Battery module and control method thereof

Abstract

The invention discloses a battery module and a control method thereof, and relates to the technical field of batteries, a plurality of battery cell units are connected in series and in parallel to form an energy storage module; the module controller is in communication connection with the DC / DC converter; the first IO end of the DC / DC converter is connected to the DC bus, and the second IO end of the DC / DC converter is electrically connected with the energy storage module; the battery cell switch is electrically connected with the battery cells to form positive and negative electrodes of the battery cell units; and the battery cell controller is in communication connection with the battery cells, the battery cell switch and the module controller. By adopting the embodiment of the invention, the battery module can be ensured to meet the load requirement through the buck-boost control of the DC / DC converter, and the battery module is always in the optimal operation state. Meanwhile, through cooperative control of the module controller and the battery cell controller, active balance control over all the battery cells can be achieved, and bypass control is achieved when the performance of the battery cells is degraded.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery module and a control method thereof. Background Art

[0002] In recent years, the global demand for clean energy has surged, driving battery technology to the core of the energy sector. However, during use, batteries often experience problems such as voltage and temperature imbalances, and cell degradation, which seriously affect system performance and service life.

[0003] Existing battery configurations typically rely on application scenarios with varying voltage, power, and capacity requirements. Single cells are connected in series and parallel to form battery modules, which are then connected in series and parallel to form battery clusters, ultimately forming battery compartments. Traditional battery management utilizes a centralized BMS (Battery Management System) to monitor overall battery energy parameters. Some designs currently connect single cells via the output of a DC / DC converter to achieve cell-level regulation and combination. However, these designs result in a complex overall battery module structure and require complex control of numerous switches. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a battery module and a control method thereof, which can meet the load requirements of the battery module through the coordinated design of the battery cell unit, DC / DC converter and module controller, while simplifying the active balancing control of each battery cell.

[0005] An embodiment of the present invention provides a battery module, comprising a plurality of battery cell units, a DC / DC converter and a module controller; the battery cell units comprise battery cells, a battery cell switch and a battery cell controller; Several battery cells are connected in series and parallel to form an energy storage module; the module controller is in communication with the DC / DC converter; the first IO terminal of the DC / DC converter is connected to the DC bus, and the second IO terminal of the DC / DC converter is electrically connected to the energy storage module; the battery cell switch is electrically connected to the battery cell to form the positive and negative poles of the battery cell unit; the battery cell controller is in communication with the battery cell, the battery cell switch, and the module controller; The module controller is used to receive bus operation data from the DC / DC converter, receive cell operation data from the cell controller, and send control instructions to the DC / DC converter and the cell controller; the DC / DC converter is used to transmit the collected bus operation data to the module controller, and respond to the instructions of the module controller to realize the power exchange between the DC bus and the energy storage module; the cell controller is used to transmit the collected cell operation data of the cell to the module controller, and respond to the instructions of the module controller to control the cell switch; the cell switch controls the on and off of the cell in response to the instructions of the cell controller.

[0006] As an improvement to the above solution, the DC / DC converter includes an H-bridge buck-boost converter and a first magnetic latching relay; the H-bridge buck-boost converter includes P-channel MOSFET switches T1 to T4 and an inductor; The drain of the MOSFET switch tube T1 is electrically connected to the first end of the first magnetic latching relay and one pole of the DC bus; the source of the MOSFET switch tube T1 is electrically connected to one end of the inductor and the drain of the MOSFET switch tube T2; the source of the MOSFET switch tube T2 is electrically connected to the other pole of the DC bus, the source of the MOSFET switch tube T4, and one pole of the second IO terminal of the DC / DC converter; the drain of the MOSFET switch tube T4 is electrically connected to the other end of the inductor and the source of the MOSFET switch tube T3; the drain of the MOSFET switch tube T3 is electrically connected to the other end of the first magnetic latch and the other pole of the second IO terminal of the DC / DC converter.

