsed independently. For example, a system 100 having N battery modules, each having M batteries, can be composed of NM (N multiplied by M) converter or switch circuits. Other levels of granularity are also possible, such as the ability to pulse charge groups of batteries within each battery module (e.g., the batteries can be divided into two groups, each of which can be controlled independently so that the system has 2N converter or switch circuits). Control of the switching network for various battery modules and / or batteries can be performed by a control system 102 (e.g., MCD112, which is communicatively coupled to LCD114) which is communicatively coupled to system module 108. (Exemplary Embodiments of High-Speed Charging Techniques)

[0163] Exemplary embodiments related to high-speed or rapid charging of an energy source at an improved rate are provided herein. The exemplary embodiments relate to the application of voltage or current pulses to a battery to raise the temperature of the battery through localized heating, the application of voltage or current pulses to the battery to charge the battery, the application of a constant (non-pulsed) voltage or constant current to the battery to charge the battery at a higher temperature, the monitoring of the battery for degradation conditions during charging, and any combination thereof. The embodiments described herein can enable stationary and mobile energy storage systems to be charged at a wide range of C-rates, subject to not exceeding certain voltage and temperature constraints with respect to the battery cells. For example, the present embodiments can enable an EV with a 100 kilowatt-hour (kWh) storage capacity to be charged from zero to 80% capacity in 10 minutes (or less) without substantially degrading the capacity over the rated life of the battery pack.

[0164] Figure 11A is a plot depicting a framework for illustrating 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 timeframe of less than 15 minutes. Figure 11B is a plot of embodiments of protocol 1100 to which exemplary values ​​are applied. The fast charging protocol 1100 described with respect to Figures 11A-11B (and elsewhere herein) can be applied to batteries having only a single battery or to battery modules having two or more batteries (e.g., 2 to 100 batteries) and can be implemented by a charging and switching network near an 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 preheating and charging signals accordingly. While such approaches are possible for charging a single battery, a battery module with multiple batteries, or even a system as a whole (e.g., a battery pack), the approaches do not allow for granular control of the preheating and charging process as applied to individual batteries within a battery module and / or individual battery modules within a system.

[0165] To provide finer-grained control, protocol 1100 may also be applied within such cascaded modular energy storage systems 100 as described herein, where each module 108 includes a battery 206 which may contain only a single battery or two or more batteries (e.g., 2 to 100 batteries), and the number of modules 108 may be two or more (e.g., 2 to 1,000 modules 108). The converter 202 of each module 108 may be controlled independently as described herein, so that protocol 1100 may be controlled independently by each module 108 of the system 100. For example, considering a battery pack having 12 modules 108, each having a battery 206 containing 12 batteries, protocol 1100 may be applied independently by each module 108 to charge each battery 206 having 12 batteries in 15 minutes or less, and thus charge the entire battery pack in the same or similar amount of time. Since the conditions of the batteries 206 in system 100 will vary, and the embodiment can adjust the charge rate based on feedback from each battery 206, the charging time for each battery 206 may vary. At the start of a charging cycle, some batteries 206 may be at 2-3% SOC, while others are at 0% or near SOC, or at some percentage in between. Some batteries 206 may have a higher capacity than others and will require a longer time to reach the desired SOC. Some batteries 206 may exhibit signs of degradation or other characteristics that require the charging process to be slowed down during charging.

[0166] To enable a more detailed discussion of protocol 1100, Figures 12A–12F will be discussed to provide context for the battery characteristics and structure. Figure 12A is a cross-sectional view of a generalized lithium-ion battery 1200. The battery 1200 comprises a repeating layered structure, each layer comprising an anode 1201 and a cathode 1202, with an isolation plate 1203 between them. Each anode 1201 comprises an anode material 1204, the anode material 1204 having an electrolyte 1208 embedded in it and a current collector 1205 positioned within the anode material 1204. Similarly, each cathode 1202 comprises a cathode material 1206 having an electrolyte 1209 embedded in it and a current collector 1207 positioned within it.

[0167] Figure 12B is an explanatory diagram illustrating enlarged views of the anode 1201 and cathode 1202 and listing examples of degradation modes that may occur in a typical lithium-ion battery. Each of the degradation modes listed herein can be caused directly or indirectly by the application of overvoltage to the anode and cathode and by charging at excessive temperatures. The exemplary embodiments described herein seek to limit the application of overvoltage and operation at excessive temperatures, and therefore limit these degradation modes.

[0168] Figure 12C is an electrical circuit diagram model of battery cell 1200. The anode is the ohm component (V ohmic ) and electrochemical interface component (V EC INTERFACE This shows the voltage drop, including V. ohmic The ohm resistance (R) of the anode is ohmic It is determined by the size of V. EC INTERFACE This is the anode bilayer sheet capacitance (C DL The activation impedance (R) is modeled as a component connected in series in parallel with ) CT ) and diffusion-based impedance (R Warburg Determined by V. A R CT V is an activation-based voltage drop across the spectrum, while V NernstR Warburg This is a diffusion-based voltage drop across the curve. The total impedance of the anode is R ohmic , R CT , and R Warburg This is the sum of the two. The cathode is modeled similarly, but with its own characteristic value. The electrolyte also has an ohmic resistance (R ohmic electrolyte The voltage (V) is determined by ) ohmic electrolyte ) Indicates descent.

[0169] Figure 12D is a plot illustrating the exemplary voltage response 1212 to a charging pulse 1214 applied to a lithium-ion battery. Resistance (V) between the anode and cathode. ohmic ), activation base (V A ), and diffusion base (V Nernst The voltage components of the anode and cathode can be determined by analysis of the response after the end of the charge pulse 1214. Figure 12E is a graph depicting exemplary voltages on a lithium-ion battery across a range of SOC, showing the voltage components attributable to the cathode, anode, and the battery itself. Voltage response analysis can be used to determine the magnitude of overvoltages on the anode and cathode, and the magnitude and frequency of the charge pulse can be maintained, increased, or decreased accordingly so that they remain within acceptable limits. The available overvoltage range with respect to the anode and cathode decreases as the charge state on the battery increases. Embodiments of this specification can be applied such that the current is reduced as the battery is charged in any of the stages 1110, 1120, 1130.

[0170] Figure 12F is a plot illustrating the exemplary impedance response of a lithium-ion battery. As the frequency of the charging pulse increases, the impedance response becomes pure R of the real impedance with a low imaginary component. ohmic It moves toward the portion. Pulsing at higher frequencies can reduce the activation component of the voltage response.

[0171] Referring again to Figures 11A-11B, protocol 1100 may have three stages: a preheating stage 1110, a first charging stage 1120, and a second charging stage 1130. The energy for the preheating and charging signals applied to battery 206 may be supplied from an external charging source (e.g., a grid or charging station), or, in some cases, from an internal source, such as through a second source 206B. Here, the pulsed preheating stage 1110 may last for a set duration (time_0 to time_1), or until a first temperature threshold is reached (temp_1). In Figure 11B, the preheating stage 1110 is applied until the battery reaches 30°C, which occurs after about 1 minute.

[0172] The preheating stage 1110 involves the application of a preheating pulse signal 1112 as a series or sequence of pulses, each pulse alternating between a charge pulse (negative current) and a discharge pulse (positive current) of equal or substantially equal duration (optionally with a time gap between the application of charge and discharge pulse pairs). Figures 11C-11D are current-vs-time graphs illustrating exemplary embodiments of the preheating pulse series 1112 with and without a time gap, respectively, where the preheating pulse series 1112 oscillates between a positive preheating current (+Iph) and an equal but opposite negative preheating current (-Iph).

[0173] The preheating step 1110 can achieve localized heating by increasing the temperatures of the anode current collector 1205, the cathode current collector 1207, and the electrolyte 1209 (Figure 12A) without activating the electrochemical reaction. In many embodiments, the frequency (F) of the preheating signal 1112 preheat ) follows the following equation (1). (1) F preheat >>1 / (R CT ×C DL )

[0174] The preheating signal 1112 is a signal at a single frequency, and each pulse may have a rectangular or substantially rectangular form (as visualized in the time domain). In other embodiments, the preheating signal 1112 can be implemented in a more complex manner having multiple frequency components, such as a primary pulse train and secondary pulses, in the frequency domain of 1 Hz to a maximum of 1 megahertz (MHz). In various embodiments, the preheating signal 1112 has a frequency range of 100 Hz to 100 kilohertz (kHz). The frequency of the preheating signal 1112 causes a voltage drop, mainly due to the action of electrolyte impedance and current collector impedance, and therefore the voltage of the preheating signal 1112 can lead to cathode and anode voltages exceeding their relative cutoff overvoltages in both relatively low and relatively high charge states.

[0175] The preheating step 1110 causes a temperature increase in a localized area within the battery by targeting the ohm impedance to heat the active material while avoiding the activation of electrochemical reactions such as side reactions (e.g., electrolyte decomposition, active material 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 identified by those skilled in the art, enabling long functional operation in their respective commercial, research, or industrial applications). Step 1110 warms the battery until the activation impedance and total impedance are sufficiently small, and therefore, overvoltage on the anode does not promote electrochemical reactions or lithium plating. Step 1110 thus enables rapid heating of the electrochemical interface and bulk material temperature control, allowing for subsequent charging without causing side reactions or damage due to material stress resulting from rapid degradation of the anode and cathode materials (e.g., lithiation or delithiation).

