Battery pack

Abstract

The embodiment of the application provides a battery pack, which comprises a box body, a plurality of battery modules, a pressure sensor and a battery management unit, the box body comprises a liquid cooling bottom plate, side plates, end plates and a cover plate, the box body has an accommodation space, the plurality of battery modules are placed in the accommodation space, and a gap exists between any two adjacent battery modules in the plurality of battery modules. The battery module comprises a plurality of battery cells, the plurality of battery cells are arranged in a stacked manner side by side along a first direction on the liquid cooling bottom plate, and the pressure sensor is attached to a side surface of any battery cell in the plurality of battery cells, which is perpendicular to the first direction. The pressure sensor is provided with a physical wire, the physical wire is used for leading out from the gap between the two adjacent battery modules and connecting the battery management unit, and the battery management unit is used for receiving expansion force data of the plurality of battery cells in the battery module output from the pressure sensor through the physical wire, so that interference between a transmission line corresponding to the pressure sensor and a transmission line of other sampling data is avoided.

Description

Technical Field

[0001] This application relates to the field of power electronics, and more particularly to a battery pack. Background Technology

[0002] In the field of battery energy storage, battery packs are typically designed using lithium iron phosphate (LFP) cells, which are then integrated into energy storage boxes to form an energy storage system. The battery pack includes multiple cells, and pressure sensors are usually sandwiched between these cells to measure their expansion pressure. The battery management unit (BMU) of the energy storage system uses the expansion force data obtained from the pressure sensors to detect whether the cells are functioning correctly, or to calibrate the estimated state of charge (SOC) of the battery pack based on the expansion force data. The pressure sensor wiring is usually connected to a flexible circuit board (PCB) within the battery pack, which serves as the battery sampling line. This PCB is used for sampling the battery pack's voltage and temperature. However, interference can easily occur between the pressure sensor wiring and the PCB, leading to unstable signals and affecting the sampling accuracy of the pressure sensor. Furthermore, since the pressure sensor includes multiple sensing units, if each sensing unit is configured with a separate transmission line, the BMU may lack sufficient detection ports. Summary of the Invention

[0003] This application provides a battery pack that can avoid interference between the transmission line corresponding to the pressure sensor and the transmission line of other sampling data when the pressure sensor is set in the battery pack, and reduces the number of detection ports required on the data receiving side when the pressure sensor includes multiple sensing units.

[0004] In a first aspect, this application provides a battery pack, which includes a housing, multiple battery modules, a pressure sensor, and a battery management unit. The housing includes a liquid-cooled base plate, side plates, end plates, and a cover plate. The housing has a receiving space in which multiple battery modules are placed, with gaps between adjacent battery modules. Each battery module includes multiple cells, which are stacked side-by-side on the liquid-cooled base plate along a first direction. The pressure sensor is attached to the side of any one of the cells perpendicular to the first direction. The pressure sensor has physical wiring for leading out from the gap between adjacent battery modules and connecting to the battery management unit. The battery management unit receives expansion force data of the multiple cells in the battery module from the pressure sensor via the physical wiring.

[0005] In this application, the pressure sensor in each battery module is positioned between two adjacent cells in the battery module, or between the first cell in the battery module and the front-end board. The physical wiring connecting the pressure sensor extends from the gaps between the battery modules and connects to the corresponding battery management unit (BMU). The flexible circuit board in the battery module and the physical wiring connecting the pressure sensor are respectively connected to different ports on the BMU. Furthermore, the BMU receives expansion force data from the pressure sensor output from the battery module via the physical wiring, and receives pressure and temperature sampling data from the multiple cells in the battery module via the flexible circuit board. Here, because the transmission line of the pressure sensor in each battery module is decoupled from the flexible circuit board—that is, the pressure sensor is connected to a separate port on the corresponding BMU via a separate transmission line—interference between the transmission line corresponding to the pressure sensor and other sampling data transmission lines is avoided, thus improving the sampling accuracy of the pressure sensor.

[0006] In one possible implementation, the pressure sensor includes multiple pressure sensing units arranged in a matrix on a plane perpendicular to a first direction. Each pressure sensing unit comprises m rows and n columns. The resistance, capacitance, or voltage across each unit varies with the expansion force of the multiple battery cells. The first ends of the n pressure sensing units in each row are connected to the battery management unit via a single physical connection. Similarly, the second ends of the m pressure sensing units in each column are connected to the battery management unit via a single physical connection. In this configuration, with m rows and n columns, the pressure sensor connects all m×n pressure sensing units to their respective battery management units via n+m physical connections. This significantly reduces the number of connections and the required number of battery management unit ports compared to connecting each pressure unit to its own independent physical connection.

[0007] In one possible implementation, the battery management unit includes a data selector and a control unit. The data selector is used to send the voltage value across at least one of the multiple pressure sensing units to the control unit in response to a selection signal output by the control unit. The data selector automatically selects the corresponding pressure sensing unit to connect to the control unit based on the received selection signal, resulting in high efficiency in expansion force data acquisition.

[0008] In one possible implementation, the data selector includes a first data selector and a second data selector. Both the first and second data selectors have a signal selection terminal, an output terminal, and multiple input terminals. The control unit includes a control terminal and an input terminal. The signal selection terminals of the first and second data selectors are respectively used to connect to the first and second control terminals of the control unit. The first data selector has m input terminals, each used to connect to the first terminals of n pressure sensing units in a row of pressure sensing units. The second data selector has n input terminals, each used to connect to the second terminals of m pressure sensing units in a column of pressure sensing units. The output terminal of the first data selector is used to connect to the input terminal of the control unit and to a DC power supply via a resistor. The output terminal of the second data selector is used to ground. The first and second data selectors, respectively responding to the selection signals output by the first and second control terminals of the control unit, select one pressure sensing unit from the multiple pressure sensing units and electrically connect it to the input terminal of the control unit, so that the control unit receives the voltage value across the pressure sensing unit. Here, when the pressure sensor includes multiple pressure sensing units, the battery pack uses two data selectors to select the corresponding pressure sensing units in the row and column respectively for electrical connection to the control unit. This significantly reduces the number of ports while ensuring that the control unit receives voltage values ​​from all pressure sensing units to obtain expansion force data. Furthermore, the two data selectors automatically select the corresponding pressure sensing unit to connect to the control unit based on the received selection signal, resulting in high efficiency in expansion force data acquisition.

[0009] In one possible implementation, the data selector includes a first data selector and a second data selector. Both the first and second data selectors have signal selection terminals, output terminals, and multiple input terminals. The control unit includes a control terminal and an input terminal. The signal selection terminals of the first and second data selectors are respectively used to connect to the first and second control terminals of the control unit. The first data selector has m input terminals, each used to connect to the first terminals of n pressure sensing units in a row of pressure sensing units. The second data selector has n input terminals, each used to connect to the second terminals of m pressure sensing units in a column of pressure sensing units. The battery pack also includes a differential sampling circuit. The output terminals of the first and second data selectors are respectively used to connect to the first and second input terminals of the differential sampling circuit. The output terminal of the differential sampling circuit is used to connect to the input terminal of the control unit via a resistor. The first and second data selectors, in response to the selection signals output by the first and second control terminals of the control unit, respectively, select one pressure sensing unit from the multiple pressure sensing units and electrically connect it to the input terminal of the control unit, so that the control unit receives the voltage value across the pressure sensing unit. Here, when the pressure sensor includes multiple pressure sensing units, the battery pack uses two data selectors to select the corresponding pressure sensing units in the row and column respectively for electrical connection to the control unit. This significantly reduces the number of ports while ensuring that the control unit receives the voltage values ​​of all pressure sensing units to obtain expansion force data, resulting in high expansion force data acquisition efficiency. Furthermore, compared to measuring the voltage of each pressure sensing unit to ground in the pressure sensor, using a differential sampling circuit to directly measure the actual voltage drop across each pressure sensing unit and output it to the control unit avoids the influence of interference signals such as common-mode interference, further improving the accuracy of expansion force data acquisition.

