Battery cell unit, battery module and battery cell management method

Abstract

The invention discloses a battery cell unit, a battery module and a battery cell management method, and belongs to the technical field of electric power, each battery cell monomer comprises a battery cell monomer and a battery cell management unit, and the battery cell management unit comprises a bypass branch, a DC / DC converter and a battery cell controller; the input end of the converter is respectively connected in parallel with the single battery cell and the bypass branch, and the output end of the converter is respectively connected in series with the electric equipment and the output end of the other battery cell unit; the battery cell controller is used for collecting operation parameters of the battery cell monomers in real time and uploading the operation parameters to the battery management unit; the battery cell controller is also used for executing a control instruction issued by the battery management unit; the bypass branch is a magnetic latching relay; the converter adopts an H-bridge inverter circuit topology. According to the scheme, the battery cell controller can perform on-off control on the magnetic latching relay or the four switching tubes in the converter, so that the degraded battery cell monomers are bypassed, or the output power of each battery cell monomer tends to be consistent, and the battery cell level balance control is realized.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a battery cell unit, a battery module and a battery cell management method. Background Art

[0002] The "short board effect" of the battery refers to the differences in capacity, voltage and state of charge (SOC) between the single cells in the battery module. These differences will gradually amplify during the use of the battery, resulting in a decline in the overall performance of the battery module and even affecting the safety and life of the entire system. Passive balancing and active balancing are two common battery balancing technologies. Passive balancing balances the voltage differences in the battery module by consuming excess energy. Although this method is relatively simple, its balancing efficiency is low, the balancing current is small, and the balancing time is long, which makes it difficult to meet application scenarios with high power requirements. In contrast, the addition of a DC / DC converter not only realizes active balancing, but also can effectively dynamically adjust the voltage and power of the single cells in the series battery module through specific control strategies, and can realize more functions. However, the existing battery balancing technology has various defects. For example: Patent CN114243840A discloses a three-level DC / DC balancing method to maintain the balance of battery modules and bypass abnormal modules. However, this method cannot achieve cell-level balancing control and solve the problem of cell degradation. Patent CN117254553A discloses an active balancing circuit and a balancing method thereof, which realizes automatic adjustment of the state of charge of multiple battery packs through the coordinated action of a battery cluster management unit, a bidirectional DC / DC module and multiple battery management units, thereby achieving the purpose of balancing. However, simple state of charge balancing cannot solve the problem of serious degradation of battery cells, and this method also cannot achieve cell-level balancing control.

[0003] Patent CN115622187A proposes a method for active equalization circuit of battery module, which realizes energy transfer between adjacent battery cells and maintains voltage balance in battery module by switching between Boost and Buck modes through bidirectional DC / DC module. However, it does not provide a solution for handling serious degradation of battery cells. Summary of the invention

[0004] The present invention aims to at least solve the technical problems existing in the prior art. To this end, the first aspect of the present invention provides a battery cell unit, wherein the battery cell unit comprises a battery cell monomer and a battery cell management unit, wherein the battery cell management unit comprises: a bypass branch, a DC / DC converter and a battery cell controller; the input end of the DC / DC converter is respectively connected in parallel with the battery cell monomer and the bypass branch, and the output end of the DC / DC converter is respectively connected in series with the power-consuming device and the output end of another battery cell unit; in: The cell controller is used to collect the operating parameters of the cell monomer in real time and upload the operating parameters to the battery management unit; the cell controller is also used to receive the control instructions issued by the battery management unit and execute the control instructions; The bypass branch is a magnetic latching relay, and the magnetic latching relay is connected in parallel at both ends of the battery cell; The DC / DC converter adopts an H-bridge inverter circuit topology, and comprises a first switch tube and a second switch tube respectively connected in parallel with two ends of the bypass branch, a third switch tube connected to the electrical equipment, and a fourth switch tube connected to another battery cell unit; the first switch tube and the second switch tube form a half-bridge structure as the input end of the H-bridge inverter circuit; the third switch tube and the fourth switch tube form a half-bridge structure as the output end of the H-bridge inverter circuit; The DC / DC converter also includes an inductor and a capacitor; two ends of the inductor are respectively connected to the two half-bridge structures, and the third switch tube, the fourth switch tube and the capacitor are connected in parallel.

