Battery module power balancing method and device

Abstract

The present application discloses a method and device for equalizing the charge of a battery module. The battery module includes a plurality of single cells connected in parallel. The method includes: obtaining the current of the battery module and the operating status information of each single cell; determining the state of charge value of each single cell according to the current and the operating status information; determining the maximum state of charge value and the minimum state of charge value of the single cell in the battery module according to the state of charge value of each single cell, and determining the difference between the maximum state of charge value and the minimum state of charge value; when it is determined that the difference is greater than a preset threshold value and the operating status of each single cell satisfies the first trigger condition, controlling the equalization switch of the single cell to enable, so as to complete the charge equalization of the battery module. The present application has a simple calculation structure and a small amount of calculation, which significantly improves the accuracy of the charge equalization of each single cell and the charge equalization efficiency of the battery module, and greatly reduces the burden of the main control circuit.

Description

Technical Field

[0001] The present application relates to the field of electric energy storage technology, and specifically to a method and device for balancing the electric quantity of a battery module. Background Art

[0002] Large-capacity battery energy storage systems are widely used in power systems, such as grid frequency regulation, peak shaving and valley filling, uninterrupted power supply and improvement of power quality. In large-capacity battery energy storage power stations, energy storage batteries are usually composed of dozens or even hundreds of battery modules. Differences in battery module materials, manufacturing processes and use environments will cause inconsistencies in parameters such as voltage, internal resistance and capacity of the batteries in the battery module. The differences are mainly reflected in the fact that during the charging process of the battery module, batteries with too high voltage may be overcharged; during the discharge process of the battery module, batteries with too low voltage may be over-discharged. As the discreteness of the batteries in the battery module increases, the overall capacity of the energy storage battery decreases, and in severe cases, the battery module will fail prematurely.

[0003] In the prior art, there are two main methods for balancing battery modules: active balancing and passive balancing. Active balancing transfers the energy of the single cell with the highest energy to the single cell with the lowest energy, or uses the energy of the entire group to supplement the single cell with the lowest energy. During the implementation process, an energy storage link is required to redistribute the energy through this link. Although active balancing effectively achieves the balance of the battery module, the balancing circuit is complex, the stability is poor and the cost is high. Passive balancing consumes the energy of the single cell with high energy to achieve the purpose of overall balance. The passive balancing circuit has a simple structure and low cost, but the balancing current of traditional passive balancing is about 0.2A, which is difficult to meet the real-time requirements of power grid frequency modulation, peak shaving and valley filling and other applications. Summary of the invention

[0004] In view of the above problems, the present application is proposed to provide a method and device for balancing the power of a battery module that overcomes the above problems or at least partially solves the above problems.

[0005] According to one aspect of the present application, a method for balancing a battery module is provided, wherein the battery module includes a plurality of single cells connected in parallel, including:

[0006] Obtain the current of the battery module and the operating status information of each single battery, the operating status information includes the voltage and temperature of each single battery;

[0007] Determine the state of charge value of each single battery according to the current and operating status information;

[0008] Determine the maximum state of charge value and the minimum state of charge value of the single battery in the battery module according to the state of charge value of each single battery, and determine the difference between the maximum state of charge value and the minimum state of charge value;

[0009] When it is determined that the difference is greater than a preset threshold and that the operating state of each single cell satisfies the first trigger condition, the balancing switches of a part of the single cells are first enabled, and then the balancing switches of another part of the single cells are enabled to complete the power balancing of the battery module.

[0010] Optionally, in the above method, firstly controlling the balancing switches of a part of the single cells to be enabled, and then controlling the balancing switches of another part of the single cells to be enabled, so as to complete the power balancing of the battery module includes:

[0011] First, the balancing switches of the single cells with odd numbers are controlled to be enabled, and then the balancing switches of the single cells with even numbers are controlled to be enabled to complete the power balancing of the battery module.

[0012] Optionally, in the above method, determining whether the operating state of each single battery satisfies the first trigger condition includes:

[0013] When it is determined that the voltage of each single battery is less than the first preset voltage, determining that the operating state of each single battery meets the first trigger condition;

[0014] and / or,

[0015] When it is determined that the temperature of each single battery is lower than the preset temperature, it is determined that the operating state of each single battery satisfies the first trigger condition.

