Battery equalization method and device, battery management system, equipment and storage medium

Abstract

The application relates to a battery equalization method and device, a battery management system, equipment and a storage medium. The device is applied to a battery pack comprising a plurality of battery monomers connected in series, and the device comprises a transformer, an isolation switch and a control unit. The primary winding of the transformer is connected with a total positive electrode and a total negative electrode of the battery pack, the secondary winding of the transformer comprises a plurality of secondary windings, and the plurality of secondary windings are connected with the plurality of battery monomers in the battery pack one by one. The isolation switch assembly corresponds to the plurality of battery monomers in the battery pack one by one, and each isolation switch assembly is connected in series between the corresponding battery monomer and the secondary winding. The control unit is connected with the battery monomer and the isolation switch assembly to detect the voltage signal of each battery monomer and control the isolation switch assembly to be closed according to the voltage signal, so that the transformer balances the energy among the battery monomers in the battery pack. The application solves the problems of high cost, high complexity and slow equalization speed of the battery equalization function of the BMS system.

Description

Technical Field

[0001] This application relates to the field of battery balancing technology, and in particular to a battery balancing method and apparatus, a battery management system, equipment and storage medium. Background Technology

[0002] A series battery pack is a battery module consisting of multiple battery cells connected in series. Due to differences in manufacturing processes, lifespan, and ambient temperature, there may be differences in voltage and capacity between different battery cells in a series battery pack, which can affect the performance and lifespan of the entire battery pack.

[0003] Currently, related technologies address this issue primarily by utilizing the battery balancing function of a Battery Management System (BMS) to adjust the voltage or current of individual cells in a series-connected battery pack. This redistributes energy within the pack, ensuring all cells maintain a relatively consistent state, thereby improving the performance and lifespan of the battery pack. BMS systems achieve battery balancing mainly through active or passive balancing. Active balancing uses external circuitry or control algorithms to actively adjust the voltage or current of individual cells; passive balancing achieves balancing by connecting resistors or placing windings to allow natural charge dissipation between cells. However, active balancing consumes additional energy and control resources, potentially increasing system cost and complexity; passive balancing is slower, potentially taking a considerable amount of time to balance the cells in the series-connected battery pack to the required level. In summary, the battery balancing function of BMS systems in related technologies suffers from high cost, high complexity, and slow balancing speed.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This application provides a battery balancing method and apparatus, a battery management system, a device and a storage medium to solve the technical problems of high cost, high complexity and slow balancing speed of the battery balancing function of the battery management system.

[0006] According to one aspect of the embodiments of this application, this application provides a battery balancing device applied to a battery pack, the battery pack including multiple battery cells connected in series, the device including: a transformer, the transformer including a primary winding and a secondary winding, the two ends of the primary winding being connected to the total positive terminal and the total negative terminal of the battery pack respectively, the secondary winding including multiple secondary windings being arranged one-to-one with multiple battery cells in the battery pack, the two ends of each secondary winding being connected to the positive terminal and the negative terminal of the corresponding battery cell respectively; a disconnecting switch assembly, the disconnecting switch assembly including multiple disconnecting switch assemblies being arranged one-to-one with multiple battery cells in the battery pack, each disconnecting switch assembly being connected in series between the corresponding battery cell and the secondary winding; a control unit, the control unit being connected to the battery cells and the disconnecting switch assembly respectively, the control unit being used to detect the voltage signal of each battery cell and control the disconnecting switch assembly to close according to the voltage signal, so that the transformer performs energy balancing among the battery cells in the battery pack.

[0007] Optionally, the control unit includes a voltage detection terminal, a first switch, and an equalization control terminal, which are connected in series. The voltage detection terminal is connected to the positive and negative terminals of each battery cell to detect the voltage signal of each battery cell. The equalization control terminal includes multiple terminals, each of which is connected to a corresponding battery cell in the battery pack. When the control unit starts equalization, the first switch closes to connect the voltage detection terminal and the equalization control terminal.

[0008] Optionally, the isolating switch assembly includes: a first MOSFET, the input terminal of which is connected to the negative terminal of the corresponding battery cell, and the output terminal of which is connected to the corresponding secondary winding in the transformer; and an optocoupler switch having a control side and a switching side, configured such that the switching side closes when current flows through the control side, the control side being connected in series between the equalization control terminal and the voltage detection terminal, and the switching side being connected in series between the control terminal of the first MOSFET and the voltage detection terminal corresponding to the high-number-count battery cell; wherein the potential of the high-number-count battery cell in the battery pack is higher than the potential of the battery cell corresponding to the isolating switch assembly, and the high-number-count battery cell is used to provide the driving voltage required for the first MOSFET to conduct.

[0009] Optionally, the device further includes an isolated voltage regulator connected to the individual battery cell in the battery pack that is closest to the overall positive terminal of the battery pack.

[0010] Optionally, the device further includes a discharge module, which is connected to both the battery pack and the control unit, and is configured to discharge the battery pack under the control of the control unit.

[0011] Optionally, the control unit is provided with an output control terminal; the discharge module includes a power resistor and a second MOSFET, the power resistor is connected in parallel with the battery pack, the control terminal of the second MOSFET is connected to the output control terminal, the input terminal of the second MOSFET is connected to the power resistor, and the output terminal of the second MOSFET is connected to the total negative terminal of the battery pack.