[0176] The preheating stage 1110 can be applied until all batteries of the source 206 reach a minimum temperature threshold, provided that no battery exceeds a maximum temperature threshold. If a battery reaches a maximum threshold, the preheating stage 1110 can be slowed down or stopped, or protocol 1100 can proceed to the next stage (first or second charging stage 1120, 1130) as described herein. Battery temperature can be measured directly or indirectly (e.g., temperature in a subgroup of batteries or in close proximity to the batteries) using a temperature sensor (e.g., infrared). Alternatively, or in combination with direct sensing, the temperature of one or more batteries (including all batteries) can be measured using a single sensor (e.g., infrared images of multiple batteries). Temperature can also be inferred, optionally, based on data collected from previously characterized batteries, by using a model or lookup table that references other indirect metrics (e.g., voltage, current, impedance). The temperature thresholds for this stage and other stages are preferably related to the internal temperature of the battery where the electrolyte and active material are located. Therefore, if the battery surface temperature is measured (for example, using a thermistor or optical device), the thresholds are set based on estimation, a lookup table, or a model, with respect to the surface temperature that is related to the desired internal battery temperature.

[0177] The preheating stage 1110 raises the temperature of the battery 206 to a first temperature threshold, which in the example of Figure 11B is 30 degrees Celsius (°C) measured on the battery surface. The temperature threshold may depend on the battery type and, for lithium-ion batteries, may be, for example, 25 to 70°C (including those values). In other embodiments, the preheating stage 1110 may last for a predetermined duration (time_0 to time_1), such as less than 1 minute, 1 minute, 2 minutes, 3 minutes, 5 minutes, or other. The duration of stage 1110 varies based on the starting temperature, with lower starting temperatures requiring relatively longer times. 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, staying at or near the initial SOC. Furthermore, the applied frequency pattern of the pulse sequence is preferably selected so as not to initiate any electrochemical reactions of storage reactions or side reactions. The preferred frequency range for the preheating pulse signal 1112 is 100 Hz to 100 kHz.

[0178] The C-rate of the pulses applied during the preheating stage 1110 can vary widely and depend primarily on the ohmic characteristics, applied voltage, and thermal behavior of the battery during this stage. C-rates up to 30C and higher can be applied in stage 1110. Furthermore, stage 1110 can be applied so that no net charge or discharge occurs, but in other embodiments, the length of the charge pulse may be slightly longer (e.g., 1-15%) than the length of the discharge pulse to initiate charging of the battery at a relatively lower rate compared to subsequent stages. This can occur, for example, when the battery 206 is heating towards a transition threshold temperature or time, moving towards the transition from the preheating stage 1110 to the first charge stage 1120. Thus, stage 1110 can be divided into a first sub-stage 1114 in which no charge occurs, and a second subsequent sub-stage 1116 after reaching a higher temperature where the charge pulse length is longer than the discharge pulse length to initiate charging, but at a slower rate than the second stage of pulse charging described below. An exemplary embodiment of the preheating signal 1112 applied between both sub-stages 1114 and 1116 is depicted in Figure 11E. The second sub-stage 1116 can introduce charging at a fixed rate (e.g., a charging pulse longer than 5%) or it can start charging by gradually increasing amounts over the duration until transitioning to the first charging stage 1120 (e.g., a charging pulse 1% longer over 30 seconds, followed by a charging pulse 2% longer over 30 seconds, etc.).

[0179] The transition from stage 1110 to the first charging stage 1120, or alternatively, the transition from the first sub-stage 1114 to the second sub-stage 1116, can occur under conditions where pulse charging can occur at a high C rate for fast charging without causing significant side reactions such as lithium plating. In some embodiments, this condition is the average current × Warburg impedance (R) of the intended pulse charging rate. Warburg ) may be such that the voltage does not exceed the overvoltage range for any of the electrodes. In other embodiments, this condition which may affect the transition to pulse charging is R WarburgHowever, with respect to each electrode, the total impedance may be reduced to 50% or less, 40% or less, 30% or less, 20% or less, or 10% or less. In embodiments in which the preheating stage 1110 transitions directly to the constant current charging stage 1130 (without the pulse charging stage 1120), the transition conditions may, in some examples, be when the activation impedance drops to 50% or less, 40% or less, 30% or less, 20% or less, or 10% or less, with respect to each electrode, the total impedance.

[0180] The first charging stage 1120 is a pulsed charging stage in which a pulsed charging signal is applied to the battery 206. Stage 1120 enables fast charging at a high C rate with reduced activation overvoltage and reduced occurrence of side reactions, as will be described in more detail herein. Figure 11F is a current-versus-time graph depicting an exemplary embodiment of a pulsed 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 a duration 1124 and a duty cycle of 50%. 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 in order to further reduce the overvoltage on the electrochemical interface. While current-controlled pulses are described with respect to the preheating signal 1112 and the pulsed charging signal 1122, voltage-controlled pulses can also be used in a similar manner.

[0181] The pulse applied in step 1110 may have a voltage exceeding the cutoff voltage (upper and lower) of the energy source 206. In some embodiments, the amount by which the step 1110 pulse can exceed the cutoff voltage is limited by the breakdown voltage of the electrolyte. The pulse applied in step 1120 may also have a voltage exceeding the cutoff voltage (upper and lower) of the energy source 206. In some embodiments, the amount by which the step 1120 pulse can exceed the cutoff voltage is less than or equal to the pulse charging current multiplied by the activation impedance with respect to the electrode.

[0182] The optimal frequency and duration 1124 of the Inca pulse depend on the battery type. In many embodiments, the frequency (F pulse ) of the pulse charging signal 1122 follows the following equation (2). (2) F pulse > 1 / (R CT × C DL )

[0183] An F value greater than twice that of equation (2) substantially eliminates the activation impedance and activation overvoltage (e.g., V in FIG. 12C pulse and R A and CTBy eliminating the component, faster charging is possible without exceeding the maximum overvoltage at the EC interface. In one embodiment of a lithium-ion battery with graphite anode and nickel-cobalt cathode chemicals, it has been found that a charge pulse duration 1124 of 2 milliseconds (m sec) (e.g., 250 Hz at a 50% duty cycle) can be used in protocol 1100 to charge the battery 206 at a fast rate (e.g., 0-75% charge in less than 15 minutes) with no substantial capacity degradation over time (e.g., over the course of numerous charge cycles in which the battery 206 cycles from low charge or no charge to a nominal SOC level) compared with a constant current charge signal at a similar amperage. A charge pulse duration 1124 of 5 m sec or less can charge the battery 206 at a fast rate with significant improvement in capacity retention over time compared with a constant current charge signal at a similar amperage. The exemplary embodiments described herein can be applied to any charge pulse duration 1124 that is operable with respect to battery type. Embodiments include charge pulse durations for lithium-ion batteries of 5 msec or less, 4 msec or less, 3 msec or less, 2 msec or less, and 1 msec or less. Durations can be as short as 0.05 msec or 0.1 msec. Although data were collected at a 50% duty cycle, pulses can be applied at various different duty cycles such as 25–75%, 40–60%, and 45–55%. In an embodiment, a pulse is applied at a pulse C rate of 10.67C to charge 80% in 9 minutes, which, given a 50% duty cycle, results in a time-averaged C rate of 5.33C with respect to the second stage (10.67C / 2).

[0184] Depending on the duty cycle, the time-averaged C rate may be greater or less than the desired target (e.g., 80% SOC within approximately 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 or the chemical and physical constraints of the battery cells, and the electrical and physical constraints of the system being charged and the charger, as described herein. Thus, the time-averaged C rate for the second stage may vary considerably across embodiments. In one example, the time-averaged C rate for the pulse charging stage 1120 is 4C to 8C, but the subject is not so limited. With respect to protocol 1100, 30C and higher time-averaged C rates are within the scope of the subject.

[0185] The pulse signal 1122 can be applied with a current magnitude such that each battery cell exhibits a voltage response that is above the open-circuit voltage of the battery but below the upper cutoff voltage of the electrochemical interface voltage (excluding ohmic overvoltage) on the anode and cathode electrodes. In various embodiments, the pulse is applied so that each battery does not exceed the anode-only overvoltage range, the cathode-only overvoltage range, or the combined anode and cathode overvoltage range. As a result of the reduced activation overvoltage, pulse charging can drive the battery voltage to a higher voltage than constant current charging in the same (lower) temperature range.

[0186] The optimal duration of stage 1120 depends on the battery type, and longer pulse charging stages can be used for chemicals that have more activation or activation that persists at higher temperatures. Pulse charging stage 1120 can continue until the activation impedance is reduced to 50% or less of the total 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%, 30%, 20%, or 10% or less of the total impedance. Other constraints, such as battery temperature and cutoff voltage, can also determine when stage 1120 terminates.

[0187] Referring again to Figures 11A and 11B, the first charging stage 1120 can continue for a predetermined duration (e.g., time_1 to time_2), until a state of charge (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., ending when any of the time, SOC, or temperature thresholds is reached). Stage 1120 is intended, but not limited to, charging at relatively low temperatures where the benefits of pulsed charging outweigh the drawbacks. For example, stage 1120 could also be designed to further increase the temperature to one which is suitable for transitioning to a second charging stage 1130 in order to apply constant current charging to charge to a higher charge state.