[0007] As an improvement to the above solution, the cell switch includes a second magnetic latching relay; the second magnetic latching relay is a three-contact magnetic latching relay; The common contact of the second magnetic latching relay is one end of the battery cell unit; the normally closed contact of the second magnetic latching relay is electrically connected to the positive pole of the battery cell; the normally open contact of the second magnetic latching relay is electrically connected to the negative pole of the battery cell and the other end of the battery cell unit.

[0008] As an improvement to the above solution, the module controller is further connected to a host computer for communication. The host computer is used to receive signals collected by the module controller and send control instructions to the module controller.

[0009] An embodiment of the present invention further provides a control method executed by a module controller in any of the above-mentioned battery modules, comprising: Communicate with each cell controller in a polling manner to obtain cell operation data and bus operation data sent by the DC / DC converter; Obtaining the power supply access status and load access status of the DC bus according to the bus operation data, and obtaining the battery SOC according to the operation data of each battery cell; When the DC bus is connected to the power supply, if the battery SOC is not greater than the preset SOC lower limit, a charging instruction is sent to the DC / DC converter to charge the battery module. When the battery SOC is not less than the preset SOC upper limit, a stop charging instruction is sent to the DC / DC converter. When the DC bus is not connected to the power supply and is connected to a load within the battery module's tolerance range, a constant voltage discharge command is sent to the DC / DC converter until the battery SOC is no greater than the preset SOC lower limit, and then a stop discharge command is sent to the DC / DC converter.

[0010] As an improvement to the above solution, when the DC bus is connected to the power supply, if the battery SOC is not greater than a preset SOC lower limit, a charging instruction is sent to the DC / DC converter to charge the battery module until the battery SOC is not less than a preset SOC upper limit, and then a stop charging instruction is sent to the DC / DC converter, including: When the DC bus is connected to the power supply, if there is a battery cell whose battery SOC is not greater than the preset SOC lower limit, the target battery cell is screened; Sending an access instruction to the cell controller of the target cell unit and sending a bypass instruction to the cell controllers of the non-target cell units; Sending charging instructions to the DC / DC converter to charge the target battery cell; When the battery SOC of the target battery cell unit is not less than a preset SOC upper limit, a bypass instruction is sent to the battery cell controller of the target battery cell unit, and the target battery cell unit is updated; When there is no target battery cell, a stop charging instruction is sent to the DC / DC converter.

[0011] As an improvement to the above solution, the control method further includes: During the charging process of the battery module, it is determined whether the cell unit is overcharged according to the cell operation data; if so, a bypass instruction is sent to the cell controller corresponding to the cell unit until the cell unit is no longer overcharged, and an access instruction is sent to the cell controller; During the discharge process of the battery module, it is determined whether the cell unit is over-discharged based on the cell operation data; if so, a bypass instruction is sent to the cell controller corresponding to the cell unit until the cell unit is no longer over-discharged, and an access instruction is sent to the cell controller.

[0012] As an improvement of the above solution, the sending of a bypass instruction to the cell controller corresponding to the cell unit includes: sending a bypass instruction to the cell controller corresponding to the cell unit to control the normally open contact of the second magnetic latching relay to close and the normally closed contact to disconnect through the cell controller; The sending of the access instruction to the cell controller includes: sending the access instruction to the cell controller corresponding to the cell unit, so as to control the normally closed contact of the second magnetic latching relay to close and the normally open contact to open through the cell controller.

[0013] As an improvement to the above solution, the control method further includes: When the DC bus is not connected to a power source and a load, a constant voltage pulse discharge instruction is sent to the DC / DC converter to cause the battery module to perform pulse discharge through the DC / DC converter.

[0014] As an improvement to the above solution, the control method further includes: The battery cell units are divided into primary battery cell units and secondary battery cell units according to the battery SOC; the battery SOC of the primary battery cell unit is higher than that of the secondary battery cell unit; When the DC bus is not connected to the power supply, a balancing instruction is sent to the DC / DC converter to control the energy of the primary battery unit to be transferred to the secondary battery unit through the DC / DC converter until the battery SOC of the primary battery unit and the secondary battery unit are at the same level.