[0010] In one possible implementation, the first control terminal of the control unit is used to output multiple first selection signals, and the second control terminal of the control unit is used to simultaneously output multiple second selection signals. Each first selection signal corresponds to an input terminal of a first data selector, and each second selection signal corresponds to an input terminal of a second data selector. When the signal selection terminal of the first data selector receives any first selection signal, and the signal selection terminal of the second data selector receives any second selection signal, the first and second data selectors jointly electrically connect the target pressure sensing unit to the input terminal of the control unit, so that the input terminal of the control unit receives the voltage value across the target pressure sensing unit, thereby allowing the input terminal of the control unit to receive the voltage values ​​across multiple pressure sensing units to obtain the expansion force data of multiple cells in the battery module. The target pressure sensing unit is a pressure sensing unit jointly connected to the input terminals of the first data selector corresponding to any first selection signal and the second data selector corresponding to any second selection signal. Here, when the pressure sensor includes multiple pressure sensing units, the battery pack uses two data selectors to select the corresponding pressure sensing units in the row and column respectively for electrical connection to the control unit. This significantly reduces the number of ports while ensuring that the control unit receives voltage values ​​from all pressure sensing units to obtain expansion force data. Furthermore, the two data selectors automatically select the corresponding pressure sensing unit to connect to the control unit based on the received selection signal, resulting in high efficiency in expansion force data acquisition.

[0011] In one possible implementation, the data selector includes a signal selection terminal, an output terminal, and multiple input terminals. The control unit includes a control terminal and input terminals. The signal selection terminal of the data selector is used to connect to the control terminal of the control unit. The control unit includes m input terminals, each of which is used to connect to the first terminals of n pressure sensing units in a row of pressure sensing units and to a DC power supply through a resistor. The data selector includes n input terminals, each of which is used to connect to the second terminals of m pressure sensing units in a column of pressure sensing units. The output terminal of the data selector is grounded. The data selector responds to the selection signal output by the control terminal of the control unit, selecting one column of pressure sensing units from the multiple pressure sensing units and electrically connecting it to the input terminal of the control unit, so that the control unit receives the voltage values ​​across the pressure sensing units in that column. Here, when the pressure sensor includes multiple pressure sensing units, the battery pack, by combining the data selector to select the corresponding column of pressure sensing units for electrical connection to the control unit, achieves a significant reduction in the number of ports while ensuring that the control unit receives the voltage values ​​of all pressure sensing units to obtain expansion force data. In addition, the data selector automatically selects the corresponding column of pressure sensing units to be connected to the control unit based on the received selection signal. The control unit can simultaneously acquire the voltage values ​​across all pressure sensing units in a column of pressure sensing units, further improving the efficiency of expansion force data acquisition.

[0012] In one possible implementation, the control terminal of the control unit outputs multiple selection signals, each corresponding to an input terminal of a data selector. The data selector, upon receiving any selection signal, electrically connects the target pressure sensing unit to the input terminal of the control unit, allowing the control unit's input terminal to receive the voltage values ​​across the target pressure sensing unit. This enables the control unit's input terminal to receive voltage values ​​across multiple pressure sensing units, thus obtaining the expansion force data of multiple cells in the battery module. The target pressure sensing unit consists of m pressure sensing units in a column connected to the input terminal corresponding to any selection signal. The data selector automatically selects the corresponding column of pressure sensing units based on the received selection signals and connects it to the control unit. The control unit can simultaneously acquire the voltage values ​​across all pressure sensing units in a column, further improving the efficiency of expansion force data acquisition.

[0013] In one possible implementation, the pressure sensor includes multiple pressure sensing unit sets, each set comprising multiple pressure sensing units arranged in a matrix on a plane perpendicular to a first direction. Each pressure sensing unit comprises x rows and y columns of pressure sensing units. The resistance, capacitance, or voltage across each pressure sensing unit varies with the expansion force of the multiple battery cells. The x pressure sensing units in each column are connected in series, and the first ends of the y-column pressure sensing units are connected to the battery management unit via a physical wiring connection. Similarly, the second ends of the y-column pressure sensing units are also connected to the battery management unit via a physical wiring connection. By dividing the pressure sensor into multiple pressure sensing unit sets, and connecting the pressure units in each set in series and then in parallel to the corresponding battery management unit, compared to connecting each pressure unit to the battery management unit via independent physical wiring, the number of wiring connections and the required number of battery management unit ports are significantly reduced.

[0014] In one possible implementation, the battery management unit includes a data selector and a control unit. The data selector is used to send the voltage values ​​across the pressure sensing units in column y of one of the multiple pressure sensing unit sets to the control unit in response to the selection signal output by the control unit. The data selector automatically selects the corresponding pressure sensing unit to connect to the control unit based on the received selection signal, resulting in high efficiency in expansion force data acquisition.

[0015] In one possible implementation, the data selector includes a signal selection terminal, an output terminal, and multiple input terminals. The control unit includes a control terminal and an input terminal. The signal selection terminal of the data selector is used to connect to the control terminal of the control unit. One input terminal of the data selector is used to connect to the first terminal of a pressure sensing unit in a set of pressure sensing units (e.g., column y), and is connected to a DC power supply through a resistor. The output terminal of the data selector is used to connect to the input terminal of the control unit. The second terminal of each pressure sensing unit in a set of pressure sensing units (e.g., column y) is grounded. The data selector responds to a selection signal output by the control terminal of the control unit, selecting one pressure sensing unit set from the multiple pressure sensing unit sets and electrically connecting it to the input terminal of the control unit, so that the control unit receives the voltage values ​​across the pressure sensing units in a set of pressure sensing units (e.g., column y). Here, the control unit can send different selection signals to the signal selection terminal of the data selector in sequence. The data selector responds to the different selection signals to connect the pressure sensing units in column y of different pressure sensing unit sets to the input terminal of the control unit. This allows the input terminal of the control unit to receive the voltage values ​​at both ends of all pressure sensing units in the pressure sensor to obtain the expansion force data of multiple cells in the battery module. This significantly reduces the number of ports while ensuring that the control unit receives the voltage values ​​of all pressure sensing units to obtain the expansion force data.

