Battery management system for power battery, power battery system and vehicle
By using an integrated flexible circuit board to integrate the cell management controller in the power battery system, the problems of complex wiring and electromagnetic interference are solved, resulting in space saving, cost reduction, and improved connection stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-17
- Publication Date
- 2026-03-27
AI Technical Summary
Existing power battery systems suffer from complex wiring, severe electromagnetic interference, and increased weight and space requirements due to wiring harnesses, resulting in high production costs.
The battery management controller is integrated into a flexible circuit board, and the battery management controller and data acquisition device are directly connected through a flexible wire harness. This eliminates the need for printed circuit boards and complex wire harnesses, simplifying the structure and reducing weight.
It simplifies the configuration of the power battery system, saves space and cost, reduces electromagnetic interference, and improves connection stability.
Smart Images
Figure CN224053182U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to a battery management system for a power battery, and to a power battery system comprising the battery management system and a vehicle comprising the power battery system. BACKGROUND
[0002] Generally, a power battery system of an electric vehicle can comprise a power battery, usually referred to as a battery pack, and a battery management system for the power battery. The power battery can be composed of a large number of battery cells arranged into a plurality of cell modules, and the battery cells in each cell module are connected in series and / or in parallel. The battery management system can comprise a battery management controller (BMS) disposed outside the power battery and a data acquisition device disposed inside the power battery, the data acquisition device comprising a cell management controller (CMS) for each cell module. The sampling chip of each cell management controller is usually electrically connected to the tab of each battery cell in the cell module through a wire harness. However, due to the large number of battery cells in the cell module, the wiring environment inside the power battery is complex, which is not conducive to the production and assembly of the power battery, and there are potential electromagnetic interference problems. More acquisition wire harnesses also increase the weight of the power battery, which is not conducive to cost reduction. In addition, the data acquisition device disposed inside the power battery and the battery management controller disposed outside the power battery usually use a printed circuit board for data collection and forwarding, and the printed circuit board is connected to each cell management controller of the data acquisition device and the battery management controller through a wire harness, thereby occupying a large space outside the power battery and the wiring is quite complicated. SUMMARY
[0003] The purpose of the present application is to simplify the power battery system, specifically to simplify the battery management system thereof.
[0004] This object is achieved by the battery management system for a power battery of the present application. In the battery management system for a power battery of the present application, the power battery comprises a plurality of cell modules, each cell module comprising a plurality of battery cells, each battery cell having two tabs of opposite polarity. The battery management system comprises a data acquisition device disposed inside the power battery, comprising a common flexible circuit board and cell management controllers integrated in the common flexible circuit board, each cell management controller corresponding to one or more cell modules of the plurality of cell modules and comprising a sampling channel, wherein the common flexible circuit board is an elongated strip that is bendably extended across the respective cell modules of the plurality of cell modules, and the sampling channel is electrically and mechanically connected to the tab of the respective battery cell or a busbar electrically connected to the tab by means of plug-in or fastener connection.
[0005] In one embodiment, the number of the cell management controllers is equal to the number of the cell modules, and each of the cell management controllers corresponds to one of the cell modules.
[0006] In one embodiment, the elongated strip-shaped body comprises: main sections for being fixed to and integrating the cell management controllers corresponding to the cell modules, and connecting sections connecting adjacent main sections and bridging between adjacent cell modules.
[0007] In one embodiment, the common flexible circuit board further comprises branch sections extending transversely from each of the main sections and integrating the sampling channels.
[0008] In one embodiment, the sampling channels are conductive traces integrated in the branch sections.
[0009] In one embodiment, the battery management system further comprises a battery management controller disposed independently of the power battery, the battery management controller being directly connected with the data acquisition device through a flexible wire harness.
[0010] In one embodiment, each of the cell management controllers further comprises a sampling chip, the sampling channels of the cell management controller being electrically connected with the sampling chip, the sampling chip comprising:
[0011] a voltage sampling chip and a current sampling chip, the sampling channels comprising voltage sampling channels and current sampling channels, respectively, the voltage sampling channels and the current sampling channels being configured to be electrically connected to the tabs of the corresponding cell or the bus bars electrically connected thereto; and
[0012] a temperature sampling chip, the sampling channels comprising temperature sampling channels, the temperature sampling channels being configured to be electrically connected to temperature sensors attached to or electrically connected to the bus bars of the tabs of the corresponding cell.