[0005] Optionally, the electrical device is a load or a charging device.

[0006] Optionally, when the battery cell unit operates normally, the magnetic latching relay is in a disconnected state.

[0007] The second aspect of the present invention provides a battery module, wherein the battery module is composed of at least two battery core units described in the first aspect connected in series, and the at least two battery core units are cascaded through the output end of the DC / DC converter; The battery module also includes a battery management unit, which is connected to the upper controller and the battery cell controller; The battery management unit is used to receive the operating parameters sent by each battery cell controller in the battery module, and calculate the health status parameters of the battery cell monomer according to the operating parameters; The battery management unit is further used to send each of the health status parameters to the upper-level controller, so that the upper-level controller determines the control strategy for the battery module according to the health status parameters included in each of the battery modules, and generates a control instruction according to the control strategy; The battery management unit is also used to receive control instructions from the upper-level controller and send the control instructions to the battery cell controller.

[0008] A third aspect of the present invention provides a battery cell management method, which is applied to the battery module in the second aspect, wherein the battery module includes at least two battery cell units connected in series, a battery management unit, and an upper controller, and the method includes: The battery management unit receives the operating parameters of the battery cells sent by each battery cell controller in the battery module, calculates the health status parameters of the battery cells according to the operating parameters, and sends the health status parameters to the corresponding upper controller; When the upper controller determines that the target battery cell has deteriorated according to the health status parameter, the upper controller generates a bypass instruction for the target battery cell; the battery management unit receives the bypass instruction and sends the bypass instruction to the battery controller corresponding to the target battery cell; When the upper controller determines, according to the health status parameter, that the power currently output by each battery cell unit in the battery module is different, the upper controller generates a balancing instruction, wherein the balancing instruction includes a sub-balancing instruction for each battery cell unit; the battery management unit receives the balancing instruction and sends each sub-balancing instruction to the corresponding battery cell controller; The cell controller performs on-off control on the magnetic latching relay or the switch tube in the DC / DC converter according to the bypass instruction or the balancing instruction.

[0009] Optionally, after the battery management unit receives the bypass instruction and sends the bypass instruction to the cell controller corresponding to the target cell, the method further includes: The cell controller controls the first switch tube, the second switch tube, and the fourth switch tube to be turned on according to the bypass instruction, so that the target cell monomer discharges to the inductor; When the power level of the target battery cell is 0, the battery cell controller controls the first switch tube to be disconnected; The cell controller sends a switch-on instruction to the magnetic latching relay, so that the target cell unit is bypassed.

[0010] Optionally, after the battery management unit receives the balancing instruction and sends each of the sub-balancing instructions to a corresponding battery cell controller, the method further includes: The battery cell controller controls the on / off state and on / off duration of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube according to the sub-balancing instruction, so that the battery cell unit outputs the corresponding preset voltage until the power output by each battery cell unit in the battery module is equal.

[0011] Optionally, after sending the health status parameter to the corresponding upper-level controller, the method further includes: When the upper-level controller determines that a short-circuit fault occurs in the target battery cell according to the health status parameter, the upper-level controller determines the fault type of the short-circuit fault; When the fault type is a load short circuit, the upper controller generates a first short circuit protection instruction; when the fault type is a cell short circuit, the upper controller generates a second short circuit protection instruction; The upper controller sends the first short-circuit protection instruction or the second short-circuit protection instruction to the battery management unit; The battery management unit sends the first short-circuit protection instruction or the second short-circuit protection instruction to the cell controller corresponding to the target cell unit; The cell controller executes the first short-circuit protection instruction or the second short-circuit protection instruction.