[0016] In one possible implementation, the control terminal of the control unit outputs at least one selection signal, and each selection signal corresponds to an input terminal of a data selector. The data selector, upon receiving any selection signal at the signal selection terminal, electrically connects the target pressure sensing unit to the input terminal of the control unit based on that selection signal. This allows the input terminal of the control unit to receive the voltage value across the target pressure sensing unit, thereby enabling the control unit to receive the voltage values ​​across multiple pressure sensing units in a set of multiple pressure sensing units to obtain the expansion force data of multiple cells in the battery module. This significantly reduces the number of ports while ensuring that the control unit receives the voltage values ​​of all pressure sensing units to obtain expansion force data. The target pressure sensing unit is a pressure sensing unit in column y of a set of pressure sensing units connected to the input terminal corresponding to any selection signal. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the framework structure of a photovoltaic system; Figure 2 This is a schematic diagram showing the relationship between battery thickness and battery voltage and state of charge; Figure 3 This is a structural schematic diagram of the battery pack provided in this application; Figure 4 This is another structural schematic diagram of the battery pack provided in this application; Figure 5This is another structural schematic diagram of the battery pack provided in this application; Figure 6 This is another structural schematic diagram of the battery pack provided in this application; Figure 7 This is another structural schematic diagram of the battery pack provided in this application; Figure 8 This is a schematic diagram of the structure of the pressure sensor provided in this application; Figure 9 This is another structural schematic diagram of the pressure sensor provided in this application; Figure 10 This is another structural schematic diagram of the pressure sensor provided in this application; Figure 11 This is another structural schematic diagram of the pressure sensor provided in this application; Figure 12 This is another structural schematic diagram of the pressure sensor provided in this application; Figure 13 This is another structural schematic diagram of the pressure sensor provided in this application; Figure 14 This is a schematic diagram of the data register matrix provided in this application; Figure 15 This is another structural schematic diagram of the pressure sensor provided in this application; Figure 16 This is another structural schematic diagram of the pressure sensor provided in this application; Figure 17 This is another structural schematic diagram of the pressure sensor provided in this application.

[0018] Figure label: X - First direction; 110 - Photovoltaic array; 120 - Power converter; 130 - Power grid; 140 - External load; 150 - Energy storage device; 20 - Battery pack; 301 - Liquid cooling base plate; 302 - Side plate; 3031 - Front panel; 3032 - Rear panel; 304 - Cover plate; 41-First battery module; 42-Second battery module; 43-Third battery module; 44-Fourth battery module; 50-Battery cell; 60-Flexible circuit board; 70-Pressure sensor; 80-Physical wiring; 90-Differential sampling circuit. Detailed Implementation

[0019] The battery pack provided in this application is applicable to energy storage power supply scenarios, photovoltaic-storage hybrid power supply scenarios, UPS power supply scenarios, and electric vehicle battery swapping station scenarios. The following explanation uses a photovoltaic-storage hybrid power supply scenario as an example. (See also...) Figure 1 , Figure 1 This is a schematic diagram of the framework structure of a photovoltaic system, such as... Figure 1 As shown, the photovoltaic system includes a photovoltaic array 110, a power converter 120, an energy storage device 150, and a power grid 130 / external load 140. The power converter 120 integrates a DC / DC conversion circuit and a DC / AC conversion circuit. The energy storage device 150 can be located between the DC / DC conversion circuit and the DC / AC conversion circuit. The electrical energy generated by the photovoltaic array 110 is boosted or bucked by the DC / DC conversion circuit to charge the energy storage device 150. When the electrical energy generated by the photovoltaic array 110 is insufficient to supply power to the power grid 130 / external load 140, the electrical energy stored in the energy storage device 150 can be transferred to the power grid 130 / external load 140 via the DC / AC conversion circuit within the power converter 120. Conversely, the energy storage device 150 can also receive power from the power grid 130. The AC power output from the power grid 130 is converted to DC power by the DC / AC conversion circuit and then transmitted to the energy storage device 150, thus charging the energy storage device 150. Alternatively, the power converter 120 may only include a DC / AC conversion circuit, while the energy storage device 150 may have a built-in DC / DC conversion circuit, and the energy storage device 150 may directly receive the DC power generated by the photovoltaic array 110.

[0020] The battery pack provided in this application can be used in... Figure 1 The energy storage device 150 shown includes a battery pack containing multiple battery cells. During battery pack operation, the battery pack's state is typically monitored to assess its performance and reliability, including its State of Charge (SOC). Because common SOC estimation methods have significant errors, and the accuracy of SOC estimation during use is easily affected by charge / discharge rates, temperature, and charge / discharge ranges, pressure sensors are usually installed between the battery cells in the battery pack. These pressure sensors measure the expansion pressure of the corresponding cell. By combining the expansion force data obtained from the pressure sensors, the normal operating state of the cell is detected, or the SOC estimation results of the battery pack are calibrated based on the expansion force data. Specifically, during the charging and discharging process of the battery pack, the battery pack's voltage, SOC, thickness, and expansion state are related; please refer to [further details omitted]. Figure 2 , Figure 2 This is a schematic diagram illustrating the relationship between battery thickness and battery voltage and state of charge. For example... Figure 2 As shown, during the entire charging process of the battery, i.e., the process of SOC increasing from 0 to 1, the curve corresponding to the change in battery thickness will show inflection points 1 and 2, and each inflection point corresponds to a battery voltage and a battery SOC. Taking the battery SOC as an example, inflection point 1 corresponds to an SOC of 0.33, and inflection point 2 corresponds to an SOC of 0.62. Therefore, during the SOC detection process of the battery, when the battery thickness reaches inflection point 1 or inflection point 2, the estimated SOC result of the battery can be calibrated based on the SOC corresponding to inflection point 1 and inflection point 2.

[0021] The pressure sensor's wiring is typically connected to a flexible circuit board (PCB) within the battery pack, which serves as the battery sampling line. This PCB is used for voltage and temperature sampling within the battery pack. The expansion force data acquired by the pressure sensor can be transmitted via the PCB to the relevant control unit in the Battery Management System (BMS) for processing. For example, the Battery Management Unit (BMU) in the BMS receives the aforementioned expansion force data, along with voltage and temperature sampling data, through the PCB. The BMU can then send the expansion force data of the corresponding battery pack to the Battery Control Unit (BCU). The BCU uses the received expansion force data to detect whether the cell's operating status is normal, or to calibrate the battery pack's State of Charge (SOC) estimation results based on the expansion force data.

[0022] However, the aforementioned method of sharing the pressure sensor's data transmission lines with the flexible circuit board—where the flexible circuit board includes multiple transmission lines for transmitting expansion force data, voltage sampling data, and temperature sampling data—is prone to interference between different transmission lines due to the large number and small spacing of these lines, leading to data interference and affecting the sampling accuracy of the pressure sensor. Furthermore, since the pressure sensor comprises multiple sensing units, configuring each sensing unit with a separate transmission line and connecting it to the BMU (Browser Receiver Unit) as the data receiving side places high demands on the number of detection ports in the BMU, potentially resulting in insufficient BMU detection ports.