[0015] Compared to existing technologies, the present invention discloses a battery module and control method thereof. This method connects a DC / DC converter to an energy storage module formed by several battery cells. This method utilizes boost and buck control to ensure that the battery module meets load requirements and maintains optimal operating conditions. Each battery cell has its own independent cell controller and cell switch. Through the coordinated control of the module and cell controllers, active balancing control of each cell is achieved. When cell performance deteriorates, bypass control is implemented, eliminating the need to remove degraded cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 1 is a schematic structural diagram of a battery module provided by an embodiment of the present invention; Figure 2 This is a structural diagram of another battery module provided by an embodiment of the present invention; Figure 3 It is a flowchart of the steps of a battery module control method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] In the description of the specification and claims, it should be understood that the terms "first," "second," etc., are used solely for descriptive purposes to distinguish between identical technical features and are not to be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to, nor do they necessarily describe a sequential or chronological order. The terms are interchangeable where appropriate. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one of those features.

[0019] The main functional indicators for the reliable use of battery cells and battery modules include: (1) real-time acquisition of voltage / temperature data of each battery cell; (2) timely equalization of battery cells with uneven charge and discharge to make the SOC of all battery cells consistent; (3) deteriorated battery cells can be bypassed in real time without affecting the use of the entire battery module; (4) the battery module controller can obtain the voltage / temperature data of each battery cell in real time; (5) the battery module control can perform real-time charging control when the battery module is connected to an external power supply, and each battery cell unit is charged according to the optimal charging target; (6) the battery module control can perform real-time discharge control when the battery module is connected to an external load, and each battery cell unit is discharged according to the optimal discharge target to maintain reliable and stable power supply to the load; (7) the battery module control can prevent the battery module from overcharging and over-discharging; and bypass itself when the battery module performance deteriorates.

[0020] For current battery management solutions, there are few methods that can achieve all the above functional indicators. Even if there are solutions with similar functions, their circuit structures are complex and the control logic is very cumbersome. The signal interaction process is easily interfered with, which brings great inconvenience to battery management.

[0021] Based on the above considerations, an embodiment of the present invention provides a battery module. Figure 1 In this embodiment, the battery module includes a plurality of battery cell units 1, a DC / DC converter 2 and a module controller 3; the battery cell unit 1 includes a battery cell 11, a battery cell switch 12 and a battery cell controller 13; Several battery cells 1 are connected in series and parallel to form an energy storage module; the module controller 3 is in communication with the DC / DC converter 2; the first IO terminal of the DC / DC converter 2 is connected to the DC bus, and the second IO terminal of the DC / DC converter is electrically connected to the energy storage module; the battery cell switch 12 is electrically connected to the battery cell 11 to form the positive and negative poles of the battery cell unit 1; the battery cell controller 13 is in communication with the battery cell 11, the battery cell switch 12 and the module controller 3; The module controller 3 is used to receive bus operation data from the DC / DC converter 2, receive cell operation data from the cell controller 13, and send control instructions to the DC / DC converter 2 and the cell controller 13; the DC / DC converter 2 is used to transmit the collected bus operation data to the module controller 3, and respond to the instructions of the module controller 3 to realize the power exchange between the DC bus and the energy storage module; the cell controller 13 is used to transmit the collected cell operation data of the cell 11 to the module controller, and respond to the instructions of the module controller 3 to control the cell switch 12; the cell switch 12 controls the on and off of the cell 11 in response to the instructions of the cell controller 13.

[0022] It should be noted that the first IO terminal and the second IO terminal of the DC / DC converter each have two terminals. The two terminals of the first IO terminal direct the signal or load on the DC bus to the battery module, while the two terminals of the second IO terminal are respectively connected to the positive and negative poles of the energy storage module, allowing the energy storage module to be controlled by the DC / DC converter. The two most typical scenarios are: when the DC bus is connected to a power source, it can supply power to the battery module as needed, and the battery module is in a charging state; when the DC bus is connected to a load, it can supply power to the load based on the battery module's charge, and the battery module is in a discharging state.

