Battery management device and method for energy storage balance control

Abstract

The invention discloses a battery management device and method for energy storage balance control. The battery management device comprises a power supply monitoring unit, an electric connection control unit, a charge and discharge control unit and a bidirectional flyback converter. The power supply monitoring unit monitors electrical parameters of the energy storage module, the charging and discharging control unit sends a connection control instruction and an equalization control instruction based on an energy storage equalization control rule and according to electric quantity information obtained through monitoring, and the electrical connection control unit responds to the connection control instruction. And connecting the battery pack or the single battery cell which needs to be equalized to a bidirectional flyback converter, wherein the bidirectional flyback converter performs charging and discharging control on the battery pack and the single battery cell which need to be equalized based on the equalization control instruction. The equalization of the battery packs, the single battery cells and the energy storage module can be simultaneously considered through one circuit, so that the equalization among the battery packs is realized, the equalization of the single battery cells among different groups or in the same group and the equalization between the single battery cells and the battery packs can also be realized, and the time required by energy equalization and the cost of the equalization circuit are greatly reduced.

Description

Technical Field

[0001] This application relates to the field of high-voltage battery power technology, specifically to a battery management device and method for energy storage equalization control. Background Technology

[0002] To improve the supply voltage or power of the battery power supply, it is generally achieved by connecting multiple cells in series or parallel to form a battery pack. However, as the charge and discharge cycle progresses or the modules are inconsistent, the performance of any single cell in the battery pack will degrade, which will lead to a decrease in the capacity of the entire high-voltage battery power system. Therefore, it is necessary to perform energy storage balancing control on the high-voltage battery power system. Summary of the Invention

[0003] The main technical problem addressed in this application is how to optimize the energy storage balance control method of a high-voltage battery power system.

[0004] According to the first aspect, one embodiment provides a battery management device for energy storage balancing control, used for dynamic balancing control of the energy storage module of a high-voltage battery power system. The energy storage module of the high-voltage battery power system includes multiple battery packs connected in series, and each battery pack includes multiple individual cells connected in series. The battery management device includes a power monitoring unit, an electrical connection control unit, a charge / discharge control unit, and a bidirectional flyback converter; The power monitoring unit is used to monitor the electrical parameters of each battery pack, each individual cell, and the energy storage module in the energy storage module, so as to obtain the total power of each battery pack and the power of each individual cell; The electrical connection control unit is used to connect two battery packs in the energy storage module to the bidirectional flyback converter respectively, based on the group connection control command issued by the charge-discharge control unit; the electrical connection control unit is also used to connect two individual cells in the energy storage module to the bidirectional flyback converter respectively, based on the cell connection control command issued by the charge-discharge control unit; the electrical connection control unit is also used to connect one battery pack and one individual cell in the energy storage module to the bidirectional flyback converter respectively, based on the group-cell connection control command issued by the charge-discharge control unit. The bidirectional flyback converter is used to control the charging and discharging of two battery packs connected to the bidirectional flyback converter via the electrical connection control unit, based on inter-pack balancing control commands issued by the charge and discharge control unit, to achieve energy balance between battery packs; the bidirectional flyback converter is also used to control the charging and discharging of two individual cells connected to the bidirectional flyback converter via the electrical connection control unit, based on inter-cell balancing control commands issued by the charge and discharge control unit, to achieve energy balance between individual cells; and the bidirectional flyback converter is also used to control the charging and discharging of one battery pack and one individual cell connected to the bidirectional flyback converter via the electrical connection control unit, based on inter-pack balancing control commands issued by the charge and discharge control unit, to achieve energy balance between individual cells and battery packs. The charging and discharging control unit is used to send the group connection control command, cell connection control command / or group-cell connection control command to the electrical connection control unit based on a preset energy storage balance control rule and according to the total power of each battery pack and the power of each individual cell monitored and obtained by the power monitoring unit, and to send the inter-group balance control command, the inter-cell balance control command or the cell-group balance control command to the bidirectional flyback converter. The energy storage balance control rules include: The difference in charge between the battery packs is evaluated based on the difference in electrical parameters between each battery pack and the energy storage module, so as to output the inter-pack balancing control command and the pack connection control command. The difference in charge capacity of each individual cell within the same battery pack is evaluated based on the difference in electrical parameters, so as to output the cell pack equalization control command and the cell pack connection control command. The difference in charge capacity of each individual cell is evaluated based on the differences in electrical parameters of each individual cell in different battery packs, so as to output the inter-cell equalization control command and the cell connection control command; The differences in electrical parameters between different battery packs and the differences in electrical parameters of each individual cell are evaluated to assess the differences in charge capacity between different battery packs and each individual cell, so as to output the cell pack equalization control command and the cell pack connection control command.

