Balancing circuit and method

Abstract

One or more embodiments of the present embodiments provide a balancing circuit, the balancing circuit comprising: a plurality of cell stack stacks, each stack comprising: a plurality of cell stacks; and a plurality of balance controllers, each of which is configured to control a different circuit so as to balance a different subset of the plurality of single cell groups, and a plurality of stack controllers, each stack controller configured to control a different subset of the plurality of balance controllers.

Description

[0001] This application is a divisional application of the invention patent application with the application date of August 8, 2019, application number "201980052902.0", and invention name "Enhanced switching balancing network for battery packs".

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 16 / 101,032, filed on August 10, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0004] The present application relates to an enhanced switching balancing network for balancing battery cells. Background Art

[0005] High-performance battery systems have been developed and deployed for different use case applications, such as for the storage and management of grid and microgrid energy, and for renewable energy integration (e.g., solar, wind, hydro, etc.). For example, solar energy can be collected and stored in a battery system for use during high energy consumption times, such as in the summer when the energy demand for air conditioning is much higher than average. In order to maximize the capacity of the battery system and utilize the battery system safely, battery balancing techniques and strategies have been deployed. For example, when the battery cell voltage drops below a lower limit, the battery cell becomes a fire hazard and must be discarded. Similarly, if the battery cell is overcharged and the battery cell voltage increases above an upper limit, the battery cell will also become a fire hazard.

[0006] Various active and passive balancing techniques have been developed to allow more of the battery to be used when charging and discharging, and to increase safety. However, active and passive balancing incur costs. For example, passive balancing wastes energy by discharging battery cells above a threshold relative to the average cell voltage, resulting in parasitics and efficiency losses. Active balancing typically uses inefficient components for charging, resulting in greater efficiency losses. Although various balancing strategies have been developed, the balancing strategy is deployed as a static decision for most battery systems, such as deploying a simple balancing technique to balance the cell voltages of all batteries to the average cell voltage for all cells or to a target voltage. However, different use cases can be improved by adopting more efficient and robust balancing strategies. Summary of the invention

[0007] This Summary is provided to introduce selected concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0008] One or more embodiments of the present embodiment provide a battery cell balancing system and strategy that can more efficiently utilize battery capacity according to the needs of different use cases. For example, a balancing circuit is provided that supports passive balancing and active balancing of a target battery cell according to a balancing strategy of a use case. In addition, the balancing circuit allows battery cell balancing to be performed while charging or discharging the battery cell together.

[0009] Furthermore, instead of having a static, single balancing strategy, one or more of the embodiments of the present invention provide a suite of preset and customizable balancing applications that can be configured, selected, and implemented to match the requirements of the current use case. The suite of preset and customizable balancing applications can be presented to and selected by the user to adapt the balancing system to a particular use case. Alternatively, the balancing system can automatically select a balancing application, such as based on one or more inputs, to adapt the balancing system to the current use case.

[0010] In one embodiment, a balancing circuit is provided. The balancing circuit includes a voltage source coupled to the balancing circuit via a charging balancing relay and a load coupled to the balancing circuit via a discharging balancing relay. The balancing circuit also includes a plurality of cell group controllers, wherein each of the plurality of cell group controllers is configured to couple a cell group in the plurality of cell groups to the balancing circuit via a cell group balancing relay in the plurality of cell group balancing relays. The balancing controller is further configured to balance the plurality of cell groups by controlling the charging balancing relay, the discharging balancing relay, and the plurality of cell controllers.

[0011] In yet another embodiment, another balancing circuit is provided. The balancing circuit includes a plurality of single cell stacks and a plurality of stack controllers. Each single cell stack includes a plurality of single cell groups and a plurality of balancing controllers. In addition, each balancing controller is configured to control different circuits to balance the single cell groups of different subsets in the plurality of single cell groups, and each stack controller is configured to control the balancing controllers of different subsets in the plurality of balancing controllers. The balancing circuit may also include: a power supply configured to deliver power to the plurality of stacks; a battery management system (BMS) configured to control the power distribution to the plurality of single cell groups by controlling the plurality of stack controllers; and an energy management system (EMS) configured to control the power delivery by the power supply.

[0012] In another embodiment, yet another balancing circuit is provided. The balancing circuit includes a plurality of cell groups and a plurality of cell group controllers, the plurality of cell group controllers being configured to control different cell balancing relays to couple different cell groups to the balancing circuit. The balancing circuit also includes a plurality of balancing controllers, the plurality of balancing controllers being configured to control the charging and discharging of cell groups of different subsets in the plurality of cell groups. The balancing circuit also includes: a plurality of string controllers, which are configured to control balancing controllers of different subsets in the plurality of balancing controllers; and a battery management system, which is configured to control the power distribution in the balancing circuit by controlling the plurality of string controllers. The balancing circuit may also include an energy management system, which is configured to control the power delivery to the balancing circuit.

[0013] The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a diagram illustrating an example balancing circuit that may implement one or more of the methods described herein.

[0015] Figure 2 is a diagram illustrating another example balancing circuit that may implement one or more of the methods described herein.

[0016] Figure 3 is a diagram illustrating yet another example balancing circuit that may implement one or more of the methods described herein.

[0017] Figure 4 is a flow chart of an example implementation for balancing a group of cells based on a balancing profile.

[0018] Figure 5 is a flow chart of an example implementation for performing a balancing technique for balancing a single pool group based on a user-selected balancing application.

[0019] Figure 6 is a flow chart of another example implementation for performing a balancing technique for balancing a single pool group based on a user-selected balancing application. DETAILED DESCRIPTION

[0020] I. General Considerations

[0021] Disclosed below are representative embodiments of methods, devices, and systems for battery cell balancing systems and implementing battery cell balancing strategies. The disclosed methods, devices, and systems should not be construed as limiting in any way. On the contrary, the present disclosure is directed to all novel and non-obvious features and aspects of the various disclosed embodiments, either alone or in various combinations and sub-combinations with each other. In addition, any features or aspects of the disclosed embodiments may be used in various combinations and sub-combinations with each other. For example, one or more system components or methods from one embodiment may be used with one or more system components or methods from another embodiment, and vice versa. The disclosed methods, devices, and systems are not limited to any particular aspect or feature or combination thereof, nor do the disclosed embodiments require the presence of any one or more specific advantages or the resolution of one or more specific problems.

[0022] Although the operations of some disclosed methods are described in a specific sequential order for ease of presentation, it should be understood that this description includes rearrangement unless the specific language set forth below requires a specific order. For example, in some cases, the operations described in a sequential manner can be rearranged or performed simultaneously. In addition, for simplicity, the accompanying drawings may not show the various ways in which the disclosed methods can be used in combination with other methods. In addition, the description sometimes uses terms such as "determine", "generate" and "evaluate" to describe the disclosed technology. These terms are high-level abstractions of the actual operations performed. The actual operations corresponding to these terms can vary depending on the specific implementation and can be easily discerned by a person of ordinary skill in the art.

[0023] Various alternatives to the examples described herein are possible. For example, some methods described herein may be changed by changing the order of the described method actions, such as by segmenting, repeating, or omitting certain method actions. Various aspects of the disclosed technology may be used in combination or alone. Different implementations use one or more of the innovations described. Some of the innovations described herein solve one or more of the problems mentioned in the background technology. Typically, a given technology / tool ​​cannot solve all of these problems.