[0188] In the embodiment of Figure 11B, stage 1120 ends when the temperature of the battery 206 is about 50°C. In other embodiments, for example, the temperature threshold (temp_2) may be above 30°C, such as 30-60°C or 40-55°C. Thresholds outside these ranges are also possible, based on the battery chemistry. In the embodiment of Figure 11B, the temperature threshold for ending stage 1120 is reached when the battery SOC reaches about 55%. In embodiments using an SOC threshold, that threshold may be 30%-80%, 40%-70%, or 50-60%. In the embodiment of Figure 11B, the second stage ends after a duration of about 5 minutes. In other embodiments, for example, the duration may be above 1 minute, such as 1-9 minutes, 2-8 minutes, 3-7 minutes, or 5-7 minutes.

[0189] The second charging stage 1130 is a constant current charging stage in which a constant current signal is applied to the battery 206 without being pulsed. In stage 1130, the impedance of its activation and diffusion base is reduced (for example, V in Figure 12C). A , R CT , V Nernst , and R WarburgThe components are intended to have relatively high temperatures at the electrochemical interface, and therefore the benefits of pulsed charging are reduced. The reduced activation and diffusion impedances allow constant current charging at higher rates and higher states of charge without exceeding the maximum overvoltage. Stage 1130 can be started after the completion of the first charging stage 1120 and can continue until the battery 206 is fully charged or partially charged (>50%). As the open-circuit voltage of each battery increases, the magnitude of the charging pulse is preferably controlled so as not to exceed the upper cutoff voltage of each battery.

[0190] Constant current can be applied at relatively high time-averaged C rates, such as 4C to 8C (or higher). Using a constant current, generally, there will be no difference between the time-averaged C rate and the actual C rate when current is applied; however, in some cases, slight fluctuations in current can make the time-averaged C rate a more relevant metric.

[0191] 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 start phase 1130 at a relatively high C rate and then gradually shift to lower C rate values ​​as the charging process progresses to avoid exceeding the overvoltage range as the SOC increases (see Figure 12E). Relatively short pauses or pauses can occur during constant current charging to allow the battery voltage to stabilize. Figure 13A is a graph illustrating exemplary levels of the constant current charging signal 1132 in stage 1130, where in the first substage 1133, the signal 1132 is applied at a first C rate (e.g., 6C to 8C) for a first duration T1 (e.g., 60 to 120 seconds), followed by a relatively short pause period (e.g., 5 to 15 seconds) during which no signal is applied, and then in the second substage 1134, the signal 1132 is applied at a second relatively lower C rate (e.g., 4C to 6C) for a second duration T2 (e.g., 90 to 150 seconds), and again, no signal is applied. A relatively short pause period (e.g., 5-15 seconds) follows, then during the third sub-stage 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), again followed by a relatively short pause period (e.g., 5-15 seconds) during which no signal is applied, then during the fourth sub-stage 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 durations T1-T4 during which the signal 1132 is applied in each sub-stage 1133-1136 may be constant or variable, and the signal 1132 is stopped when it reaches a threshold selected to avoid the battery (or cell) voltage entering an overvoltage condition. The exemplary C rates and durations provided herein are for illustrative purposes only and are not limiting, as embodiments are practical beyond these scopes.Stage 1130 can be carried out using a single constant current rate, or any number of two or more substages (e.g., 1133-1136) in which the constant current rate is iteratively reduced.

[0192] Figure 13B is a graph of another exemplary embodiment of protocol 1100 in which a second charging stage 1130 is in which a constant current signal is applied in a progressively decreasing magnitude, as described with respect to Figure 13A. Each of the substages 1133–1136 can be terminated and transitioned to the next substage in response to the occurrence of a time threshold, temperature threshold, SOC threshold, voltage threshold, and / or any combination thereof.

[0193] Protocol 1100 is not required to perform 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 then terminate. In yet another embodiment, the pulse preheating stage 1110 can be omitted, for example, if the battery 206 is already sufficiently heated. Exemplary embodiments of these and other modifications of protocol 1100 are described with reference to Figures 19B-19G.

[0194] Protocol 1100 also includes monitoring each battery 206 for indications of potentially degrading conditions. This monitoring, which may be carried out in any and all of stages 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, for example, Figure 12F). Detection of side reactions may be used to modify the characteristics of the charging signal, for example, the voltage of the charging signal may be reduced to decelerate a side reaction, the duration of the charging pulse may be reduced to decelerate a side reaction, the frequency of application of the charging pulse may be reduced to decelerate a side reaction, or the opposite may be carried out if it is determined that the rate of side reactions is low enough to allow for faster charging. Voltage and impedance analysis can be performed during any of the three stages (1110, 1120, 1130), specifically during the preheating stage 1110, the first charging stage 1120, the second charging stage 1130, or any combination thereof.

[0195] Figure 14 is a series of plots illustrating an exemplary embodiment 1400 of monitoring for an indication of lithium plating occurring. In this embodiment, signal 1402 is applied to battery 206, and signal 1402 includes a charge pulse, as shown in the upper row of plot 1401, followed immediately by a discharge pulse of equal or substantially equal duration. A small time gap may exist 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, and no lithium plating has occurred, while a second charge pulse 1406 and a second discharge pulse 1407 are shown with respect to Example 1409, and lithium plating has occurred.

[0196] The voltage response of battery 206 to signal 1402 can be monitored as shown in intermediate plot 1410. A normal voltage response 1412 is shown on the left in the case where no lithium plating has occurred, and a voltage response 1414 indicating lithium plating has occurred, specifically indicating that plated lithium has been stripped, is shown on the right. If a lithium plating event is occurring, it is evident in the portion of voltage response 1414 to discharge pulse 1406, typically in the relatively rapid transition in response 1414 from one voltage to another while the discharge pulse is applied at approximately constant magnitude. This rapid transition in voltage response 1414 indicates that plated lithium is being stripped further. Thus, the response is generated by lithium stripping and therefore indicates that lithium plating occurred before the application of discharge pulse 1407.

[0197] Plating can be detected directly from the voltage response or from the derivative of the voltage response 1422, as depicted below in plot 1420. The derivative of the voltage response generates a transition (e.g., a positive or negative peak or spike) at times when the voltage response undergoes a relatively significant nonlinear transition (e.g., when current pulses begin and end 1424, and when lithium peeling events occur as shown by 1426). In some embodiments, only the voltage response to a 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 any of the three stages: only during the preheating stage 1110, only during the first charging stage 1120, only during the second charging stage 1130, or any combination thereof. For example, the monitoring routine 1400 can be performed once every 5 seconds, every 10 seconds, every 20 seconds, or at any other desired interval. Routine 1400 may include the application of one pair (e.g., 1404 and 1405) or more pairs of pulses. The pulse length can range from 0.1 msec to 10 seconds, preferably about 100 msec or less, so as not to have much effect on the charging time of routine 1400.

[0198] Figure 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 and determined for use in power applications such as in conventional EV car battery packs. Data 1502 shows the results from batteries charged with constant current at a 1C rate, and data 1504 shows the results from batteries pulse-charged in a manner similar to that described with respect to pulse charging stage 1120. Figure 15A compares capacity and cycle time in milliampere-hours (mAh), which is a measure of the cumulative time the battery was tested in repeated cycles. Constant current charging cycles were formed by applying 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. Pulse cycles were formed by applying a 1C pulse with a duration of 2ms in a 50% duty cycle over 1 hour, followed by discharge over 1 hour at a 1C rate, and then the cycle was repeated. Experimental data were collected at 25°C, and the cycles were performed over approximately 280 hours. Figure 15A shows that the pulsed charging battery achieved an average of 10% higher capacity than the constant-current charging battery in each cycle, and the cycle life of both decreased at approximately the same rate.

[0199] Figure 15B shows the same data as Figure 15A in a normalized form, with capacity shown as a percentage of the initial capacity achieved. This again shows nearly identical reductions in cycle life for pulsed charging battery data 1514 compared to constant current data 1512. Thus, the data in Figures 15A-15B show that pulsed charging does not cause an increased reduction in cycle life compared to constant current batteries. Pulsed charging can reduce activation impedance and result in improved capacity. If the conditions are adjusted to pulse-charge the battery to a lower capacity than the constant current battery achieved, the cycle life for pulsed charging batteries will be improved compared to constant current charging batteries.

[0200] Figure 16A is a plot of experimental data comparing the effectiveness of fast charging protocol 1100 to constant current charging for a pair of lithium-ion battery cells rated and determined for use in power applications (such as in conventional EV car battery packs). Protocol 1100 was implemented using a preheating phase 1110, a first charging phase 1120, and a second charging phase 1130, followed by cooling and discharging to form one cycle. This cycle was repeated continuously and independently on the two battery cells. Figure 16C is a capacity vs. time graph, and Figure 16D is a voltage vs. time graph, both showing data collected from the implementation of an exemplary cycle of protocol 1100 on the battery cells. This exemplary embodiment of protocol 1100 included a net-zero charge pulse preheating phase 1110 that raised the battery temperature from approximately 20°C to approximately 35°C. This was followed by a pulsed charging phase 1120 lasting 3 minutes, with a 2ms pulse applied at 5C and a 50% duty cycle. This was followed, in order, by a constant-current charging phase 1130 having a first sub-phase 1133 with a 10-second pause and a 7C rate for 90 seconds, a second sub-phase 1134 with a 10-second pause and a 5C rate for 120 seconds, a third sub-phase 1135 with a 10-second pause and a 3.3C rate for 120 seconds, and a fourth sub-phase 1136 with a 1.8C rate for 6 minutes. The pulsed charging phases 1120 and sub-phases 1133-1136 also met the battery voltage limits (4.25V for phase 1120 and 4.2V for sub-phases 1133-1136). This example of protocol 1100 achieved a nominal capacity of over 75% in less than 13 minutes. After charging, a relatively long rest period of approximately 60 seconds was performed to allow the battery to cool, and then the battery was discharged at a rate that achieved zero capacity one hour after the start of protocol 1100.