[0005] In one embodiment, the electrical parameters of the battery pack include the battery pack SOC value, the electrical parameters of the individual battery cell include the cell SOC value, and the electrical parameters of the energy storage module include the power supply SOC value.

[0006] In one embodiment, the step of assessing the power difference between the battery packs based on the differences in electrical parameters between each battery pack and the energy storage module, and outputting the inter-pack balancing control command and the pack connection control command, includes: When the difference between the SOC value of the battery pack and the SOC value of the energy storage module is greater than a preset value, the battery pack with the largest SOC value difference is transferred to the battery pack with the smallest SOC value difference for energy balancing according to the inter-group balancing control command and the group connection control command.

[0007] In one embodiment, the step of assessing the charge difference of individual cells based on the differences in electrical parameters of each individual cell within the same battery pack, and outputting the inter-cell equalization control command and the cell connection control command, includes: When the difference between the SOC value of a single cell in the same battery pack and the SOC value of the battery pack is greater than a preset threshold, the single cell with the largest SOC value difference in the same battery pack is transferred to the single cell with the smallest SOC value difference for energy equalization according to the cell pack equalization control command and the cell pack connection control command.

[0008] In one embodiment, the step of assessing the capacity differences of different battery packs and individual cells based on the differences in electrical parameters between different battery packs and the differences in electrical parameters of each individual cell, in order to output the cell pack equalization control command and the cell pack connection control command, includes: When the difference between the SOC value of the battery pack and the SOC value of the power supply of the energy storage module is greater than the preset value, and the difference between the SOC value of the individual cell in each battery pack and the SOC value of the battery pack to which it belongs is greater than the preset threshold, according to the cell pack equalization control command and the cell pack connection control command, the individual cell with the largest difference between the cell SOC value and the battery pack SOC value is moved to the battery pack with the smallest difference between the battery pack SOC value and the power supply SOC value for energy equalization.

[0009] In one embodiment, the step of assessing the charge difference of each individual cell based on the differences in electrical parameters of each individual cell in different battery packs, in order to output the inter-cell equalization control command and the cell connection control command, includes: When the difference between the SOC value of the battery packs of different battery packs and the SOC value of the power supply of the energy storage module is greater than the preset value, and the difference between the SOC value of the individual cell in each battery pack and the SOC value of the battery pack to which it belongs is greater than the preset threshold, according to the inter-cell equalization control command and the cell connection control command, the individual cell with the largest difference between the SOC value of the cell in the battery pack with the largest capacity and the SOC value of the battery pack is moved to the individual cell with the smallest difference between the SOC value of the cell in the battery pack with the smallest capacity and the SOC value of the battery pack.

[0010] In one embodiment, the energy storage balancing control rules further include: The priority of the energy storage balance control is, in order, the energy balance between battery packs, the balance of individual cells between different battery packs, and the balance of different individual cells within the same battery pack.

[0011] In one embodiment, the bidirectional flyback converter includes a transformer, the transformer including a group winding the same number as the battery pack of the energy storage module, a core winding the same number as the individual battery cells, and a system winding; The system windings are connected to the positive and negative output terminals of the energy storage module; Each of the said windings is connected to the positive and negative connection terminals of one of the battery packs; Each of the core windings is connected to the positive and negative terminals of one of the individual battery cells; The bidirectional flyback converter achieves energy balance between individual cells, between battery packs, and between individual cells and battery packs through a bidirectional flyback circuit.

[0012] In one embodiment, the electrical connection control unit is used to control an electronic switching circuit to achieve electrical connection or disconnection between the system windings, between the system windings and the battery pack, and between the core winding and the individual battery cell.