[0023] It should also be noted that the module controller, the cell controller, and the components they control are all connected by communication. In some preferred embodiments of the present invention, Bluetooth communication is used. The module controller and the cell controller use the same Bluetooth protocol and can communicate directly, avoiding the trouble of laying communication lines and reducing failure points. It is worth noting that the distance between each cell unit in the battery module and the module controller is relatively close, and their communication signals are shielded inside the battery module box, ensuring reliable and confidential communication.

[0024] It can be understood that the overall energy storage module formed by several battery cells connected in series and parallel has positive and negative poles. Generally speaking, when connected in series, the positive and negative poles of each battery cell are connected in sequence, and when connected in parallel, the positive and negative poles of each battery cell are connected correspondingly.

[0025] In some preferred embodiments, the battery module can also be connected to other battery modules to expand the overall capacity. The connection can also be achieved by connecting to a DC bus, which will not be described in detail here.

[0026] In this solution, a DC / DC converter is connected to an energy storage module formed by several battery cells. Buck-boost control ensures that the battery module meets load requirements and maintains optimal operation. Each battery cell has its own independent cell controller and cell switch. The coordinated control of the module and cell controllers enables active balancing of each cell and enables bypass control when cell performance deteriorates, eliminating the need to remove degraded cells.

[0027] As a preferred embodiment, see Figure 2 The DC / DC converter includes an H-bridge buck-boost converter and a first magnetic latching relay; the H-bridge buck-boost converter includes P-channel MOSFET switches T1 to T4 and an inductor; The drain of the MOSFET switch tube T1 is electrically connected to the first end of the first magnetic latching relay and one pole of the DC bus; the source of the MOSFET switch tube T1 is electrically connected to one end of the inductor and the drain of the MOSFET switch tube T2; the source of the MOSFET switch tube T2 is electrically connected to the other pole of the DC bus, the source of the MOSFET switch tube T4, and one pole of the second IO terminal of the DC / DC converter; the drain of the MOSFET switch tube T4 is electrically connected to the other end of the inductor and the source of the MOSFET switch tube T3; the drain of the MOSFET switch tube T3 is electrically connected to the other end of the first magnetic latch and the other pole of the second IO terminal of the DC / DC converter.

[0028] The combination of MOSFET switches T1-T4 and the inductor supports bidirectional voltage conversion, both step-up and step-down. When a power source is connected to the DC bus, the battery module voltage is lower than the bus voltage. This voltage can be boosted by turning on T1 and T4, then turning off T1. When a load is connected to the DC bus, the battery module voltage is higher than the bus voltage. This voltage can be stepped down by turning on T2 and T3, then turning off T3. The H-bridge structure supports high-frequency switching, enabling rapid response to bus voltage fluctuations or sudden load changes, maintaining a stable output voltage.

[0029] In this embodiment of the present invention, the first magnetic latching relay has a dual-contact structure, similar to a switch. Of course, those skilled in the art may also select other types of magnetic latching relays. Their primary purpose is to provide fault isolation and power-off protection. In the event of a power outage, the first magnetic latching relay maintains its current state, preventing circuit malfunctions caused by loss of control signals.

[0030] As a preferred embodiment, see Figure 2 , the cell switch includes a second magnetic latching relay; the second magnetic latching relay is a three-contact magnetic latching relay; The common contact of the second magnetic latching relay is one end of the battery cell unit; the normally closed contact of the second magnetic latching relay is electrically connected to the positive pole of the battery cell; the normally open contact of the second magnetic latching relay is electrically connected to the negative pole of the battery cell and the other end of the battery cell unit.

[0031] It can be understood that in the embodiment of the present invention, at the same time, the second magnetic latching relay can only close a single contact at most. When the normally open contact is closed, the battery cell is connected normally, and when the normally closed contact is closed, the battery cell will be bypassed so that the current bypasses the battery cell, and other battery cell units are not affected.