[0012] Optionally, the cell controller executes the first short-circuit protection instruction or the second short-circuit protection instruction, including: When the cell controller receives the first short-circuit protection instruction, it controls the first switch tube to be disconnected; When the cell controller receives the second short-circuit protection instruction, it controls the third switch tube to be turned off.

[0013] Optionally, the health status parameters include charge status parameters and health status parameters of each battery cell connected to the battery management unit.

[0014] The embodiments of the present invention have the following beneficial effects: In an embodiment of the present invention, a battery cell unit includes a battery cell and a battery cell management unit, and the battery cell management unit includes: a bypass branch, a DC / DC converter and a battery cell controller; the input end of the DC / DC converter is respectively connected in parallel with the battery cell and the bypass branch, and the output end of the DC / DC converter is respectively connected in series with the power-consuming device and the output end of another battery cell; wherein: the battery cell controller is used to collect the operating parameters of the battery cell in real time, and upload the operating parameters to the battery management unit; the battery cell controller is also used to receive control instructions issued by the battery management unit and execute the control instructions; the bypass branch is a magnetic latching relay, and the magnetic latching relay is connected in parallel with the battery cell. The DC / DC converter adopts an H-bridge inverter circuit topology, and the DC / DC converter includes a first switch tube and a second switch tube respectively connected in parallel with the two ends of the bypass branch, a third switch tube connected to the electrical equipment, and a fourth switch tube connected to another cell unit; the first switch tube and the second switch tube form a half-bridge structure, which serves as the input end of the H-bridge inverter circuit; the third switch tube and the fourth switch tube form a half-bridge structure, which serves as the output end of the H-bridge inverter circuit; the DC / DC converter also includes an inductor and a capacitor; the two ends of the inductor are respectively connected to two half-bridge structures, and the third switch tube and the fourth switch tube are connected in parallel with the capacitor. In this solution, the cell controller can perform on-off control on the magnetic latching relay or the four switch tubes in the DC / DC converter, thereby bypassing the degraded cell monomer, or making the power output of each cell monomer close to the same, to achieve cell-level balanced control. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a circuit structure diagram of a battery module provided by an embodiment of the present invention; Figure 2 It is a flowchart of the steps of a battery cell management method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "multiple" means two or more. In addition, the use of "based on" or "according to" means openness and inclusiveness, because the process, steps, calculations or other actions "based on" or "according to" one or more of the conditions or values ​​may be based on additional conditions or values ​​beyond the described values ​​in practice.

[0018] Figure 1 It is a circuit structure diagram of a battery module provided by an embodiment of the present invention.

[0019] like Figure 1 As shown, the battery module includes a cell unit. The cell unit includes a cell single body V and a cell management unit, and the cell management unit includes: a bypass branch, a DC / DC converter and a cell controller; the input end of the DC / DC converter is respectively connected in parallel with the cell single body and the bypass branch, and the output end of the DC / DC converter is respectively connected in series with the output end of the power consumption device and another cell unit.

[0020] A cell is the smallest unit that makes up a battery system. It is mainly composed of four parts: positive electrode, negative electrode, electrolyte and separator, and generates electricity through electrochemical reactions.

[0021] The battery module includes multiple battery cells, and the battery cell management unit is used to manage the input and output status of multiple battery cells through bypass branches, DC / DC converters and battery cell managers.

[0022] The bypass branch is a magnetic latching relay K1, which is connected in parallel to both ends of the battery cell V.

[0023] A DC / DC converter, or direct current-to-direct current converter, is a direct current conversion device that first inverts (boosts or steps down) direct current into alternating current, and then rectifies and converts it into another direct current voltage.

[0024] The DC / DC converter adopts the H-bridge inverter circuit topology. The H-bridge inverter circuit is a bridge circuit composed of four switching devices (usually MOSFET or IGBT). By controlling the conduction and cutoff of these four switching devices, the positive and negative polarities of the DC power supply can be reversed to generate an AC signal.