[0023] To avoid interference between the transmission lines corresponding to the pressure sensor and other sampling data transmission lines when a pressure sensor is installed in the battery pack, improve the sampling accuracy of the pressure sensor, and reduce the number of detection ports required on the data receiving side when the pressure sensor includes multiple sensing units, please refer to [link to relevant documentation]. Figure 3 , Figure 3 This is a structural schematic diagram of the battery pack provided in this application. Figure 3 As shown, the battery pack 20 provided in this application includes a housing, which includes a liquid-cooled bottom plate 301, a side plate 302, a front plate 3031, a rear plate 3032, and a cover plate. Figure 3(Not shown). The battery pack 20 also includes multiple battery modules. Taking a battery pack 20 comprising four battery modules as an example, it includes a first battery module 41, a second battery module 42, a third battery module 43, and a fourth battery module 44. The aforementioned housing has a receiving space, and the four battery modules are arranged side by side within the receiving space and fixed on the liquid-cooled base plate 301. There are gaps between adjacent battery modules among the four battery modules. Each battery module includes multiple cells 50, and the multiple cells 50 of each battery module are stacked side by side on the liquid-cooled base plate 301 along a first direction. Figure 3 Taking the X direction as an example, where the X direction represents the first direction, multiple cells 50 of each battery module are stacked side-by-side on the liquid-cooled base plate 301 along the X direction, with gaps between cells in adjacent battery modules. Furthermore, the multiple cells 50 in each battery module of the battery pack 20 are also connected to a flexible circuit board 60, which is positioned above the multiple cells 50 along the X direction. Further, each battery module in the battery pack 20 also includes a pressure sensor 70, which is attached to the side of any one of the multiple cells perpendicular to the first direction. For example, the pressure sensor 70 can be positioned and attached between two cells; please refer again to... Figure 3 The pressure sensor 70 is positioned between two adjacent cells 50 in the battery module. Figure 3 The pressure sensor 70 shown is in the state of being removed from the battery module. The various end plates constituting the housing, the battery module, the flexible circuit board 60, and the pressure sensor 70 are reinforced with fasteners.

[0024] Optionally, each battery module in the battery pack 20 can also be equipped with multiple pressure sensors 70; please refer to [link / reference]. Figure 4 , Figure 4 This is another structural schematic diagram of the battery pack provided in this application. (See diagram below.) Figure 4 As shown, each battery module in the battery pack 20 is equipped with two pressure sensors 70, and each pressure sensor 70 is located between two adjacent cells 50 in the multiple cells of the corresponding battery module. Figure 4 The pressure sensor 70 shown is in the state of being removed from the battery module.

[0025] Optionally, the pressure sensor 70 can also be positioned between the first battery cell 50 and the front-end board 3031 in the battery module. Please refer to [link / reference]. Figure 5 , Figure 5 This is another structural schematic diagram of the battery pack provided in this application. (See diagram below.) Figure 5As shown, the pressure sensor 70 is positioned between the first cell 50 and the front-end board 3031 in the battery module. Compared to positioning the pressure sensor 70 between two adjacent cells 50 within a given battery module, positioning it on the front-end board 3031 reduces the space occupied by the pressure sensor 70 in the battery pack 20, facilitating a compact design for the battery pack 20. Figures 3 to 5 In the battery pack 20 shown, the pressure sensor 70 is attached to the side of the corresponding battery cell 50 that is perpendicular to the X direction. For example... Figure 5 The pressure sensor 70 is attached to the side of the first cell 50 in the battery module that is perpendicular to the X direction. So when any cell 50 in the battery module expands, the pressure sensor 70 can directly detect the expansion force data on the side of the cell 50 that is perpendicular to the X direction.

[0026] Furthermore, the pressure sensor has physical wiring for connecting to the battery management unit from the gap between two adjacent battery modules. See also... Figure 6 , Figure 6 This is another structural schematic diagram of the battery pack provided in this application. (See diagram below.) Figure 6 As shown, each battery module in the battery pack 20 is fixed between the cover plate 304 and the liquid-cooled base plate 301, and a pressure sensor 70 is installed in each battery module. Figure 6 The pressure sensor 70 shown is in its withdrawn state from the battery module, connected to the physical wiring 80, which extends from the gap between the battery modules. Understandably, because... Figure 6 The viewing angle is from the front-end board 3031 to the rear-end board 3032 and parallel to the aforementioned X direction; therefore, the X direction is represented by a dot. Specifically, the physical wiring 80 connected to each pressure sensor 70 is led out from the gap between the battery modules and connected to the corresponding BMU. Please refer to... Figure 7 , Figure 7 This is another structural schematic diagram of the battery pack provided in this application. (See diagram below.) Figure 7As shown, the battery pack 20 includes a first battery module 41, a second battery module 42, a third battery module 43, and a fourth battery module 44, with gaps between adjacent battery modules. Each battery module includes multiple battery cells 50, and the first battery module 41, the second battery module 42, the third battery module 43, and the fourth battery module 44 are respectively connected to BMU1, BMU2, BMU3, and BMU4. BMU1, BMU2, BMU3, and BMU4 are used to acquire the sampling data (expansion force data, voltage, and temperature sampling data) output by the corresponding battery modules and send them to the BCU. Taking the first battery module 41 as an example, the pressure sensor 70 in the first battery module 41 is located between the first cell 50 and the front-end board 3031. The physical wiring 80 connected to the pressure sensor 70 is led out from the gap between the first battery module 41 and the second battery module 42 and connected to the BMU1. The flexible circuit board 60 in the first battery module 41 and the physical wiring 80 connected to the pressure sensor 70 are respectively connected to different ports on the BMU1. The BMU1 is used to receive the expansion force data of multiple cells 50 in the first battery module 41 output from the pressure sensor 70 through the physical wiring 80, and to receive the pressure and temperature sampling data of multiple cells 50 in the first battery module 41 through the flexible circuit board 60. Here, since the transmission line of the pressure sensor in each battery module is decoupled from the flexible circuit board, that is, the pressure sensor is connected to a separate port on the corresponding BMU through a separate transmission line, interference between the transmission line corresponding to the pressure sensor and the transmission line of other sampling data is avoided, thus improving the sampling accuracy of the pressure sensor.

[0027] In some feasible implementations, the pressure sensor includes multiple pressure sensing units, and these multiple pressure sensing units are all arranged on the same plane perpendicular to the first direction described above. For example, the aforementioned... Figure 5 In the battery pack 20 shown, the pressure sensor 70 is attached to the side of the first cell 50 in the battery module, perpendicular to the X direction. The pressure sensor 70 includes multiple pressure sensing units arranged on the same plane perpendicular to the X direction. Further, the multiple pressure sensing units of the pressure sensor 70 are arranged in a matrix. See also... Figure 8 , Figure 8 This is a structural schematic diagram of the pressure sensor provided in this application. Figure 8As shown, the pressure sensor 70 includes multiple pressure sensing units arranged in a matrix. These multiple pressure sensing units comprise m rows and n columns, totaling m × n pressure sensing units. For example, each row of pressure sensing units includes n pressure sensing units a11 to a1n in the first row, and n pressure sensing units in rows 2 to m. Similarly, each column of pressure sensing units includes m pressure sensing units a11 to am1 in the first column, and m pressure sensing units in columns 2 to n. The resistance, capacitance, or voltage across each of these m × n pressure sensing units varies with the compressive force applied in the X direction; in other words, it varies with the expansion force of the multiple cells.