[0024] As used in this application and the claims, the singular forms "a", "an", and "the" include the plural forms unless the context clearly indicates otherwise. In addition, as used herein, the term "including" means "comprising". Furthermore, as used herein, the term "and / or" refers to any one or any combination of terms in the phrase.

[0025] II. Introduction of the Disclosed Technology

[0026] One or more embodiments of the present invention provide a battery cell balancing system and strategy that can more efficiently utilize battery capacity according to the needs of different use cases. For example, a balancing circuit is provided that supports passive balancing and active balancing of a target battery cell according to a balancing strategy. In addition, the balancing circuit allows battery cell balancing to be performed while charging or discharging the battery cells together for an application use case.

[0027] Furthermore, in certain embodiments, instead of having a static, single balancing strategy, a suite of preset and customizable balancing applications is provided that can be configured, selected, and / or implemented to match the requirements of an application use case. The suite of preset and customizable balancing applications can be presented to and selected by a user to adapt the balancing system to a particular use case. Alternatively, the balancing system can automatically select a balancing application based on one or more inputs to adapt the balancing system to the use case.

[0028] III. Example Implementations

[0029] The embodiments discussed below provide and / or utilize balancing circuits to balance multiple battery cells or groups of battery cells. For example, the balancing circuit can be configured as a circuit dedicated to balancing. The balancing circuit can be used to implement one or more balancing strategies, thereby allowing the selection of a balancing strategy that is particularly suitable for the use case application. For example, a mix of passive balancing and target charging can be used to charge balance and / or discharge balance multiple battery cells or groups of battery cells. Implementing the selected balancing strategy allows the battery cells to more effectively meet the requirements of the use case application while increasing the safety and service life of the battery cells.

[0030] A. Example System

[0031] Figure 1 is a schematic block diagram illustrating an example balancing circuit that may implement one or more of the methods described herein. The balancing circuit may be implemented in a larger battery cell balancing system that is configured to implement balancing strategies to deliver more efficient battery usage as required by different use cases. For example, a single battery cell may be targeted for passive and active balancing, depending on the use case. Additionally, targeted passive and active balancing may be provided while the battery cell is in use (e.g., while the battery cell is being charged or discharged).

[0032] refer to Figure 1, balancing circuit 100 illustrates components of a battery pack. For example, the balancing circuit (100) includes a voltage source (102) and a load (104). The voltage source (102) is any voltage source capable of charging a battery cell, such as a balancing charger. For example, the voltage source (102) is a battery charger configured to convert alternating current into direct current to charge a battery cell or a battery cell group. The voltage source (102) can also be configured to convert three-phase alternating current into single-phase alternating current. The voltage source can be coupled to a generator, such as in conjunction with a renewable energy source, or can be coupled to an energy grid or microgrid, such as via an inverter or AC power source. The load (104) is any electrical load, such as a resistor, an inductor, a capacitor, another component, or a combination of components that serve as an electrical load that consumes electrical energy.

[0033] A voltage source (102) is coupled to a balancing circuit (100) via a charge balancing relay (106), and a load (104) is coupled to the balancing circuit (100) via a discharge balancing relay (108). The charge balancing relay (106) is configured to selectively couple the voltage source (102) to the balancing circuit (100) to charge a battery cell or a battery pack. Similarly, the discharge balancing relay (108) is configured to selectively couple the load (104) to the balancing circuit (100) to discharge a battery cell or a battery pack. As described below, the voltage source (102) or the load (104) is connected to or disconnected from the balancing circuit (100) to facilitate a charge balancing configuration, a discharge balancing configuration, or a non-balancing configuration.

[0034] For example, the voltage source (102) and the load (104) can be set at a higher level than the battery cells, such as at the same control level as the balancing controller (116) (discussed below). In one embodiment, the voltage source (102) is coupled to the balancing circuit (100) via a double-pole single-throw (DPST) charging relay (106). When the charging relay (106) is closed, the voltage source (102) can charge the cell group coupled to the balancing circuit (100). Similarly, the load (104) is coupled to the balancing circuit (100) through a DPST discharge relay (108). When the discharge relay (108) is closed, the load (104) can discharge the cell group coupled to the balancing circuit (100).

[0035] exist Figure 1In the example shown, the voltage source (102) or the load (104) is configured to be coupled in series to the charge balancing circuit (100). Thus, at any point in time, the charge balancing circuit (100) can be configured to charge or discharge one battery cell or group of cells during that time. In other embodiments, the voltage source (102) or the load (104) is configured to be coupled to the charge balancing circuit (100) in a manner that allows different battery cells or groups of cells to be charged simultaneously while one battery cell or group of cells is being discharged.

[0036] The charging balancing circuit (100) includes a plurality of cell group controllers (110(1), 110(2), ..., 110(N)). For example, the cell group controllers (110(1), 110(2), ..., 110(N)) are battery module controllers (BMC) or similar controllers. Each of the cell group controllers (110(1), 110(2), ..., 110(N)) is configured to couple a cell group among a plurality of cell groups (114(1), 114(2), ..., 114(N)) to the balancing circuit (100) via a cell group balancing relay among a plurality of cell group balancing relays (112(1), 112(2), ..., 112(N)). Each of the cell groups (114(1), 114(2), ..., 114(N)) includes one or more battery cells. The battery cells may be lithium-ion batteries or another known or future battery cell type. As will be discussed below, the battery cell pack may be implemented as a battery cell stack including a string controller (discussed below), a plurality of balancing controllers, a plurality of pack controllers, a plurality of pack relays, and a plurality of packs.

[0037] In one embodiment, a single cell group controller (110(1), 110(2), ..., 110(N)) is implemented on a circuit board (e.g., a printed circuit board) having a single cell group balancing relay (112(1), 112(2), ..., 112(N)). On each circuit board, the single cell group balancing relay (112(1), 112(2), ..., 112(N)) can be implemented as a double-pole single-throw (DPST) relay for each single cell group. In this example, when the single cell group balancing relay is closed, the relay attaches the single cell group to the balancing circuit (100). Additional or different relays may be used. In addition, additional or different components may be included on the circuit board, such as a balancing controller (discussed below) or one or more microprocessors, microcontrollers, FPGAs, and / or ASICs configured to perform the disclosed behaviors.

[0038] In addition to controlling the cell group balancing relays (112(1), 112(2), ..., 112(N)), each of the cell group controllers (110(1), 110(2)), ..., 110(N)) is configured to measure voltage, temperature, and other information for its corresponding cell group. The cell group controllers (110(1), 110(2), ..., 110(N)) are also configured to send the measured voltage, temperature, and other information to a balancing controller (discussed below) or to another control system coupled to the balancing circuit (100).