[0013] According to a second aspect, one embodiment provides a battery management method for energy storage balancing control, characterized in that it is applied to a battery management device as described in the first aspect, the battery management method comprising: Monitor the electrical parameters of each battery pack, each individual cell, and the energy storage module in the energy storage module to obtain the total capacity of each battery pack and the capacity of each individual cell; Based on a preset energy storage balance control rule, according to the total power of each battery pack and the power of each individual cell monitored and obtained by the power monitoring unit, the group connection control command, cell connection control command / or group-cell connection control command is sent to the electrical connection control unit, and the inter-group balance control command, the inter-cell balance control command or the cell-group balance control command is sent to the bidirectional flyback converter. Based on the group connection control command issued by the charge / discharge control unit, the two battery packs in the energy storage module are respectively connected to the bidirectional flyback converter; the electrical connection control unit is also used to connect two individual cells in the energy storage module to the bidirectional flyback converter respectively based on the cell connection control command issued by the charge / discharge control unit; the electrical connection control unit is also used to connect one battery pack and one individual cell in the energy storage module to the bidirectional flyback converter respectively based on the group-cell connection control command issued by the charge / discharge control unit. Based on the inter-group balancing control command issued by the charge / discharge control unit, the charging and discharging of two battery packs connected to the bidirectional flyback converter via the electrical connection control unit can be controlled to achieve energy balance between battery packs; the bidirectional flyback converter is used to control the charging and discharging of two individual cells connected to the bidirectional flyback converter via the electrical connection control unit based on the cell balancing control command issued by the charge / discharge control unit, to achieve energy balance between individual cells; the bidirectional flyback converter is also used to control the charging and discharging of one battery pack and one individual cell connected to the bidirectional flyback converter via the electrical connection control unit based on the cell-group balancing control command issued by the charge / discharge control unit, to achieve energy balance between individual cells and battery packs.

[0014] According to the battery management device of the above embodiment, a single circuit can simultaneously balance the battery pack, individual cells and energy storage module. It can not only balance between battery packs, but also balance between cells in different packs or within the same pack, as well as balance between individual cells and battery packs, which greatly reduces the time required for energy balancing and the cost of the balancing circuit itself. Attached Figure Description

[0015] Figure 1 This is a functional block diagram of a battery management device in one embodiment; Figure 2 This is a schematic diagram of the electrical connections of a transformer in one embodiment; Figure 3 This is a flowchart illustrating a battery management method in one embodiment; Figure 4 This is a schematic diagram of the electrical connection for energy balance between battery packs in one embodiment; Figure 5 This is a schematic diagram of the electrical connection for energy balance between a single battery cell and the battery pack in one embodiment; Figure 6 This is a schematic diagram of the energy storage balance control process in one embodiment. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0017] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0018] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0019] For high-voltage battery systems, solving the energy balancing problem requires addressing both the inconsistency in charge levels between modules and the inconsistency in charge levels of individual cells within a module. Current technologies can only balance cells and modules separately, meaning they can only balance individual modules or cells. Furthermore, they cannot transfer cell energy to other modules; the energy can only be transferred from the cell to the module itself, or from the module to other modules or the entire system. This results in complex circuit designs, long balancing times, high costs, and large space requirements.

[0020] In this embodiment, a method is designed to simultaneously achieve cell balancing between battery packs and between individual cells within a battery pack. This addresses the problem in existing high-voltage battery systems where two circuits are required to achieve cell balancing across the entire system. First, cell balancing and battery pack balancing are achieved using a selector switch. Then, energy transfer is performed via a bidirectional flyback transformer. Next, cell balancing and high-voltage system energy storage module balancing also utilizes a bidirectional flyback transformer. Finally, the transformers for individual cells and battery packs are integrated with those for the battery pack and energy storage module. This enables cell balancing across modules, reducing and saving transformers, and significantly lowering the cost and heat generation of the balancing circuit itself. Example

[0021] Please refer to Figure 1This is a functional block diagram of a battery management device in one embodiment. The battery management device is used to perform dynamic balancing control on the energy storage module 1 of the high-voltage battery power system. The energy storage module 1 of the high-voltage battery power system includes multiple battery packs 10 connected in series, and each battery pack 10 includes multiple individual battery cells 11 connected in series. The battery management device includes a power monitoring unit 2, an electrical connection control unit 3, a charge / discharge control unit 4, and a bidirectional flyback converter 5. The power monitoring unit 2 is used to monitor the electrical parameters of each battery pack 10, each individual battery cell 11, and the energy storage module 1 to obtain the total capacity of each battery pack 10 and the capacity of each individual battery cell 11. The electrical connection control unit 3 is used to connect two battery packs 10 in the energy storage module to the bidirectional flyback converter 5 respectively, based on the group connection control command issued by the charge / discharge control unit 4. The electrical connection control unit 3 is also used to connect two individual cells 11 in the energy storage module 1 to the bidirectional flyback converter 5 respectively, based on the cell connection control command issued by the charge / discharge control unit 4. The electrical connection control unit 3 is also used to connect a battery pack 10 and one individual cell 11 in the energy storage module 1 to the bidirectional flyback converter 5 respectively, based on the group connection control command issued by the charge / discharge control unit 4. The bidirectional flyback converter 5 is used to control the charging and discharging of the two battery packs 10 connected to the bidirectional flyback converter 5 via the electrical connection control unit 3, based on the inter-pack balancing control command issued by the charge / discharge control unit 4, to achieve energy balance between battery packs. The bidirectional flyback converter 5 is also used to control the charging and discharging of the two individual cells 11 connected to the bidirectional flyback converter 5 via the electrical connection control unit 3, based on the inter-cell balancing control command issued by the charge / discharge control unit 4, to achieve energy balance between individual cells. The bidirectional flyback converter 5 is used to control the charging and discharging of a battery pack 10 and a single cell 11 connected to the bidirectional flyback converter 5 via the electrical connection control unit 3, based on the inter-cell equalization control command issued by the charge / discharge control unit 4, to achieve energy balance between the single cell and the battery pack. The charge / discharge control unit 4, based on a preset energy storage equalization control rule and according to the total charge of each battery pack 10 and the charge of each single cell 11 obtained by the power monitoring unit 2, sends a pack connection control command, a cell connection control command, and / or a pack-cell connection control command to the electrical connection control unit 3, and sends an inter-pack equalization control command, an inter-cell equalization control command, or an inter-cell equalization control command to the bidirectional flyback converter 5. In one embodiment, the electrical parameters of the battery pack include the battery pack SOC value, the electrical parameters of the single cell include the cell SOC value, and the electrical parameters of the energy storage module include the power SOC value.