[0013] In one embodiment, each of the cell management controllers further comprises at least one circuit module, the at least one circuit module comprising: an overvoltage / undervoltage protection circuit; an equalization module; an EMC filtering module; a communication module; a high / low voltage isolation module; a power supply module.
[0014] In one embodiment, the sampling chip and the at least one circuit module of the cell management controller are integrated on the common flexible circuit board by surface mounting technology.
[0015] In one embodiment, the cell management controllers are electrically connected in series with each other.
[0016] The application also relates to a power battery system, comprising: a power battery comprising at least one cell module, each cell module comprising a plurality of cells, each cell having two tabs of opposite polarity, and adjacent tabs of adjacent cells being electrically connected by a busbar; and the above-mentioned battery management system for the power battery, wherein the sampling channel of each cell management controller is electrically connected to the tab of the cell or the busbar electrically connected to the tab.
[0017] The application also relates to a vehicle comprising the above-mentioned power battery system.
[0018] The battery management system for the power battery of the application generally comprises a battery management controller (BMS) arranged outside the power battery, and a one-piece data acquisition device arranged inside the power battery and comprising a cell management controller (CMS) for each cell module of the power battery, the input port of the battery management controller outside the power battery and the output port of the data acquisition device inside the power battery being directly connected by a flexible wire harness. This arrangement no longer requires an additional printed circuit board for data transfer between the cell management controller and the battery management controller or the data acquisition device, and thus no longer requires the connection wire harness between the printed circuit board and each cell management controller and the battery management controller, simplifying the configuration of the power battery management system, saving the occupied space, eliminating the need for the printed circuit board and the complicated wire harness associated therewith, and thus saving the cost associated therewith and all problems such as space arrangement, electromagnetic interference, etc. associated with these components.
[0019] Further, inside the power battery, all cell management controllers of the data acquisition device are integrated into a common flexible circuit board to form an integral piece extending across all cell modules of the power battery, the common flexible circuit board not only integrating the sampling chips and circuit modules of all cell management controllers for all cell modules, but also integrating the sampling channels for electrically connecting the sampling chips to the tabs of all cells in the cell module. Inside the power battery, a large number of complicated wire harnesses connecting the sampling chips and the tabs of the cells are no longer required, simplifying the structure and reducing the weight of the power battery. In addition, the flexible nature of the integral flexible circuit board makes its arrangement in each cell module and across different cell modules flexible, and can be applied to the case where the tabs of the cells extend in any direction. BRIEF DESCRIPTION OF DRAWINGS
[0020] Exemplary embodiments of the application will be described in detail below with reference to the accompanying drawings, it should be understood that the embodiments described below are only used to explain the application, and are not a limitation on the scope of the application, in the drawings:
[0021] Figure 1is a schematic simplified block diagram of a power battery system according to an embodiment of the present application;
[0022] Figure 2 is Figure 1 part of the power battery system of
[0023] Figure 3 is Figure 2 partly enlarged view, showing one of the cell modules and the corresponding cell management controller;
[0024] Figure 4a and 4b shows various different ways in which the sampling channels in the branch sections of the flexible circuit board of the data acquisition device are electrically connected to the busbars in the cell module that electrically connect adjacent cells. DETAILED DESCRIPTION
[0025] The exemplary embodiments of the present application will be described in detail below with reference to examples. However, it should be understood by those skilled in the art that the exemplary embodiments are not intended to limit the present application in any way. In addition, the features in the embodiments of the present application can be combined with each other without conflict, if possible. In the drawings, other constituent components are omitted for brevity, but this does not mean that the power battery system of the present application does not include other components.
[0026] Figure 1 shows a simplified block diagram of the configuration of a power battery system 100 for a vehicle according to an exemplary embodiment of the present application. The power battery system of the present application can be applied to a pure electric vehicle or a hybrid vehicle.