[0039] The charging balancing circuit (100) further includes a balancing controller (116). For example, the balancing controller (116) is a battery pack controller (BPC) or a similar controller. The balancing controller (116) can be implemented by one or more microprocessors, microcontrollers, FPGAs and / or ASICs. In this embodiment, the balancing controller (116) is responsible for implementing a balancing strategy. For example, the balancing controller (116) is configured to balance multiple single cell groups (114 (1), 114 (2), ..., 114 (N)) by controlling a charging balancing relay (106), a discharging balancing relay (108) and multiple single cell controllers (110 (1), 110 (2), ..., 110 (N)). In addition, by controlling the charge balancing relay (106), the discharge balancing relay (108) and the plurality of cell controllers (110(1), 110(2), ..., 110(N)), the balancing controller (116) can independently target specific cell groups using passive balancing or active balancing techniques. The balancing controller (116) can also be configured to aggregate data received from the plurality of cell group controllers (110(1), 110(2), ..., 110(N)), such as voltage, temperature and other information measured for each cell group in the cell groups (114(1), 114(2), ..., 114(N)), and store or buffer the data in a volatile memory (e.g., register, cache, RAM) or a non-volatile memory (e.g., ROM, EEPROM, flash memory, etc.). The balancing controller (116) can then use the aggregated data to make balancing decisions for the charge balancing circuit (100).

[0040] In one embodiment, a balancing controller (116) is configured to balance a plurality of cell groups (114(1), 114(2), ..., 114(N)) based on an external configuration in combination with measured voltage, temperature, and other information received from each of the plurality of cell group controllers (110(1), 110(2), ..., 110(N)). In one example, the external configuration includes a discharge balancing configuration, a charge balancing configuration, or a no balancing configuration. Additional and / or different external configurations may be provided.

[0041] In the example provided above, three balancing configurations can be used to balance the single cell group (114 (1), 114 (2), ..., 114 (N)). The balancing configuration can be referred to as a balancing state, which includes a discharge balancing state, a charge balancing state, or an unbalanced state. In this example, only one balancing configuration is implemented at any given time. Thus, only one of the charging relay (106) or the discharging relay (108) can be closed at a time, or both the charging relay (106) and the discharging relay (108) can be opened.

[0042] In one example, a charge balancing configuration may include setting a charge balancing relay (106) to be closed, setting a discharge balancing relay (108) to be open, setting one of the single cell group balancing relays (112 (1)) to be closed, and setting other single cell group balancing relays (112 (2), ..., 112 (N)) to be open. In this configuration, a single cell group (112 (1)) is charged to, for example, a target balancing voltage. Similarly, a discharge balancing configuration may include setting a charge balancing relay (106) to be open, setting a discharge balancing relay (108) to be closed, setting one of the single cell group balancing relays (112 (1)) to be closed, and setting other single cell group balancing relays (112 (2), ..., 112 (N)) to be open. In this configuration, a single cell group is discharged to, for example, a target balancing voltage. Finally, the no-balance configuration may include: setting the charge balancing relay (106) to open, setting the discharge balancing relay (108) to open, and setting the plurality of single-cell balancing relays (112(1), 112(2), ..., 112(N)) to open. In this configuration, no single-cell group is charged or discharged.

[0043] In one embodiment, to facilitate the above-described charge balancing configuration, balancing permissions may be provided, such as by a high-level control system (discussed below). For example, a charge balancing permission may include a flag input indicating whether the balancing controller (116) is permitted to charge. If the flag is set to false, the balancing controller (116) is not permitted to close the charge balancing relay (106). Similarly, a discharge balancing permission may include a flag input indicating whether the balancing controller (116) is permitted to discharge. If the flag is set to false, the balancing controller (116) is not permitted to close the discharge balancing relay (106). Additional and different permissions may be provided, such as to facilitate additional or different external configurations. The high-level control system for setting the permission flag may include a battery management system (BMS), an energy management system (EMS), or another high-level control system component, which will be referenced below. Figure 2 Have a discussion.

[0044] Figure 2 is a diagram illustrating another example balancing circuit that may implement one or more of the methods described herein. The balancing circuit may be implemented in a larger battery cell balancing system that is configured to implement balancing strategies to provide more efficient battery usage as needed for different use cases. For example, one or more battery cells may be targeted for passive balancing and active balancing, depending on the use case. Additionally, targeted passive balancing and active balancing may be provided while the battery cells are in use (e.g., charging or discharging the battery cells).

[0045] refer to Figure 2 The balancing circuit (200) includes a plurality of cell stacks (220(1), 220(2), ..., 220(N)). Each cell stack includes a plurality of battery packs within each stack, as described above with respect to Figure 1 As discussed. For example, each battery pack includes a voltage source (102) and a load (104). The voltage source (102) is any voltage source capable of charging a battery cell. Alternatively, the voltage source (102) is one of a plurality of voltage sources, such as a plurality of battery chargers (discussed below) configured to distribute power to different cell stack stacks. In this example, the voltage source (102) is coupled to a power source (226), such as Figure 2As shown. For example, the power supply (226) can be coupled to the energy grid and configured to convert alternating current into direct current to charge the battery cell group. Alternatively, the power supply (226) can be configured to provide AC power to the voltage source (102), wherein the voltage source (102) is configured to convert alternating current into direct current. Accordingly, the power supply (226) is configured to deliver power to multiple cell stacks. As discussed, AC power is provided via the power supply (226). Alternatively, a DC power supply, an inventive component, or one or more battery cells in a battery cell can be configured to deliver power to multiple cell stacks in place of the power supply (226) or in addition to the power supply (226). In one example, DC power from one or more battery cells in a battery cell is delivered to one or more other battery cells for balancing. The load (104) is any electrical load, such as a resistor or another component that acts as an electrical load for consuming electrical energy. In this embodiment, different battery packs may be charged and / or discharged simultaneously independent of other battery packs.

[0046] In an alternative embodiment, each cell stack (220(1), 220(2), ..., 220(N)) includes a dedicated charging relay (106) and a dedicated discharging relay (108) for the stack. Likewise, each stack may also include a dedicated voltage source (102) and load (104). In this embodiment, different stacks of cell stacks (220(1), 220(2), ..., 220(N)) can be charged and / or discharged simultaneously, independently of other stacks.

[0047] The balancing circuit (200) includes a plurality of cell stacks (220 (1), 220 (2), ..., 220 (N)). Each cell stack (220 (1), 220 (2), ..., 220 (N)) includes: a plurality of cell groups, such as cell groups (114 (1), 114 (2), ..., 114 (N)); a plurality of cell relays, such as relays (112 (1), 112 (2), ..., 112 (N)); a plurality of cell controllers, such as cell controllers (110 (1), 110 (2), ..., 110 (N)) and a plurality of balancing controllers, such as balancing controller (116). In a particular embodiment, each stack includes seventeen (17) balancing controllers, but each stack may include additional or fewer balancing controllers. In an embodiment having seventeen (17) balancing controllers, each stack also has seventeen (17) charging relays (106) and seventeen (17) discharging relays (108). Each balancing controller is configured to control a different circuit to balance a different subset of the plurality of cell groups via a different subset of the cell group relays and a different subset of the cell group controllers. In an alternative embodiment, the cell group stack (220(1), 220(2), ..., 220(N)) does not include a cell group controller, and the plurality of cell group relays are directly controlled by the balancing controller.

[0048] The balancing circuit (200) further includes a plurality of stack controllers (218(1), 218(2), ..., 218(N)). For example, the stack controllers (218(1), 218(2), ..., 218(N)) are configured as a string controller. The stack controllers (218(1), 218(2), ..., 218(N)) are each configured to control a different subset of the balancing controllers.