[0012] Optionally, the control unit includes an analog front-end chip.

[0013] Optionally, the device further includes a current sampling resistor connected in series between the primary winding and the total negative terminal of the battery pack, and the current sampling resistor is used at least to collect the primary current of the transformer.

[0014] Optionally, the device further includes a circuit protection element connected in series between the primary winding and the total positive terminal of the battery pack; and / or, the circuit protection element is connected in series between each secondary winding and the corresponding battery cell.

[0015] According to another aspect of the embodiments of this application, this application provides a battery management system including the battery balancing device described above.

[0016] According to another aspect of the embodiments of this application, this application provides a battery balancing method applicable to the above-mentioned battery balancing device. The method includes: detecting the voltage signal of each battery cell in the battery pack, determining a target battery cell based on the voltage signal; controlling the balancing control terminal and voltage detection terminal corresponding to the target battery cell to be turned on, so that the corresponding isolating switch assembly is closed to connect the target battery cell to the transformer; coupling the electrical energy released by the target battery cell to the primary winding through the secondary winding corresponding to the target battery cell in the transformer, and distributing it to other battery cells through the primary winding, so as to balance the energy of multiple battery cells in the battery pack.

[0017] Optionally, when the battery pack is a multi-string battery pack, the method further includes: detecting the battery pack with the highest energy among the multi-string battery packs and taking it as the target battery pack; controlling the input and output terminals of the second MOS to conduct through the control signal of the output control terminal of the control unit, so that the power resistor and the target battery pack form a parallel circuit; and discharging the target battery pack through the power resistor to balance the energy among the multiple battery packs.

[0018] According to another aspect of the embodiments of this application, this application provides an electronic device, including a memory, a processor, a communication interface and a communication bus. The memory stores a computer program that can run on the processor. The memory and the processor communicate with each other through the communication bus and the communication interface. When the processor executes the computer program, it implements the steps of the above-mentioned battery balancing method.

[0019] According to another aspect of the embodiments of this application, this application also provides a computer-readable medium having processor-executable non-volatile program code that causes the processor to perform the battery balancing method described above.

[0020] Compared with related technologies, the technical solutions provided in this application have the following advantages: This application connects a disconnecting switch assembly in series between each battery cell and its corresponding secondary winding in a battery pack. The control unit detects the voltage signal of each battery cell to control the closing of the corresponding disconnecting switch assembly. This allows the battery cells requiring energy balancing to be connected to the transformer. The transformer's characteristics then redistribute the electrical energy of the battery cells requiring energy balancing, achieving both passive balancing control and active balancing energy transfer. This reduces the number of components and voltage withstand requirements in the device, enabling low cost and low voltage withstand capability. Furthermore, it can simultaneously perform energy balancing between multiple battery cells at a fast speed. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0023] Figure 1 This is a topology diagram of a battery balancing device provided according to an embodiment of this application; Figure 2 This is a topology diagram of an isolating switch assembly of a battery balancing device according to an embodiment of this application; Figure 3 This is a topology diagram of an isolated regulated power supply for a battery equalization device according to an embodiment of this application; Figure 4 This is a schematic flowchart of a battery balancing method provided according to an embodiment of this application; Figure 5 This is a schematic diagram of an optional electronic device structure provided according to an embodiment of this application.

[0024] Figure label: 100. Battery equalization device; 110. Transformer; 111. Primary winding; 112. Secondary winding; 120. Isolating switch assembly; 121. First MOSFET; 122. Optocoupler switch; 1221. Light-emitting diode; 1222. Phototransistor; 130. Discharge module; 131. Power resistor; 132. Second MOSFET; 140. Current sampling resistor; 150. Resettable fuse. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] In the following description, the use of suffixes such as "module," "part," or "unit" to denote elements is solely for the purpose of illustration and has no specific meaning in itself. Therefore, "module" and "part" may be used interchangeably.

[0027] In related technologies, battery management systems (BMS) mainly achieve battery balancing through active or passive balancing. Active balancing uses external circuits or control algorithms to actively adjust the voltage or current of individual battery cells to achieve balancing, which requires additional energy and control resources and may increase system cost and complexity. Passive balancing achieves balancing by connecting resistors or placing windings to allow the natural dissipation of charge between battery cells, but it is slower and may take a long time to balance the battery cells in the series battery pack to the required level.

[0028] To address the problems mentioned in the background art, according to one aspect of the embodiments of this application, an embodiment of a battery balancing device 100 is provided. The battery balancing device 100 is applied to a battery pack, which includes multiple battery cells connected in series. The battery pack has a total positive electrode BAT+ and a total negative electrode BAT- for outputting electrical energy.

[0029] like Figure 1 As shown, the battery balancing device 100 provided in this application embodiment includes a transformer 110, an isolation switch assembly 120, and a control unit.