[0027] As shown in Figure 1 , generally, the power battery system 100 includes a power battery 10 and a battery management system 20. The power battery 10 can include at least one, usually a plurality of cell modules 15, as shown in Figure 1 In an exemplary embodiment of the present application, the power battery 10 includes six cell modules 15. The battery management system 20 can include a battery management controller (BMS) 30 disposed outside the power battery 10 and a data acquisition device 40 disposed inside the power battery 10, which in turn can include a cell management controller (CMS) 50 configured for each cell module 15 of the power battery 10, the cell management controllers 50 being electrically connected in series. The data acquisition device 40 and the battery management controller 30 have output ports 42 and input ports 32, respectively.
[0028] One aspect of this application is that the output port 42 of the data acquisition device 40 and the input port 32 of the battery management controller 30 are directly connected via a flexible wiring harness 60. Therefore, in this application, as... Figure 1 As shown, the battery management system 20 no longer requires an additional printed circuit board outside the power battery 10 for data transfer between the battery management controller 30 and the data acquisition device 40 (or with each cell management controller 50 of the data acquisition device 40). Therefore, it also eliminates the need for wiring harnesses connecting the printed circuit board to the data acquisition device 40 (or to each cell management controller 50) and to the battery management controller 30. This eliminates the need for printed circuit boards and their associated complex wiring harnesses, saving associated costs and all problems related to these components, such as layout and electromagnetic interference. It simplifies the configuration of the power battery management system 20 and the entire power battery system 100, and in particular saves space requirements outside the power battery.
[0029] Other aspects of the power battery system 100 will now be described in detail with reference to the accompanying drawings.
[0030] As mentioned above, in Figure 1 In an exemplary embodiment, the power battery 10 includes six cell modules 15. Each cell module 15 may include multiple cells (or "cells"), which are the smallest energy storage units of the power battery and have high energy density and may have any type or specification known in the art. Each cell includes two tabs with opposite polarities, typically arranged on opposite sides of the cell (e.g., ...). Figure 2 and 3 The cells within the cell module 15 can be arranged as needed, such as in series, parallel, or any combination thereof. Figure 2 and 3 In an exemplary embodiment, all the cells 12 in the cell module 15 are connected in series, and adjacent tabs (with opposite polarities) of two adjacent cells are electrically connected through a busbar 14. Specifically, as Figure 2 Adjacent cells 12a and 12b are arranged in opposite orientations such that their positive electrode tabs 12a1 and negative electrode tabs 12b1 are electrically connected via bus 14a; on the opposite, invisible side perpendicular to the paper direction, adjacent cells 12b and 12c are arranged in opposite orientations such that their negative electrode tabs and positive and negative electrode tabs are electrically connected via another bus; the positive electrode tab 12c1 of cell 12c is electrically connected to the positive electrode tab 12d1 of cell 12d, which is adjacent to cell 12b on the opposite side, via bus 14b. And so on. Figure 2It is also shown that adjacent cell modules 15a and 15b are connected in series via busbars 14d. It is understood by those skilled in the art that the present application is not limited to the details of the power battery shown in the figures and described herein. For example, by changing the orientation of the adjacent cells, series and parallel connection modes can be achieved between the cells in any cell module 15 and between different cell modules 15 of the power battery 10 to achieve the desired total output power of the power battery 10.
[0031] As previously mentioned, the battery management controller 30 of the battery management system 20 of the power battery system is disposed outside the power battery 10, and the data acquisition device 40 is disposed inside the power battery 10, which is configured to acquire the data of the state, parameters, etc. of each cell 12 of each cell module 15 of the power battery 10, and transmit the data to the battery management controller 30 via the flexible wire harness 60. The battery management controller 30 is configured to monitor and manage the data of the state, parameters, etc. of each cell 12 of each cell module 15 of the power battery 10, and control the charging and discharging of the power battery 10. The aspects of the battery management controller 30 are not the focus of the present application and are not described in detail herein.
[0032] The data acquisition device 40 includes a flexible circuit board 70 made of insulating material, and each cell management controller 50 for each cell module 15 is integrated in the flexible circuit board 70. The flexible circuit board 70 has an elongated strip shape extending across all cell modules 15 of the power battery 10, as shown schematically. Figure 1 As a non-limiting example, the elongated strip-shaped flexible circuit board 70 can include a main section 72 corresponding to each cell module 15. Optionally, according to the arrangement of the cell modules, adjacent main sections 72 corresponding to adjacent cell modules 15 can be connected by connecting sections 74 having the same or different width and / or thickness dimensions. However, the connecting sections 74 are not necessary.