[0028] Furthermore, in the pressure sensor 70, the first ends of the n pressure sensing units in each row are connected to the BMU via a single physical wiring connection. For example, the first ends of pressure sensing units a11 to a1n in the first row are connected to the BMU via a single physical wiring connection. Thus, a total of m physical wiring connections are used to connect the first ends of the pressure sensing units in the m rows. Similarly, the second ends of the m pressure sensing units in each column are connected to the BMU via a single physical wiring connection. For example, the second ends of pressure sensing units a11 to am1 in the first column are connected to the BMU via a single physical wiring connection. Thus, a total of n physical wiring connections are used to connect the second ends of the pressure sensing units in the n columns. In other words, the pressure sensor 70 connects the two ends of all m×n pressure sensing units to their corresponding BMUs via n+m physical wiring connections. Compared to connecting each pressure sensing unit to the BMU via independent physical wiring connections, this significantly reduces the number of wiring connections and the required number of BMU ports.

[0029] Furthermore, the BMU includes a multiplexer (MUX) and a control unit. The multiple pressure sensing units included in the pressure sensor 70 can be connected to the control unit in the BMU via the multiplexer. See again. Figure 8All pressure sensing units in pressure sensor 70 are connected to a MUX at both ends. The MUX is connected to the analog-to-digital converter (ADC) port and general-purpose input / output (GPIO) port of the control unit. The GPIO port of the control unit sends a selection signal to the data selector MUX. In response to the selection signal output by the control unit, the MUX sends the voltage value across at least one of the m×n pressure sensing units connected to it to the ADC port of the control unit. Thus, the control unit can receive the voltage values ​​across the m×n pressure sensing units to obtain the expansion force data of multiple cells in the battery module corresponding to the pressure sensor 70.

[0030] In some feasible implementations, the data selector in the BMU includes a first data selector and a second data selector, and the control unit in the BMU can be a microcontroller unit (MCU). See also Figure 9 , Figure 9 This is another structural schematic diagram of the pressure sensor provided in this application. (See diagram below.) Figure 9 As shown, the data selector includes a first data selector (which can be simply referred to as MUX1) and a second data selector (which can be simply referred to as MUX2). Both MUX1 and MUX2 include a signal selection terminal, an output terminal, and multiple input terminals. Here, taking the pressure sensor 70, which includes 8 rows of pressure sensing units and 8 columns of pressure sensing units, as an example, the pressure sensor 70 includes a total of 64 pressure sensing units.

[0031] Furthermore, each input terminal of MUX1 is used to connect to the first end of n pressure sensing units in a row of pressure sensing units. Since the pressure sensor 70 includes 8 rows of pressure sensing units, MUX1 can include 8 input terminals from IN1 to IN8. Specifically, input terminal IN1 is used to connect to the first end of pressure sensing units a11 to a18 in the first row of pressure sensing units, and so on. Input terminals IN2 to IN8 are respectively used to connect to 8 pressure sensing units in the second to eighth rows of pressure sensing units. Each input terminal of MUX2 is used to connect to the first end of m pressure sensing units in a column of pressure sensing units. Since the pressure sensor 70 includes 8 columns of pressure sensing units, MUX2 can include 8 input terminals from IN9 to IN16. Specifically, input terminal IN9 is used to connect to the second end of pressure sensing units a11 to a81 in the first column of pressure sensing units, and so on. Input terminals IN10 to IN16 are respectively used to connect to the eight pressure sensing units in the second to eighth columns of pressure sensing units. In other words, for each pressure sensing unit in pressure sensor 70, its two ends are connected to one input terminal of MUX1 and MUX2, respectively.

[0032] Furthermore, the signal selection terminals of MUX1 and MUX2 are used to connect to the first and second control terminals of the MCU, respectively. For details, please refer again... Figure 9 The MCU's first control terminal may include GPIO1 to GPIO3 ports. MUX1 includes signal selection terminals S1, S2, and S3, which are used to connect to the MCU's GPIO1, GPIO2, and GPIO3 ports, respectively. The MCU's second control terminal may include GPIO4 to GPIO6 ports. MUX2 includes signal selection terminals S4, S5, and S6, which are used to connect to the MCU's GPIO4, GPIO5, and GPIO6 ports, respectively. The MCU's input terminal can be an ADC port. MUX1's output terminal OUT1 is used to connect to the DC power supply VCC through resistor R and to the MCU's ADC port. MUX2's output terminal OUT2 is used to ground.

[0033] During the process of the BMU acquiring the expansion force data output by the pressure sensor 70, the first control terminal of the MCU is used to output multiple first selection signals, each corresponding to an input terminal of MUX1. For example, taking the first selection signal as a binary address code, when the first selection signal output by the MCU's GPIO1, GPIO2, and GPIO3 ports is "000", then this first selection signal corresponds to the input terminal IN1 of MUX1. MUX1 responds to this first selection signal and connects the pressure sensing unit connected to the input terminal IN1 to the output terminal OUT1. Similarly, the first selection signals output by the MCU's GPIO1, GPIO2, and GPIO3 ports can also be "001", "010", "011", "100", "101", "110", and "111". The first selection signals "001" to "111" can respectively correspond to the input terminals IN2 to IN8 of MUX1. MUX1 responds to any of the above first selection signals and connects the pressure sensing unit connected to the corresponding input terminal to the output terminal OUT1.

[0034] Similarly, the second control terminal of the MCU is used to output multiple second selection signals, each corresponding to an input terminal of the MUX2. For example, if the second selection signal output by the MCU's GPIO4, GPIO5, and GPIO6 ports is "000", then this second selection signal corresponds to the input terminal IN9 of the MUX2. The MUX2 responds to this second selection signal and connects the pressure sensing unit connected to the input terminal IN9 to the output terminal OUT2. Similarly, the second selection signals output by the MCU's GPIO4, GPIO5, and GPIO6 ports can also be "001", "010", "011", "100", "101", "110", and "111". The second selection signals "001" to "111" can respectively correspond to the input terminals IN5 to IN16 of the MUX2. The MUX2 responds to any of the above second selection signals and connects the pressure sensing unit connected to the corresponding input terminal to the output terminal OUT2.

[0035] Next, when either the first selection signal is received at the signal selection terminal of MUX1 and either the second selection signal is received at the signal selection terminal of MUX2, MUX1 and MUX2 jointly connect the target pressure sensing unit to the ADC port of the MCU, so that the ADC port of the MCU receives the voltage value across the target pressure sensing unit. The target pressure sensing unit is a pressure sensing unit jointly connected to the input terminals of MUX1 corresponding to either the first selection signal and MUX2 corresponding to either the second selection signal. For example, if the signal selection terminals S1, S2, and S3 of MUX1 receive a first selection signal of "000", and the signal selection terminals S4, S5, and S6 of MUX2 receive a second selection signal of "001", then the first selection signal corresponds to input terminal IN1 of MUX1 and the second selection signal corresponds to input terminal IN10 of MUX2. Therefore, the target pressure sensing unit is pressure sensing unit a12 jointly connected to input terminals IN1 and IN10. Since the first end of pressure sensing unit a12 is connected to resistor R and DC power supply VCC through MUX1, and also to the ADC port of the MCU through MUX1, and the second end of pressure sensing unit a12 is grounded through MUX2, pressure sensing unit a12 and resistor R are connected in series to divide the voltage, and pressure sensing unit a12 is electrically connected to the ADC port of the MCU, allowing the MCU's ADC port to obtain the voltage across pressure sensing unit a12. Similarly, when the MCU sends different first selection signals and second selection signals to the signal selection terminals of MUX1 and MUX2 respectively, MUX1 and MUX2 respond to the different first selection signals and second selection signals to connect different pressure sensing units to the MCU's ADC port, thereby enabling the MCU's ADC port to receive the voltage values ​​across all pressure sensing units in pressure sensor 70 to obtain the expansion force data of multiple cells in the battery module. Here, when the pressure sensor includes multiple pressure sensing units, the battery pack uses two data selectors to select the corresponding pressure sensing units in the row and column respectively for electrical connection to the control unit. This significantly reduces the number of ports while ensuring that the control unit receives voltage values ​​from all pressure sensing units to obtain expansion force data. Furthermore, the two data selectors automatically select the corresponding pressure sensing unit to connect to the control unit based on the received selection signal, resulting in high efficiency in expansion force data acquisition.