[0201] Referring again to Figure 16A, data 1602 shows the results from a battery charged using a constant current at a 3.2C rate, and data 1604 shows the results from a battery charged using protocol 1100, as described with respect to Figures 16B-16C. Figure 16A compares capacity (mAh) to cycle time, which is a measure of the cumulative time the battery was tested in repeated cycles. The constant current charging cycle for data 1602 was formed by applying a constant current of 3.2C for 13 minutes, followed by discharge at a rate that achieved complete discharge 1 hour from the start, thereby a complete constant current cycle lasting 1 hour, and then the cycle was repeated continuously. The cycle was run for approximately 200 hours. Figure 16B shows the same data as Figure 16A in a normalized form, and capacity is shown as a percentage of the initial capacity achieved.

[0202] Figures 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 battery by constant-current charging. Conversely, fast charging protocol 1100 avoids this impedance growth, enabling substantially improved capacity retention (similar to the 1C baseline rate in Figures 15A-15B) while achieving 75% nominal capacity in less than 13 minutes. Further refinement of the parameters of protocol 1100 could lead to even faster charging times of less than 10 minutes to reach the same or similar capacity.

[0203] The battery cells used to collect the data in Figures 15A-15B underwent slow-charge cycle characterization analysis, and the results are presented in the voltage-to-capacity plots in Figures 17A-17B. Figure 17A depicts data for a 1C constant-current charging battery, with characterization curve 1702 taken at the beginning of life (BOL) before the test described in relation to Figures 15A-15B, and characterization curve 1704 taken at the end of life (EOL) after the test was completed. A comparison of curves 1702 and 1704 shows that the constant-current battery underwent an irreversible capacity loss of approximately 15%. Figure 17B depicts data for a 1C pulsed charging battery, with characterization curve 1712 taken at the beginning of life (BOL) before the test described in relation to Figures 15A-15B, and characterization curve 1714 taken at the end of life (EOL) after the test was completed. A comparison of curves 1712 and 1714 shows that pulse-charged batteries also experienced an irreversible capacity loss of approximately 15%. Therefore, at EOL, pulse-charged batteries had an irreversible capacity loss similar to that of constant-current batteries (BOL). Cycle life was also comparable. Pulse charging, therefore, does not significantly degrade the battery or cause rapid impedance growth.

[0204] Figure 18A plots the imaginary and real impedance components for constant-current and pulsed-charged batteries at end-of-life (EOL). Data 1802 corresponds to the constant-current-charged battery, and data 1804 corresponds to the pulsed-charged battery. Both battery pairs exhibit substantially the same impedance characteristics, with the pulsed-charged battery showing only slightly higher ohm and activation components relative to their impedances. This is likely due to SEI layer accumulation and resulting impedance growth caused by temperatures higher than the optimal temperature, which can be mitigated through further refinement of the parameters of protocol 1100, allowing for further temperature control.

[0205] Figure 18B is a battery voltage-versus-time plot illustrating experimental data collected for lithium-ion batteries subjected to constant current charging (1812), pulsed charging with a pulse duration of 10 msec (1814), and pulsed charging with a pulse duration of 2 msec (1816). Charging in either constant current or pulsed charging, followed by pauses, allows for rapid measurement of ohmic / activation versus diffusion contributions. The measurements are summarized in Table 1 below. These findings indicate that pulsed charging 1816 reduces activation impedance and activation overpotential, while maintaining similar diffusion overpotential. [Table 1]

[0206] Figures 19A-G are block diagrams illustrating exemplary embodiments of the implementation of the fast charging protocol 1100 for various battery types. In these figures, the battery temperature generally increases with time. Figure 19A depicts protocol 1100-1 implemented according to embodiments of Figures 11A-11B, in which a pulsed preheating stage 1110 is performed first, followed by a pulsed charging stage 1120, and ending with a relatively high-temperature constant current (CC) charging stage 1130. Protocol 1100-1 can be used with, for example, NMC or NCA battery cells.

[0207] Figure 19B illustrates protocol 1100-2, in which a pulsed preheating stage 1110 is performed first, followed by a pulsed charging stage 1120, and a constant current charging stage 1130 is omitted. As an example, this embodiment may be suitable for battery types that have chemicals with relatively high activation but relatively low diffusion at an acceptable charging temperature, compared to NMC or NCA battery cells.

[0208] Figure 19C depicts protocol 1100-3, which has only a pulsed charging stage 1120, omitting the preheating stage 1110 and the constant current charging stage 1130. As an example, this embodiment may be suitable for battery types that have chemicals with relatively high activation at an acceptable charging temperature compared to NMC or NCA battery cells.

[0209] Figure 19D depicts protocol 1100-4, which has a pulsed charging stage 1120 followed by a constant-current charging stage 1130, but omits a preheating stage 1110. As an example, this embodiment may be suitable for battery types that have chemicals with relatively low activation at high charge states, enabling constant-current charging at their high charge states, compared to NMC or NCA battery cells.

[0210] Figure 19E depicts protocol 1100-5, which has a pulsed preheating stage 1110, immediately followed by a constant current charging stage 1130. The pulsed charging stage 1120 is omitted. As an example, this embodiment may be suitable for battery types that have chemicals with relatively low activation at an acceptable charging temperature compared to NMC or NCA battery cells.

[0211] Figure 19F depicts protocol 1100-6, which is similar to 1100-5, with a first preheating phase 1110-1 and a constant current phase 1130-1, but protocol 1100-6 repeats this embodiment with a second pulse preheating phase 1110-2 and a second constant current charging phase 1130-2. As an example, this embodiment may be suitable for battery types having chemicals with relatively low activation at an acceptable charging temperature compared to NMC or NCA battery cells, and is implemented across two distinct temperature modes.

[0212] Figure 19G depicts protocol 1100-7, which has a pulsed preheating stage 1110, immediately followed by a first constant-current charging stage 1130-1, then a pulsed charging stage 1120 and a second constant-current charging stage 1130-2. As an example, this embodiment may be suitable for battery types that have chemicals with relatively high activation in the intermediate range of charge states compared to NMC or NCA battery cells.

[0213] The protocol embodiments described in relation to Figures 19A-19G and elsewhere in this specification can be implemented independently with respect to each energy source in a charged system. Information about the conditions 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 enable the application of protocol 1100 and coordinated system-wide management of power distribution in power connections (e.g., 110) to each module or source. For example, in a modular energy system 100 having an array of N different modules 108, each having an energy source 206, protocol 1100-1 of Figure 19A can be implemented independently in each of the N modules 108. The decision of when each source 206 has reached a transition condition (e.g., from stages 1110, 1120 to stages 1120, 1130, or between sub-stages 1114, 1116, 1133-1136) can be made by the control system 102 (e.g., MCD112), and an appropriate command can be issued so that the module 108 transitions to the next stage with respect to each source 206 within it (e.g., by the MCD112 commanding the LCD114 to modify the switching signal to the converter 202 to generate a charging pulse (or constant current) as opposed to a preheating pulse train). A first group of one or more modules 108 may have met the conditions for transitioning from pulse preheating stage 1110 to pulse charging stage 1120 (e.g., at the minimum temperature), while a second group of one or more different modules 108 may not yet have met the conditions. Therefore, the system 100 can control and divide the power application using the control system 102 (for example, as instructed by the MCD 112) so that a first group of one or more modules 108 is in the pulse charging phase 1120 while a second group of one or more different modules 108 remains in the pulse preheating phase 1110. When each module 108 of the second group independently reaches a transition condition, that module 108 can enter the pulse preheating phase together with the first group of modules 108.Similarly, when each module 108 in pulse charging stage 1120 independently reaches the conditions for transitioning to constant current charging stage 1130, that module 108 can transition from stage 1120 to stage 1130. In some examples, all of the different stages 1110, 1120, and 1130 may be executed simultaneously on different energy sources within the same system. The same applies to the execution of protocol substages on sources within the system (e.g., 1114, 1116, and 1133-1136), so that different substages may be executed simultaneously on different sources.

[0214] Figure 20 is a block diagram depicting exemplary embodiments of applications that may be configured to apply protocol 1100 as described herein. Here, the charging source 150 is shown in the lower row, and the energy source configuration to be charged is shown in the upper row. In exemplary configuration 2010, charging source 150-1 is configured as a DC charger with a switching network to enable the DC charging voltage to be pulsed for 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 exemplary configuration 2020, charging source 150-2 is configured as a DC charger and is used to charge a conventional powertrain 2014, which is configured with a switching network to enable the received DC charging voltage to be pulsed for preheating and / or charging prior to input to a battery energy storage device. In exemplary configuration 2030, the charge source 150-3 is configured according to an embodiment of system 100 described with respect to Figure 1A-10F and supplies a pulsed DC or AC voltage to a conventional powertrain 2012. In exemplary configuration 2040, the charge source 150-4 is configured as a DC charger used to supply a DC charging voltage to an energy system 100 configured according to an embodiment described with respect to Figure 1A-10F. In exemplary configuration 2050, the charge source 150-5 is configured as an AC charger used to supply an AC charging voltage to an energy system 100 configured according to an embodiment described with respect to Figure 1A-10F. In exemplary configuration 2060, the charge source 150-3 (as in configuration 2030) is used to supply a DC or AC voltage to an energy system 100 configured according to an embodiment described with respect to Figure 1A-10F, in which case either the charge source or system 100 can supply pulse capability.