[0022] In one embodiment, the energy storage balance control rules include: 1. Evaluate the power differences between battery packs based on the differences in electrical parameters between each battery pack and energy storage module, and output inter-pack balancing control commands and pack connection control commands.

[0023] When the difference between the SOC value of the battery pack and the SOC value of the energy storage module is greater than a preset value, the battery pack with the largest SOC value difference is transferred to the battery pack with the smallest SOC value difference for energy balancing according to the inter-group balancing control command and the group connection control command.

[0024] 2. Evaluate the difference in charge of individual cells based on the differences in electrical parameters of each cell in the same battery pack, and output cell pack equalization control commands and cell pack connection control commands.

[0025] When the difference between the SOC value of a single cell in the same battery pack and the SOC value of the battery pack is greater than a preset threshold, the cell with the largest SOC value difference in the same battery pack will be used for energy balancing to the cell with the smallest SOC value difference, according to the cell pack balancing control command and the cell pack connection control command.

[0026] 3. Evaluate the difference in charge of each individual cell based on the differences in electrical parameters of each cell in different battery packs, and output cell equalization control commands and cell connection control commands.

[0027] When the difference between the SOC value of the battery pack and the SOC value of the energy storage module is greater than a preset value, and the difference between the SOC value of a single cell in each battery pack and the SOC value of the battery pack is greater than a preset threshold, the single cell with the largest difference between its SOC value and the SOC value of the battery pack is moved to the battery pack with the smallest difference between its SOC value and the SOC value of the power supply, according to the cell pack balancing control command and the cell pack connection control command.

[0028] 4. Evaluate the differences in electrical parameters between different battery packs and the differences in electrical parameters of each individual cell to assess the differences in charge capacity between different battery packs and each individual cell, and output cell pack equalization control commands and cell pack connection control commands.

[0029] When the difference between the SOC value of different battery packs and the SOC value of the energy storage module is greater than a preset value, and the difference between the SOC value of a single cell in each battery pack and the SOC value of the battery pack it belongs to is greater than a preset threshold, according to the cell balancing control command and the cell connection control command, the single cell with the largest difference between the SOC value of the cell and the SOC value of the battery pack in the battery pack with the largest capacity is moved to the single cell with the smallest difference between the SOC value of the cell and the SOC value of the battery pack in the battery pack with the smallest capacity for energy balancing.

[0030] 5. The priority of energy storage balance control is as follows: energy balance between battery packs, balance of individual cells between different battery packs, and balance of different individual cells within the same battery pack.

[0031] Please refer to Figure 2 This is a schematic diagram of the electrical connection of the transformer in one embodiment. In one embodiment, the bidirectional flyback converter 5 includes a transformer, which includes a set winding the same number as the battery packs 10 of the energy storage module 1, a core winding the same number as the individual battery cells 11, and a system winding. The system windings are connected to the positive and negative output terminals of the energy storage module 1. Each set winding is connected to the positive and negative connection terminals of a battery pack, and each core winding is connected to the positive and negative terminals of an individual battery cell. The bidirectional flyback converter 5 achieves energy balance between individual battery cells, between battery packs, and between individual battery cells and battery packs through a bidirectional flyback circuit. In one embodiment, the electrical connection control unit 3 is used to control the electronic switching circuit to achieve electrical connection or disconnection between system windings and system windings, between set windings and battery packs, and between core windings and individual battery cells.