[0025] like Figure 1As shown, the DC / DC converter includes a first switch tube Q1 and a second switch tube Q2 respectively connected in parallel with the two ends of the bypass branch, a third switch tube Q3 connected to the electrical equipment, and a fourth switch tube Q4 connected to another battery cell unit. The first switch tube Q1 and the second switch tube Q2 form a half-bridge structure as the input end of the H-bridge inverter circuit; the third switch tube Q3 and the fourth switch tube Q4 form a half-bridge structure as the output end of the H-bridge inverter circuit.

[0026] The cell controller is used to collect the operating parameters of the cell in real time and upload the operating parameters to the battery management unit (BMU). The cell controller is also used to receive control instructions from the battery management unit BMU and execute the control instructions. The operating parameters of the cell may specifically include the voltage, temperature and other parameters of the cell.

[0027] The DC / DC converter also includes an inductor L and a capacitor C. The two ends of the inductor L are respectively connected to the two half-bridge structures, and the third switch tube Q3 and the fourth switch tube Q4 are connected in parallel with the capacitor C. The inductor L is connected between the two half-bridge structures to play the role of energy storage and filtering. The capacitor C is connected to the output end to filter and stabilize the output voltage.

[0028] In this battery cell unit, the DC / DC converter can achieve balanced control, power control, bilateral buck-boost voltage control and bilateral short-circuit protection by adjusting the on-off and duty cycle of each switch tube, thereby realizing the control function of the battery cell level. The bypass branch cooperates with the DC / DC converter to short-circuit the degraded battery cell and maintain the normal operation of the battery module, and consume the residual energy of the degraded battery cell to improve the safety of the system. Each battery cell unit is regulated according to the internal controller and cascaded through its own DC / DC output port to form a battery module, which improves the overall performance and reliability of the battery module.

[0029] In summary, the battery cell unit provided by the embodiment of the present invention includes a battery cell and a battery cell management unit, and the battery cell management unit includes: a bypass branch, a DC / DC converter and a battery cell controller; the input end of the DC / DC converter is respectively connected in parallel with the battery cell and the bypass branch, and the output end of the DC / DC converter is respectively connected in series with the power-consuming equipment and the output end of another battery cell; wherein: the battery cell controller is used to collect the operating parameters of the battery cell in real time, and upload the operating parameters to the battery management unit; the battery cell controller is also used to receive control instructions issued by the battery management unit and execute the control instructions; the bypass branch is a magnetic holding Relay, magnetic latching relay is connected in parallel at both ends of the battery cell; the DC / DC converter adopts H-bridge inverter circuit topology, and the DC / DC converter includes a first switch tube, a second switch tube, and a third switch tube and a fourth switch tube respectively connected in parallel with the two ends of the bypass branch; the first switch tube and the second switch tube form a half-bridge structure as the input end of the H-bridge inverter circuit; the third switch tube and the fourth switch tube form a half-bridge structure as the output end of the H-bridge inverter circuit; the DC / DC converter also includes an inductor and a capacitor; the two ends of the inductor are respectively connected to two half-bridge structures, and the third switch tube and the fourth switch tube are connected in parallel with the capacitor. In this solution, the battery cell controller can perform on-off control on the magnetic latching relay or the four switch tubes in the DC / DC converter, so as to bypass the degraded battery cell, or make the power output of each battery cell close to the same, so as to achieve battery cell level balanced control.

[0030] In a possible implementation manner, the electrical device is a load or a charging device.

[0031] like Figure 1 As shown, the output end of the battery cell is connected to the power-consuming device. Figure 1 Specifically, it is the load.

[0032] In addition, the load can be replaced by a charging device, which charges each battery cell after being modulated by a DC / DC converter.

[0033] In a possible implementation manner, when the battery cell unit operates normally, the magnetic latching relay is in a disconnected state.

[0034] Under normal conditions, the magnetic latching relay K1 of the bypass branch remains disconnected. In this way, the battery cell inputs current into the DC / DC converter, and the DC / DC converter can reverse the positive and negative polarities of the battery cell by controlling the conduction and cutoff of the four switching devices Q1, Q2, Q3, and Q4, thereby generating an AC signal, which is output to the load to supply power to the load.