[0215] While not limited thereto, configurations 2010, 2020, and 2030 may be particularly suitable for relatively low voltage applications (e.g., 10 watt-hours to 20 kilowatt-hours (kWh)), 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).

[0216] All of the aforementioned embodiments relating to pulsed charging are implemented according to a pulse width modulation control scheme or a hysteresis-based control scheme as described herein, and additional constraints on pulse length may be implemented where applicable, such that they do not violate the pulse duration conditions of any embodiment described herein.

[0217] All of the aforementioned embodiments relating to fast charging can similarly be used to discharge the system in a similar manner.

[0218] In all embodiments described herein, the primary energy source of each module in a particular system may have the same voltage (either standard operating voltage or nominal voltage). Such a configuration simplifies the management and structure of the system. The primary and secondary energy sources may have the same voltage (standard or nominal). Other configurations can also be implemented, such as those in which the primary energy sources of different modules in the same system have different voltages (standard or nominal), and those in which the primary and secondary energy sources of a module have different voltages (standard or nominal). Configurations can also be implemented in which the primary energy sources of modules in the system are primary energy source batteries of different chemicals, or in which modules in the system have a primary energy source battery of a first chemical and a secondary energy source battery of a second chemical. Different modules may be based on their placement in the system (for example, modules in a staged array may be different from IC modules).

[0219] Various aspects of this subject matter are described below by reviewing and / or supplementing the embodiments described herein, with the interrelationships and interchangeability of the following embodiments being emphasized. In other words, it is emphasized that, unless otherwise expressly stated or taught, each feature of the embodiments may be combined with any other features.

[0220] In many embodiments, a method for charging an energy source is provided, the method comprising applying a preheating signal to the energy source, which includes a sequence of alternating charge and discharge energy pulses, such that the temperature of the energy source increases, and then applying a charge signal to the energy source, such that the amount of charge of the energy source increases.

[0221] In some embodiments, a preheating signal is applied until the energy source reaches a first temperature, and a charging signal is applied after the energy source has reached the first temperature.

[0222] In some embodiments, a preheating signal is applied over a first duration, and a charging signal is applied after the first duration.

[0223] In some embodiments, the preheating signal has a frequency such that no electrochemical storage reactions or side reactions occur in the energy source.

[0224] In some embodiments, the energy source is a lithium-ion battery, and the preheating signal has a frequency above 1 kilohertz.

[0225] In some embodiments, the preheating signal has a frequency such that electrochemical charge transfer of the main storage reaction and side reactions of the energy source is avoided. Electrochemical charge transfer can be avoided by the interfacial capacitance of the electrodes of the energy source to the electrolyte of the energy source.

[0226] In some embodiments, the charging signal includes a plurality of charging pulses. The plurality of charging pulses may have pulse durations of 10 milliseconds or less, 5 milliseconds or less, or 2 milliseconds or less. The energy source may have an open-circuit voltage and an upper cutoff voltage, and the plurality of charging pulses may be at a voltage between the open-circuit voltage and the upper cutoff voltage.

[0227] In some embodiments, the charging signal is a first charging signal comprising a plurality of pulses, and the method may further include applying a second charging signal to the energy source after applying the first charging signal, the second charging signal may be a constant current charging signal. A preheating signal may be applied until the energy source reaches a first temperature, the first charging signal may be applied until the energy source reaches a second temperature, and the second charging signal may be applied after the energy source reaches the second temperature. The first temperature may be 25 degrees Celsius or higher, or 25 to 40 degrees Celsius. The second temperature may be 45 degrees Celsius or higher, or 45 to 55 degrees Celsius. A first charging signal may be applied until the energy source reaches a first charge state, and the second charging signal may be applied after the energy source reaches the first charge state. A second charging signal may be applied until the energy source reaches a charge state of 95% or more. A method wherein the energy source may have a charge state of 5% or less during a first time when a first charging signal is applied, and may have a charge state of 75% or more during a second time after a second charging signal is applied, and the difference between the first time and the second time may be 10 minutes or less. A method wherein the preheating signal may be applied for a period of 2 minutes or less before the application of the first charging signal.

[0228] In some embodiments, the energy source is a lithium-containing battery, and the method may further include monitoring the energy source with respect to lithium plating. Monitoring the energy source with respect to lithium plating may include determining whether the voltage response of the energy source to the application of a charge pulse followed by a discharge pulse contains a lithium peel signature. Monitoring the energy source with respect to lithium plating may include applying a charge pulse, immediately followed by a discharge pulse, to the energy source, performing a derivative of at least the voltage response to the discharge pulse, and determining whether the derivative contains a lithium peel signature. Monitoring the energy source with respect to lithium plating may be performed intermittently during the charging phase of the energy source when a charge signal is applied.

[0229] In some embodiments, the method may further include monitoring the impedance of the energy source with respect to degradation indicators. The method may further include adjusting the application of a charging signal in response to the monitored impedance. Monitoring the impedance of the energy source may be performed intermittently during the charging phase of the energy source when a charging signal is applied.

[0230] In some embodiments, the energy source is a battery.

[0231] In some embodiments, the energy source is a battery module containing multiple battery cells.

[0232] In some embodiments, the charging signal includes multiple charging pulses, and when the Warburg impedance of the energy source electrodes is 20% or less of the total impedance of the electrodes, the application of the preheating signal is stopped and the application of the charging signal is started.

[0233] In some embodiments, the charging signal includes multiple charging pulses, and when the Warburg impedance of the energy source electrodes is 10% or less of the total impedance of the electrodes, the application of the preheating signal is stopped and the application of the charging signal is started.

[0234] In some embodiments, the charging signal includes multiple charging pulses, and when the Warburg impedance of the electrode multiplied by the average current of the charging signal falls below the available overvoltage of the electrode, the application of the preheating signal is stopped and the application of the charging signal is started.

[0235] In some embodiments, the charging signal is a constant current charging signal, and when the activation impedance of the energy source electrode is 20% or less of the total impedance of the electrode, the application of the preheating signal is stopped and the application of the charging signal is started.

[0236] In some embodiments, the charging signal is a constant current charging signal, and when the activation impedance of the energy source electrode is 10% or less of the total impedance of the electrode, the application of the preheating signal is stopped and the application of the charging signal is started.

[0237] In some embodiments, when the activation impedance of the energy source electrode is 50% or less of the total impedance of the electrode, the application of the first charge signal is stopped and the application of the second charge signal is started.

[0238] In some embodiments, when the activation impedance of the energy source electrode is 20% or less of the total impedance of the electrode, the application of the first charge signal is stopped and the application of the second charge signal is started.

[0239] In some embodiments, when the activation impedance of the energy source electrode is 10% or less of the total impedance of the electrode, the application of the first charge signal is stopped and the application of the second charge signal is started.

[0240] In some embodiments, the pulsed preheating signal is applied at a voltage greater than the upper and lower cutoff voltages of the energy source.

[0241] In some embodiments, the charging signal includes multiple charging pulses at a peak voltage greater than the cutoff voltage of the energy source.

[0242] In many embodiments, a system is provided configured to charge an energy source, the system including a control system configured to (a) control a switch network to apply a preheating signal to the energy source so that the temperature of the energy source increases until the energy source satisfies a certain condition, the preheating signal comprising a sequence of alternating charge and discharge energy pulses, and (b) control the switch network to apply a charge signal to the energy source after the energy source has satisfied the condition.

[0243] In some embodiments, the control system includes a processing network communicatively coupled to a memory, which stores instructions that, when executed by the processing network, cause the control system to perform steps (a) and (b).

[0244] In some embodiments, the control system is further configured to detect when the energy source meets a condition, or to receive an indication that the energy source has met a condition.

[0245] In some embodiments, the condition is a temperature condition, and the control system is configured to control a switch network to apply a preheating signal until the energy source reaches a first temperature, and then apply a charging signal after the energy source has reached the first temperature.

[0246] In some embodiments, the control system is configured to control the switch network to apply a preheating signal over a first duration and a charging signal after the first duration.

[0247] In some embodiments, the preheating signal has a frequency configured to prevent the occurrence of electrochemical storage reactions and side reactions in the energy source.

[0248] In some embodiments, the energy source is a lithium-ion battery, and the preheating signal has a frequency above 1 kilohertz.

[0249] In some embodiments, the preheating signal has a frequency configured to avoid electrochemical charge transfer in the main storage reaction and side reactions of the energy source.

[0250] In some embodiments, the charging signal includes multiple charging pulses.

[0251] In some embodiments, the multiple charging pulses have a pulse duration of 10 milliseconds or less. The multiple charging pulses may have a pulse duration of 5 milliseconds or less, or 2 milliseconds or less. The energy source may have an open-circuit voltage and an upper cutoff voltage, and the multiple charging pulses may be at a voltage between the open-circuit voltage and the upper cutoff voltage.

[0252] In some embodiments, the charging signal is a first charging signal comprising a plurality of pulses, and the control system is configured to control the switch network to apply a second charging signal to the energy source after the application of the first charging signal, the second charging signal being a constant current charging signal. The control system can be configured to control the switch network to apply a preheating signal until the energy source reaches a first temperature, apply a first charging signal until the energy source reaches a second temperature, and apply a second charging signal after the energy source reaches the second temperature. The first temperature may be 25 degrees Celsius or higher, or 25 to 40 degrees Celsius. The second temperature may be 45 degrees Celsius or higher, or 45 to 55 degrees Celsius. The control system is configured to control the switch network to apply a first charging signal until the energy source reaches a first charge state, and apply a second charging signal after the energy source reaches the first charge state. The control system can be configured to control the switch network to apply a second charging signal until the energy source reaches a charge state of 95% or more.