[0032] As a preferred embodiment, the module controller is further communicatively connected to a host computer, and the host computer is used to receive signals collected by the module controller and send control instructions to the module controller.

[0033] In the above solution, the host computer can directly send control signals of the DC / DC converter and specific battery cells to the module controller and request the module controller to forward them. The host computer can also inform the module controller of the source and requirements of the signals currently connected to the DC bus for the module controller to make decisions. In addition, the host computer can more importantly coordinate and control multiple battery modules in a unified manner to achieve greater energy storage capabilities.

[0034] A battery module provided by an embodiment of the present invention is connected to an energy storage module formed by several battery cell units via a DC / DC converter. This allows for step-up and step-down voltage control to ensure that the battery module meets load requirements and maintains optimal operating conditions. Each battery cell unit has an independent battery cell controller and battery cell switch. Through the coordinated control of the module controller and the battery cell controller, active balancing control of each battery cell can be achieved. When battery cell performance deteriorates, bypass control is implemented, avoiding the inconvenience of removing deteriorated batteries.

[0035] The embodiment of the present invention provides a control method executed by the module controller in the above battery module. Figure 3 , the control method is specifically performed through steps S1-S4: S1. Communicate with each cell controller in a polling manner to obtain cell operation data and bus operation data sent by the DC / DC converter.

[0036] It should be noted that the polling frequency can be set based on the required accuracy. The polling mechanism can collect the cell status and bus parameters in real time to ensure information synchronization.

[0037] S2. Obtain the power supply access status and load access status of the DC bus according to the bus operation data, and obtain the battery SOC according to the operation data of each battery cell.

[0038] In the embodiment of the present invention, the battery SOC corresponding to each cell unit is obtained to perform SOC consistency management. Moreover, when the operating data of some cells is abnormal, cross-verification can be performed based on the status of adjacent cells to avoid misjudgment.

[0039] S3. When the DC bus is connected to the power supply, if the battery SOC is not greater than the preset SOC lower limit, a charging instruction is sent to the DC / DC converter to charge the battery module until the battery SOC is not less than the preset SOC upper limit, and then a stop charging instruction is sent to the DC / DC converter.

[0040] When the DC bus is connected to a power source, the charging process is automatically controlled based on the battery SOC. By setting upper and lower SOC thresholds as the criteria for charging start and stop, closed-loop management of the battery module charging process is achieved. This ensures that charging automatically starts when the battery is low on power, preventing the battery from being affected by low power. When the power reaches the target value, charging is stopped promptly to prevent overcharging and damage to battery performance. This ensures that the battery power level is maintained within a reasonable range while ensuring battery safety, thereby improving the reliability and stability of battery use.

[0041] S4. When the DC bus is not connected to the power supply and is connected to a load within the tolerance range of the battery module, a constant voltage discharge command is sent to the DC / DC converter until the battery SOC is no greater than the preset SOC lower limit, and then a stop discharge command is sent to the DC / DC converter.

[0042] The above solution ensures that when there is no external power supply, the battery supplies power to the load at a stable voltage to maintain normal operation of the load. At the same time, discharge is stopped promptly when the battery power drops to the preset lower limit to prevent battery over-discharge damage. This ensures discharge stability while protecting battery safety and extending battery life.

[0043] The overall solution uses closed-loop charge and discharge control based on the SOC threshold to achieve automatic charging management of the battery module when there is an external power supply and constant voltage discharge control when there is no power supply. It can avoid overcharging during the charging stage and over-discharge during the discharge stage to ensure battery safety, and maintain normal operation of the load through voltage stability control. At the same time, it relies on the threshold judgment mechanism to achieve reasonable maintenance of power and improve the reliability and stability of battery use. The overall solution has simple logic and effective control, which can optimize its usage efficiency and life while ensuring battery safety.