[0049] In one embodiment, the balancing circuit (200) further includes a battery management system (BMS) (222) and / or an energy management system (EMS) (224). The BMS (222) is configured to control the distribution of power to the plurality of cell groups by controlling the plurality of stack controllers (218 (1), 218 (2), ..., 218 (N)). The EMS (224) is configured to control the delivery of power through the power source (226). The BMS (222) and the EMS (224) are high-level control systems for balancing the stacks (220 (1), 220 (2), ..., 220 (N)). In one example, the BMS (222) and / or the EMS (224) are implemented as a software control system on a server computer or within another computing environment such as a virtual machine environment. For example, the BMS (222) and EMS (224) may be implemented on one or more server computers, such as a computer platform having hardware including one or more central processing units (CPUs), system memory, random access memory (RAM), and (one or more) input / output (I / O) interfaces. The BMS (222) and EMS (224) may be implemented on a single server computer or a single computing environment. Alternatively, the BMS (222) and EMS (224) may be implemented on a single controller or on multiple controllers.

[0050] To implement the balancing strategy, each stack controller in the plurality of stack controllers (218(1), 218(2), ..., 218(N)) is configured to operate based on a balancing mode or an external configuration received from the BMS (222). For example, the balancing mode may include a target voltage mode for a cell group within each cell group stack (220(1), 220(2), ..., 220(N)). In the target voltage mode, the cell group voltage is balanced based on the target voltage of the cell group.

[0051] In one embodiment, the balancing controller of each stack is configured to determine a balancing target voltage for each stack. Alternatively, the balancing controller is configured to receive a target voltage from a stack controller (218(1), 218(2), ..., 218(N)), from a BMS (222), from an EMS (224), or from another component, and balance each stack based on the received target voltage. Together with the target voltage, the balancing controller can be configured to receive a balancing strategy for balancing based on the target voltage for each stack.

[0052] For example, the balancing controller determines the balancing target voltage as: the balancing controller will attempt to charge and / or discharge all battery groups to match the target voltage. Referring back to the permission discussed above, if the charge balance permission flag is set to true, any battery below the target voltage will be charged and balanced. If the discharge balance permission flag is set to true, any battery below the target voltage will be discharged and balanced.

[0053] The target voltage can be determined based on different cell groups and / or cell group stack values. For example, the target voltage can be set to the average value of the cells in the cell group, cell group stack, or battery pack. Alternatively, the target voltage can be set to a fixed value. In another alternative, the target voltage can be set to the lowest or highest voltage of the cells in the cell group, cell group stack, or battery pack. The target voltage type can be set based on which of the above values ​​is used to determine the target voltage.

[0054] For example, the target voltage type can be set to average, fixed, minimum or maximum. Additional and different target voltage types can be provided based on different single cell groups and / or single cell group stack values ​​or based on other balancing indicators. The balancing controller can be configured to ignore the target values ​​that are not used for the balancing strategy. For example, when a fixed target voltage type is used, the average, minimum and maximum target voltages will be ignored. Similarly, if the voltage type is average, minimum or maximum, the fixed target voltage is ignored.

[0055] In addition to the target voltage, some embodiments also include a dead-hand voltage that can be set within the balancing controller and / or determined by the balancing controller. For example, a charge balancing voltage dead-hand can be set. Based on the charge balancing voltage dead zone, a cell group voltage greater than the dead-hand value (e.g., the number of millivolts below the balancing target voltage) does not need to be balanced and will not be charged. Similarly, a discharge balancing voltage dead-hand set that provides a cell group voltage greater than the dead-hand value (e.g., the number of millivolts above the balancing target voltage) does not need to be balanced and will not be discharged. The dead-hand voltage can be modified according to the balancing strategy, such as the cell voltage is close to the maximum voltage or the minimum voltage. For example, the dead-hand voltage can be modified to prevent the battery cell from being overcharged or undercharged (e.g., for safety, life, etc.). In addition, the dead-hand value can be modified to make the balancing strategy more aggressive or less aggressive.

[0056] As described above, to implement a balancing strategy, each of the plurality of stack controllers (218(1), 218(2), ..., 218(N)) is configured to operate based on a balancing mode or an external configuration such as received from a BMS (222). In one embodiment, the balancing mode may be an average target voltage mode, a fixed target voltage mode, a low target voltage mode, a high target voltage mode, a charging voltage dead angle mode, and a discharging dead angle mode. Additional and different balancing modes may be provided.

[0057] In order to realize the average target voltage mode, the stack controller will instruct the balancing controller to charge, discharge, or charge and discharge a single cell group to the average voltage of all cell groups. In order to realize the fixed target voltage mode, the stack controller is configured to instruct the balancing controller to charge and / or discharge a single cell group to the fixed voltage of all cell groups. In order to realize the low target voltage mode, the stack controller is configured to instruct the balancing controller to charge and / or discharge a single cell group to the lowest voltage of the cell group. In order to realize the high target voltage mode, the stack controller is configured to instruct the balancing controller to charge and / or discharge a single cell group to the highest voltage of the cell group. In order to realize the charging voltage dead angle mode, the stack controller is configured to instruct the balancing controller to realize one of the above modes, but ignore the cell group whose voltage is less than the threshold value below the target voltage. In order to realize the discharge voltage dead angle mode, the stack controller is configured to instruct the balancing controller to ignore the cell group whose voltage is greater than the threshold value above the target voltage.

[0058] Figure 3 is a diagram illustrating yet another example balancing circuit that may implement one or more of the methods described herein. The balancing circuit may be implemented in a larger battery cell balancing system that is configured to implement balancing strategies to deliver more efficient battery usage as required by different use cases. For example, one or more battery cells may be targeted for passive balancing and active balancing, depending on the use case. Additionally, targeted passive balancing and active balancing may be provided while the battery cells are in use (e.g., charging or discharging the battery cells).

[0059] refer to Figure 3The balancing circuit (300) includes a plurality of cell groups (314) and a plurality of cell group controllers (310). Each cell group controller (310) is configured to control a different cell balancing relay, such as a cell group relay (112 (1), 112 (2), ..., 112 (N)), to couple a different cell group (314) to the balancing circuit (300), as discussed above. The balancing circuit (300) also includes a plurality of balancing controllers (316). Each balancing controller (316) is configured to control the charging and discharging of a different subset of the cell groups in the plurality of cell groups (314). The balancing controllers also include a plurality of string controllers (318). Each string controller (318) is configured to control a different subset of the balancing controllers in the plurality of balancing controllers (316). Accordingly, the cell group controller (310), the balancing controller (316) and the string controller (318) are configured to perform low-level control of the cell group (314) of the balancing circuit (300).

[0060] In one embodiment, the balancing circuit (300) may also include high-level control of the cell groups (314). For example, the balancing circuit (300) includes a battery management system (BMS) (322) configured to control power distribution in the balancing circuit (300) by controlling a plurality of string controllers (318). By controlling the string controllers (313), the BMS ultimately has control over the cell group controllers (310) and power distribution to the cell groups (314). Accordingly, the BMS (322) controls power distribution within the balancing circuit (300) by charging and / or discharging specific cell groups of the cell groups (314) via a plurality of cell group controllers (310), a plurality of balancing controllers (314), and a plurality of string controllers (318).

[0061] In another embodiment, the balancing circuit (300) further includes an energy management system configured to control power delivery to the balancing circuit. For example, when the BMS (322) controls power distribution in the balancing circuit (300), the EMS (324) controls power input to the balancing circuit (300). The EMS (324) is configured to control power distribution by controlling inventive components (such as power sources (226)) and / or voltage sources (such as voltage sources (102)).