[0030] The transformer 110 includes a primary winding 111 and a secondary winding 112. The two ends of the primary winding 111 are connected to the positive and negative terminals of the battery pack, respectively. Multiple secondary windings 112 are included, each corresponding to a specific battery cell in the battery pack. Each secondary winding 112 is connected to the positive and negative terminals of its corresponding battery cell. Multiple disconnector assemblies 120 are included, each corresponding to a specific battery cell in the battery pack. Each disconnector assembly 120 is connected in series between its corresponding battery cell and the secondary winding 112. A control unit is connected to both the battery cell and the disconnector assemblies 120. The control unit detects the voltage signal of each battery cell and controls the disconnector assemblies 120 to close based on the voltage signal, thereby enabling the transformer 110 to balance the energy among the battery cells in the battery pack.

[0031] In this embodiment, multiple secondary windings 112 of the transformer 110 are connected to corresponding battery cells in the battery pack. An isolating switch assembly 120 is provided between the battery cell and the secondary windings 112. The control unit controls the isolating switch assembly 120 to close based on the voltage signal of each battery cell, allowing the battery cell requiring energy balancing to connect to the transformer 110. The transformer 110 transfers a portion of the energy from the high-energy battery cell to the low-energy battery cell, achieving energy balancing among different battery cells within the battery pack. Compared to the method of actively balancing each battery cell in turn, this device has fewer switching devices, a simpler structure, and lower cost. Furthermore, the balancing channel for each battery cell in the battery pack is controlled by the control unit to open and close the corresponding isolating switch assembly 120. The balancing channels are not reused and do not interfere with each other, enabling simultaneous balancing of multiple battery cells within the battery pack at a faster speed.

[0032] Understandably, when a current change occurs in one of the coil windings of transformer 110, energy is transferred to other coil windings through a magnetic field to form current. Therefore, in this embodiment, the primary winding 111 of transformer 110 is set to one, and the two ends of the primary winding 111 are connected to the total positive terminal BAT+ and the total negative terminal BAT- of the battery pack. The secondary winding 112 of transformer 110 is set to correspond one-to-one with multiple battery cells in the battery pack, and the two ends of each secondary winding 112 are connected to the positive and negative terminals of the corresponding battery cell. In this embodiment, the battery pack uses 12 battery cells connected in series as an example. The overall positive terminal of the 12 battery cells connected in series is BAT+, and the overall negative terminal is BAT-. The positive and negative terminals of each battery cell extending from the overall negative terminal to the overall positive terminal of the battery pack include BAT1-, BAT1+, BAT2-, BAT2+, BAT3-, BAT3+, BAT4-, BAT4+, BAT5-, BAT5+, BAT6-, BAT6+, BAT7-, BAT7+, BAT9-, BAT9+, BAT10-, BAT10+, BAT11-, BAT11+, BAT12-, and BAT12+. For this battery pack, the corresponding transformer 110 has 13 channels, including one channel formed by the primary winding and 12 channels formed by the secondary windings.

[0033] Thus, when the energy of a certain battery cell in the battery pack is greater than that of other battery cells, this battery cell can be connected to the corresponding secondary winding 112. The magnetic field of the transformer 110 will induce a current in the primary winding 111. Based on this induced current, the primary winding 111 will then induce a secondary current in the secondary winding 112 through the magnetic field. This secondary induced current will charge the lower-energy battery cell and discharge the higher-energy battery cell in the battery pack. The discharged energy will then be redistributed to the other lower-energy battery cells through the transformer 110, thus achieving a battery balancing process and enabling energy balance among the different battery cells in the battery pack.

[0034] Understandably, the number of turns and magnetic flux of the transformer 110 in this embodiment are adjusted according to the actual switching frequency to ensure that the battery equalization device can operate stably and reliably.

[0035] Furthermore, in this embodiment, an isolating switch assembly 120 is connected in series between each battery cell and its corresponding secondary winding 112. On one hand, the isolating switch assembly 120 can independently control the connection and disconnection between each battery cell and the secondary winding 112, enabling multiple battery cells to perform active balancing simultaneously, thus improving battery balancing efficiency. On the other hand, the isolating switch assembly 120 can effectively isolate the control side and the power side of the device, reducing the withstand voltage requirements on both sides (withstand voltage requirement refers to the maximum voltage that can be withstood). This avoids the risk of current doubling caused by adjacent battery cells in the same battery pack being simultaneously connected to the secondary winding, improving the stability and safety of the battery balancing process.

[0036] Specifically, the closing or opening of the isolating switch assembly 120 is controlled by a control unit. The control unit detects the voltage signal corresponding to each battery cell, determines the battery cell that needs to be discharged based on the detected voltage signal, and controls the corresponding isolating switch assembly 120 to close so that the battery cell that needs to be discharged is connected to the corresponding secondary winding 112. Finally, the primary winding 111 of the transformer 110 charges other low-energy battery cells. This control unit can realize the function of passive balancing control of the transformer 110. By controlling the transformer 110 through this control unit, not only can energy balancing between different battery cells in the same battery pack be achieved, but the use of switching devices can also be reduced and the withstand voltage requirement can be lowered, thus reducing the cost of the battery balancing device.

[0037] Optionally, the control unit in this embodiment includes a voltage detection terminal, a first switch, and an equalization control terminal, which are connected in series. The voltage detection terminal is connected to the positive and negative terminals of each battery cell to detect the voltage signal of each battery cell. Multiple equalization control terminals are connected one-to-one with multiple battery cells in the battery pack. When the control unit initiates equalization, the first switch closes to connect the voltage detection terminal and the equalization control terminal.