[0033] The cell management controller 50 disposed on each cell module 15 and integrated in (e.g., embedded in) the corresponding main section 72 can include at least one sampling chip (AFE, Analog Front End) 52 and at least one circuit module 54. The sampling chip 52 is configured to be electrically connected to each cell 12 of the corresponding cell module 15 via a sampling channel 56 to acquire or monitor the data of the voltage, temperature, current, etc. of each cell 12, and convert these analog signals into digital signals. The sampling channel 56 can be in the form of a conductive trace integrated in a branch section 76 extending transversely from the main section 72 of the flexible circuit board 70. The sampling channel 56 can be configured to be electrically connected to the opposite two tabs of each cell 12 or to be electrically connected to the busbar 14 electrically connecting the opposite tabs of adjacent cells.
[0034] ReferringFigure 3 In exemplary embodiments of the application, the sampling chip 52 can include, but is not limited to, a voltage sampling chip 52a that can be electrically connected to two tabs of each cell 12 through the sampling channel 56 and can detect the voltage of each cell through an internal ADC (analog-to-digital converter); a temperature sampling chip 52b that can be electrically connected to a temperature sensor (not shown) for measuring the temperature of the tabs of each cell 12 through the sampling channel 56, the temperature sensor can be directly attached to the tabs of the cell or can be attached to the bus bar 14 that is electrically connected to the tabs; a current sampling chip 52c that measures the charging and discharging current of each cell through a sampling resistor (not shown) provided for this purpose, and the like. Examples of the circuit module 54 can include an overvoltage / undervoltage protection circuit 54a that triggers a protection function to prevent damage to the cell when the voltage of the cell exceeds a set upper limit or is lower than a lower limit; an equalization module that integrates a MOSFET switch and a discharge resistor; an EMC filter module, typically a low-pass filter circuit, for filtering out the ripple of the voltage and temperature levels to ensure the stability of the sampling signal; a communication module 54b for providing a communication connection between the cell management controllers 50 corresponding to different cell modules 15; a high-low voltage isolation module for isolating the direct connection of the high-voltage devices of the battery management controller 30 and the cell management controller 50, and the like. Those skilled in the art will understand that the present application does not describe all the details of the sampling chip 52, the circuit module 54, and the sampling channel 56 of the cell management controller 50 in great detail, but only exemplarily lists some aspects. These are not the focus of the present application and will not be described in detail here. All electrical devices of the cell management controller 50 of each cell module 15 (including, but not limited to, the sampling chip, the circuit module, the sampling channel, etc.) can be integrated into the corresponding main section 72.
[0035] In addition, as Figure 2 and 3 The branch section 76 is an integral part extending transversely from the main section 72 of the flexible circuit board 70, and depending on the arrangement of the two tabs of the cell 12 and the spatial layout within the cell module 15 and between adjacent cell modules 15, the branch section 76 can extend from both transverse sides of the corresponding main section 72 or from the same side. Figure 2 The branch section marked 76a in the figure indicates that the branch section is bent when extending to the opposite side of the cell to extend and connect to the tabs on that side. Optionally, the width of the main section 72 can be greater than the width of the connecting section 74 and the branch 76. Optionally, the entire integral flexible circuit board 70 has the same width and / or the same thickness over the entire length of its extension.
[0036] Depending on the actual spatial arrangement within the individual cell modules 15, between the individual cell modules 15 and within the housing of the traction battery 10, the flexible circuit boards 70 can be provided mechanically fixed on some or each of the cell modules 15. As an example, each main section 72 of the flexible circuit board 70 is fixed to a corresponding one of the cell modules 15, e.g. each branch section 76 of the flexible circuit board 70 is mechanically fixed and electrically connected to the tab of the individual cell or to the busbar electrically connected to the tab.
[0037] Figure 4a and 4b Two examples are shown in which the branch section 76 is mechanically fixed to the busbar 14. In Figure 4a , the electrically conductive trace (e.g. a copper trace) of the branch section 76 as the sampling channel 56 comprises a metal end portion 56a exposed by removing an insulating circuit board portion, which is inserted into a spring tab 16 attached to the busbar 14 connecting the oppositely polarized tabs of the adjacent two cells. On the one hand, the sampling channel 56 connected to the acquisition chip 52 and the two oppositely polarized tabs of the adjacent two cells connected to the busbar 14 achieve an electrical connection, on the other hand, the branch section 76 is mechanically fixed to the cell module 15. Figure 4b In , the metal end portion 56a of the electrically conductive trace of the branch section 76 as the sampling channel 56 is mechanically and electrically connected to the busbar 14 by means of a fastener 18 (e.g. a screw or bolt or rivet as shown).