[0062] The above components of the balancing circuits 100, 200, and 300 are configured to be coupled together and communicate via a software application programming interface (API) and / or via known or future communication protocols. For example, Modbus, CANbus, DNP3, Web service interfaces, or other protocols may be used to facilitate communication, and the API may be utilized to communicate between components at similar and different control levels. In one embodiment, the BMS (322) is configured to communicate with the string controller (316) via a ModBus API or another balancing application API. In this embodiment, the API exposes or virtually couples a set of ModBus communication points (e.g., compatible with MESA-ESS (energy storage system) and SunSpec) to allow activation and configuration of all balancing applications for downstream components, reporting of current settings, and reporting of current battery status and the impact of balancing applications.

[0063] As described above, the balancing controller (316) is configured to operate in multiple balancing states or configurations. For example, the balancing controller is configured to operate in one or more of the following states: a charging balanced state, which is used to charge the cell group (314) to a target voltage; a discharging balanced state, which is used to discharge the cell group (314) to a target voltage; or a non-balancing state, which is used to decouple the cell group (314) from the balancing circuit (300). In the non-balancing state, no cell group (314) is charged or discharged for the purpose of balancing. In one embodiment, when the balancing controller (316) transitions between the charging balanced and discharging balanced states, or when transitioning between charging or discharging different cell groups (314), the balancing controller transitions to non-balancing before charging or discharging different cell groups (314).

[0064] In addition, at any time, the balancing controller (316) can perform one of many behaviors. In one embodiment, the balancing controller (316) can operate in one of the following three behaviors: balancing monitoring; charging balancing or discharging balancing. As discussed above, in one embodiment, when transitioning from one behavior to the next (e.g., charging balancing to discharging balancing), the balancing controller will transition through an unbalanced state or a balanced monitoring state. For example, in an unbalanced state or a balanced monitoring state, all relays must be disconnected, and all cell groups must confirm that all cell group relays are disconnected before charging or discharging the cell group by closing any relays. In one embodiment, even if the behavior remains the same, the balancing controller must transition through an unbalanced state or a balanced monitoring state (i.e., transitioning from charging balancing of one cell group to charging balancing of another cell group). In this example, if the balancing controller transitions from charging and balancing the first battery group to charging and balancing the second battery group, the balancing controller will: (1) transition from the charging and balancing state to the unbalanced state; (2) confirm that all relays are disconnected; (3) transition from the unbalanced state back to the charging and balancing state. By transitioning between the charging and discharging balanced states to the unbalanced state, the balancing controller can provide safe and reliable operation.

[0065] During the balancing monitoring, the balancing controller monitors each cell group assigned to the balancing controller to determine which cells (if any) need to be balanced. In one embodiment, the balancing controller performs balancing monitoring by periodically calculating a balancing target voltage. The balancing target voltage may be based on a current balancing mode or may be a fixed balancing target voltage. The balancing controller may also calculate the balancing offset voltage of each cell group as the voltage difference of each cell group relative to the dead angle range. Next, in order for the balancing controller to determine which cells need to be charged and / or discharged, the balancing controller determines whether each cell voltage is higher or lower than the balancing target voltage.

[0066] If the cell group voltage is higher than the balance target voltage, the balance controller can determine how to handle the cell group as follows. If the discharge balance permission is set to false (e.g., discharge balance is not allowed), all cell groups are ignored for the purpose of discharge balance. Next, if the cell group voltage is less than the discharge balance dead angle (e.g., less than the balance target voltage value plus the discharge balance voltage dead angle value), the cell group is also ignored. Finally, for the remaining cell groups (e.g., the cell groups that are not ignored), the balance offset is calculated for each cell group (e.g., the cell group voltage minus the balance target voltage and the discharge balance voltage dead angle value).

[0067] If the cell group voltage is lower than the balance target voltage, the balance controller can determine how to handle the cell group as follows. If the charge balance permission is set to false (e.g., charge balance is not allowed), all cell groups are ignored for the purpose of charge balance. Next, if the cell group voltage is greater than the charge balance dead angle (e.g., greater than the balance target voltage value minus the charge balance voltage dead angle value), the cell group is also ignored. Finally, for the remaining cell groups (e.g., the cell groups that are not ignored), the balance offset (e.g., the balance target voltage minus the discharge balance voltage dead angle value and the cell group voltage) is calculated for each cell group.

[0068] Based on the calculated balance offset value, the balance controller transitions to a balancing behavior. If no cell group has a balance offset (e.g., no cell group is outside a dead angle and / or has an appropriate position for balancing based on permission), the balance monitoring process is repeated. However, when calculating the balance offset, the cell group with the highest balance offset is selected for balancing. If the voltage of the selected cell group is higher than the balance target voltage, the balance controller transitions to discharge balance. If the voltage of the selected cell group is lower than the balance target voltage, the balance controller transitions to charge balance. After balancing the selected cell group, the balance controller can select another cell group with the next highest balance offset for balancing and corresponding transition.

[0069] During charge balancing, the balancing controller charges the cell group, such as by continuing to charge the cell group until the cell group voltage reaches the charge target voltage or another value. As discussed above, the cell group with the highest offset value can be selected for charging. For example, when the balancing controller transitions to charge balancing, energy is transmitted or injected into the selected cell group. Energy will continue to be transmitted until the selected cell group voltage is equal to the balance target voltage. In another embodiment, the selected cell group will continue to be charged until the cell group voltage is within the cell balance dead zone. While charging balancing, the balancing controller can continue to calculate the balance target voltage and determine whether the charge balancing should stop. For example, if the charge balancing permission becomes false or the cell group voltage becomes greater than or equal to the balance target voltage, the charge balancing should stop. If the charge balancing stops, the balancing controller transitions to balance monitoring.

[0070] Similarly, during discharge balance, the balancing controller discharges the cell group, such as continuing to discharge the cell group until the cell group voltage reaches the discharge target voltage or another value. As discussed above, the cell group with the highest offset value can be selected for discharge. For example, when the balancing controller transitions to discharge balance, energy is removed or dissipated from the selected cell group. Energy will continue to be removed until the selected cell group voltage is equal to the balance target voltage. In another embodiment, the selected cell group will continue to be discharged until the cell group voltage is within the cell balance dead angle. While discharging balance, the balancing controller can continue to calculate the balance target voltage and determine whether the discharge balance should stop. For example, if the discharge balance permission becomes false or the cell group voltage becomes less than or equal to the balance target voltage, the discharge balance should stop. If the discharge balance stops, the balancing controller transitions to balance monitoring.

[0071] B. Sample applications and usage scenarios

[0072] As discussed above, instead of having a static single balancing strategy, one or more embodiments of the present embodiment provide multiple balancing applications selected and implemented to match the requirements of the current use case. The balancing application is selected to adapt the above balancing circuit to a specific use case, so as to adopt passive balancing and active balancing strategies to more effectively meet the requirements of the use case while increasing the safety and service life of the battery cell.

[0073] Figure 4 is a flow chart of an example implementation for balancing a cell group based on a balancing configuration. The method may be performed by Figures 1 to 3 The method may be implemented by any system in the system and / or different systems. Additional, different or fewer actions may be provided. For example, various actions may be omitted or performed by separate systems. Although the method is presented in the order shown, other orders may be provided and / or actions may be repeated, such as repeating actions 410, 412 and 414 based on receiving different balancing configuration forms.