[0038] Optionally, the control unit in this embodiment includes an analog front-end chip (AFE), and in this embodiment, the ADBMS6815 model is selected. The ADBMS6815 is a 12-channel multi-cell battery monitor analog front-end chip with high-precision voltage measurement capabilities, capable of measuring the voltage of up to 12 series-connected battery cells within the 0V to 5V range; this chip can complete the measurement of all 12 battery cells in the system in a very short time.

[0039] Specifically, the analog front-end chip has a CELL pin, an S pin, and a GPIO pin. The CELL pin serves as a voltage detection terminal, connected to the positive and negative terminals of each battery cell to measure the battery voltage of each cell, and can also be used as the positive and negative terminals of the battery cells. The S pin serves as a balancing control terminal, used to implement the passive balancing control function of the control unit. GPIO is a general signal input / output pin, which can be used for output control or temperature acquisition; in this embodiment, it is only used for output control.

[0040] In this embodiment, since the potentials of the positive and negative terminals connected between two adjacent battery cells are the same, only one CELL pin needs to be connected between two adjacent battery cells. That is, when connecting a battery pack including 12 battery cells, the analog front-end chip is connected to the positive and negative terminals of each battery cell sequentially through 13 CELL pins to collect the battery voltage of the 12 battery cells. However, in this embodiment, in order to distinguish the positive and negative terminals, one CELL pin between two adjacent battery cells is represented as one positive terminal pin and one negative terminal pin. Thus, each battery cell corresponds to one CELL positive terminal pin and one CELL negative terminal pin. That is, the CELL pin corresponding to the nth battery cell can be represented as CELL(n)+ and CELL(n)-, where n≤12. Since multiple equalization control terminals are connected one-to-one with multiple battery cells in the battery pack, the number of S pins is the same as the number of battery cells, which is also 12. The 12 S pins are connected to the corresponding battery cells respectively, where each S pin can be represented as S(n), where n≤12.

[0041] Furthermore, the first switch between the CELL pin and the S pin is built into the analog front-end chip, and the first switch is connected in series between CELL(n)+ and S(n) or in series between CELL(n)- and S(n). In this embodiment, taking the first switch connected in series between CELL(n)+ and S(n) as an example, when the analog front-end chip detects through the CELL pin that the voltage of the nth battery cell BAT(n) is higher than that of other battery cells and determines that it needs to discharge, the control unit triggers the passive equalization control logic, controlling the built-in first switch to close, thus connecting CELL(n)+ and S(n). At this time, current flows from the positive terminal of BAT(n) through CELL(n)+ and the closed first switch to S(n). S(n) is connected to the isolating switch assembly 120, thereby driving the isolating switch assembly 120 to close, forming a path between the positive and negative terminals of BAT(n) and the corresponding secondary winding 112, allowing BAT(n) to discharge its connected secondary winding 112.

[0042] Furthermore, the secondary winding 112 is magnetically coupled to the primary winding 111. When the current generated by the discharge of BAT(n) flows through the secondary winding 112, it induces an alternating current in the primary winding 111. This alternating current is then generated in different secondary windings 112 through the magnetic coupling characteristics of the transformer 110. The magnitude of the current generated in the secondary winding 112 is negatively correlated with the energy of the battery cell corresponding to that secondary winding 112. The lower the remaining energy of the battery cell corresponding to the secondary winding 112, the larger the current generated in that secondary winding 112. The battery cells are then charged based on the current in the secondary winding 112, so as to maintain the energy balance among the battery cells. In this way, the energy released by BAT(n) can be distributed to the secondary windings 112 corresponding to other battery cells with lower energy through the transformer 110, thereby charging the battery cells with lower energy. In this process, the first switch built into the analog front-end chip can replace the additional control switch in the traditional solution. The first switch can control the connection between the CELL pin and the S pin of the analog front-end chip, so that the battery cell can transmit current to the isolation switch assembly 120 through the S pin, thereby driving the isolation switch assembly 120. There is no need to add an additional MCU control circuit. This not only reduces the number of switching devices used, but also, through the synergistic isolation between the analog front-end chip, the transformer 110 and the isolation switch assembly 120, the withstand voltage requirements of the control side (AFE side) and the power side (battery pack and transformer 110) of the battery equalization device can be greatly reduced. It only needs to withstand the voltage of a single battery cell, which significantly improves the stability of the battery equalization device and reduces the cost of the battery equalization device.

[0043] Optionally, refer to Figure 2 As shown, the isolating switch assembly 120 in this embodiment includes a first MOSFET 121 and an optocoupler switch 122. The input terminal of the first MOSFET 121 is connected to the negative terminal of the corresponding battery cell, and the output terminal of the first MOSFET 121 is connected to the corresponding secondary winding 112 in the transformer 110. The optocoupler switch 122 has a control side and a switching side. The optocoupler switch 122 is configured such that the switching side closes when current flows through the control side. The control side is connected in series between the equalization control terminal and the voltage detection terminal, and the switching side is connected in series between the control terminal of the first MOSFET 121 and the voltage detection terminal corresponding to the high-number battery cell.