[0036] In some feasible implementations, the battery pack further includes a differential sampling circuit. The output terminals of the first and second data selectors are respectively connected to the first and second input terminals of the differential sampling circuit, and the output terminal of the differential sampling circuit is connected to the input terminal of the control unit. See also... Figure 10 , Figure 10This is another structural schematic diagram of the pressure sensor provided in this application. (See diagram below.) Figure 10 As shown, the data selector includes a first data selector (which can be simply referred to as MUX1) and a second data selector (which can be simply referred to as MUX2). Both MUX1 and MUX2 include a signal selection terminal, an output terminal, and multiple input terminals. Here, taking the pressure sensor 70, which includes 8 rows of pressure sensing units and 8 columns of pressure sensing units, as an example, the pressure sensor 70 includes a total of 64 pressure sensing units. The connections of the input terminals and signal selection terminals of MUX1 and MUX2 are as described above. Figure 9 The MUX1 and MUX2 shown are similar and will not be described again here. The output terminal OUT1 of MUX1 is used to connect to the first input terminal of the differential sampling circuit 90, and the output terminal OUT2 of MUX2 is used to connect to the second input terminal of the differential sampling circuit 90. The input terminal of the MCU can be the ADC port, and the output terminal of the differential sampling circuit 90 is used to connect to the MCU's ADC port. Here, the differential sampling circuit 90 is used to output the difference between the voltages received at its first and second input terminals through its output terminal.

[0037] Similarly, during the process of the BMU acquiring the expansion force data output by the pressure sensor 70, the first control terminal of the MCU is used to output multiple first selection signals, each corresponding to an input terminal of MUX1. The second control terminal of the MCU is used to output multiple second selection signals, each corresponding to an input terminal of MUX2. When the signal selection terminal of MUX1 receives any first selection signal and the signal selection terminal of MUX2 receives any second selection signal, MUX1 and MUX2 together electrically connect the target pressure sensing unit to the ADC port of the MCU, so that the ADC port of the MCU receives the voltage value across the target pressure sensing unit. The target pressure sensing unit is a pressure sensing unit jointly connected to the input terminal of MUX1 corresponding to any first selection signal and the input terminal of MUX2 corresponding to any second selection signal. For example, if signal selection terminals S1, S2, and S3 of MUX1 receive a first selection signal of "000", and signal selection terminals S4, S5, and S6 of MUX2 receive a second selection signal of "001", then the first selection signal corresponds to input terminal IN1 of MUX1, and the second selection signal corresponds to input terminal IN10 of MUX2. Therefore, the target pressure sensing unit is pressure sensing unit a12, which is connected to both input terminals IN1 and IN10. Since the first terminal of pressure sensing unit a12 is connected to resistor R and DC power supply VCC through MUX1, and also to the first input terminal of differential sampling circuit 90 through MUX1, and the second terminal of pressure sensing unit a12 is connected to the second input terminal of differential sampling circuit 90 through MUX2, the ADC port of the MCU can obtain the voltage difference between the first and second terminals of pressure sensing unit a12 output by the output terminal of differential sampling circuit 90. Similarly, when the MCU sends different first selection signals and second selection signals to the signal selection terminals of MUX1 and MUX2 respectively, MUX1 and MUX2 respond to the different first selection signals and second selection signals to connect the two ends of different pressure sensing units to the differential sampling circuit 90. This allows the MCU's ADC port to receive the voltage difference between the two ends of all pressure sensing units in the pressure sensor 70 to obtain the expansion force data of multiple cells in the battery module. Here, when the pressure sensor includes multiple pressure sensing units, the battery pack uses two data selectors to select the corresponding pressure sensing units in the row and column respectively and connect them to the control unit. This significantly reduces the number of ports while ensuring that the control unit receives the voltage values ​​of all pressure sensing units to obtain expansion force data, resulting in high expansion force data acquisition efficiency.Furthermore, compared to measuring the voltage to ground of each pressure sensing unit in a pressure sensor, using a differential sampling circuit to directly measure the actual voltage drop across each pressure sensing unit and output it to the control unit can avoid the influence of interference signals such as common-mode interference, thereby further improving the accuracy of expansion force data acquisition.

[0038] In some feasible implementations, the control unit in the BMU can be a battery management IC (BMIC), see [link to relevant documentation]. Figure 11 , Figure 11 This is another structural schematic diagram of the pressure sensor provided in this application. (See diagram below.) Figure 11 As shown, the data selector includes a first data selector (which can be simply referred to as MUX1) and a second data selector (which can be simply referred to as MUX2). Both MUX1 and MUX2 include a signal selection terminal, an output terminal, and multiple input terminals. Here, again taking the pressure sensor 70, which includes 8 rows of pressure sensing units and 8 columns of pressure sensing units, as an example, the connection method between MUX1 and MUX2 and each pressure sensing unit can refer to the above. Figure 9 The description will not be repeated here.

[0039] Furthermore, the signal selection terminals of MUX1 and MUX2 are used to connect to the first and second control terminals of the BMIC, respectively. For details, please refer again... Figure 11 The first control terminal of the BMIC can include GPIO1 to GPIO3 ports. MUX1 includes signal selection terminals S1, S2, and S3, which are used to connect to the GPIO1, GPIO2, and GPIO3 ports of the BMIC, respectively. The second control terminal of the BMIC can include GPIO4 to GPIO6 ports. MUX2 includes signal selection terminals S4, S5, and S6, which are used to connect to the GPIO4, GPIO5, and GPIO6 ports of the BMIC, respectively. The input terminals of the BMIC can be ADC ports. The output terminal OUT1 of MUX1 is used to connect to the DC power supply VCC through resistor R and to the ADC port of the BMIC. The output terminal OUT2 of MUX2 is used to ground. The BMIC can also be connected to the MCU in the BCU through a bridge chip. Specifically, a bridge chip is a communication bridging chip that is responsible for converting the parallel or serial control signals of the MCU in the BCU into daisy-chain communication protocols, enabling the MCU to perform remote register read and write operations on the BMICs in multiple BMUs through the daisy-chain bus.