[0074] At act 410, a balancing configuration is received to balance the battery cells in a balancing circuit. In one embodiment, a battery management system (BMS) or an energy management system (EMS) receives the balancing configuration from a user device (such as a mobile device or a workstation (328) coupled to the EMS, BMS, or another component of the balancing circuit (300)) via an application programming interface (API). The workstation (328) may operate in a client-server implementation, where the workstation (328) is remote from the other components of the balancing circuit (300). The workstation (328) may be implemented as a computer platform having hardware including one or more central processing units (CPUs), system memory, random access memory (RAM), and (one or more) input / output (I / O) interfaces.

[0075] For example, the workstation presents a predefined or user-configurable collection, library, or menu of balancing configuration forms that can be enabled and configured for different use cases of the battery cell. In another embodiment, the balancing configuration form is received by the BMS from the EMS or another control system component to automatically select the balancing configuration form based on the use case application of the battery cell. As discussed above, the API can be implemented using known or future communication protocols such as Modbus, CANbus, DNP3, a Web service interface, or another protocol that allows the API to communicate between components at similar and different control levels.

[0076] The balancing configuration can rely on a balancing report from a stack that includes the current state of the battery cell group and the impact of the current balancing configuration on the battery cell. In addition, a schedule can be used to provide a balancing configuration. For example, a balancing configuration can be implemented using a time of day, a date, and a collection of stacks to create balancing times for different stacks within a balancing circuit. In this way, the balancing schedule will be an overlay of the balancing configuration, thereby changing the functionality of the system to optimize usage time, efficiency, consumption requirements, and / or other factors. For example, a battery cell group is typically deployed for solar power generation and is configured to store energy generated by a solar cell. Solar power generation follows a predictable schedule curve, and matching the balancing strategy with the schedule curve can allow the balancing strategy to be appropriately adjusted (e.g., knowing that the battery cell may be slowly charged early in the day, the battery will not be charged at night, etc.). In addition, many other balancing strategies and use case applications are driven by schedules. For example, if the schedule requires maximum energy at a specific time of the day (e.g., participating in an energy market), knowing that the battery cell must be fully charged at a specific time may be a key input to the balancing strategy.

[0077] In one embodiment, the library of predefined or user-configurable balancing configurations includes two or more of the following: no balancing configuration; basic balancing configuration; full discharge optimized configuration; full charge optimized configuration; slow charge optimized configuration; slow discharge optimized configuration; and high efficiency configuration. Additional and different balancing configurations may be included in the library. For example, the library of balancing configurations may also include one or more additional balancing configurations that are defined to manage voltage differences between battery cell groups based on additional or different use cases for the battery cell groups.

[0078] For example, refer to Figure 3 , the BMS (322) includes an unbalanced configuration that is configured to perform no balancing at all. In other words, the voltage difference between the cell groups (314) is not minimized. As discussed above, when the BMS (322) transitions between balanced configurations, an unbalanced configuration can be achieved.

[0079] The BMS (322) may also include a basic balancing configuration configured to minimize the voltage difference between the cell groups by balancing the cell groups by charging and / or discharging the cell groups. For example, the basic balancing configuration includes an out-of-balance trigger value (e.g., in mV), an in-balance trigger value (e.g., in mV), and a cell voltage dead zone (e.g., in mV). In this example, the balancing controller (316) monitors the cell groups (314) to determine whether any cell group (314) has a cell voltage outside the battery voltage dead zone. Starting from the cell group with the largest difference relative to the average cell voltage of the cell groups (314), the cell groups are charged and / or discharged to balance the cell group voltages between all cell groups (314). Specifically, if the cell voltage spread between the cell group voltage and the average voltage of the cell group is greater than the balance outer trigger value, the cell group is actively balanced or passively balanced until the cell group voltage is equal to the average voltage of the cell group or is within the balance inner trigger value.

[0080] In another embodiment of the basic balancing configuration, the voltage difference between the cell groups is minimized without considering the battery state of charge (SOC) value. In this way, if the cell group voltage is outside the balancing dead zone around the average cell group voltage, the cell group is charged or discharged. In another embodiment, the basic balancing configuration is configured to balance the cell groups based on the dead zone value. For example, based on the basic balancing configuration, the balancing controller identifies a subset of cell groups in the cell group whose voltage is outside the dead zone value, and determines a cell group from the subset of cell groups in the cell group as having the highest voltage difference with the average voltage of the cell group, and charges or discharges the cell group. Then, the balancing controller repeats the process to balance the cell group with the second highest voltage difference with the average voltage of the cell group.

[0081] The BMS (322) may also include a full charge optimized balancing configuration configured similarly to the basic balancing configuration, but the full charge balancing configuration only performs downward passive balancing for a cell group above a dead angle value. In this example, the BMS (322) dynamically adjusts the dead angle to actively operate the voltage knee. For example, because the relationship between the state of charge (SOC) (e.g., from 0% to 100%) and the voltage is not a straight line, a small change in SOC near the edge of the SOC range may require a very large voltage change, resulting in an increased risk when operating the battery cell from the plateau of the curve to the knee, because the battery cell may be accidentally driven to a dangerous low (or high) voltage. Therefore, dynamically adjusting the dead angle when charging the battery cell from the plateau of the curve to the knee can improve safety while actively charging the battery cell. Therefore, active balancing is only used for cell groups that are far outside the dead angle value and away from the average voltage at which the cell group becomes dangerous. By dynamically adjusting the deadband, battery cells that are above or below average may be balanced more aggressively to allow more of the knee region of the curve to become a usable SOC range.

[0082] In another embodiment, the fully charged optimized configuration is configured to manage the battery voltage difference between the cell groups so as to maximize the battery SOC value by charging the cell groups at the lowest voltage. In this example, only the cell groups with voltages above the high charge threshold are discharged. In yet another embodiment, the fully charged optimized configuration is configured to balance the cell group voltages upward. In this example, only the cell groups with voltages above the high charge threshold are balanced downward, while the cell groups with voltages below the low charge dead zone are balanced upward.

[0083] The BMS (322) may also include a fully discharged optimized balancing configuration configured in a manner similar to the basic balancing configuration, but the fully discharged balancing configuration only actively balances upward for cell groups below the deadband value. Again, in this example, the BMS (322) dynamically adjusts the deadband to actively operate the voltage inflection point. Thus, passive balancing is only used for cell groups that are far outside the deadband value and far from the average voltage at which the cell group becomes dangerous.

[0084] In another embodiment, the full discharge optimization configuration is configured to manage the voltage difference between the cell groups so as to minimize the battery SOC value by discharging the cell group with the highest voltage. In this example, only the cell groups with voltages below the low charge threshold are charged. In yet another embodiment, the full discharge optimization configuration is configured to balance the cell group voltages downward. In this example, only the cell groups with voltages below the low charge threshold are balanced upward, and only the cell groups with voltages above the high discharge dead zone are balanced downward.

[0085] The BMS (322) may also include a slow charge optimization configuration configured in a manner similar to the basic balance configuration, but given a target voltage, the voltage source is used to slowly raise all cells to the target voltage. For example, the slow charge configuration manages the voltage difference between the cell groups to increase the battery SOC value by charging or discharging the cell groups whose voltage is outside the charging dead zone. In addition, as the cell group voltage approaches the high charging threshold, the voltage charging dead zone decreases.