[0044] Understandably, in this embodiment, a high-number-count battery cell refers to a battery cell with a higher potential in the battery pack compared to the battery cell that needs to be discharged. Referring to the battery pack containing 12 battery cells in the above embodiment, the potential of each battery cell increases sequentially in the direction of extension from the total negative electrode to the total positive electrode. Therefore, the potentials of BAT1, BAT2, ..., BAT12 gradually increase. In this embodiment, assuming that the battery cell that needs to be discharged is BAT(n), then the high-number-count battery cells can be set as BAT(n+1), BAT(n+2), ..., BAT(12). For example... Figure 2 The high-number battery cell connected to the switching side of the optocoupler switch 122 shown is BAT(n+2). Therefore, in this embodiment, by controlling the high-number battery cell connected to the switching side of the optocoupler switch 122, the driving voltage required for the first MOS transistor to be turned on can be stably and reliably provided, ensuring the balancing effect of the device. Furthermore, the circuit structure of the device can be further simplified, the use of additional components can be reduced, and the cost and balancing complexity can be reduced.

[0045] Optionally, when the battery cell requiring discharge is a BAT12 (the highest series number battery cell), there are no higher series number battery cells to provide drive voltage for the first MOSFET. Therefore, an external isolated regulated power supply can be used to replace the high series number battery cell in providing drive voltage. The isolated regulated power supply is connected to the battery cell closest to the overall positive terminal of the battery pack (i.e., the highest transmitting battery cell). The isolated regulated power supply is selected according to actual needs, such as... Figure 3 As shown, in this embodiment, a 5V power supply is selected as the isolated voltage regulator, and the negative terminal of the 55V power supply is connected to the total positive terminal BAT+ of the battery pack.

[0046] Optionally, such as Figure 2 As shown, in this embodiment, the control side of the optocoupler switch 122 is set as a light-emitting diode 1221, and the switch side is set as a phototransistor 1222. When current flows through the light-emitting diode 1221, the light-emitting diode 1221 will light up. After the phototransistor 1222 senses the light emitted by the light-emitting diode 1221, it will conduct. Using this optocoupler switch 122, a good isolation and withstand voltage effect can be achieved.

[0047] Specifically, in this embodiment, when the analog front-end chip detects that the voltage of the target battery cell BAT(n) is too high and equalization needs to be initiated, the passive equalization control logic is triggered to control the first switch between CELL(n)+ and S(n) to close, so that S(n) and CELL(n)+ are connected. The current flows from CELL(n)+, the first switch, and S(n) sequentially into the light-emitting diode 1221, so that the light-emitting diode 1221 emits light. The phototransistor 1222 senses the light and turns on, connecting the high potential of the high-series-number battery to the control terminal of the first MOSFET 121 to form a driving circuit. The control terminal of the first MOSFET 121 turns on after obtaining the driving voltage, so that a closed circuit is formed between the target battery cell BAT(n) and the corresponding secondary winding 112. The optocoupler switch 122, through the combined use of the light-emitting diode 1221 and the phototransistor 1222, can isolate the control side and the power side of the battery equalization device, avoiding the direct superposition of potentials on the control side and the power side, which would increase the risk of voltage failure. The control side only needs to withstand the voltage of the target battery cell BAT(n), which is much smaller than the 1500V voltage requirement required by MCU control. The voltage requirement of the power side also does not need to match the total voltage of the battery pack, but only needs to adapt to the potential difference between a single battery cell and a high number of battery cells in series. This greatly reduces the voltage selection requirements of the devices in the battery equalization device of this embodiment, thereby reducing the cost and failure rate.

[0048] Understandably, the analog front-end chip in this embodiment has a built-in equalization resistor, which is set between the interconnected S pin and CELL pin. Since the multiple battery cells in the battery pack are connected in series, when adjacent equalization channels are turned on, two adjacent battery cells will be connected in series to one equalization resistor, and the other equalization resistor will be short-circuited by the corresponding S pin, resulting in the current doubling. Therefore, in order to protect the device, this embodiment can prevent adjacent equalization channels from being turned on through the built-in program of the analog front-end chip, so as to ensure that the battery equalization device can stably and reliably perform energy equalization on the multiple battery cells in the battery pack.

[0049] Optionally, the battery balancing device in this embodiment further includes a discharge module 130, which is connected to the battery pack and the control unit respectively. The discharge module 130 is configured to discharge the battery pack under the control of the control unit.

[0050] Optionally, the control unit is also provided with an output control terminal; when the control unit is set as the analog front-end chip in the above embodiment, the output control terminal is configured as the GPIO pin of the analog front-end chip.

[0051] Optionally, the discharge module 130 includes a power resistor 131 and a second MOSFET 132. The power resistor 131 is connected in parallel with the battery pack. The control terminal of the second MOSFET 132 is connected to the output control terminal. The input terminal of the second MOSFET 132 is connected to the power resistor 131. The output terminal of the second MOSFET 132 is connected to the total negative terminal of the battery pack.