[0253] In some embodiments, the energy source is a lithium-containing battery, and the control system is configured to monitor the energy source with respect to lithium plating. The control system may be configured to determine whether the voltage response of the energy source to the application of a charge pulse followed by a discharge pulse contains a lithium peel signature.

[0254] In some embodiments, the control system is configured to control a switch network to apply a charge pulse, immediately followed by a discharge pulse, to the energy source, perform differentiation of at least the voltage response to the discharge pulse, and determine whether the differentiation includes a lithium peel signature. The control system can be configured to intermittently monitor the energy source with respect to lithium plating during the charging phase of the energy source to which the charge signal is applied.

[0255] In some embodiments, the control system is configured to monitor the impedance of the energy source with respect to degradation indications. The control system may be configured to control a switch network to adjust the application of a charge signal in response to the monitored impedance. The control system may be configured to intermittently monitor the impedance of the energy source during the charging phase of the energy source to which the charge signal is applied.

[0256] In some embodiments, the energy source is a battery.

[0257] In some embodiments, the energy source is a battery module containing multiple battery cells.

[0258] In many embodiments, a method is provided for charging multiple energy sources in an energy storage system, the energy storage system comprising multiple modules connected together in a cascaded manner, each of the multiple modules comprising an energy source and a switching network, the energy storage system configured to generate AC power with superposition of output signals generated by the multiple modules, the method comprising applying a preheating signal to the energy source of each module via the switching network of each module, which includes a sequence of alternating charge and discharge energy pulses, such that the temperature of the energy source of each module increases, and then applying a charge signal to the energy source of each module via the switching network of each module.

[0259] In some embodiments, a preheating signal is applied until the energy source reaches a first temperature, and a charging signal is applied after the energy source has reached the first temperature.

[0260] In some embodiments, the energy source includes multiple batteries, and a preheating signal is applied until all batteries reach a first minimum temperature, or until at least one battery reaches a maximum temperature.

[0261] In some embodiments, a preheating signal is applied over a first duration, and a charging signal is applied after the first duration.

[0262] In some embodiments, the charging signal includes a plurality of charging pulses. The plurality of charging pulses may have pulse durations of 10 milliseconds or less, 5 milliseconds or less, or 2 milliseconds or less. The energy source of each module may have an open-circuit voltage and an upper cutoff voltage, and the plurality of charging pulses may be in voltages between the open-circuit voltage and the upper cutoff voltage.

[0263] In some embodiments, the charging signal is a first charging signal comprising a plurality of charging pulses, and the method may further include applying a second charging signal to the energy source of each module after applying the first charging signal by the switching network of each module, wherein the second charging signal is a constant current charging signal. A preheating signal may be applied until the energy source reaches a first temperature, the first charging signal may be applied until the energy source reaches a second temperature, and the second charging signal may be applied after the energy source reaches the second temperature. The first temperature may be 25 degrees Celsius or higher, or 25 to 40 degrees Celsius. The second temperature may be 41 degrees Celsius or higher, or 41 to 60 degrees Celsius. A first charging signal may be applied until the energy source reaches a first charge state, and the second charging signal may be applied after the energy source reaches the first charge state. A second charging signal may be applied until the energy source reaches a charge state of 95% or more. A method wherein the energy source may have a charge state of 5% or less during a first time when a first charging signal is applied, and may have a charge state of 75% or more during a second time after a second charging signal is applied, and the difference between the first time and the second time may be 10 minutes or less. A method wherein the preheating signal may be applied for a period of 2 minutes or less before the application of the first charging signal.

[0264] In some embodiments, the energy source of each module is a lithium-containing battery, and the method may further include monitoring the energy source of each module with respect to lithium plating. Monitoring the energy source of each module with respect to lithium plating may include determining whether the voltage response of the energy source to the application of a charge pulse followed by a discharge pulse contains a lithium delamination signature. Monitoring the energy source of each module with respect to lithium plating may include applying a charge pulse, immediately followed by a discharge pulse, to the energy source, performing a derivative of at least the voltage response to the discharge pulse, and determining whether the derivative contains a lithium delamination signature. Monitoring the energy source of each module with respect to lithium plating may be performed intermittently during the charging phase of the energy source of each module when a charge signal is applied. The method may further include monitoring the impedance of the energy source in each module with respect to degradation indicators. The method may further include adjusting the application of the charge signal in response to the monitored impedance. Monitoring the impedance of the energy source in each module may be performed intermittently during the charging phase of the energy source when a charge signal is applied.

[0265] In some embodiments, the energy source is a battery.

[0266] In some embodiments, the energy source is a battery module containing multiple battery cells.

[0267] In many embodiments, an energy storage system is provided, comprising a plurality of modules connected together in a cascaded manner, each of which comprises an energy source and a switch network, wherein the energy storage system is configured to generate AC power with superposition of output signals generated by the plurality of modules, and with respect to each module, the energy storage system is configured to (a) control the switch network to apply a preheating signal to the energy source so that the temperature of the energy source increases until the energy source reaches a first temperature, the preheating signal comprising a sequence of alternating charge and discharge energy pulses, and (b) control the switch network to apply a charge signal to the energy source when the energy source is above the first temperature.

[0268] In some embodiments, the system may further include a control system configured to carry out (a) and (b). The control system may include a master control device and a plurality of local control devices associated with a plurality of modules, wherein the master control device is communicatively coupled to the plurality of local control devices, and the plurality of local control devices are configured to output switching control signals to a switching network of the plurality of modules.

[0269] In some embodiments, the system may further include a processing network communicatively coupled to a memory, which stores instructions that, when executed by the processing network, cause the system to perform (a) and (b).

[0270] In some embodiments, the system can be configured to control a switch network to apply a preheating signal until the energy source reaches a first temperature, and then apply a charging signal after the energy source has reached the first temperature.

[0271] In some embodiments, the system can be configured to control the switch network to apply a preheating signal over a first duration and a charging signal after the first duration.

[0272] In some embodiments, the preheating signal has a frequency configured to prevent the occurrence of electrochemical storage reactions and side reactions in the energy source.

[0273] In some embodiments, the energy source is a lithium-ion battery, and the preheating signal has a frequency above 1 kilohertz.

[0274] In some embodiments, the preheating signal has a frequency configured to avoid electrochemical charge transfer in the main storage reaction and side reactions of the energy source.

[0275] In some embodiments, the charging signal includes a plurality of charging pulses. The energy source has an open-circuit voltage and an upper cutoff voltage, and the plurality of charging pulses are in a voltage between the open-circuit voltage and the upper cutoff voltage.

[0276] In some embodiments, the charging signal is a first charging signal comprising a plurality of pulses, and the control system is configured to control the switch network to apply a second charging signal to the energy source after the application of the first charging signal, wherein the second charging signal is a constant current charging signal. The control system can be configured to control the switch network to apply a preheating signal until the energy source reaches a first temperature, apply a first charging signal until the energy source reaches a second temperature, and apply a second charging signal after the energy source reaches the second temperature. The control system can be configured to control the switch network to apply a first charging signal until the energy source reaches a first charge state, and apply a second charging signal after the energy source reaches the first charge state. The control system can be configured to control the switch network to apply a second charging signal until the energy source reaches a charge state of 95% or more.

[0277] In some embodiments, the energy source is a lithium-containing battery, and the control system is configured to monitor the energy source with respect to lithium plating. The control system may be configured to determine whether the voltage response of the energy source to the application of a charge pulse followed by a discharge pulse contains a lithium peel signature.

[0278] In some embodiments, the control system is configured to control a switch network to apply a charge pulse, immediately followed by a discharge pulse, to the energy source, perform differentiation of at least the voltage response to the discharge pulse, and determine whether the differentiation includes a lithium peel signature. The control system may be configured to intermittently monitor the energy source with respect to lithium plating during the charging phase of the energy source when a charge signal is applied.

[0279] In some embodiments, the control system is configured to monitor the impedance of the energy source with respect to degradation indications. The control system may be configured to control a switch network to adjust the application of a charge signal in response to the monitored impedance. The control system is configured to intermittently monitor the impedance of the energy source during the charging phase of the energy source when a charge signal is applied.

[0280] In some embodiments, all energy sources are batteries.

[0281] In some embodiments, all energy sources are battery modules containing multiple battery cells.

[0282] In some embodiments, the system further comprises a second plurality of modules connected together in a cascaded manner, each of which includes an energy source and a switch network, and the energy storage system is configured to generate AC power with superposition of output signals generated by the second plurality of modules, and a third plurality of modules connected together in a cascaded manner, each of which includes an energy source and a switch network, and the energy storage system is configured to generate AC power with superposition of output signals generated by the third plurality of modules, and the AC power includes three-phase AC power. The system can be configured to power the motor of an electric vehicle.

[0283] In many embodiments, a method is provided for charging an energy source, the method comprising applying a preheating signal to the energy source, which includes a sequence of alternating charge and discharge energy pulses, such that the temperature of the energy source increases, the preheating signal being at a frequency that passes through the double-layer capacitance of the energy source.