[0086] The BMS (322) may also include a slow discharge optimization configuration configured in a manner similar to the basic balance configuration, but given a target voltage, the load is used to slowly raise all cells to the target voltage. For example, the discharge configuration manages the voltage difference between the cell groups to reduce the SOC value of the cell group by charging or discharging the cell group whose voltage is outside the discharge dead zone. In addition, as the cell group voltage approaches a low charge threshold, the discharge dead zone decreases.

[0087] In one embodiment, the charging configuration and the discharging configuration are configured to balance the cell group voltage upward or downward to the target voltage by charging or discharging the cell group whose voltage is outside the dead zone. In addition, the dead zone decreases when the cell group voltage approaches the high charge threshold or the low voltage threshold, respectively.

[0088] The BMS (322) may also include a high efficiency configuration configured to implement a variation of the above balancing configuration that only balances the cell group up or down to a cell group voltage for maintaining maximum efficiency (such as when the cell group voltage is close to a voltage inflection point). For example, the high efficiency configuration manages the voltage difference between the cell groups to minimize charging and discharging of the cell groups, such as to minimize energy consumption and / or dissipation. In one embodiment, only the cell group voltage is balanced when the voltage is close to a high charge threshold or a low charge threshold.

[0089] In one embodiment, the high efficiency configuration is configured to balance the cell group voltage to a target voltage by minimizing the complete charging and discharging of the cell group, thereby consuming and dissipating less energy than other balancing configurations, such as by minimizing energy consumption and dissipation. For example, a cell group voltage that is not near a high charge threshold or a low charge threshold may not be balanced.

[0090] Return to reference Figure 4 , in action 412, the plurality of single cell string controllers are controlled based on the received balancing configuration. In one embodiment, the BMS controls the plurality of single cell string controllers by instructing the string controllers to balance each battery cell stack based on the balancing configuration. As discussed above, each string controller is configured to control a different subset of balancing controllers in the balancing controllers.

[0091] In action 414, multiple single-cell balancing controllers are controlled by the single-cell group string controller based on the received balancing configuration form. In one embodiment, each single-cell group balancing controller balances a different plurality of single-cell groups. As discussed above, each balancing controller is configured to control a different subset of single-cell group controllers in the single-cell group controllers to balance the single-cell group. The single-cell group controller, the balancing controller, and the string controller provide low-level control of the single-cell group based on the received balancing controller.

[0092] Return to reference Figure 1-3 , provides an exemplary single-cell group balancing system. For example, reference Figure 3, a single cell group balancing system can be implemented as a balancing circuit (300). The balancing circuit (300) includes a plurality of single cell groups (314) and a plurality of single cell group controllers (310). As discussed above, each of the single cell group controllers (310) is configured for a different single cell group in the plurality of single cell groups (314). The balancing circuit (300) also includes a plurality of balancing controllers (316) and a plurality of string controllers (318), wherein the plurality of balancing controllers (316) are configured to control different subsets of single cell group controllers in the plurality of single cell group controllers (310), and the plurality of string controllers (318) are configured to control different subsets of balancing controllers in the plurality of balancing controllers (316). In this embodiment, the single cell group controller (310), the balancing controller (316), and the string controller (318) are configured to perform low-level control on the single cell groups (314) of the balancing circuit (300).

[0093] The balancing circuit (300) further includes: a battery management system (BMS) (322) configured to control the plurality of string controllers (318); and an energy management system (EMS) (324) configured to implement a balancing technique for balancing the cell group based on a user-selected balancing application. The BMS (322) and the EMS (324) are configured to perform high-level control of the cell group (314) of the balancing circuit (300). As discussed above, the aforementioned low-level and high-level control components may communicate with an application programming interface (API), such as according to Modbus, CANbus, DNP3, a Web service interface, or another communication protocol.

[0094] Figure 5 is a flow chart of an example implementation for performing a balancing technique for balancing a single pool group based on a balancing application selected by a user. As discussed above, the method may be performed by Figures 1 to 3 The method may be implemented on a system and / or on a different system. Additional, different, or fewer actions may be provided. For example, various actions may be omitted or performed by separate systems. Although the method is presented in the order shown, other orders may be provided and / or actions may be repeated, such as repeating actions 510, 512, and 514 based on repeatedly presenting a menu and receiving a different user-selectable balancing application.

[0095] At act 510, a menu of user-selectable balancing applications is presented to the user. In one example, the user-selectable balancing applications are presented via a graphical user interface, such as at a user workstation. For example, the menu may include predefined balancing applications, such as: no balancing application; basic balancing application; full discharge optimization application; full charge optimization application; slow charge optimization application; slow discharge optimization application; and high efficiency application. Furthermore, the menu may include additional customizable balancing applications. Additional and different balancing applications may be included in the library.

[0096] In one exemplary embodiment, a basic graphical user interface presents a menu to a user to control one or more stacks or battery groups within a stack as a target and is set with a balancing mode (e.g., no balancing, average target voltage mode, fixed target voltage mode, low target voltage mode, high target voltage mode, charging voltage dead zone mode and discharge dead zone mode or other modes); target voltage type (e.g., average, fixed, minimum, maximum or other types); optional voltage targets; permission to charge / discharge a single cell group, charging and discharging the dead zone and other balancing settings. In this way, the basic graphical user interface can be configured to control individual balancing schemes very specifically, such as in the case of maintenance events or operational events. In another embodiment, a balancing application graphical user interface can be provided for a higher-level balancing application to implement a balancing strategy, such as by selecting a pre-configured balancing application (e.g., no balancing application, basic balancing application, full discharge optimization application, full charge optimization application, slow charge optimization application, slow discharge optimization application, high efficiency application or other application). In another embodiment, the high-level graphical user interface is configured to pair the balancing application with an energy management application. For example, an energy management application may be selected to implement a higher level balancing strategy (e.g., "fully charge the battery before 4AM"), which is paired with an applicable balancing application (e.g., a full charge optimization application, a slow charge optimization application, a high efficiency application, or other application). Additional and different graphical user interfaces may be provided, and the aforementioned example interfaces may be combined and / or used simultaneously.

[0097] In action 512, a user-selected balancing application is received from a user. In one example, the user-selected balancing application is received by a user workstation via a graphical user interface. The user can select a balancing application based on how the battery cell is used. For example, different balancing applications can be selected for different needs of grid and microgrid energy storage and management and renewable energy integration. For example, in the summer, during the daytime period, energy consumption increases sharply (e.g., due to increased demand for air conditioning, etc.). Accordingly, during the evening period, a full charge optimization application can be selected to prepare for the increased demand of the next day. In another example, the battery cell can be configured to provide a full discharge at a given time the next day. Therefore, a balancing application can be selected to drive the battery cell to a maximum SOC the night before the charging cycle to keep the battery cell fully charged without power during the preparation period and provide a maximum discharge during a given time during the next day or during the activity. In yet another example, the battery cell can be configured to provide a balanced frequency response at all times using the entire SOC range. Accordingly, a balancing application can be selected to keep the balance of the battery cell at an average SOC, or to balance as closely as possible. Alternatively, the battery cells may be configured to always provide a balanced frequency response, but only use the middle portion of the SOC range (e.g., 20% to 80%). In this case, a balancing application may be selected for high energy efficiency to balance only the cells that are out of range. In another example, the battery cells may be configured to provide unbalanced service during the day and expect to be fully charged at night. In this way, an average balancing application may be selected during the day, and then a charge optimization balancing application may be selected at night. Furthermore, if the charging period is narrow (e.g., as in a frequency response application), a balancing application may be selected for fast charging, and if the charging period is wide, a balancing application may be selected for full charging. Additional and different use cases may be provided, and one or more different balancing applications may be selected based on the use case.