[0016] Optionally, the above method further includes:

[0017] When it is determined that the difference and / or the operating state of each single battery meets the second trigger condition, it is determined that the battery module power balancing is completed.

[0018] Optionally, in the above method, determining whether the difference and / or the operating state of each single battery satisfies the second trigger condition includes:

[0019] When it is determined that the difference is less than or equal to the preset threshold, determining that the difference satisfies a second trigger condition;

[0020] and / or,

[0021] When it is determined that the voltage of each single cell is less than or equal to a second preset voltage, it is determined that the operating state of each single cell meets the second trigger condition; and / or, when it is determined that the temperature of each single cell is greater than or equal to a preset temperature, it is determined that the operating state of each single cell meets the second trigger condition.

[0022] According to another aspect of the present application, a battery module power balancing device is provided, the battery module includes a plurality of single cells connected in parallel, and the device includes:

[0023] An acquisition unit, used to acquire the current of the battery module and the operating status information of each single battery, the operating status information including the voltage and temperature of each single battery;

[0024] A data processing unit, used to determine the state of charge value of each single cell according to the current and operation status information; used to determine the maximum state of charge value and the minimum state of charge value of the single cells in the battery module according to the state of charge value of each single cell, and used to determine the difference between the maximum state of charge value and the minimum state of charge value;

[0025] The control unit is used to control the balancing switches of a part of the single cells to be enabled first, and then control the balancing switches of another part of the single cells to be enabled, so as to complete the power balancing of the battery module when it is determined that the difference is greater than a preset threshold and the operating status of each single cell meets the first trigger condition.

[0026] Optionally, in the above device, the control unit is used to first control the balancing switches of the single cells with odd numbers to be enabled, and then control the balancing switches of the single cells with even numbers to be enabled, so as to complete the power balancing of the battery module.

[0027] Optionally, in the above device, the control unit is used to determine that the operating state of each single battery meets the first trigger condition when it is determined that the voltage of each single battery is less than the first preset voltage;

[0028] and / or,

[0029] Used to determine whether the operating state of each single battery meets the first trigger condition when it is determined that the temperature of each single battery is less than a preset temperature.

[0030] Optionally, in the above device, the control unit is further used to determine that the battery module power balancing is completed when it is determined that the difference and / or the operating state of each single battery meets the second trigger condition.

[0031] Optionally, in the above-mentioned device, the control unit is used to determine that the difference satisfies the second trigger condition when it is determined that the difference is less than or equal to a preset threshold;

[0032] and / or,

[0033] Used to determine that the operating state of each single cell meets the second trigger condition when it is determined that the voltage of each single cell is less than or equal to a second preset voltage; and / or, when it is determined that the temperature of each single cell is greater than or equal to a preset temperature, determine that the operating state of each single cell meets the second trigger condition.

[0034] According to a third aspect of the present application, an electronic device is provided, comprising: a processor; and a memory arranged to store computer executable instructions, wherein when the executable instructions are executed, the processor executes any of the above-described methods for implementing a customized mode of an electronic device.

[0035] According to a fourth aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores one or more programs, and when the one or more programs are executed by a processor, the implementation method of the electronic device customization mode as described in any of the above.

[0036] The beneficial effect of the present application is that the power balancing method provided by the present application takes into account the advantages of both active balancing and passive balancing. The method has a simple calculation structure and a small amount of calculation, and takes into account the transmission between each single cell between battery modules, which significantly improves the accuracy of power balancing of each single cell and the power balancing efficiency of the battery module, and greatly reduces the burden on the main control circuit.

[0037] It can be seen from the above that the technical solution of the present application and the above description are only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0039] Figure 1 A schematic structural diagram of a battery system according to an embodiment of the present application is shown;

[0040] Figure 2 An exploded diagram of a battery balancing device for a battery module according to an embodiment of the present application is shown;

[0041] Figure 3 A schematic diagram of a flow chart of a method for balancing a battery module according to an embodiment of the present application is shown;

[0042] Figure 4 A schematic diagram showing a flow chart of a method for balancing a battery module according to another embodiment of the present application is shown;

[0043] Figure 5A schematic structural diagram of a battery module power balancing device according to an embodiment of the present application is shown;

[0044] Figure 6 A schematic diagram of the structure of an electronic device according to an embodiment of the present application is shown;

[0045] Figure 7 A schematic diagram of the structure of a computer-readable storage medium according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0046] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0047] The idea of ​​the present application is to provide a battery module power balancing method to address the defects of the active power balancing method and the passive power balancing method in the prior art. The method combines the charging conditions of each single cell through the state of charge value to determine the timing for the battery module to enter power balancing, and balances the power of each single cell independently to achieve a balance between the power of each single cell.