[0040] Optionally, a data register can be set inside the BMIC. During the process of the BMU acquiring the expansion force data output by the pressure sensor 70, the BMIC outputs a selection signal to the corresponding data selector each time to acquire and store the voltage value across one pressure sensing unit in the pressure sensor 70. For example, the MCU in the BCU can sequentially issue multiple expansion force detection commands to the BMIC. Each expansion force detection command includes control operations on each GPIO port of the BMIC and acquisition operations on the ADC port. For example, after receiving an expansion force detection command, the BMIC controls the first selection signal output by GPIO1, GPIO2, and GPIO3 ports to "000" and controls the second selection signal output by GPIO4, GPIO5, and GPIO6 ports to "000", thereby enabling MUX1 and MUX2 to connect the pressure sensing unit a11 to the BMIC. The BMIC also receives the voltage value across pressure sensing unit a11 from the ADC port controlled by this instruction, and stores the voltage value across pressure sensing unit a11 into the BMIC's internal data register. This allows the MCU in the BCU to read the voltage value across pressure sensing unit a11 from the BMIC's internal data register. Further, after reading the voltage value across pressure sensing unit a11 from the BMIC's internal data register, the MCU in the BCU sends a new expansion force detection instruction to the BMIC. Based on this new instruction, the BMIC controls MUX1 and MUX2 to sequentially connect other pressure sensing units in pressure sensor 70 to the BMIC. After obtaining the voltage value across each pressure sensing unit, the MCU stores the voltage value into the BMIC's internal data register, allowing the MCU in the BCU to again read the voltage value across the pressure sensing unit from the BMIC's internal data register. In other words, every time the MCU in the BCU sends an expansion force detection command to the BMIC, after the BMIC acquires and stores the voltage value across one pressure sensing unit based on the expansion force detection command, the MCU in the BCU reads the voltage value across the pressure sensing unit in the BMIC's internal data register once, and so on, until the MCU in the BCU reads the voltage values ​​across all pressure sensing units in the pressure sensor 70.

[0041] Optionally, the BMIC includes multiple data registers, and can preset the control operations of each GPIO port and the acquisition operations of the ADC port. Thus, during the process of the BMU acquiring the expansion force data output by the pressure sensor 70, the BMIC can sequentially output multiple selection signals to the corresponding data selectors to obtain the voltage values ​​across all pressure sensing units in the pressure sensor 70. For example, when the BMIC receives the expansion force detection command from the MCU in the BCU, the BMIC can first control the second selection signal output from GPIO4, GPIO5, and GPIO6 ports to "000". The MUX2 responds to this second selection signal and connects the first column of pressure sensing units connected to the input terminal IN9 to the output terminal OUT2. Next, the first selection signals output by the BMIC from the GPIO1, GPIO2, and GPIO3 ports are “000”, “001”, “010”, “011”, “100”, “101”, “110”, and “111”, respectively. This causes the MUX1 and MUX2 to connect the pressure sensing units a11 to a81 in the first column of pressure sensing units to the BMIC in sequence. The ADC port of the BMIC can receive the voltage values ​​across the pressure sensing units a11 to a81 in sequence, and the voltage values ​​across the pressure sensing units a11 to a81 are stored in the corresponding data registers inside the BMIC. Next, the BMIC can continue to control the second selection signals output by GPIO4, GPIO5, and GPIO6 ports to update to "001", "010", "011", "100", "101", "110", and "111" respectively. After each update of the second selection signal, the BMIC controls the first selection signals output by GPIO1, GPIO2, and GPIO3 ports to be "000", "001", "010", "011", "100", "101", "110", and "111" respectively. This allows MUX1 and MUX2 to connect each pressure sensing unit in columns 2 to 8 to the BMIC in sequence, and finally store the voltage values ​​across each pressure sensing unit into multiple data registers inside the BMIC. The BMIC can include 64 data registers, each storing the voltage value across one pressure sensing unit, thus storing the voltage values ​​across pressure sensing units a11 to a88 in the pressure sensor 70. Once the voltage values ​​at both ends of each pressure sensing unit are stored in the corresponding data register inside the BMIC, the MCU in the BCU can read the data from multiple data registers inside the BMIC, thereby obtaining the voltage values ​​at both ends of each pressure sensing unit at once, and obtaining the expansion force data of multiple cells in the corresponding battery module based on the voltage values ​​at both ends of each pressure sensing unit.Here, when the BMIC receives the expansion force detection command from the MCU in the BCU, the BMIC can output multiple selection signals to MUX1 and MUX2 in sequence according to the set timing to connect different pressure sensing units to the BMIC. This eliminates the need for the MCU in the BCU to frequently send control operation commands to each GPIO port of the BMIC, reducing the load rate of serial communication between the MCU and the bridge chip, as well as the load rate of communication between the bridge chip and the BMIC (such as daisy-chain communication), and improving the efficiency of expansion force data acquisition.

[0042] For some feasible implementation methods, please refer to Figure 12 , Figure 12 This is another structural schematic diagram of the pressure sensor provided in this application. (See diagram below.) Figure 12 As shown, the control unit in the BMU can be an MCU. The data selector MUX includes a signal selection terminal, an output terminal, and multiple input terminals. The MCU includes a control terminal and input terminals. Here, taking a pressure sensor 70 with 8 rows and 8 columns of pressure sensing units as an example, the pressure sensor 70 includes a total of 64 pressure sensing units. The signal selection terminal of the MUX is used to connect to the control terminal of the MCU. Specifically, the control terminal of the MCU can include GPIO1 to GPIO3 ports. The MUX includes signal selection terminals S1, S2, and S3, which are used to connect to the GPIO1, GPIO2, and GPIO3 ports of the MCU, respectively.

[0043] Furthermore, the input terminals of the MCU can be ADC ports, and each input terminal of the MCU is used to connect to the DC power supply VCC through a resistor R, and to connect to the first terminals of n pressure sensing units in a row of pressure sensing units. Since the pressure sensor 70 includes 8 rows of pressure sensing units, the MCU can include 8 input terminals, from ADC1 to ADC8. ADC1 is used to connect to the first terminals of pressure sensing units a11 to a18 in the first row of pressure sensing units, and so on. ADC2 to ADC8 are respectively used to connect to the 8 pressure sensing units in the second to eighth rows of pressure sensing units. Each input terminal of the MUX is used to connect to the second terminals of m pressure sensing units in a column of pressure sensing units. Since the pressure sensor 70 includes 8 columns of pressure sensing units, the MUX can include 8 input terminals, from IN1 to IN8. The input terminal IN1 is used to connect the second end of pressure sensing units a11 to a81 in the first column of pressure sensing units, and so on. Input terminals IN2 to IN8 are used to connect one-to-one with the eight pressure sensing units in the second to eighth columns of pressure sensing units, respectively. The output terminal OUT of the MUX is used for grounding.