[0052] Specifically, when the analog front-end chip detects that the voltage of the current battery pack is higher than that of other battery packs, the battery pack needs to be discharged through the discharge module 130. The GPIO pin of the analog front-end chip will output a high-level control signal. After the control terminal of the second MOSFET 132 receives the high-level signal, its input and output terminals will be connected. Since the power resistor 131 is connected in parallel with the battery pack, when the second MOSFET is turned on, a complete discharge circuit is formed between the battery pack, the power resistor 131, and the second MOSFET 132. Excess electrical energy in the battery pack can be released through this discharge circuit. Specifically, the power resistor 131 converts the electrical energy released by the battery pack into heat energy and dissipates it, realizing high-power passive discharge of the battery pack. Furthermore, when the analog front-end chip detects that the voltage of the battery pack drops to a level that is balanced with other battery packs, its GPIO pin will switch to output a low-level signal. After the second MOSFET 132 receives the low-level signal, it disconnects the path between its input and output terminals, and the discharge circuit terminates, thereby achieving energy balance between different battery packs. In this embodiment, the power resistor 131 has excellent heat dissipation performance compared to the ordinary resistor used in traditional passive equalization, which can improve the equalization power of the device; the high voltage of the multi-string battery pack can greatly reduce the current required for the same power, reducing the requirements for the overcurrent performance of the wires; and the passive equalization of the discharge module 130 and the active equalization between individual battery cells in the battery pack can be carried out in parallel without interference, which significantly improves the efficiency of battery equalization.

[0053] Optionally, the battery balancing device in this embodiment further includes a current sampling resistor 140, which is connected in series between the primary winding 111 and the total negative terminal of the battery pack. The current sampling resistor 140 is used at least to collect the primary current of the transformer 110.

[0054] Understandably, the current sampling resistor 140 is a resistor with a very small resistance value. The control unit detects the voltage on the current sampling resistor 140 and converts it into current to monitor whether the balance between different battery packs is normal, and whether there is excessive or no current in the monitoring device.

[0055] Optionally, in this embodiment, when the equalization current exceeds the range of the analog front-end chip, the current sampling resistor 140 can be replaced with a dedicated bidirectional current detection chip (e.g., INA282), which is connected in series with the primary winding 111 to replace the current sampling resistor 140. It can then be linked with the front-end chip through the communication interface to achieve wide-range, high-precision current monitoring and overcurrent protection.

[0056] Optionally, the battery balancing device in this embodiment further includes a circuit protection element connected in series between the primary winding 111 and the positive terminal of the battery pack. This circuit protection element, connected in series between the primary winding 111 and the positive terminal of the battery pack, can be a one-time fuse, such as a circuit breaker. When an abnormal fault such as overcurrent occurs in the circuit, it can quickly melt and break, thus providing reliable protection for the battery pack and all circuit components and preventing the fault from escalating and causing greater losses.

[0057] Optionally, a circuit protection element is connected in series between each secondary winding 112 and the corresponding battery cell. The circuit protection element between the secondary winding 112 and the battery cell can be configured as a self-resetting fuse, for example... Figure 2 The resettable fuse 150 is configured such that, assuming the current carrying capacity of the resettable fuse 150 is 2A, the resettable fuse 150 will automatically disconnect the circuit when the current in the circuit exceeds 2A. When the current in the circuit returns to less than 2A, the resettable fuse 150 will automatically restore the circuit to the conducting state. It can provide hardware protection or cut off the discharge when the transformer 110 is not well controlled, thereby improving the safety of the circuit.

[0058] Optionally, in this embodiment, a feedback module and a protection module can be added to the secondary side of the transformer 110 according to actual needs. For example, a TZ thermal shutdown signal circuit can be added. When the secondary winding 112 of the transformer is detected to be over-temperature or over-current, the TZ signal triggers the emergency protection logic and quickly disconnects the corresponding equalization channel. A voltage feedback branch can also be added to collect the output voltage of the secondary winding 112 in real time and feed it back to the analog front-end chip to optimize the equalization control logic and further improve the battery equalization accuracy and circuit reliability.

[0059] According to another aspect of the embodiments of this application, this application also provides a battery management system, including the battery balancing device 100 described above.

[0060] According to another aspect of the embodiments of this application, this application also provides a battery balancing method, which is applicable to the above-described battery balancing device, such as... Figure 4 As shown, the battery balancing method includes: Step S202: Detect the voltage signal of each battery cell in the battery pack, and determine the target battery cell based on the voltage signal; Step S204: Control the equalization control terminal and voltage detection terminal corresponding to the target battery cell to be turned on, so that the corresponding isolation switch assembly 120 is closed to connect the target battery cell to the transformer 110. In step S206, the electrical energy released by the target battery cell is coupled to the primary winding 111 through the secondary winding 112 corresponding to the target battery cell in the transformer 110, and then distributed to other battery cells through the primary winding 111 to balance the energy of multiple battery cells in the battery pack.