[0032] Please refer to Figure 3 This is a flowchart illustrating a battery management method in one embodiment. The battery management method is used for energy storage balance control and is applied to the battery management device described above. The battery management method includes: Step 101: Monitor electrical parameters.

[0033] Monitor the electrical parameters of each battery pack, each individual cell, and the energy storage module to obtain the total capacity of each battery pack and the capacity of each individual cell.

[0034] Step 102: Output control commands.

[0035] Based on the energy storage balancing control rules described above, and according to the total capacity of each battery pack and the capacity of each individual cell monitored by the power monitoring unit, the system sends a group connection control command, a cell connection control command, or a group-cell connection control command to the electrical connection control unit, and sends an inter-group balancing control command, an inter-cell balancing control command, or a cell-group balancing control command to the bidirectional flyback converter.

[0036] Step 103: Execute the connection command.

[0037] Based on the group connection control command issued by the charge / discharge control unit, the two battery packs in the energy storage module are respectively connected to the bidirectional flyback converter. The electrical connection control unit is also used to connect two individual cells in the energy storage module to the bidirectional flyback converter, based on the cell connection control command issued by the charge / discharge control unit. Furthermore, the electrical connection control unit is used to connect one battery pack and one individual cell in the energy storage module to the bidirectional flyback converter, based on the group-cell connection control command issued by the charge / discharge control unit.

[0038] Step 104: Execute the equalization command.

[0039] Based on inter-pack balancing control commands issued by the charge / discharge control unit, the charging and discharging of two battery packs connected to the bidirectional flyback converter via the electrical connection control unit can be controlled to achieve energy balance between the battery packs. The bidirectional flyback converter, based on inter-cell balancing control commands issued by the charge / discharge control unit, can control the charging and discharging of two individual cells connected to the bidirectional flyback converter via the electrical connection control unit to achieve energy balance between the individual cells. The bidirectional flyback converter, based on inter-pack balancing control commands issued by the charge / discharge control unit, can control the charging and discharging of one battery pack and one individual cell connected to the bidirectional flyback converter via the electrical connection control unit to achieve energy balance between the individual cell and the battery pack.

[0040] To facilitate understanding of the application of the battery management method disclosed in this application, specific embodiments are described below, including: like Figure 2 As shown, a single battery pack in energy storage module 1 has multiple individual cells connected in series, and the entire energy storage module 1 has multiple battery packs connected in series. The winding Tn+1 connected to the bidirectional flyback converter, the windings T1-Tn of a single battery pack, and the windings W1-Wm of a single cell are all wound on the same transformer. The cell selection switch group P1-Pm+1 is connected to the positive and negative terminals of the individual cell. The number of switch groups is the number of cells + 1. The cell selection switch is connected to the battery positive / negative switching switches M1-M4 (odd / even) to switch the positive and negative terminals of the individual cell. There are 4 sets of switches for cell positive / negative switching. The positive / negative switching switches are connected to the flyback winding and flyback MOSFET of the individual cell, and each battery pack has this circuit. The selection switch can be used to select any single cell within a single battery pack, and is used to select the cell that needs to be balanced. The battery positive / negative switching switch is used to switch the positive and negative terminals of the cell connected to the flyback winding. The starting points of the high-voltage system windings and individual cell windings are connected to a control switch, as are the ending points of the battery pack windings. The high-voltage system and battery pack are bidirectional flyback circuits, as are the individual cells and the battery pack itself, and also bidirectional flyback circuits with other battery packs. The battery pack uses PWM control via switch group Q1-Qn to achieve bidirectional energy flow through the transformer. The high-voltage system uses PWM control via switch group Qn+1 to achieve bidirectional energy flow through the transformer. Individual cells use PWM control via switch V1 to achieve bidirectional energy flow through the transformer. Adjacent battery packs can be connected in series via switch group Q-Qn-1, allowing two or more battery modules to flow bidirectionally through the transformer.