[0048] like Figure 1 The schematic diagram of the structure of a battery system according to an embodiment of the present application is shown, the battery system includes a battery module, the battery module includes a plurality of single cells connected in parallel, the battery module may be a lithium battery, or a flow battery, etc. The battery system also includes a power balancing device, the device includes an information acquisition and control circuit board and a power balancing circuit board, the information acquisition and control circuit board can collect the current of the battery module, as well as the voltage and temperature of each single cell; the power balancing circuit board is used to balance the power of each single cell, including but limited to the power of the single cell with high power consumption.

[0049] According to some embodiments of the present application, a battery module power balancing device is provided, such as Figure 2 As shown, Figure 2 An exploded diagram of a battery module power balancing device according to an embodiment of the present application is shown. Figure 2 As shown, the power balancing device 200 includes: a housing 210 , a base 220 , at least one information collection and control circuit board 230 , and at least one power balancing circuit board 240 .

[0050] The shell 210 and the base 220 can be fixed by screw connection but are not limited to it. The two constitute a housing cavity of the power balancing device 200. The information acquisition and control circuit board 230 and the power balancing circuit board 240 are arranged in the housing cavity. The information acquisition and control circuit board 230 and the power balancing circuit board 240 are electrically connected, specifically including but not limited to the connection between the pin header of the information acquisition and control circuit board and the female header of the power balancing circuit board.

[0051] The information collection and control circuit board 230 is provided with a battery information collection interface 231 , and the battery information collection interface 231 is connected to the collection signal line of the battery module.

[0052] In addition, in order to obtain the current of the battery module, a current transformer (not shown in the figure) can be set. The current transformer can be set inside the power balancing device of the above-mentioned battery module, or it can be set outside it, and the current information is transmitted to the information acquisition and control circuit board 230 by being electrically connected to the information acquisition and control circuit board 230.

[0053] In some embodiments of the present application, the power balancing circuit board 240 includes a plurality of mutually isolated balancing circuits 241 , each of which is connected in parallel with a single battery, wherein the balancing circuit includes a balancing switch and a current limiting resistor connected in series.

[0054] In order to enable the power balancing circuit board 240 to dissipate heat better, the power balancing device 200 further includes a thermally conductive adhesive strip 250; the thermally conductive adhesive strip 250 is adhered to the base 220, and the power balancing circuit board 240 is closely arranged on the thermally conductive adhesive strip 250, so that the heat generated by the power balancing circuit board 240 during the power balancing process of the battery module can be dissipated from the base 220 to the outside of the accommodating cavity of the power balancing device 200 through the thermally conductive adhesive strip 250.

[0055] In some embodiments of the present application, the information acquisition and control circuit board 230, the power balancing circuit board 240, and the thermal conductive adhesive strip 250 are sequentially arranged in the accommodating cavity from top to bottom. The information acquisition and control circuit board 230 and the power balancing circuit board 240 are fixed to the base 220 through the insulating connecting column 260.

[0056] In the case where there are multiple information acquisition and control circuit boards 230, multiple power balancing circuit boards 240, and multiple thermal conductive adhesive strips 250, one information acquisition and control circuit board 230, one power balancing circuit board 240, and one thermal conductive adhesive strip 250 are sequentially arranged in the accommodating cavity from top to bottom; each information acquisition and control circuit board 230, power balancing circuit board 240, and thermal conductive adhesive strip 250 can be arranged in parallel.

[0057] Compared with the prior art, the battery module power balancing device provided in the present application adopts a design in which the information acquisition and control circuit board 230 and the power balancing circuit board 240 are separated. In this way, the heat generated by the power balancing circuit board 230 will not be transmitted to the information acquisition and control circuit board 230, which significantly improves the accuracy and precision of the operation information collection of each single cell.

[0058] It should be noted that the above-mentioned battery module power balancing device is only an exemplary description, and the method provided in this application is not limited to being used in the above-mentioned device, and any device that can meet the requirements of the method provided in this application can be used.