[0061] Specifically, the analog front-end chip collects the voltage data of each battery cell in real time through the CELL pin. The built-in algorithm of the analog front-end chip compares and analyzes the collected voltage data, and filters out battery cells with voltage higher than the preset equalization threshold and excess energy, marking them as target equalization battery cells, such as BAT5 and BAT8. Then, control BAT5 to turn on the first switch between its corresponding CELL pin and S pin, and control BAT8 to turn on the first switch between its corresponding CELL pin and S pin, so that the current flowing out from BAT5 and BAT8 flows into the control side of the optocoupler switch 122 along the corresponding CELL and S pins, respectively, causing the LED 1221 on the control side to turn on and emit light, triggering the phototransistor 1222 on the switching side of the optocoupler switch 122 to close; after the phototransistor 1222 closes, the voltage of the high-number battery cell (for example, BAT5 uses BAT6 as the high-number battery cell, and BAT7 uses BAT8 as the high-number battery cell) provides the driving voltage for the first MOSFET 121, so that the input and output terminals of the first MOSFET 121 are turned on. After the first MOSFET 121 is turned on, the negative terminal of the target equalization battery cell is connected to the corresponding secondary winding 112. The excess electrical energy released by the target equalization battery cell generates current in the corresponding secondary winding 112. Through the magnetic field coupling of the transformer 110, the energy is transferred to the primary winding 111. The primary winding 111 then distributes the energy to the secondary windings 112 corresponding to other battery cells with low voltage and insufficient energy through magnetic field coupling, replenishing the electrical energy of these battery cells and realizing the energy transfer balance between different battery cells in the same battery pack.

[0062] Thus, the energy balance between different battery cells in the battery pack depends on the control of the transformer 110 and the isolating switch assembly 120 by the analog front-end chip. The transformer 110 achieves energy balance between different battery cells, improving the overall energy utilization rate of the battery pack. Furthermore, combined with the coordinated control of the optocoupler switch 122, the first MOSFET 121, and the multiple secondary windings 112 of the transformer 110, not only can multiple battery cells be balanced simultaneously, further improving the efficiency of battery balancing, but also reducing the withstand voltage requirement.

[0063] Optionally, when the battery pack in this embodiment consists of multiple strings, the above-mentioned battery equalization method further includes: Step S208: Detect the battery pack with the highest energy among the multiple battery packs and use it as the target battery pack; Step S210: Control the input and output terminals of the second MOS to be turned on by the control signal of the output control terminal of the control unit, so that a parallel circuit is formed between the power resistor and the target battery pack; Step S212: Discharge the target battery pack through the power resistor to balance the energy among multiple battery packs.

[0064] Specifically, the simulation front-end chip collects the total voltage of different battery packs and compares it with a preset inter-pack balancing threshold. Battery packs with high total voltage and excess overall energy are selected and marked as target battery packs. The simulation front-end chip outputs a control signal through its GPIO pin to drive the second MOSFET corresponding to the power resistor connected in parallel with the target battery pack to conduct, forming a complete parallel discharge circuit between the power resistor and the target battery pack. This parallel discharge circuit enables the target battery pack to discharge, releasing electrical energy as heat through the power resistor. During discharge, the simulation front-end chip monitors the real-time changes in the total voltage of the target battery pack. When the total voltage drops to below the preset inter-pack balancing threshold, the simulation front-end chip outputs a turn-off signal through its GPIO pin, disconnecting the parallel circuit of the power resistor and stopping the discharge.

[0065] Thus, in the above embodiments of this application, the balancing between different battery packs can be synchronized with the balancing between different battery cells within the same battery pack. That is, while the target battery pack is being discharged as a whole, the battery cells with higher voltages within the target battery pack can still be connected to the transformer 110 through the isolation switch assembly 120 to achieve energy transfer within the battery pack. The two balancing modes do not interfere with each other, which can greatly improve the overall balancing efficiency and shorten the balancing time.

[0066] According to another aspect of the embodiments of this application, this application provides an electronic device, such as... Figure 3 As shown, the system includes a memory 301, a processor 303, a communication interface 305, and a communication bus 307. The memory 301 stores a computer program that can run on the processor 303. The memory 301 and the processor 303 communicate through the communication interface 305 and the communication bus 307. When the processor 303 executes the computer program, it implements the steps of the above method.

[0067] The memory and processor in the aforementioned electronic devices communicate with each other via a communication bus and a communication interface. The communication bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into an address bus, a data bus, a control bus, etc.

[0068] The memory may include random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0069] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0070] According to another aspect of the embodiments of this application, a computer program product or computer program is also provided, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the steps of any of the above embodiments.

[0071] Optionally, in embodiments of this application, the computer-readable medium is configured to store program code for the processor to perform the following steps: Step S202: Detect the voltage signal of each battery cell in the battery pack, and determine the target battery cell based on the voltage signal; Step S204: Control the equalization control terminal and voltage detection terminal corresponding to the target battery cell to be turned on, so that the corresponding isolation switch assembly 120 is closed to connect the target battery cell to the transformer 110. In step S206, the electrical energy released by the target battery cell is coupled to the primary winding 111 through the secondary winding 112 corresponding to the target battery cell in the transformer 110, and then distributed to other battery cells through the primary winding 111 to balance the energy of multiple battery cells in the battery pack.

[0072] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments, and will not be repeated here.

[0073] In specific implementation, the embodiments of this application can be referred to the above embodiments and have corresponding technical effects.

[0074] It is understood that the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described herein, or combinations thereof.

[0075] For software implementation, the techniques described herein can be implemented by units that perform the functions described herein. The software code can be stored in memory and executed by a processor. The memory can be implemented in the processor or external to the processor.