[0038] Figure 4a In 4b and , since the busbar 14 connects the respective one of the tabs of the adjacent two cells, the sampling channel 56 is connected to the busbar 14, i.e. electrically connected to the tabs of the two cells, and can acquire the voltage, current, etc. parameters of the two tabs (i.e. two cells). If a temperature sensor (e.g. a temperature sensor patch) is attached at the position of the busbar 14 connected to the tab, the sampling channel 56 can be connected to the temperature sensor to achieve the acquisition of the temperature of the cell.
[0039] The power battery system described above, the battery management system of the power battery system, the battery management controller arranged outside the power battery is directly connected between the data acquisition device arranged inside the power battery through the flexible wire harness, the requirement of arranging the printed circuit board and the associated wire harness outside the power battery is saved, the cost corresponding to the arrangement of these components and the space occupied by these components are saved, the configuration of the whole battery management system is simplified, and the weight of the whole power battery system is reduced. All electrical devices of the data acquisition device (including the cell management controller for each cell module) are integrated in the flexible circuit board of the integrated or one-piece structure, so that any wire harness is no longer needed inside the power battery, the arrangement inside the power battery is simplified, any technical problems related to the complicated wire harness are eliminated, the stability of the electrical connection is enhanced, and the space occupation, material cost and time consumption of the production process of the connection are reduced.
[0040] In the case of meeting the above technical principles, the application is applicable to any structure, any arrangement of the power battery, which can include one or more cell modules, and the number of cells contained in each cell module can be the same or different. In addition, due to the flexible nature of the flexible circuit board, it does not limit the orientation of the tabs of the cells in the cell module (for example, as shown arranged on the opposite two sides, or arranged on the upward top in the orientation shown), and does not limit any other details of the cells.
[0041] Although in the illustrated embodiment, each cell management controller corresponds to one cell module, or in other words, one cell management controller is arranged on each cell module, the application also envisages the case where the number of cell management controllers is less than the number of cell modules. In this case, one cell management controller can correspond to more than one cell module. At this time, the cell management controller, especially its sampling chip, is arranged on one of the more than one cell modules, and the sampling channel of the cell management controller extends to and is electrically connected to the tabs of each cell of each cell module corresponding to the cell management controller. Depending on the arrangement of the cell modules (for example, arranged in a line, or arranged in a matrix as shown), the common flexible circuit board can be flexibly extended across the corresponding cell module, for example, the cell module on which each cell management controller is mounted.
[0042] Although the figures show that the flexible circuit board achieves the electrical connection and mechanical connection capable of collecting the parameters or data of the battery cell by means of plugging (tab connection) or fasteners (such as bolts, screws, rivets, etc.) connecting the sampling channels in its branches with the bus bars electrically connected with the battery cell tabs, the present application does not limit this specific connection manner. The detachable connection by means of bolts, etc. also allows convenient maintenance and disassembly, improves the maintenance efficiency, and simplifies the whole package production process. In addition, it can be envisaged that the flexible circuit board also adds mechanical connection points at other positions outside the integrated electrical devices.
[0043] Further, it can be envisaged that, due to the flexible nature of the flexible circuit board, its arrangement in the battery cell module is relatively flexible. For example, a part of the flexible circuit board (such as some or all branch sections 76) can be arranged to be embedded near the tabs (or called "polar columns") of the battery cells of the corresponding battery cell module. The flexible circuit board can be designed to be relatively thin, occupying a small space or basically negligible space, which can be fixed to the shell of the battery cell module at some positions (such as discrete positions) by means of adhesion, riveting, etc., while ensuring that each electrical device of the data collection device can be embedded therein.