[0098] In action 514, instructions for balancing multiple cell groups are sent based on the balancing application selected by the user. In one example, instructions are sent to one or more of the above-mentioned low-level and high-level control components via an application programming interface (API). As discussed above, the balancing API is configured to communicate between components in the balancing circuit to allow activation and configuration of downstream components to implement the selected balancing application, report current settings, report current battery status, and report the impact of the balancing application. In one or more embodiments, the API is configured to send instructions for balancing multiple cell groups to a balancing controller. Additionally or alternatively, the API is configured to send instructions for balancing multiple cell groups to multiple string controllers. In addition, additionally or alternatively, the API is configured to send instructions for balancing multiple cell groups to a BMS and / or EMS.

[0099] As discussed above, a schedule can be used to implement a balancing application. For example, the selected balancing application can be adapted to the time of day, date, and subset of stacks within the balancing circuit. In this way, the schedule can change the function of the selected balancing application to optimize for usage time, efficiency, consumption requirements, and / or other factors.

[0100] Figure 6 is a flow chart of another example implementation for performing a balancing technique for balancing a single pool group based on a balancing application selected by a user. The method is Figures 1 to 3 The method may be implemented by a system and / or a different system. Additional, different, or fewer actions may be provided. For example, various actions may be omitted or performed by separate systems. Although the method is shown in the order shown, other orders may be provided and / or actions may be repeated, such as repeating actions 610, 612, 614 based on receiving different balancing applications.

[0101] In action 610, a balancing application is received based on a user selection from a library of balancing applications. In one embodiment, the balancing application is received by an energy management system (EMS). The EMS is configured to provide an application framework for configuring and managing different balancing applications that is compatible with existing balancing circuits. The balancing application is selected from a library of balancing applications, which includes a plurality of available predefined balancing applications configured for different use cases of a single cell group. In addition, a customizable balancing application can be selected to further configure the application to a use case for a single cell group.

[0102] At action 612, a balancing instruction is generated by the EMS, a battery management system (BMS), or another high-level control system component based on the received balancing application. The instruction is generated to implement the balancing application on a low-level control system component (e.g., a string controller, a balancing controller, a single cell group controller, and / or other controllers).

[0103] At act 614, a balancing instruction is sent to balance the cell group. In one embodiment, the instruction is sent from a high-level control component to a low-level cell group control component via an application programming interface (API).

[0104] At act 616, the cell group is balanced based on the balancing instruction. In this embodiment, the cell group is balanced via a low-level cell group control component as discussed above.

[0105] IV. Conclusion

[0106] In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it should be appreciated that the illustrated embodiments are merely preferred examples of the invention and should not be viewed as limiting the scope of the invention. Instead, the scope of the invention is defined by the appended claims. Therefore, we claim all inventions that fall within the scope and spirit of these claims as our invention.

Claims

1. A balancing circuit, comprising: A plurality of single cell stacks, each stack comprising: Multiple single-cell groups; and a plurality of balancing controllers, each balancing controller being configured to control a different circuit to balance a different subset of the plurality of cell groups; and A plurality of stack controllers, each stack controller configured to control a different subset of the balancing controllers of the plurality of balancing controllers.

2. The balancing circuit according to claim 1, further comprising: a power source configured to deliver power to the plurality of cell stacks; a battery management system (BMS) configured to control power distribution to the plurality of cell groups by controlling the plurality of stack controllers; as well as An energy management system (EMS) is configured to control power delivery through the power source.

3. The balancing circuit according to claim 2, wherein: Each stack controller of the plurality of stack controllers is configured to operate based on a balancing pattern received from the battery management system, wherein the balancing pattern includes a target voltage pattern for equalizing voltages of the plurality of cell groups.

4. The balancing circuit according to claim 3, wherein: The target voltage mode includes: an average mode configured to charge, discharge, or charge and discharge one or more of the plurality of cell groups to a target voltage set as an average voltage of the plurality of cell groups; or A fixed target voltage mode is configured to charge, discharge, or charge and discharge one or more of the plurality of cell groups to a target voltage set as a fixed voltage of the plurality of cell groups.

5. The balancing circuit according to claim 3, wherein: The target voltage mode includes: a low target voltage mode configured to charge, discharge, or charge and discharge one or more of the plurality of cell groups to a target voltage set as a lowest voltage of the plurality of cell groups; or A high target voltage mode is configured to charge, discharge, or charge and discharge one or more of the plurality of cell groups to a target voltage set as a highest voltage of the plurality of cell groups.

6. The balancing circuit according to claim 3, wherein: The balancing mode includes a charging voltage dead zone configured to ignore a cell group whose voltage is less than a threshold below a target voltage.

7. A balancing circuit, comprising: Multiple single pool groups; Multiple single-cell balancing relays; a plurality of balancing controllers, each balancing controller being configured to control charging and discharging of a different subset of the plurality of cell groups; a plurality of string controllers, each string controller configured to control a different subset of balancing controllers of the plurality of balancing controllers; as well as A battery management system is configured to control power distribution in the balancing circuit by controlling the plurality of string controllers.

8. A balancing circuit, comprising: A single cell stack, the single cell stack comprising: Multiple single-cell groups; and A plurality of single-cell group balancing relays, each of the single-cell group balancing relays being electrically coupled to one of the single-cell groups; Voltage source; a charging balancing relay electrically coupled to the voltage source and the plurality of single cell group balancing relays; load; a discharge balancing relay electrically coupled to the load and the plurality of single cell group balancing relays; and A balancing controller is communicatively coupled to the plurality of single-cell group balancing relays, the charging balancing relay, and the discharging balancing relay, wherein the balancing controller controls the opening and closing states of the plurality of single-cell group balancing relays, the charging balancing relay, and the discharging balancing relay based on the balancing state of the single-cell group stack.

9. A method comprising: Determining a balance target value of at least one single cell group parameter; measuring at least one single cell group parameter of the plurality of single cell groups; Determining a charge balance offset of at least one cell group among the plurality of cell groups based on a measurement of at least one cell group parameter of the at least one cell group among the cell groups and the balance target value; Determining a state of balance of the plurality of battery groups based at least in part on the charge balance offset; as well as The charge level of the at least one of the cell groups is adjusted based on the determined state of balance.

10. A balancing circuit, comprising: A single cell stack, the single cell stack comprising: Multiple single pool groups; A plurality of single-cell group balancing relays, each of the single-cell group balancing relays being electrically coupled to one of the single-cell groups; a charge balancing relay configured to selectively electrically couple a voltage source to the plurality of single cell group balancing relays; a discharge balancing relay configured to selectively electrically couple a load and the plurality of single cell group balancing relays; and A balancing controller is communicatively coupled to the plurality of single-cell group balancing relays, the charging balancing relay, and the discharging balancing relay, wherein the balancing controller controls the opening and closing states of the plurality of single-cell group balancing relays, the charging balancing relay, and the discharging balancing relay based on the balancing state of the single-cell group stack.

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