[0059] Figure 3 The flowchart of the method for balancing the power of a battery module according to an embodiment of the present application is shown. The method for balancing the power of the present application can be implemented by, but not limited to, any of the above-mentioned power balancing devices, wherein: Figure 3 As shown, the power balancing method includes:

[0060] Step S310, obtaining the current of the battery module and the operating status information of each single battery, where the operating status information includes the voltage and temperature of each single battery;

[0061] First, obtain the current of the battery module, as well as the voltage and temperature of each single cell.

[0062] In this embodiment, it is assumed that the number of single cells is 24, and the voltage and temperature of each single cell are V(n) and Temp(n), wherein n is the number of the single cell in the battery module, n=1, 2, ..., 24, and the same below, and V(n) represents the voltage of the single cell numbered n.

[0063] Since the single cells are connected in parallel, the current in each part of the battery module is equal; and since the charge amount of each single cell is different, the voltage and temperature of each single cell are different.

[0064] Step S320, determining the state of charge value of each single battery according to the current and the operating state information.

[0065] The battery state of charge (SOC) is used to reflect the remaining capacity of the battery. Its numerical value is defined as the ratio of the remaining capacity to the battery capacity, usually expressed as a percentage. SOC = 100% - DOD, DOD is the amount of electricity discharged by the battery, and SOC = 100% means that the battery is fully charged.

[0066] The state of charge value of each single cell can be calculated or estimated from the current, voltage and temperature of each single cell to obtain the SOC(n) of each single cell, where n is the number of the single cell in the battery module, n=1, 2, ..., 24. The calculation method can adopt any one of the existing technologies, such as the integration method.

[0067] Step S330 , determining the maximum state of charge value and the minimum state of charge value of the single cells in the battery module according to the state of charge value of each single cell, and determining the difference between the maximum state of charge value and the minimum state of charge value.

[0068] In this application, in order to balance the power between each single cell, the power transfer between each single cell is taken into consideration, and the difference between the maximum state of charge value and the minimum state of charge value of the single cell in the battery module is used as one of the criteria for whether the battery module enters the power balancing mode.

[0069] Specifically, the maximum state of charge value and the minimum state of charge value are first determined from the calculated state of charge values ​​of each single battery, wherein the single battery corresponding to the maximum state of charge value has the largest power, and the single battery corresponding to the minimum state of charge value has the least power.

[0070] Then, the maximum state of charge value is subtracted from the minimum state of charge value to obtain the difference between the two.

[0071] Step S340, when it is determined that the difference is greater than a preset threshold and the operating state of each single cell satisfies the first trigger condition, firstly control the balancing switches of a part of the single cells to be enabled, and then control the balancing switches of another part of the single cells to be enabled, so as to complete the power balancing of the battery module.

[0072] The obtained difference is compared with a preset threshold value, such as 1%. If the difference is greater than the preset threshold value, it means that the power difference between each single cell is too large, and it is very likely that power balancing is required. Then, it is further determined whether the operating status at each single cell point meets the first trigger condition. If so, the balancing switches of a part of the single cells are enabled first, and then the balancing switches of another part of the single cells are enabled to complete the power balancing of the battery module.

[0073] The first trigger condition can be set according to the requirements of power balancing accuracy, such as setting the voltage of each single cell to be less than the upper limit of the balancing threshold. If the above conditions are met, the battery module is controlled to enter the power balancing mode. Specifically, the balancing switches of a part of the single cells are enabled first, and then the balancing switches of another part of the single cells are enabled to complete the power balancing of the battery module.

[0074] from Figure 3It can be seen from the described method that the power balancing method provided by the present application can take into account the advantages of both active balancing and passive balancing. The method has a simple calculation structure and a small amount of calculation. It also takes into account the power transfer between each single cell between battery modules, which significantly improves the accuracy of power balancing of each single cell and the power balancing efficiency of the battery module, and greatly reduces the burden on the main control circuit.

[0075] In some embodiments of the present application, in the above method, first controlling the balancing switches of a part of the single cells to be enabled, and then controlling the balancing switches of another part of the single cells to be enabled to complete the power balancing of the battery module includes: first controlling the balancing switches of the single cells with odd numbers to be enabled, and then controlling the balancing switches of the single cells with even numbers to be enabled to complete the power balancing of the battery module.

[0076] In order to facilitate the control of each single cell, each single cell can be numbered, such as 1-24 as mentioned above. After entering the power balancing mode, the balancing switches of the single cells with odd numbers can be enabled, and then the balancing switches of the single cells with even numbers can be enabled to complete the power balancing of the battery module.