[0284] In some embodiments, the double-layer capacitance includes the double-layer capacitance of the anode of the energy source and the double-layer capacitance of the cathode of the energy source.

[0285] In some embodiments, the preheating signal does not substantially charge the energy source.

[0286] In some embodiments, a preheating signal is applied for a first duration so that the energy source is heated without substantially charging, and then the preheating signal is applied for a second duration so that the energy source is heated and charged. The duration of the charging energy pulse can be gradually increased over the second duration relative to the discharge energy pulse.

[0287] In some embodiments, the energy source is a battery.

[0288] In some embodiments, the energy source is a battery module containing multiple battery cells.

[0289] In some embodiments, a preheating signal is applied until the energy source reaches a first temperature, and a charging signal is applied after the energy source has reached the first temperature.

[0290] In some embodiments, a preheating signal is applied over a first duration, and a charging signal is applied after the first duration.

[0291] In some embodiments, the preheating signal has a frequency such that no electrochemical storage reactions or side reactions occur in the energy source.

[0292] In some embodiments, the energy source is a lithium-ion battery, and the preheating signal has a frequency above 1 kilohertz.

[0293] In some embodiments, the preheating signal has a frequency such that electrochemical charge transfer of the main storage reaction and side reactions of the energy source is avoided. Electrochemical charge transfer can be avoided by the interfacial capacitance of the electrodes of the energy source to the electrolyte of the energy source.

[0294] In many embodiments, a method is provided for monitoring a lithium-containing battery with respect to the occurrence of lithium plating, the method comprising applying a charge pulse, followed by a discharge pulse, to the battery, and determining whether the voltage response of the battery to the application of a charge pulse followed by a discharge pulse includes a lithium stripping signature.

[0295] In some embodiments, determining whether the voltage response includes a lithium-stripping signature includes at least performing a derivative of the battery's voltage response to a discharge pulse and determining whether the derivative includes a lithium-stripping signature. The lithium-stripping signature may be a transition of the derivative while the discharge pulse is applied.

[0296] In some embodiments, determining whether the voltage response includes a lithium delamination signature involves determining whether the variation in the voltage response during the application of a discharge pulse exceeds a threshold.

[0297] In some embodiments, the method is performed intermittently during the battery charging phase.

[0298] In some embodiments, the battery includes a single battery cell.

[0299] In some embodiments, the battery includes multiple battery cells.

[0300] In many embodiments, a method for charging an energy source is provided, the method comprising: applying a first charging signal to the energy source, comprising charging pulses, each charging pulse having a duration of less than 10 milliseconds; determining when the energy source satisfies a transition condition; and, after determining that the transition condition is satisfied, applying a second charging signal to the energy source, the second charging signal being a constant current charging signal.

[0301] In some embodiments, the duration of each charging pulse is 5 milliseconds or less.

[0302] In some embodiments, the duration of each charging pulse is 2 milliseconds or less.

[0303] In some embodiments, the energy source has an open-circuit voltage and an upper cutoff voltage, and the charging pulse is at a voltage between the open-circuit voltage and the upper cutoff voltage.

[0304] In some embodiments, the transition condition is a charge state threshold.

[0305] In some embodiments, the energy source is a battery comprising lithium, and the method further includes monitoring the energy source with respect to lithium plating.

[0306] In some embodiments, monitoring the energy source with respect to lithium plating includes determining whether the voltage response of the energy source to the application of a charge pulse followed by a discharge pulse has a lithium peel signature.

[0307] In some embodiments, monitoring the energy source with respect to lithium plating includes applying a charge pulse, immediately followed by a discharge pulse, to the energy source; performing a differentiation of the voltage response to at least the discharge pulse; and determining whether the differentiation includes a lithium peel signature.

[0308] In some embodiments, monitoring the energy source with respect to lithium plating is performed intermittently during the charging phase of the energy source when a charging signal is applied.

[0309] In some embodiments, the method further includes monitoring the impedance of the energy source with respect to degradation indicators.

[0310] In some embodiments, the method further includes adjusting the application of a charging signal in response to the monitored impedance.

[0311] In some embodiments, monitoring the impedance of the energy source is performed intermittently during the charging phase of the energy source when a charging signal is applied.

[0312] In some embodiments, the transition condition is when the activation impedance of the energy source electrode is 50% or less of the total impedance of the electrode.

[0313] In some embodiments, the transition condition is that the activation impedance of the energy source electrode is 20% or less of the total impedance of the electrode.

[0314] In some embodiments, the transition condition is that the activation impedance of the energy source electrode is 10% or less of the total impedance of the electrode.

[0315] In some embodiments, the charging pulse is at a peak voltage higher than the cutoff voltage of the energy source.

[0316] Various aspects of this subject matter are described below, building upon and / or supplementing the embodiments described herein, with emphasis placed on the interrelationships and interchangeability of the following embodiments. In other words, it is emphasized that, unless otherwise explicitly stated or logically impractical, each feature of an embodiment can be combined with any other feature.

[0317] The processing network may include one or more processors, microprocessors, controllers, and / or microcontrollers, each of which may be a separate chip or distributed across several different chips (and parts thereof). The processing network may include digital signal processors, which may be implemented in hardware and / or software. The processing network may execute software instructions stored in memory, which cause the processing network to perform many different actions and control other components.

[0318] The processing network can be adapted to run the operating system and any software applications, and to perform other functions not related to the processing of transmitted and received communications.

[0319] Memory can be shared by one or more of the various functional units present, or distributed among two or more of them (for example, as separate memories located on different chips). Memory can also be a separate chip itself. Memory can be non-transient, volatile (e.g., RAM) and / or non-volatile (e.g., ROM, flash memory, F-RAM).

[0320] Computer program instructions for performing actions according to the described subject can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java®, JavaScript®, Smalltalk, C++, C#, Transact-SQL, XML, and PHP, and traditional procedural programming languages ​​such as the C programming language or similar languages. 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. For example, in a case where identified frequencies are uploaded to a remote location for processing, the program instructions may reside partially on the user's computing device, partially on a remote computing device, or entirely on a remote computing device or server. 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 to an external computer.

[0321] It should be noted that all features, elements, components, functions, and steps described in relation to any embodiment provided herein are intended to be freely combined and substituted with those from any other embodiment. If a feature, element, component, function, or step is described in relation to only one embodiment, it should be understood that that feature, element, component, function, or step may be used with all other embodiments described herein unless otherwise expressly stated. This paragraph therefore serves as an antecedent and descriptive aid for introducing claims that, at any point, combine features, elements, components, functions, and steps from different embodiments, or replace features, elements, components, functions, and steps from one embodiment with those from another embodiment, even if the following description does not expressly state that such combinations or substitutions are possible in a particular case. In particular, it is explicitly confirmed that an explicit enumeration of all possible combinations and substitutions would be excessive, given that the permissibility of any such combinations and substitutions will be readily apparent to those skilled in the art.

[0322] To the extent that embodiments disclosed herein include or operate in relation to a memory, storage device, and / or computer-readable medium, then such memory, storage device, and / or computer-readable medium is non-transient. Thus, to the extent that such memory, storage device, and / or computer-readable medium is encompassed by one or more claims, then such memory, storage device, and / or computer-readable medium is non-transient only. The terms “non-transient” and “tangible” as used herein are intended to describe a memory, storage device, and / or computer-readable medium that excludes propagating electromagnetic signals, but are not intended to limit the types of memory, storage device, and / or computer-readable medium in terms of the persistence of memory or otherwise. For example, “non-transient” and / or “tangible” memory, storage devices, and / or computer-readable media include random access media (e.g., RAM, SRAM, DRAM, FRAM®, etc.), read-only media (e.g., ROM, PROM, EPROM, EEPROM, flash, etc.), combinations thereof (e.g., hybrid RAM and ROM, NVRAM, etc.), and volatile and non-volatile media such as variations thereof developed later.

[0323] As used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural nouns unless the context clearly determines otherwise.

[0324] The embodiments may be subject to various modifications and alternative forms, specific examples of which are shown in the drawings and described in detail herein. However, it should be understood that these embodiments are not limited to any particular form disclosed, but rather encompass all modifications, equivalents, and alternatives that fall within the spirit of this disclosure. Furthermore, any features, functions, steps, or elements of the embodiments, and any negative limitations that define the scope of the claimed invention by features, functions, steps, or elements that fall outside the scope of the claimed invention, may be enumerated or added to the claims.

Claims

1. A method for charging an energy source, wherein the method is The impedance of the energy source is monitored, wherein the capacitance of the impedance includes the double-layer sheet capacitance. The method involves applying a preheating signal at a preheating signal frequency based on the double-layer sheet capacity, wherein the preheating signal comprises a sequence of alternating charge and discharge energy pulses of equal duration to the lithium-ion battery module to induce local heating such that the temperature of the lithium-ion battery module comprising multiple batteries increases, the frequency of the preheating signal is greater than 1 kilohertz, the frequency of the preheating signal is a frequency that passes through the double-layer sheet capacity of the energy source, and the application of the preheating signal occurs to avoid electrochemical charge transfer of the main storage reaction and side reactions of the lithium-ion battery module. Next, a charging signal is applied to the lithium-ion battery module so that the charge of the lithium-ion battery module increases. Includes, A method wherein a preheating signal is applied until the lithium-ion battery module reaches a first temperature, and a charging signal is applied after the lithium-ion battery module has reached the first temperature.

2. The method according to claim 1, wherein the electrochemical charge transfer is avoided by the interfacial capacitance of the electrodes of the lithium-ion battery module with respect to the electrolyte of the energy source.