[0041] Please refer to Figure 4This is a schematic diagram of the electrical connection for energy balance between battery packs in one embodiment. In one embodiment, the power monitoring unit measures the capacity difference between different battery packs and the capacity difference between individual cells within the battery pack through an AFE front-end chip or a fuel gauge. When there is a capacity difference between two different battery packs, for example, the capacity of battery pack 1 differs from that of battery pack 2 and module 3, a capacity calculation and sorting will be performed. The sorting will be based on the difference between the SOC of the high-voltage system and the SOC of the individual battery packs. If the SOC of battery pack 1 is 50%, the SOC of battery pack 2 is 49%, the SOC of battery pack 3 is 54%, and the SOC of the high-voltage system is 51%, then the difference in SOC is -1% for battery pack 1, -2% for battery pack 2, and 3% for battery pack 3. The maximum difference is selected for battery pack 3, since battery pack 3 has a positive deviation. The balancing direction is from the battery pack to the high-voltage system, that is, T3 is the primary side, Tn+1 is the secondary side, the Q3 switch group is closed, and the module supplies energy to the magnetic core through the winding T3. When the Q3 switch group is open, the magnetic core energy is transferred to the high-voltage system through the Tn+1 winding and the Qn+1 switch group.

[0042] Please refer to Figure 5 This is a schematic diagram of the electrical connection for energy balancing between individual cells and the battery pack in one embodiment. When there are differences in capacity between individual cells within a single battery pack, they are sorted according to the difference. For example, if the SOC value of individual cell 1 is 20%, the SOC value of individual cell 2 is 21%, the SOC value of individual cell 3 is 25%, and the SOC value of battery module 1 is 22%, then the difference in SOC value between individual cell 1 and individual cell 2 is -2%, between individual cell 2 and individual cell 3 is 3%, and the largest difference value is selected for individual cell 3. Individual cell 3 has a positive deviation, and the balancing direction is from individual cell to battery pack. That is, the switch group P3, P4, M1, M2 is closed, individual cell 3 is selected, winding W1 is used as the primary side, T1 is used as the secondary side, the V1 switch group is closed, and the individual cell stores energy for the magnetic core through winding W1. When the V1 switch group is open, the energy of the magnetic core is transferred to battery pack 1 through winding T1 and switch group Q1.

[0043] When there are capacity differences between different battery packs, and between individual cells within multiple battery packs, for example, if battery pack 1 has a SOC of 28%, battery pack 2 has a SOC of 29%, battery pack 3 has a SOC of 35%, battery pack 4 has a SOC of 36%, and the high-voltage system has a SOC of 32%, then the difference in SOC values ​​is -4% for battery pack 1, -3% for battery pack 2, 3% for battery pack 3, and 4% for battery pack 4. Since two battery packs have the same absolute value, they are prioritized for equalization based on discharge. Also, since battery pack 3 and battery pack 4 are adjacent, they can be equalized simultaneously.

[0044] In battery pack 1, the SOC value of cell 1 is 25%, cell 2 is 27%, and cell 3 is 30%. In battery pack 2, the SOC value of cell 1 is 28%, cell 2 is 29%, and cell 3 is 30%. Cell 1 in battery pack 1 has the lowest SOC value. Battery pack 3 and battery pack 4 are used to balance the SOC value of cell 1 in battery pack 1. That is, switch group Q3 is closed to connect battery pack 3 and battery pack 4 in series. Switch groups P1, P2, M1, and M2 are closed to select cell 1 in battery pack 1. Switch group Q4 is closed, and the energy of battery pack 3 and battery pack 4 is transferred to the magnetic core for energy storage through T3 and T4. Switch group Q4 is opened, and the energy of the magnetic core is transferred to cell 1 in battery pack 1 through switch groups W1 and V1.

[0045] Please refer to Figure 6 The diagram below illustrates the process of energy storage balance control in one embodiment. The priority of energy storage balance control is, in order, energy balance between battery packs, balance of individual cells between different battery packs, and balance of different individual cells within the same battery pack. The decision to enable energy storage balance control is based on the obtained SOC values ​​of the battery pack, individual cells, and power supply.

[0046] First, battery pack balancing is performed. The difference between the SOC value of the battery pack and the SOC value of the power supply is taken. The battery pack with the largest difference is marked as needing to be discharged and balanced, and the battery pack with the smallest difference is marked as needing to be charged and balanced. It is then determined whether the battery packs to be charged or discharged are adjacent. If they are connected in parallel, they are charged or discharged together.

[0047] Next is the individual cell balancing. The SOC value of an individual cell is taken as the difference between the SOC value of the battery pack and the SOC value of the power supply. The individual cell with the largest difference is marked as needing to be balanced by discharge, and the individual cell with the smallest difference is marked as needing to be balanced by charge. It is determined whether the marked individual cell and the battery pack are in a one-to-one discharge and one-to-charge relationship. If so, energy balancing between the individual cell and the battery pack is performed. Otherwise, the battery pack is discharged to charge the entire energy storage module. If both charging and discharging are marked as individual cells, then energy balancing between individual cells is performed.