[0077] In some embodiments of the present application, in the above method, determining that the operating status of each single cell meets the first trigger condition includes: when it is determined that the voltage of each single cell is less than a first preset voltage, determining that the operating status of each single cell meets the first trigger condition; and / or, when it is determined that the temperature of each single cell is less than a preset temperature, determining that the operating status of each single cell meets the first trigger condition.

[0078] The first trigger condition can be set according to the requirement of power balancing accuracy. If the first trigger condition is met, power balancing is started. The specific trigger condition can be that when it is determined that the voltage of each single cell is less than the first preset voltage, it is determined that the operating state of each single cell meets the first trigger condition for setting, wherein the first preset voltage can be the upper limit value of the equalization voltage threshold of 3.3V commonly used in the prior art; it can also be that when it is determined that the temperature of each single cell is less than the preset temperature, it is determined that the operating state of each single cell meets the first trigger condition, wherein the preset temperature can be the upper limit value of the temperature threshold of 75°C commonly used in the prior art, or the voltage and temperature can be combined first, that is, the above conditions need to be met at the same time, such as first determining whether the voltage of each single cell is less than the first preset voltage, if it is determined that at least one of the voltages of each single cell is not less than the first preset voltage, then power balancing is not performed; if it is determined that the voltage of each single cell is less than the first preset voltage, then continue to determine whether the temperature of each single cell is less than the preset temperature, if it is determined that at least one of the temperatures of each single cell is not less than the preset temperature, then power balancing is not performed; if it is determined that the temperature of each single cell is less than the preset temperature, then power balancing is performed.

[0079] In some embodiments of the present application, the above method further includes: when it is determined that the difference and / or the operating state of each single battery meets the second trigger condition, determining that the power balancing of the battery module is terminated.

[0080] That is, the present application also provides a condition for exiting the power balancing process, that is, determining that the difference and / or the operating state of each single battery meets the second trigger condition.

[0081] When the battery balancing reaches a certain level, the current of the battery module, the voltage of the single battery and the temperature have changed. At this time, a certain judgment can be made on the battery balancing effect. If the effect has reached the expected effect, the battery balancing mode can be exited and switched to the normal operation mode.

[0082] Specifically, it can be judged by the difference between the maximum state of charge value and the minimum state of charge value and the operating state of each single battery.

[0083] If the difference between the maximum state of charge value and the minimum state of charge value is determined to be less than or equal to the preset threshold, it means that the power difference of each single battery is not large, then it is determined that the difference meets the second trigger condition, that is, the battery module is controlled to exit the power balancing mode.

[0084] For another example, when it is determined that the voltage of each single cell is less than or equal to a second preset voltage, it is determined that the operating state of each single cell meets the second trigger condition; and / or, when it is determined that the temperature of each single cell is greater than or equal to a preset temperature, it is determined that the operating state of each single cell meets the second trigger condition.

[0085] The second preset voltage may be the same as or different from the first preset voltage, preferably different. For example, in the present application, the second preset voltage may be set to 2.5V.

[0086] The above-mentioned second trigger conditions can be set individually or in combination.

[0087] It should be noted that since controlling the battery module to enter the power balancing mode and exit the balancing mode are different stages, the first trigger condition and the second trigger condition are compatible. For example, the first preset voltage and the second preset voltage do not affect each other, and the judgment result will not be a situation where the power balancing mode is entered and exited.

[0088] Figure 4 The flowchart of the method for equalizing the power of a battery module according to another embodiment of the present application is shown; first, the current I of the battery module and the voltage V(n) and temperature Temp(n) of each single cell are obtained, where n is the number of the single cell in the battery module, n=1, 2, ..., 24. According to the current data I and the voltage V(n) and temperature Temp(n) of the single cell, the SOC(n) of each single cell in the battery module is calculated; the maximum state of charge value max(SOC(n)) and the minimum state of charge value min(SOC(n)) are determined from the SOC(n) of each single cell, and the difference between the two is determined.