3. The method according to claim 1, wherein the charging signal comprises a plurality of charging pulses having a pulse duration of 10 milliseconds or less.

4. The method according to claim 3, wherein the lithium-ion battery module has an open-circuit voltage and an upper cutoff voltage, and the plurality of charging pulses have a voltage between the open-circuit voltage and the upper cutoff voltage.

5. The charging signal is a first charging signal comprising a plurality of pulses, and the method is The method further includes applying a second charging signal to the lithium-ion battery module after applying the first charging signal, The method according to claim 1, wherein the second charging signal is a constant current charging signal.

6. The method according to claim 5, wherein the preheating signal is applied until the lithium-ion battery module reaches a first temperature, the first charging signal is applied until the lithium-ion battery module reaches a second temperature, and the second charging signal is applied after the lithium-ion battery module has reached the second temperature.

7. The method according to claim 6, wherein the first temperature is 25 degrees Celsius or higher, and the second temperature is 45 degrees Celsius or higher.

8. The method according to claim 5, wherein the first charging signal is applied until the lithium-ion battery module reaches a first charging state, and the second charging signal is applied after the lithium-ion battery module has reached the first charging state.

9. The method according to claim 8, wherein the second charging signal is applied until the lithium-ion battery module reaches a charge state of 95% or more.

10. The method according to claim 5, wherein when the activation impedance of the electrodes of the lithium-ion battery module is 50% or less of the total impedance of the electrodes, the application of the first charging signal is stopped and the application of the second charging signal is started.

11. The method according to claim 1, further comprising monitoring the lithium-ion battery module with respect to lithium plating.

12. The method according to claim 1, further comprising monitoring the impedance of the lithium-ion battery module with respect to degradation indicators.

13. The method according to claim 12, further comprising adjusting the application of the charging signal in response to the monitored impedance.

14. The method according to claim 13, wherein monitoring the impedance of the lithium-ion battery module is performed intermittently during the charging phase of the lithium-ion battery module when the charging signal is applied.

15. The method according to claim 1, wherein the charging signal comprises a plurality of charging pulses, and when the Warburg impedance of the electrodes of the lithium-ion battery module is 20% or less of the total impedance of the electrodes, the application of the preheating signal is stopped and the application of the charging signal is started.

16. The method according to claim 1, wherein the preheating signal is applied at a voltage greater than the upper cutoff voltage and the lower cutoff voltage of the lithium-ion battery module.

17. The method according to claim 1, wherein the charging signal comprises a plurality of charging pulses at a peak voltage greater than the cutoff voltage of the lithium-ion battery module.

18. A system configured to charge an energy source, the system comprising a control system, the control system (a) Monitoring the impedance of the energy source, wherein the capacitance of the impedance includes the double-layer sheet capacitance, (b) Controlling the switch network to apply a preheating signal to the energy source at a preheating signal frequency based on the double-layer sheet capacitance, such that the temperature of the energy source increases until a certain condition is met, wherein the preheating signal comprises a sequence of alternating charge and discharge energy pulses, and the preheating signal frequency is the frequency that passes through the double-layer sheet capacitance of the energy source. (c) Controlling the switch network to apply a charging signal to the energy source after the energy source has satisfied the above conditions. A system configured to perform the following actions.

19. A method for charging multiple energy sources in an energy storage system, wherein the energy storage system comprises multiple converter modules connected together in a cascaded manner, each of the multiple converter modules comprises an energy source and a switch network, each of the multiple converter modules is independently controllable by a control system to output a module voltage, and the energy storage system is configured to generate AC power with superposition of module output voltages generated by the multiple converter modules, and the method is: The impedance of the energy source is monitored, wherein the capacitance of the impedance includes the double-layer sheet capacitance. The switching network of each module applies a preheating signal at a preheating signal frequency based on the double-layer sheet capacitance, wherein the preheating signal comprises a sequence of alternating charge and discharge energy pulses of equal duration to the energy source of each module to induce ohmic heating such that the temperature of the energy source of each module increases, the frequency of the preheating signal is greater than 1 kilohertz, the frequency of the preheating signal is the frequency that passes through the double-layer sheet capacitance of the energy source, and the application of the preheating signal occurs in such a way as to avoid electrochemical charge transfer of the main storage reaction and side reactions of the energy source. Next, the switch network of each module applies a charging signal to the energy source of each module. Methods that include...

20. The method according to claim 19, wherein the module transitions from applying the preheating signal to applying the charging signal at different times based on when each module reaches a temperature threshold.

21. The method according to claim 19, wherein the charging signal comprises a plurality of charging pulses having a pulse duration of 10 milliseconds or less.

22. The method according to claim 21, wherein the energy source has an open-circuit voltage and an upper cutoff voltage, and the plurality of charging pulses have a voltage between the open-circuit voltage and the upper cutoff voltage.

23. The charging signal is a first charging signal comprising a plurality of pulses, and the method is The method further includes applying a second charging signal to the energy source after applying the first charging signal, The method according to claim 19, wherein the second charging signal is a constant current charging signal.

24. The method according to claim 23, wherein the preheating signal is applied until the energy source reaches a first temperature, the first charging signal is applied until the energy source reaches a second temperature, and the second charging signal is applied after the energy source has reached the second temperature.

25. The method according to claim 24, wherein the first temperature is 25 degrees Celsius or higher, and the second temperature is 45 degrees Celsius or higher.

26. The method according to claim 24, wherein the first charging signal is applied until the energy source reaches a first charging state, and the second charging signal is applied after the energy source has reached the first charging state.

27. The method according to claim 26, wherein the second charging signal is applied until the energy source reaches a charge state of 95% or more.

28. The method according to claim 24, wherein when the activation impedance of the electrode of the energy source is 50% or less of the total impedance of the electrode, the application of the first charging signal is stopped and the application of the second charging signal is started.

29. The method according to claim 19, further comprising monitoring the energy source with respect to lithium plating.

30. The method according to claim 19, further comprising monitoring the impedance of the energy source with respect to degradation indications.

31. The method according to claim 30, further comprising adjusting the application of the charging signal in response to the monitored impedance.

32. The method according to claim 31, wherein monitoring the impedance of the energy source is performed intermittently during the charging phase of the energy source when the charging signal is applied.

33. The method according to claim 19, wherein the charging signal comprises a plurality of charging pulses, and when the Warburg impedance of the electrodes of the energy source is 20% or less of the total impedance of the electrodes, the application of the preheating signal is stopped and the application of the charging signal is started.

34. The method according to claim 19, wherein the preheating signal is applied at a voltage greater than the upper cutoff voltage and the lower cutoff voltage of the energy source.

35. The method according to claim 19, wherein the charging signal comprises a plurality of charging pulses at a peak voltage greater than the cutoff voltage of the energy source.

36. An energy storage system, wherein the energy storage system is The energy storage system comprises multiple modules connected together in a cascaded manner, each of which comprises an energy source and a switching network, and the energy storage system is configured to generate AC power with respect to the superposition of output signals generated by the multiple modules, and with respect to each module, (a) Monitoring the impedance of the energy source, wherein the capacitance of the impedance includes the double-layer sheet capacitance, (b) Controlling the switch network to apply a preheating signal to the energy source at a preheating signal frequency based on the double-layer sheet capacitance, such that the temperature of the energy source increases until the energy source reaches a first temperature, wherein the preheating signal comprises a sequence of alternating charge and discharge energy pulses, and the preheating signal frequency is the frequency that passes through the double-layer sheet capacitance of the energy source. (c) When the energy source is at or above the first temperature, the switch network is controlled to apply a charging signal to the energy source. An energy storage system configured to perform the following actions.

37. A method for charging an energy source, wherein the method is The impedance of the energy source is monitored, wherein the capacitance of the impedance includes the double-layer sheet capacitance. The method involves applying a preheating signal at a preheating signal frequency based on the double-layer sheet capacity, wherein the preheating signal comprises a sequence of alternating charge and discharge energy pulses to the energy source to increase the temperature of the energy source. Includes, The method wherein the preheating signal frequency is the frequency that passes through the double-layer sheet capacitance of the energy source.

38. The method according to claim 37, wherein the double-layer sheet capacitance comprises the double-layer sheet capacitance of the anode of the energy source and the double-layer sheet capacitance of the cathode of the energy source.

39. The method according to claim 37, wherein the preheating signal does not substantially charge the energy source.

40. The method according to claim 37, wherein the preheating signal comprises a first sub-stage preheating signal and a second sub-stage preheating signal, the first sub-stage preheating signal being applied for a first duration so that the energy source is heated without substantially being charged, and the second sub-stage preheating signal being applied for a second duration so that the energy source is heated and charged.

41. The method according to claim 40, wherein the first sub-stage preheating signal comprises a charging energy pulse and the discharge energy pulse of equal duration, the second sub-stage preheating signal comprises a charging energy pulse and the discharge energy pulse of different durations, and the duration of the charging energy pulse of the second sub-stage preheating signal is gradually increased over the second duration relative to the discharge energy pulse.

42. The preheating signal is applied until the energy source reaches the first temperature. The method according to claim 37, further comprising applying a charging signal after the energy source has reached the first temperature.

43. The preheating signal is applied over a first duration, The method according to claim 37, further comprising applying a charging signal after the first duration.

44. The method according to claim 37, wherein the preheating signal has a frequency such that no electrochemical storage reaction or side reaction occurs in the energy source.

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