[0044] As a preferred embodiment, step S3, when the DC bus is connected to the power supply, if the battery SOC is not greater than the preset SOC lower limit, a charging instruction is sent to the DC / DC converter to charge the battery module until the battery SOC is not less than the preset SOC upper limit, and then a stop charging instruction is sent to the DC / DC converter, including: When the DC bus is connected to the power supply, if there is a battery cell whose battery SOC is not greater than the preset SOC lower limit, the target battery cell is screened; Sending an access instruction to the cell controller of the target cell unit and sending a bypass instruction to the cell controllers of the non-target cell units; Sending charging instructions to the DC / DC converter to charge the target battery cell; When the battery SOC of the target battery cell unit is not less than a preset SOC upper limit, a bypass instruction is sent to the battery cell controller of the target battery cell unit, and the target battery cell unit is updated; When there is no target battery cell, a stop charging instruction is sent to the DC / DC converter.

[0045] In this solution, during charging, cells with lower charge levels are prioritized and other cells with sufficient SOC levels are bypassed, prioritizing charging of cells with lower SOC levels and gradually narrowing the SOC deviation between cells. By dynamically updating the target cell level, optimal allocation of charging resources can be achieved.

[0046] As a preferred embodiment, the control method further includes: During the charging process of the battery module, it is determined whether the cell unit is overcharged according to the cell operation data; if so, a bypass instruction is sent to the cell controller corresponding to the cell unit until the cell unit is no longer overcharged, and an access instruction is sent to the cell controller; During the discharge process of the battery module, it is determined whether the cell unit is over-discharged based on the cell operation data; if so, a bypass instruction is sent to the cell controller corresponding to the cell unit until the cell unit is no longer over-discharged, and an access instruction is sent to the cell controller.

[0047] The above solution provides precise protection against overcharging and over-discharging of battery cells. During the charging process, the overcharging situation is monitored in real time based on the battery cell operating data. Once an abnormality is detected, the corresponding battery cell is immediately bypassed. This can avoid risks such as battery bulging and thermal runaway caused by overcharging, prevent irreversible damage to internal active substances, and effectively ensure battery safety. After the overcharge state is removed, the battery cell is reconnected to ensure that the normal charging path is restored to the battery cell and the overall consistency of the battery module is maintained. During the discharge process, the over-discharged cell can be blocked in a timely manner to prevent its voltage from being too low, resulting in rapid capacity decay and shortened life, while maintaining the stability of the load power supply. When the cell is out of the over-discharge state, it is reconnected to ensure the continuity of the battery module discharge process. This improves the safety and reliability of the battery module operation, reduces the occurrence of failures, extends the battery life, and ensures the stable operation of the battery module.

[0048] Further, preferably, in a specific battery module, if the cell switch includes a second magnetic latching relay; the second magnetic latching relay is a three-contact magnetic latching relay; the common contact of the second magnetic latching relay is one end of the cell unit; the normally closed contact of the second magnetic latching relay is electrically connected to the positive pole of the cell; the normally open contact of the second magnetic latching relay is electrically connected to the negative pole of the cell and the other end of the cell unit; The sending of the bypass instruction to the cell controller corresponding to the cell unit includes: sending the bypass instruction to the cell controller corresponding to the cell unit to control the normally open contact of the second magnetic latching relay to close and the normally closed contact to disconnect through the cell controller; The sending of the access instruction to the cell controller includes: sending the access instruction to the cell controller corresponding to the cell unit, so as to control the normally closed contact of the second magnetic latching relay to close and the normally open contact to open through the cell controller.

[0049] In the above solution, a specific control signal of the second magnetic latching relay is given, which can control the access and bypass of the battery cell based on the structure of the second magnetic latching relay.

[0050] As a preferred embodiment, the control method further includes: When the DC bus is not connected to a power source and a load, a constant voltage pulse discharge instruction is sent to the DC / DC converter to cause the battery module to perform pulse discharge through the DC / DC converter.