[0035] The present invention also provides a battery module, which is composed of at least two of the above-mentioned battery cells connected in series. The at least two battery cells are cascaded through the output end of a DC / DC converter.

[0036] like Figure 1 As shown, the battery module includes N battery cell units, each of which includes a battery cell and a battery cell management unit. The battery module also includes a battery management unit BMU, which is connected to each battery cell controller in the battery module to receive operating parameters sent by each battery cell controller and calculate the health status parameters of each battery cell according to the operating parameters.

[0037] The battery management unit BMU is also connected to the upper controller, which Figure 1 The battery management unit BMU is also used to send the health status parameters of each battery cell to the upper controller, so that the upper controller determines the control strategy for the battery module according to the health status parameters of each battery module, and generates control instructions according to the control strategy.

[0038] Specifically, the upper controller determines the current operating state of the battery module based on the health status parameters of each battery module received, and generates a control instruction to send to the battery management unit of the abnormal battery module when the operating state is abnormal. The control instruction may be, for example, a bypass instruction, a balancing instruction, and a short circuit protection instruction.

[0039] The battery management unit is also used to receive control instructions from the upper-level controller and send the control instructions to the battery cell controller. After receiving the control instructions, the battery cell controller executes the control instructions.

[0040] Figure 2 It is a flowchart of the steps of a battery cell management method provided by an embodiment of the present invention.

[0041] This method is applied to Figure 1 A battery module in which the battery module comprises at least two battery cells connected in series, a battery management unit, and an upper controller, the method comprising: Step 101, the battery management unit receives the operating parameters of the battery cells sent by each battery cell controller in the battery module, calculates the health status parameters of the battery cells according to the operating parameters, and sends the health status parameters to the corresponding upper controller; Step 102: When the upper-level controller determines that the target battery cell has deteriorated according to the health status parameter, the upper-level controller generates a bypass instruction for the target battery cell; the battery management unit receives the bypass instruction and sends the bypass instruction to the battery cell controller corresponding to the target battery cell, so that the battery cell controller executes the bypass instruction; Step 103: When the upper-level controller determines that the power currently output by each battery cell unit in the battery module is different based on the health status parameters, the upper-level controller generates a balancing instruction, and the balancing instruction includes a sub-balancing instruction for each battery cell unit; the battery management unit receives the balancing instruction and sends each sub-balancing instruction to the corresponding battery cell controller, so that the battery cell controller executes the sub-balancing instruction.

[0042] In a possible implementation manner, the health state parameters include charge state parameters and health state parameters of each battery cell connected to the battery management unit.

[0043] The health status parameters specifically include the SOC and SOH of the battery cell. ‌SOC (State of Charge)‌ and ‌SOH (State of Health)‌ are two very important parameters in the battery management system, which represent the state of charge and state of health of the battery respectively. SOC represents the state of charge of the battery, that is, the ratio of the remaining battery power to the total capacity. Accurate SOC estimation is crucial to improving the energy utilization of the battery and extending the battery life. SOH represents the health status of the battery, that is, the ratio of the current capacity of the battery to its initial capacity. Accurate SOH estimation can help predict the remaining life of the battery and replace it when necessary, thereby ensuring the safe and efficient operation of the battery system.

[0044] In step 101 to step 103, the battery management unit calculates the state of charge SOC of each battery cell according to the voltage, temperature and other operating parameters of each battery cell sent by each battery cell controller, and calculates the state of health SOH of the battery cell according to the state of charge to obtain the health state parameters.

[0045] The battery management unit sends each health status parameter to the upper controller, which collects the health status parameters of each cell in the battery module to determine whether each cell has deteriorated. The upper controller also compares the output power of each cell in the battery module. If the output power is not equal, it is determined that the battery module is unbalanced.

[0046] If it is determined that a target cell has deteriorated, it is necessary to bypass the target cell to prevent the continued operation of the target cell from affecting the safety of the entire circuit. At this time, the upper controller sends a bypass instruction to the battery management unit corresponding to the target cell, which includes the target identifier of the target cell to be bypassed and the specific bypass operation method.