[0048] The battery management device disclosed in this application includes a power monitoring unit, an electrical connection control unit, a charge / discharge control unit, and a bidirectional flyback converter. The power monitoring unit monitors the electrical parameters of the energy storage module. The charge / discharge control unit, based on energy storage balancing control rules, sends connection control commands and balancing control commands according to the monitored power information. The electrical connection control unit responds to the connection control commands by connecting the battery packs or individual cells requiring balancing to the bidirectional flyback converter. The bidirectional flyback converter performs charge / discharge control on the battery packs and individual cells requiring balancing based on the balancing control commands. Because a single circuit simultaneously balances the battery packs, individual cells, and the energy storage module, it not only achieves balancing between battery packs but also between cells in different packs or within the same pack, as well as between individual cells and battery packs, significantly reducing the time required for energy balancing and the cost of the balancing circuit itself.

[0049] Those skilled in the art will understand that all or part of the functions of the various methods in the above embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, which may include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to achieve the above functions. For example, the program can be stored in the memory of a device, and when the program in the memory is executed by the processor, all or part of the above functions can be achieved. In addition, when all or part of the functions in the above embodiments are implemented by computer programs, the program can also be stored in a server, another computer, disk, optical disk, flash drive, or external hard drive, etc., and can be downloaded or copied to the memory of a local device, or the system of the local device can be updated. When the program in the memory is executed by the processor, all or part of the functions in the above embodiments can be achieved.

[0050] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A battery management device for energy storage equalization control, characterized by, A dynamic equalization control method for energy storage modules of a high-voltage battery power system The energy storage module of the high-voltage battery power system comprises a plurality of battery packs connected in series, and each battery pack comprises a plurality of single cells connected in series The battery management device comprises a power supply monitoring unit, an electrical connection control unit, a charge-discharge control unit and a bidirectional flyback converter The power supply monitoring unit is configured to monitor the electrical parameters of each battery pack, each single cell and the energy storage module to obtain the total electrical quantity of each battery pack and the electrical quantity of each single cell The electrical connection control unit is configured to connect two battery packs in the energy storage module to the bidirectional flyback converter based on the group connection control instruction issued by the charge-discharge control unit, and to connect two single cells in the energy storage module to the bidirectional flyback converter based on the cell connection control instruction issued by the charge-discharge control unit, and to connect one battery pack and one single cell in the energy storage module to the bidirectional flyback converter based on the group-cell connection control instruction issued by the charge-discharge control unit The bidirectional flyback converter is configured to control the charge-discharge between two battery packs connected to the bidirectional flyback converter by the electrical connection control unit based on the inter-group equalization control instruction issued by the charge-discharge control unit to achieve the energy equalization between battery packs, and to control the charge-discharge between two single cells connected to the bidirectional flyback converter by the electrical connection control unit based on the inter-cell equalization control instruction issued by the charge-discharge control unit to achieve the energy equalization between single cells, and to control the charge-discharge between one battery pack and one single cell connected to the bidirectional flyback converter by the electrical connection control unit based on the group-cell equalization control instruction issued by the charge-discharge control unit to achieve the energy equalization between single cells and battery packs The charge-discharge control unit is configured to send the group connection control instruction, the cell connection control instruction or the group-cell connection control instruction to the electrical connection control unit and send the inter-group equalization control instruction, the inter-cell equalization control instruction or the group-cell equalization control instruction to the bidirectional flyback converter based on a preset energy storage equalization control control rule and the total electrical quantity of each battery pack and the electrical quantity of each single cell obtained by the power supply monitoring unit The energy storage equalization control control rule comprises: evaluating the electrical quantity difference between battery packs based on the difference in electrical parameters of each battery pack and the energy storage module to output the inter-group equalization control instruction and the group connection control instruction; evaluating the electrical quantity difference of single cells in the same battery pack based on the difference in electrical parameters of each single cell in the same battery pack to output the group-cell equalization control instruction and the group-cell connection control instruction; The power difference of each single battery cell is evaluated according to the difference of the electrical parameters of each single battery cell in different battery groups, so as to output the inter-cell equalization control instruction and the cell connection control instruction. The power difference of each single battery cell is evaluated according to the difference of the electrical parameters of each single battery cell in different battery groups, so as to output the inter-cell equalization control instruction and the cell connection control instruction.

2. The battery management device of claim 1, wherein, The electrical parameters of the battery groups include battery group SOC values, the electrical parameters of the single battery cells include cell SOC values, and the electrical parameters of the energy storage module include power source SOC values.