[0051] In the above scheme, when the DC bus is suspended, the battery module intermittently releases energy through pulse discharge, which can activate the battery and slow performance degradation. Furthermore, since the self-discharge rates of each cell in the battery module may vary, pulse discharge can provide additional discharge to cells with high self-discharge rates, reducing the cell SOC. In some preferred embodiments, the pulse discharge device collects a voltage response curve and calculates the cell internal resistance based on this voltage response curve to measure the degree of cell aging.

[0052] As a preferred embodiment, the control method further includes: dividing the battery cell unit into a primary battery cell unit and a secondary battery cell unit according to the battery SOC; the battery SOC of the primary battery cell unit is higher than that of the secondary battery cell unit; When the DC bus is not connected to the power supply, a balancing instruction is sent to the DC / DC converter to control the energy of the primary battery unit to be transferred to the secondary battery unit through the DC / DC converter until the battery SOC of the primary battery unit and the secondary battery unit are at the same level.

[0053] In this solution, a dynamic grouping and balancing mechanism enables targeted energy transfer from high-SOC cells to low-SOC cells, precisely eliminating SOC deviations and optimizing energy utilization. Furthermore, hierarchical management further reduces management complexity compared to individual balancing solutions.

[0054] A battery module control method provided in an embodiment of the present invention deeply couples the microstructure of the battery module with the control logic, realizing a hierarchical control design concept. It can fully reuse existing components in the battery module to implement simple logic battery module control, keep it in the optimal operating state, and realize active balancing control of each battery cell.

[0055] Those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing the relevant hardware through a computer program. The program can be stored in a computer-readable storage medium, and when executed, the program can include the processes in the above-described method embodiments. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

[0056] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A battery module, characterized in that: It includes several battery cell units, DC / DC converters and module controllers; the battery cell units include battery cells, battery cell switches and battery cell controllers; Several battery cells are connected in series and parallel to form an energy storage module; the module controller is in communication with the DC / DC converter; the first IO terminal of the DC / DC converter is connected to the DC bus, and the second IO terminal of the DC / DC converter is electrically connected to the energy storage module; the battery cell switch is electrically connected to the battery cell to form the positive and negative poles of the battery cell unit; the battery cell controller is in communication with the battery cell, the battery cell switch, and the module controller; The module controller is used to receive bus operation data from the DC / DC converter, receive cell operation data from the cell controller, and send control instructions to the DC / DC converter and the cell controller; the DC / DC converter is used to transmit the collected bus operation data to the module controller, and respond to the instructions of the module controller to realize the power exchange between the DC bus and the energy storage module; the cell controller is used to transmit the collected cell operation data of the cell to the module controller, and respond to the instructions of the module controller to control the cell switch; the cell switch controls the on and off of the cell in response to the instructions of the cell controller.

2. A battery module according to claim 1, characterized in that: The DC / DC converter includes an H-bridge buck-boost converter and a first magnetic latching relay; the H-bridge buck-boost converter includes P-channel MOSFET switches T1 to T4 and an inductor; The drain of the MOSFET switch tube T1 is electrically connected to the first end of the first magnetic latching relay and one pole of the DC bus; the source of the MOSFET switch tube T1 is electrically connected to one end of the inductor and the drain of the MOSFET switch tube T2; the source of the MOSFET switch tube T2 is electrically connected to the other pole of the DC bus, the source of the MOSFET switch tube T4, and one pole of the second IO terminal of the DC / DC converter; the drain of the MOSFET switch tube T4 is electrically connected to the other end of the inductor and the source of the MOSFET switch tube T3; the drain of the MOSFET switch tube T3 is electrically connected to the other end of the first magnetic latch and the other pole of the second IO terminal of the DC / DC converter.

3. A battery module according to claim 1, characterized in that: The cell switch includes a second magnetic latching relay; the second magnetic latching relay is a three-contact magnetic latching relay; The common contact of the second magnetic latching relay is one end of the battery cell unit; the normally closed contact of the second magnetic latching relay is electrically connected to the positive pole of the battery cell; the normally open contact of the second magnetic latching relay is electrically connected to the negative pole of the battery cell and the other end of the battery cell unit.