[0047] The battery management unit sends the bypass instruction to the controller of the battery cell unit including the target battery cell, and the controller executes the bypass operation method in the bypass instruction.

[0048] If the upper controller determines that the battery module is unbalanced, the upper controller generates a balancing instruction and sends it to the battery management unit in the battery module in order to achieve balanced output of each battery cell in the battery module. The balancing instruction includes a sub-balancing instruction for each battery cell. The sub-balancing instruction specifically includes the on-off state control and on-off duration control of the four switch tubes in the DC / DC converter. By controlling the on-off of the switch tube, the battery cell outputs the preset power.

[0049] Specifically, if the battery module includes a first cell, a second cell and a third cell, the output power of the first cell is 5, the output power of the second cell is 4, and the output power of the third cell is 3. Then the sub-balancing instruction for the first cell needs to reduce the output power of the first cell, and the sub-balancing instruction for the third cell needs to increase the output power of the third cell. Thus, the output powers of the first cell, the second cell and the third cell are all close to the middle value of 4.

[0050] In summary, in an embodiment of the present invention, the battery management unit receives the operating parameters of the cell units sent by each cell controller in the battery module, calculates the health status parameters of the cell units according to the operating parameters, and sends the health status parameters to the corresponding upper-level controller; when the upper-level controller determines that the target cell unit has deteriorated according to the health status parameters, the upper-level controller generates a bypass instruction for the target cell unit; the battery management unit receives the bypass instruction, and sends the bypass instruction to the cell controller corresponding to the target cell unit, so that the cell controller executes the bypass instruction; when the upper-level controller determines that the power currently output by each cell unit in the battery module is different according to the health status parameters, the upper-level controller generates a balancing instruction, and the balancing instruction includes a sub-balancing instruction for each cell unit; the battery management unit receives the balancing instruction, and sends each of the sub-balancing instructions to the corresponding cell controller, so that the cell controller executes the sub-balancing instruction. In this solution, the battery management unit receives a bypass instruction or a balancing instruction, and sends the bypass instruction or the balancing instruction to the corresponding cell controller, so that the cell controller executes the bypass instruction or the balancing instruction. The cell controller can perform on-off control on the magnetic latching relay or the four switch tubes in the DC / DC converter, thereby bypassing the deteriorated cell monomer, or making the power output of each cell monomer close to the same, to achieve cell-level balancing control.

[0051] In a possible implementation manner, after the battery management unit receives the bypass instruction in step 102 and sends the bypass instruction to the cell controller corresponding to the target cell, the method further includes: Step 201: the cell controller controls the first switch tube, the second switch tube, and the fourth switch tube to be turned on according to the bypass instruction, so that the target cell monomer discharges to the inductor; Step 202: When the power level of the target battery cell is 0, the battery cell controller controls the first switch to be disconnected; Step 203: The cell controller sends a switch-on instruction to the magnetic latching relay, so that the target cell unit is bypassed.

[0052] In step 201 to step 203, under normal conditions, the bypass branch remains disconnected. However, when the BMU detects that the target battery cell has deteriorated, it will issue a bypass instruction to the battery cell controller corresponding to the target battery cell.

[0053] When the cell controller executes the bypass instruction, it controls Q1, Q2 and Q4 to be turned on, so that the target cell monomer discharges to the inductor L to consume the cell energy until the power of the degraded cell is 0.

[0054] Then the cell controller issues a trigger command to turn on the magnetic latching relay K1, so that the target cell unit is bypassed.

[0055] In a possible implementation manner, after the battery management unit receives the balancing instruction in step 103 and sends each of the sub-balancing instructions to the corresponding battery cell controller, the method further includes: The battery cell controller controls the on / off state and on / off duration of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube according to the sub-balancing instruction, so that the battery cell unit outputs the corresponding preset voltage until the power output by each battery cell unit in the battery module is equal.