[0044] Although not shown in the figures, those skilled in the art can envisage any possible way to integrate the electrical devices of the data collection device on the flexible circuit board, one possible example is in the form of a packaged patch. Each battery cell management controller, especially its collection chip, can be arranged as close as possible to the battery cell in the corresponding battery cell module to shorten the sampling channel, save costs, reduce collection errors, and save the material cost of the sampling channel conductive trace.
[0045] The exemplary embodiments of the power battery system of the present application are described in detail above with reference to the accompanying drawings. Those skilled in the art should understand that various additions and modifications of the details described above and shown in the drawings can be made without departing from the spirit and scope of the present application, all of which fall within the protection scope of the present application.
Claims
1. A battery management system (20) for a power battery (10), the power battery comprising a plurality of cell modules (15), each cell module comprising a plurality of cells (12), each cell having two tabs of opposite polarity, characterized in that, The battery management system comprises: a data acquisition device (40) arranged inside the power battery (10), comprising a common flexible circuit board (70) and cell management controllers (50) integrated in the common flexible circuit board, each cell management controller (50) corresponding to one or more cell modules in the plurality of cell modules and comprising a sampling channel (56), wherein the common flexible circuit board (70) is an elongated strip body that is bendably extended across the respective cell module of the plurality of cell modules (15), and the sampling channel (56) is electrically and mechanically connected to or electrically connected with the tab of the respective cell or the busbar (14) electrically connected with the tab by means of plug-in or fastener connection.
2. The battery management system (20) for a power battery (10) according to claim 1, characterized in that The number of cell management controllers is equal to the number of cell modules, and each cell management controller corresponds to one cell module.
3. The battery management system (20) for a power battery (10) according to claim 2, characterized in that The elongated strip body comprises a main section (72) for being fixed to the corresponding one cell module (15) and integrating the corresponding cell management controller (50) of the cell module, and a connecting section (74) connecting adjacent main sections (72) and bridging between adjacent cell modules.
4. The battery management system (20) for a power battery (10) according to claim 3, characterized in that The common flexible circuit board (70) further comprises a branch section (76) extending transversely from each main section (72) and integrating the sampling channel (56).
5. The battery management system (20) for a power battery (10) according to claim 4, characterized in that The sampling channel (56) is a conductive trace integrated in the branch section (76).
6. The battery management system (20) for a power battery (10) according to claim 5, characterized in that The battery management system further comprises a battery management controller (30) arranged independently of the power battery, the battery management controller (30) being directly connected with the data acquisition device (40) through a flexible wire harness (60).
7. The battery management system (20) for a power battery (10) according to claim 6, characterized in that Each cell management controller (50) further comprises a sampling chip (52), the sampling channel of the cell management controller (50) being electrically connected with the sampling chip (52), the sampling chip (52) comprising: a voltage sampling chip and a current sampling chip, the sampling channel comprising a voltage sampling channel and a current sampling channel, the voltage sampling channel and the current sampling channel being configured to be electrically connected to the tab of the corresponding cell or the busbar electrically connected therewith; and a temperature sampling chip, the sampling channel comprising a temperature sampling channel, the temperature sampling channel being configured to be electrically connected to a temperature sensor attached to the tab of the corresponding cell or the busbar electrically connected therewith.
8. The battery management system (20) for a power battery (10) according to claim 7, characterized in that Each cell management controller (50) further comprises at least one circuit module, the at least one circuit module comprising: an overvoltage / undervoltage protection circuit; an equalization module; an EMC filtering module; a communication module; a high / low voltage isolation module; a power supply module.
9. The battery management system (20) for a power battery (10) according to claim 8, characterized in that The sampling chip and the at least one circuit module of the cell management controller (50) are integrated in the common flexible circuit board (70) by surface mounting technology.
10. The battery management system (20) for a power battery (10) according to any one of claims 1-9, characterized in that, The cell management controllers (50) are electrically connected in series with each other.
11. A power battery system (100), comprising: A power battery (10) comprising at least one cell module, each cell module comprising a plurality of cells, each cell having two tabs of opposite polarity, adjacent tabs of adjacent cells being electrically connected by a busbar (14); and The battery management system (20) for a power battery (10) according to any one of claims 1-10, wherein the sampling channel (56) of each cell management controller (50) is electrically connected to a tab of a cell or a busbar (14) electrically connected to the tab.
12. A vehicle characterized by A power battery system (100) comprising the power battery (10) according to claim 11.