3. The battery management device of claim 2, wherein, The power difference of each single battery cell is evaluated according to the difference of the electrical parameters of each single battery cell in different battery groups, so as to output the inter-cell equalization control instruction and the cell connection control instruction. When the difference between the battery group SOC value of the battery group and the power source SOC value of the energy storage module is greater than a preset value, the SOC value difference is the largest, and the SOC value difference is the smallest, the inter-group equalization control instruction and the group connection control instruction are used to perform energy equalization from the battery group with the largest SOC value difference to the battery group with the smallest SOC value difference.

4. The battery management device of claim 3, wherein, The power difference of each single battery cell is evaluated according to the difference of the electrical parameters of each single battery cell in different battery groups, so as to output the inter-cell equalization control instruction and the cell connection control instruction. When the difference between the battery group SOC value of the battery group and the power source SOC value of the energy storage module is greater than a preset value, the SOC value difference is the largest, and the SOC value difference is the smallest, the inter-group equalization control instruction and the group connection control instruction are used to perform energy equalization from the battery group with the largest SOC value difference to the battery group with the smallest SOC value difference.

5. The battery management apparatus of claim 4, wherein The power difference of each single battery cell is evaluated according to the difference of the electrical parameters of each single battery cell in different battery groups, so as to output the inter-cell equalization control instruction and the cell connection control instruction. When the difference between the battery group SOC value of the battery group and the power source SOC value of the energy storage module is greater than a preset value, the SOC value difference is the largest, and the SOC value difference is the smallest, the inter-group equalization control instruction and the group connection control instruction are used to perform energy equalization from the battery group with the largest SOC value difference to the battery group with the smallest SOC value difference.

6. The battery management apparatus of claim 4, wherein The power difference of each single battery cell is evaluated according to the difference of the electrical parameters of each single battery cell in different battery groups, so as to output the inter-cell equalization control instruction and the cell connection control instruction. When the difference between the battery pack SOC value of different battery packs and the power source SOC value of the energy storage module is greater than the preset value, and the difference between the cell SOC value of the single battery cell in each battery pack and the battery pack SOC value of the battery pack is greater than the preset threshold value, the cell SOC value and the battery pack SOC value of the single battery cell with the largest difference in the battery pack with the largest amount of electricity are balanced to the single battery cell with the smallest difference in the cell SOC value and the battery pack SOC value in the battery pack with the smallest amount of electricity according to the inter-cell equalization control instruction and the core connection control instruction.

7. The battery management apparatus of claim 1, wherein The energy storage equalization control control rule further comprises: The priority of the energy storage equalization control is the energy equalization between battery packs, the equalization of single battery cells between different battery packs, and the equalization of different single battery cells in the same battery pack.

8. The battery management apparatus of claim 2, wherein, The bidirectional flyback converter comprises a transformer, the transformer comprises a group winding same as the number of battery packs of the energy storage module, a core winding same as the number of single battery cells, and a system winding; The system winding is connected with the positive output end and the negative output end of the energy storage module; Each group winding is connected with the positive connection end and the negative connection end of one battery pack; Each core winding is connected with the positive electrode and the negative electrode of one single battery cell; The bidirectional flyback converter realizes the energy equalization between single battery cells, between battery packs, and between single battery cells and battery packs through a bidirectional flyback circuit.

9. The battery management apparatus of claim 8, wherein, The electric connection control unit is used to realize the electric connection or disconnection of the system winding with the system winding, the group winding with the battery pack, and the core winding with the single battery cell through an electronic switch circuit.

10. A battery management method for energy storage equalization control, characterized in that, The battery management method comprises: Monitoring the electric parameters of each battery pack, each single battery cell, and the energy storage module in the energy storage module to obtain the total electric quantity of each battery pack and the electric quantity of each single battery cell; Based on a preset energy storage equalization control control rule, the total electric quantity of each battery pack and the electric quantity of each single battery cell obtained by the power source monitoring unit are sent to the electric connection control unit to send the group connection control instruction, the core connection control instruction, or the group-core connection control instruction to the bidirectional flyback converter to send the inter-group equalization control instruction, the inter-core equalization control instruction, or the inter-core-group equalization control instruction; Based on the group connection control instruction, the core connection control instruction, or the group-core connection control instruction, two battery packs, two single battery cells, or one battery pack and one single battery cell in the energy storage module are connected to the bidirectional flyback converter respectively; Based on the inter-group equalization control instruction, the inter-core equalization control instruction, or the inter-core-group equalization control instruction, the charging and discharging between two battery packs, two single battery cells, or one battery pack and one single battery cell connected to the bidirectional flyback converter through the electric connection control unit are controllable to realize the energy equalization between battery packs, between single battery cells, or between single battery cells and battery packs.

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