[0089] It is determined whether the difference is greater than a preset threshold (the preset threshold is 1%); if so, the total power balancing control switch is enabled. Further, it is determined whether each single cell V(n) is less than a first preset voltage V H (V H =3.3V), if so, continue to determine whether each single battery Temp(n) is less than the temperature threshold T H (T H =75°C), if so, it is determined that the first trigger condition is met, and then the balancing switches of the odd-numbered cells are enabled, and then the balancing switches of the even-numbered cells are enabled; if one of the above-mentioned first trigger conditions cannot be met, return to the power balancing master control switch enabling step and re-judge until the first trigger condition is met.

[0090] After the battery balancing process has been carried out for a period of time, it is determined whether the balancing process can be terminated. Specifically, it is determined whether the V(n) of each single battery is less than the second preset voltage V L (V L =2.5V), if so, further determine whether each single battery Temp(n) is greater than or equal to the temperature threshold T H (TH =75°C), if so, then determine whether the above difference is less than or equal to a preset threshold (the preset threshold is 1%), then control the balancing switch of each single cell to be turned off, and the power balancing process ends. If one of the above first trigger conditions cannot be met, then return to the step of first controlling the balancing switch of the single cell with an odd number to enable, and then controlling the balancing switch of the single cell with an even number to enable, and continue power balancing until the second trigger condition is met.

[0091] Figure 5 A schematic diagram of the structure of a power balancing device of a battery module according to an embodiment of the present application is shown. The battery module includes a plurality of single cells connected in parallel. The power balancing device 500 includes:

[0092] The acquisition unit 510 is used to acquire the current of the battery module and the operating status information of each single battery. The operating status information includes the voltage and temperature of each single battery.

[0093] First, obtain the current of the battery module, as well as the voltage and temperature of each single cell.

[0094] In this embodiment, it is assumed that the number of single cells is 24, and the voltage and temperature of each single cell are V(n) and Temp(n), wherein n is the number of the single cell in the battery module, n=1, 2, ..., 24, and the same below, and V(n) represents the voltage of the single cell numbered n.

[0095] Since the single cells are connected in parallel, the current in each part of the battery module is equal; and since the charge amount of each single cell is different, the voltage and temperature of each single cell are different.

[0096] The data processing unit 520 is used to determine the state of charge value of each single cell according to the current and operating status information; to determine the maximum state of charge value and the minimum state of charge value of the single cells in the battery module according to the state of charge value of each single cell, and to determine the difference between the maximum state of charge value and the minimum state of charge value.

[0097] The battery state of charge (SOC) is used to reflect the remaining capacity of the battery. Its numerical value is defined as the ratio of the remaining capacity to the battery capacity, usually expressed as a percentage. SOC = 100% - DOD, DOD is the amount of electricity discharged by the battery, and SOC = 100% means that the battery is fully charged.

[0098] The state of charge value of each single cell can be calculated or estimated from the current, voltage and temperature of each single cell to obtain the SOC(n) of each single cell, where n is the number of the single cell in the battery module, n=1, 2, ..., 24. The calculation method can adopt any one of the existing technologies, such as the integration method.

[0099] In this application, in order to balance the power between each single cell, the power transfer between each single cell is taken into consideration, and the difference between the maximum state of charge value and the minimum state of charge value of the single cell in the battery module is used as one of the criteria for whether the battery module enters the power balancing mode.

[0100] Specifically, the maximum state of charge value and the minimum state of charge value are first determined from the calculated state of charge values ​​of each single battery, wherein the single battery corresponding to the maximum state of charge value has the largest power, and the single battery corresponding to the minimum state of charge value has the least power.

[0101] Then, the maximum state of charge value is subtracted from the minimum state of charge value to obtain the difference between the two.

[0102] The control unit 530 is used to control the balancing switches of a part of the single cells to be enabled first, and then control the balancing switches of another part of the single cells to be enabled, so as to complete the power balancing of the battery module when it is determined that the difference is greater than a preset threshold and the operating status of each single cell meets the first trigger condition.

[0103] The obtained difference is compared with a preset threshold value, such as 1%. If the difference is greater than the preset threshold value, it means that the power difference between each single cell is too large, and it is very likely that power balancing is required. Then, it is further determined whether the operating status at each single cell point meets the first trigger condition. If so, the balancing switches of a part of the single cells are enabled first, and then the balancing switches of another part of the single cells are enabled to complete the power balancing of the battery module.

[0104] The first trigger condition can be set according to the requirements of power balancing accuracy, such as setting the voltage of each single cell to be less than the upper limit of the balancing threshold. If the above conditions are met, the battery module is controlled to enter the power balancing mode. Specifically, the balancing switches of a part of the single cells are enabled first, and then the balancing switches of another part of the single cells are enabled to complete the power balancing of the battery module.