[0056] In an embodiment of the present invention, the BMU sends a sub-balancing instruction to the controller of the battery cell management unit. The controller reasonably adjusts the duty cycle of the DC / DC converter switch according to the sub-balancing instruction and controls the battery cell unit to output a specific voltage, thereby achieving balance between different battery cell monomers.

[0057] Specifically, the battery cells are connected in series to form a battery module, so the current of each battery cell is the same, and the power output control of each battery cell can be achieved by controlling the output voltage of each DC / DC converter. According to the calculated state of charge of each battery cell, the balancing instruction can reasonably allocate the output power of each battery cell by controlling the on / off state and on / off duration of the first switch tube, the second switch tube, the third switch tube, and the fourth switch tube, thereby achieving power control and achieving balanced control of the battery cells at the same time according to the balancing target.

[0058] In a possible implementation manner, after sending the health status parameter to the corresponding upper controller in step 101, the method further includes: Step 301: When the upper-level controller determines that a short-circuit fault occurs in a target battery cell according to the health status parameter, the upper-level controller determines the fault type of the short-circuit fault; Step 302: When the fault type is a load short circuit, the upper controller generates a first short circuit protection instruction; when the fault type is a cell short circuit, the upper controller generates a second short circuit protection instruction; Step 303: The upper-level controller sends the first short-circuit protection instruction or the second short-circuit protection instruction to the battery management unit; Step 304: The battery management unit sends the first short-circuit protection instruction or the second short-circuit protection instruction to the cell controller corresponding to the target cell unit; Step 305: The cell controller executes the first short-circuit protection instruction or the second short-circuit protection instruction.

[0059] In a possible implementation, step 305 further includes: Step 3051: When the cell controller receives the first short-circuit protection instruction, the cell controller controls the first switch to be turned off; Step 3052: When the cell controller receives the second short-circuit protection instruction, the third switch tube is controlled to be turned off.

[0060] In step 301-step 305, when the upper controller detects a short circuit fault in the battery cell unit, it sends a first short circuit protection instruction or a second short circuit protection instruction to the battery control unit according to the type of the short circuit fault. The battery control unit sends the first short circuit protection instruction or the second short circuit protection instruction to the corresponding battery cell controller.

[0061] When the cell controller receives the first short-circuit protection instruction, it controls the first switch tube to be disconnected; when the cell controller receives the second short-circuit protection instruction, it controls the third switch tube to be disconnected. In this way, the short-circuited cell or load can be isolated, thereby realizing bilateral short-circuit protection for the battery and the load.

[0062] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0063] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that comply with the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are to be considered exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0064] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A battery cell unit, characterized in that: The battery cell unit includes a battery cell monomer and a battery cell management unit, and the battery cell management unit includes: a bypass branch, a DC / DC converter and a battery cell controller; the input end of the DC / DC converter is respectively connected in parallel with the battery cell monomer and the bypass branch, and the output end of the DC / DC converter is respectively connected in series with the power-consuming device and the output end of another battery cell unit; in: The cell controller is used to collect the operating parameters of the cell monomer in real time and upload the operating parameters to the battery management unit; the cell controller is also used to receive the control instructions issued by the battery management unit and execute the control instructions; The bypass branch is a magnetic latching relay, and the magnetic latching relay is connected in parallel at both ends of the battery cell; The DC / DC converter adopts an H-bridge inverter circuit topology, and comprises a first switch tube and a second switch tube respectively connected in parallel with two ends of the bypass branch, a third switch tube connected to the electrical equipment, and a fourth switch tube connected to another battery cell unit; the first switch tube and the second switch tube form a half-bridge structure as the input end of the H-bridge inverter circuit; the third switch tube and the fourth switch tube form a half-bridge structure as the output end of the H-bridge inverter circuit; The DC / DC converter also includes an inductor and a capacitor; two ends of the inductor are respectively connected to the two half-bridge structures, and the third switch tube, the fourth switch tube and the capacitor are connected in parallel.

2. The battery cell unit according to claim 1, characterized in that: The electrical equipment is a load or a charging device.