4. A battery module according to claim 1, characterized in that: The module controller is also connected to a host computer for communication. The host computer is used to receive signals collected by the module controller and send control instructions to the module controller.

5. A method for controlling a battery module, characterized in that: Applied to the battery module according to any one of claims 1 to 4, the execution object is a module controller, and the control method includes: Communicate with each cell controller in a polling manner to obtain cell operation data and bus operation data sent by the DC / DC converter; Obtaining the power supply access status and load access status of the DC bus according to the bus operation data, and obtaining the battery SOC according to the operation data of each battery cell; When the DC bus is connected to the power supply, if the battery SOC is not greater than the preset SOC lower limit, a charging instruction is sent to the DC / DC converter to charge the battery module. When the battery SOC is not less than the preset SOC upper limit, a stop charging instruction is sent to the DC / DC converter. When the DC bus is not connected to the power supply and is connected to a load within the battery module's tolerance range, a constant voltage discharge command is sent to the DC / DC converter until the battery SOC is no greater than the preset SOC lower limit, and then a stop discharge command is sent to the DC / DC converter.

6. A method for controlling a battery module according to claim 5, characterized in that: When the DC bus is connected to the power supply, if the battery SOC is not greater than the preset SOC lower limit, a charging instruction is sent to the DC / DC converter to charge the battery module until the battery SOC is not less than the preset SOC upper limit, and then a stop charging instruction is sent to the DC / DC converter, including: When the DC bus is connected to the power supply, if there is a battery cell whose battery SOC is not greater than the preset SOC lower limit, the target battery cell is screened; Sending an access instruction to the cell controller of the target cell unit and sending a bypass instruction to the cell controllers of the non-target cell units; Sending charging instructions to the DC / DC converter to charge the target battery cell; When the battery SOC of the target battery cell unit is not less than a preset SOC upper limit, a bypass instruction is sent to the battery cell controller of the target battery cell unit, and the target battery cell unit is updated; When there is no target battery cell, a stop charging instruction is sent to the DC / DC converter.

7. A battery module control method according to claim 5, characterized in that: The control method further includes: During the charging process of the battery module, it is determined whether the cell unit is overcharged according to the cell operation data; if so, a bypass instruction is sent to the cell controller corresponding to the cell unit until the cell unit is no longer overcharged, and an access instruction is sent to the cell controller; During the discharge process of the battery module, it is determined whether the cell unit is over-discharged based on the cell operation data; if so, a bypass instruction is sent to the cell controller corresponding to the cell unit until the cell unit is no longer over-discharged, and an access instruction is sent to the cell controller.

8. The method for controlling a battery module according to claim 7, wherein: Applied to a battery module according to claim 3, the sending of a bypass instruction to a cell controller corresponding to the cell unit comprises: sending a bypass instruction to the cell controller corresponding to the cell unit to control the normally open contact of the second magnetic latching relay to close and the normally closed contact to disconnect through the cell controller; The sending of the access instruction to the cell controller includes: sending the access instruction to the cell controller corresponding to the cell unit, so as to control the normally closed contact of the second magnetic latching relay to close and the normally open contact to open through the cell controller.

9. The method for controlling a battery module according to claim 5, wherein: The control method further includes: When the DC bus is not connected to a power source and a load, a constant voltage pulse discharge instruction is sent to the DC / DC converter to cause the battery module to perform pulse discharge through the DC / DC converter.

10. The method for controlling a battery module according to claim 5, wherein: The control method further includes: The battery cell units are divided into primary battery cell units and secondary battery cell units according to the battery SOC; the battery SOC of the primary battery cell unit is higher than that of the secondary battery cell unit; When the DC bus is not connected to the power supply, a balancing instruction is sent to the DC / DC converter to control the energy of the primary battery unit to be transferred to the secondary battery unit through the DC / DC converter until the battery SOC of the primary battery unit and the secondary battery unit are at the same level.

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