[0105] from Figure 5 It can be seen from the device that the power balancing device provided by the present application can take into account the advantages of both active balancing and passive balancing. This method has a simple calculation structure and a small amount of calculation. It also takes into account the power transfer between each single cell between battery modules, which significantly improves the accuracy of power balancing of each single cell and the power balancing efficiency of the battery module, and greatly reduces the burden on the main control circuit.

[0106] In some embodiments of the present application, in the above-mentioned device, the control unit 530 is used to first control the balancing switches of the single cells with odd numbers to be enabled, and then control the balancing switches of the single cells with even numbers to be enabled, so as to complete the power balancing of the battery module.

[0107] In some embodiments of the present application, in the above-mentioned device, the control unit 530 is used to determine that the operating state of each single cell meets the first trigger condition when it is determined that the voltage of each single cell is less than the first preset voltage; and / or is used to determine that the operating state of each single cell meets the first trigger condition when it is determined that the temperature of each single cell is less than the preset temperature.

[0108] In some embodiments of the present application, in the above-mentioned device, the control unit 530 is further used to determine that the battery module power balancing is terminated when it is determined that the difference and / or the operating status of each single battery meets the second trigger condition.

[0109] In some embodiments of the present application, in the above-mentioned device, the control unit 530 is used to determine that the difference satisfies the second trigger condition when it is determined that the difference is less than or equal to a preset threshold; and / or, to determine that the operating state of each single cell satisfies the second trigger condition when it is determined that the voltage of each single cell is less than or equal to the second preset voltage; and / or, to determine that the operating state of each single cell satisfies the second trigger condition when it is determined that the temperature of each single cell is greater than or equal to a preset temperature.

[0110] It should be noted that the specific implementation of the above-mentioned device embodiments can be carried out with reference to the specific implementation of the above-mentioned corresponding method embodiments, which will not be repeated here.

[0111] It should be noted that:

[0112] The algorithm and display provided herein are not inherently related to any particular computer, virtual device or other equipment. Various general purpose devices can also be used together with the teachings based on this. According to the above description, it is obvious to construct the structure required for this type of device. In addition, the application is not directed to any specific programming language either. It should be understood that various programming languages ​​can be utilized to realize the content of the application described herein, and the description of the specific language above is for the purpose of disclosing the best mode of the application.

[0113] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0114] Similarly, it should be understood that in order to streamline the present application and help understand one or more of the various inventive aspects, in the above description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the disclosed method should not be interpreted as reflecting the following intention: the claimed application requires more features than the features clearly stated in each claim. More specifically, as reflected in the claims below, the inventive aspects are less than all the features of the single embodiment disclosed above. Therefore, the claims following the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present application.

[0115] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and in addition they may be divided into a plurality of submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this manner may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature providing the same, equivalent or similar purpose.

[0116] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims below, any one of the claimed embodiments may be used in any combination.

[0117] The various component embodiments of the present application may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art should understand that a microprocessor or a digital signal processor (DSP) may be used in practice to implement some or all of the functions of some or all of the components of the battery module according to the embodiment of the present application. The present application may also be implemented as a device or apparatus program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program implementing the present application may be stored on a computer-readable medium, or may be in the form of one or more signals. Such a signal may be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0118] For example, Figure 6 A schematic diagram of the structure of an electronic device according to an embodiment of the present application is shown. The electronic device 600 includes a processor 610 and a memory 620 arranged to store computer executable instructions (computer readable program code). The memory 620 can be an electronic memory such as a flash memory, an EEPROM (electrically erasable programmable read-only memory), an EPROM, a hard disk or a ROM. The memory 620 has a storage space 630 for storing a computer readable program code 631 for executing any method step in the above method. For example, the storage space 630 for storing computer readable program code may include individual computer readable program codes 631 for implementing various steps in the above method respectively. The computer readable program code 631 can be read from or written to one or more computer program products. These computer program products include program code carriers such as a hard disk, a compact disk (CD), a memory card or a floppy disk. Such a computer program product is typically, for example Figure 7 The computer-readable storage medium shown. Figure 7 A schematic diagram of the structure of a computer-readable storage medium according to an embodiment of the present application is shown. The computer-readable storage medium 700 stores a computer-readable program code 631 for executing the method steps according to the present application, which can be read by the processor 610 of the electronic device 600. When the computer-readable program code 631 is executed by the electronic device 600, the electronic device 600 executes each step in the method described above. Specifically, the computer-readable program code 631 stored in the computer-readable storage medium can execute the method shown in any of the above embodiments. The computer-readable program code 631 can be compressed in an appropriate form.