3. The battery cell unit according to claim 1, characterized in that: When the battery cell unit operates normally, the magnetic latching relay is in a disconnected state.

4. A battery module, characterized in that: The battery module is composed of at least two battery cells according to any one of claims 1 to 3 connected in series, and the at least two battery cells are cascaded through the output end of the DC / DC converter; The battery module also includes a battery management unit, which is connected to the upper controller and the battery cell controller; The battery management unit is used to receive the operating parameters sent by each battery cell controller in the battery module, and calculate the health status parameters of the battery cell monomer according to the operating parameters; The battery management unit is further used to send each of the health status parameters to the upper-level controller, so that the upper-level controller determines the control strategy for the battery module according to the health status parameters included in each of the battery modules, and generates a control instruction according to the control strategy; The battery management unit is also used to receive control instructions from the upper-level controller and send the control instructions to the battery cell controller.

5. A battery cell management method, characterized in that: The battery module according to claim 4 comprises at least two battery cells connected in series, a battery management unit, and an upper controller, and the method comprises: The battery management unit receives the operating parameters of the battery cells sent by each battery cell controller in the battery module, calculates the health status parameters of the battery cells according to the operating parameters, and sends the health status parameters to the corresponding upper controller; When the upper controller determines that the target battery cell has deteriorated according to the health status parameter, the upper controller generates a bypass instruction for the target battery cell; the battery management unit receives the bypass instruction and sends the bypass instruction to the battery controller corresponding to the target battery cell; When the upper controller determines, according to the health status parameter, that the power currently output by each battery cell unit in the battery module is different, the upper controller generates a balancing instruction, wherein the balancing instruction includes a sub-balancing instruction for each battery cell unit; the battery management unit receives the balancing instruction and sends each sub-balancing instruction to the corresponding battery cell controller; The cell controller performs on-off control on the magnetic latching relay or the switch tube in the DC / DC converter according to the bypass instruction or the balancing instruction.

6. The method according to claim 5, characterized in that After the battery management unit receives the bypass instruction and sends the bypass instruction to the cell controller corresponding to the target cell monomer, the method further includes: The cell controller controls the first switch tube, the second switch tube, and the fourth switch tube to be turned on according to the bypass instruction, so that the target cell monomer discharges to the inductor; When the power level of the target battery cell is 0, the battery cell controller controls the first switch tube to be disconnected; The cell controller sends a switch-on instruction to the magnetic latching relay, so that the target cell unit is bypassed.

7. The method according to claim 5, characterized in that After the battery management unit receives the balancing instruction and sends each of the sub-balancing instructions to the corresponding battery cell controller, the method further includes: The battery cell controller controls the on / off state and on / off duration of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube according to the sub-balancing instruction, so that the battery cell unit outputs the corresponding preset voltage until the power output by each battery cell unit in the battery module is equal.

8. The method according to claim 5, characterized in that After sending the health status parameter to the corresponding upper controller, the method further includes: When the upper-level controller determines that a short-circuit fault occurs in the target battery cell according to the health status parameter, the upper-level controller determines the fault type of the short-circuit fault; When the fault type is a load short circuit, the upper controller generates a first short circuit protection instruction; when the fault type is a cell short circuit, the upper controller generates a second short circuit protection instruction; The upper controller sends the first short-circuit protection instruction or the second short-circuit protection instruction to the battery management unit; The battery management unit sends the first short-circuit protection instruction or the second short-circuit protection instruction to the cell controller corresponding to the target cell unit; The cell controller executes the first short-circuit protection instruction or the second short-circuit protection instruction.

9. The method according to claim 8, characterized in that The cell controller executes the first short-circuit protection instruction or the second short-circuit protection instruction, including: When the cell controller receives the first short-circuit protection instruction, it controls the first switch tube to be disconnected; When the cell controller receives the second short-circuit protection instruction, it controls the third switch tube to be turned off.

10. The method according to claim 5, characterized in that The health state parameters include charge state parameters and health state parameters of each battery cell connected to the battery management unit.

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