[0076] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0077] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0078] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0079] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0080] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0081] If the aforementioned function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiments of this application, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks. It should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. In the absence of further restrictions, an element defined by the phrase "comprising a..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0082] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A battery balancing device applied to a battery pack, the battery pack comprising multiple battery cells connected in series, characterized in that, The device includes: The transformer includes a primary winding and a secondary winding. The two ends of the primary winding are respectively connected to the positive and negative terminals of the battery pack. The secondary winding includes multiple secondary windings, each corresponding to one of the multiple battery cells in the battery pack. The two ends of each secondary winding are respectively connected to the positive and negative terminals of the corresponding battery cell. The disconnector assembly includes multiple disconnector assemblies, each of which is configured to correspond one-to-one with a plurality of battery cells in the battery pack, and each disconnector assembly is connected in series between the corresponding battery cell and the secondary winding. The control unit is connected to both the individual battery cells and the disconnector assembly. The control unit is used to detect the voltage signal of each individual battery cell and control the disconnector assembly to close based on the voltage signal, so that the transformer can balance the energy among the individual battery cells in the battery pack.

2. The battery balancing device according to claim 1, characterized in that, The control unit includes a voltage detection terminal, a first switch, and an equalization control terminal, wherein the voltage detection terminal, the first switch, and the equalization control terminal are connected in series, wherein: The voltage detection terminal is connected to the positive and negative terminals of each battery cell to detect the voltage signal of each battery cell. The equalization control terminal includes multiple terminals, and each of the multiple equalization control terminals is connected to a corresponding battery cell in the battery pack. When the control unit initiates the equalization process, the first switch closes to connect the voltage detection terminal and the equalization control terminal.

3. The battery balancing device according to claim 2, characterized in that, The disconnector switch assembly includes: The first MOSFET has its input terminal connected to the negative terminal of the corresponding battery cell, and its output terminal connected to the corresponding secondary winding in the transformer. An optocoupler switch having a control side and a switching side, wherein the optocoupler switch is configured such that the switching side closes when current flows through the control side, the control side is connected in series between the equalization control terminal and the voltage detection terminal, and the switching side is connected in series between the control terminal of the first MOS transistor and the voltage detection terminal corresponding to the high-number battery cell; Wherein, the potential of the high-number battery cell in the battery pack is higher than the potential of the battery cell corresponding to the isolating switch assembly, and the high-number battery cell is used to provide the driving voltage required for the first MOS transistor to turn on.

4. The battery balancing device according to claim 2, characterized in that, The device also includes an isolated voltage regulator connected to the individual battery cell in the battery pack that is closest to the overall positive terminal of the battery pack.

5. The battery balancing device according to claim 1, characterized in that, The device further includes a discharge module, which is connected to both the battery pack and the control unit. The discharge module is configured to discharge the battery pack under the control of the control unit.

6. The battery balancing device according to claim 5, characterized in that, The control unit is provided with an output control terminal; The discharge module includes a power resistor and a second MOSFET. The power resistor is connected in parallel with the battery pack. The control terminal of the second MOSFET is connected to the output control terminal. The input terminal of the second MOSFET is connected to the power resistor. The output terminal of the second MOSFET is connected to the negative terminal of the battery pack.

7. The battery balancing device according to any one of claims 1 to 6, characterized in that, The control unit includes an analog front-end chip.

8. The battery balancing device according to any one of claims 1 to 6, characterized in that, The device further includes a current sampling resistor connected in series between the primary winding and the total negative terminal of the battery pack. The current sampling resistor is used at least to collect the primary current of the transformer.

9. The battery balancing device according to any one of claims 1 to 6, characterized in that, The device further includes a circuit protection element connected in series between the primary winding and the total positive terminal of the battery pack; and / or, the circuit protection element connected in series between each of the secondary windings and the corresponding battery cell.

10. A battery management system, characterized in that, The battery equalization device includes any one of claims 1 to 9.

11. A battery balancing method, characterized in that, The method, applicable to any one of claims 1 to 9, comprises: Detect the voltage signal of each battery cell in the battery pack, and determine the target battery cell based on the voltage signal; The equalization control terminal and voltage detection terminal corresponding to the target battery cell are turned on, so that the corresponding isolation switch assembly is closed to connect the target battery cell to the transformer. The electrical energy released by the target battery cell is coupled to the primary winding through the secondary winding corresponding to the target battery cell in the transformer, and then distributed to other battery cells through the primary winding, so as to balance the energy of multiple battery cells in the battery pack.

12. A battery balancing method according to claim 11, characterized in that, When the battery pack consists of multiple series, the method further includes: Detect the battery pack with the highest energy among the multiple battery packs and use it as the target battery pack; The control signal at the output control terminal of the control unit controls the input and output terminals of the second MOS to be turned on, so that a parallel circuit is formed between the power resistor and the target battery pack; The target battery pack is discharged through the power resistor to achieve energy balance among the multiple battery packs.

13. An electronic device comprising a memory, a processor, a communication interface, and a communication bus, wherein the memory stores a computer program executable on the processor, and the memory and the processor communicate via the communication bus and the communication interface, characterized in that... When the processor executes the computer program, it implements the battery balancing method as described in claim 11 or 12.

14. A computer-readable medium having processor-executable non-volatile program code, characterized in that, The program code causes the processor to execute the battery balancing method as described in claim 11 or 12.

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