[0119] It should be noted that the above embodiments illustrate the present application rather than limit the present application, and that those skilled in the art may design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets should not be constructed as a limitation to the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of multiple such elements. The present application may be implemented by means of hardware including several different elements and by means of a suitably programmed computer. In a unit claim that lists several devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names.

Claims

1. A method for balancing the charge of a battery module, wherein the battery module comprises a plurality of single cells connected in parallel, characterized in that: include: Acquire the current of the battery module and the operating status information of each of the single cells, wherein the operating status information includes the voltage and temperature of each of the single cells; Determining the state of charge value of each of the single cells according to the current and the operating state information; Determine the maximum state of charge value and the minimum state of charge value of the single cells in the battery module according to the state of charge value of each single cell, and determine the difference between the maximum state of charge value and the minimum state of charge value; When it is determined that the difference is greater than a preset threshold and that the operating state of each of the single cells satisfies a first trigger condition, firstly controlling the balancing switches of a part of the single cells to be enabled, and then controlling the balancing switches of another part of the single cells to be enabled, so as to complete the power balancing of the battery module, specifically includes: First, the balancing switches of the single cells with odd numbers are controlled to be enabled, and then the balancing switches of the single cells with even numbers are controlled to be enabled to complete the power balancing of the battery module; Wherein, determining whether the operating state of each of the single cells satisfies the first trigger condition comprises: In the case where it is determined that the voltage of each of the single cells is less than the first preset voltage, determining that the operating state of each of the single cells meets the first trigger condition; and, When it is determined that the temperature of each of the single cells is lower than a preset temperature, determining that the operating state of each of the single cells meets a first trigger condition; In the case where it is determined that the difference is less than or equal to the preset threshold, determining that the difference satisfies a second trigger condition; and, When it is determined that the voltage of each of the single cells is less than or equal to the second preset voltage, it is determined that the operating state of each of the single cells meets the second trigger condition; and / or, when it is determined that the temperature of each of the single cells is greater than or equal to the preset temperature, it is determined that the operating state of each of the single cells meets the second trigger condition, and it is determined that the power balancing of the battery module is terminated.

2. A battery module power balancing device, the battery module comprising a plurality of single cells connected in parallel, characterized in that: include: An acquisition unit, used to acquire the current of the battery module and the operating status information of each of the single cells, wherein the operating status information includes the voltage and temperature of each of the single cells; A data processing unit, used to determine the state of charge value of each of the single cells according to the current and the operating state information; Used to determine the maximum state of charge value and the minimum state of charge value of the single cells in the battery module according to the state of charge value of each single cell, and used to determine the difference between the maximum state of charge value and the minimum state of charge value; The control unit is used to control the balancing switches of a part of the single cells to be enabled first, and then control the balancing switches of another part of the single cells to be enabled, to complete the power balancing of the battery module, when it is determined that the difference is greater than a preset threshold value and the operating state of each of the single cells meets the first trigger condition, specifically including: First, the balancing switches of the single cells with odd numbers are controlled to be enabled, and then the balancing switches of the single cells with even numbers are controlled to be enabled to complete the power balancing of the battery module; Wherein, determining whether the operating state of each of the single cells satisfies the first trigger condition comprises: In the case where it is determined that the voltage of each of the single cells is less than the first preset voltage, determining that the operating state of each of the single cells meets the first trigger condition; and, When it is determined that the temperature of each of the single cells is lower than a preset temperature, determining that the operating state of each of the single cells meets a first trigger condition; for determining that the difference satisfies a second trigger condition when it is determined that the difference is less than or equal to a preset threshold; and, for determining that the operating state of each of the single cells meets the second trigger condition when it is determined that the voltage of each of the single cells is less than or equal to a second preset voltage; and / or, for determining that the operating state of each of the single cells meets the second trigger condition when it is determined that the temperature of each of the single cells is greater than or equal to a preset temperature, and determining that the power balancing of the battery module is terminated.

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