[0044] During the process of the BMU acquiring the expansion force data output by the pressure sensor 70, the MCU's control terminal outputs multiple selection signals, each corresponding to an input terminal of the MUX. For example, taking the selection signal as a binary address code, when the first selection signal output by the MCU's GPIO1, GPIO2, and GPIO3 ports is "000", this selection signal corresponds to the MUX's input terminal IN1. The MUX responds to this selection signal and connects the pressure sensing unit connected to input terminal IN1 to the output terminal OUT. Similarly, the first selection signal output by the MCU's GPIO1, GPIO2, and GPIO3 ports can also be "001", "010", "011", "100", "101", "110", and "111". The first selection signals "001" to "111" can respectively correspond to the MUX's input terminals IN2 to IN8. The MUX responds to any of these selection signals and connects the pressure sensing unit connected to the corresponding input terminal to the output terminal OUT.

[0045] Next, when any selection signal is received at the signal selection terminal of the MUX, the MUX electrically connects the target pressure sensing unit to the ADC1 to ADC8 ports of the MCU, so that the ADC1 to ADC8 ports of the MCU receive the voltage value across the target pressure sensing unit. The target pressure sensing unit is one of the eight pressure sensing units in a row of pressure sensing units connected to the input terminal of the MUX corresponding to any selection signal. For example, if the selection signal received by the signal selection terminals S1, S2, and S3 of the MUX is "000", then the selection signal corresponds to the input terminal IN1 of the MUX. Therefore, the target pressure sensing units are pressure sensing units a11 to a81 in the first row of pressure sensing units connected to the input terminal IN1. Since the first ends of pressure sensing units a11 to a81 are respectively connected to the ADC1 to ADC8 ports of the MCU, and the first ends of pressure sensing units a11 to a81 are respectively connected to the power supply VCC through a resistor R. The second terminals of pressure sensing units a11 to a81 are grounded through the MUX. At this time, the ADC1 to ADC8 ports of the MCU can respectively obtain the voltages across pressure sensing units a11 to a81. The MCU simultaneously receives the voltages across all eight pressure sensing units a11 to a81 through the ADC1 to ADC8 ports. Similarly, when the MCU sequentially sends different selection signals to the signal selection terminal of the MUX, the MUX responds to these signals by connecting all pressure sensing units in different columns to the MCU's ADC port. This allows the MCU's ADC port to receive the voltage values ​​across all pressure sensing units in the pressure sensor 70, thus obtaining the expansion force data of multiple cells in the battery module. Here, when the pressure sensor includes multiple pressure sensing units, the battery pack selects a corresponding column of pressure sensing units and connects it to the control unit via a data selector. This significantly reduces the number of ports while ensuring the control unit receives the voltage values ​​of all pressure sensing units to obtain the expansion force data. In addition, the data selector automatically selects the corresponding column of pressure sensing units to be connected to the control unit based on the received selection signal. The control unit can simultaneously acquire the voltage values ​​across all pressure sensing units in a column of pressure sensing units, further improving the efficiency of expansion force data acquisition.

[0046] In some feasible implementations, the control unit in the BMU can be a BMIC; see [link to relevant documentation]. Figure 13 , Figure 13 This is another structural schematic diagram of the pressure sensor provided in this application. (See diagram below.) Figure 13As shown, the MUX includes a signal selection terminal, an output terminal, and multiple input terminals. Similarly, taking the pressure sensor 70, which includes 8 rows and 8 columns of pressure sensing units, as an example, the connection method between the MUX and each pressure sensing unit can be referred to the above. Figure 12 The description will not be repeated here.

[0047] Furthermore, the input terminals of the BMIC can be ADC ports, and each input terminal of the BMIC is used to connect to the DC power supply VCC through a resistor R, and to connect to the first terminals of n pressure sensing units in a row of pressure sensing units. Since the pressure sensor 70 includes 8 rows of pressure sensing units, the BMIC can include 8 input terminals, from ADC1 to ADC8. Specifically, the ADC1 port is used to connect to the first terminals of pressure sensing units a11 to a18 in the first row of pressure sensing units, and so on. Similarly, the ADC2 to ADC8 ports are used to connect one-to-one with the 8 pressure sensing units in the second to eighth rows of pressure sensing units. The BMIC is also connected to the MCU in the BCU via a bridge chip.

[0048] Optionally, each input terminal of the BMIC can be configured with a corresponding data register. During the process of the BMU acquiring the expansion force data output by the pressure sensor 70, the BMIC outputs a selection signal to the corresponding data selector each time to acquire and store the voltage value across a row of pressure sensing units in the pressure sensor 70. For example, each of the BMIC's ADC1 to ADC8 ports is configured with a corresponding data register, meaning the BMIC contains eight data registers. The MCU in the BCU can sequentially issue multiple expansion force detection commands to the BMIC. Each expansion force detection command includes control operations on each GPIO port of the BMIC and acquisition operations on the ADC port. For example, after receiving an expansion force detection command, the BMIC controls the selection signals output by the GPIO1, GPIO2, and GPIO3 ports to "000" based on the command. The MUX responds to this first selection signal and connects the first row of pressure sensing units connected to the input terminal IN1 to the output terminal OUT. The BMIC also controls ports ADC1 to ADC8 to simultaneously receive the voltage values ​​across pressure sensing units a11 to a81 based on this instruction, and stores these voltage values ​​into the corresponding data registers of ports ADC1 to ADC8. This allows the MCU in the BCU to read the voltage values ​​across pressure sensing units a11 to a81 from the BMIC's internal data registers. Further, after reading the voltage values ​​across pressure sensing units a11 to a81 from the BMIC's internal data registers, the MCU in the BCU sends a new expansion force detection instruction to the BMIC. Based on this new instruction, the BMIC controls MUX1 and MUX2 to sequentially connect other columns of pressure sensing units in pressure sensor 70 to the BMIC. After obtaining the voltage values ​​across each column of pressure sensing units, the MCU stores these values ​​into the BMIC's internal data registers, allowing the MCU in the BCU to again read the voltage values ​​across the pressure sensing units from the BMIC's internal data registers. In other words, every time the MCU in the BCU sends an expansion force detection command to the BMIC, after the BMIC acquires and stores the voltage values ​​across one column of pressure sensing units based on the expansion force detection command, the MCU in the BCU reads the voltage values ​​across the pressure sensing units in the BMIC's internal data register once, and so on, until the MCU in the BCU reads the voltage values ​​across all pressure sensing units in the pressure sensor 70.

[0049] Optionally, the BMIC includes multiple data registers, and the control operations of each GPIO port and the acquisition operations of the ADC port can be preset within the BMIC. For example, when the BMIC receives the expansion force detection command from the MCU in the BCU, the BMIC can first control the first selection signal output by the GPIO1, GPIO2, and GPIO3 ports to "000". The MUX responds to this first selection signal and connects the first column pressure sensing unit connected to the input terminal IN1 to the output terminal OUT. Then, the BMIC can control the ADC1 to ADC8 ports to simultaneously receive the voltage values ​​across the pressure sensing units a11 to a81, and store the voltage values ​​across the pressure sensing units a11 to a81 into the corresponding data registers within the BMIC. Similarly, the BMIC can continue to control the first selection signal output from the GPIO1, GPIO2, and GPIO3 ports to be updated to "001", "010", "011", "100", "101", "110", and "111". After each update of the first selection signal, the BMIC controls the ADC1 to ADC8 ports to simultaneously receive the voltage values ​​across the pressure sensing units corresponding to the first selection signal. This allows the MUX to sequentially connect each pressure sensing unit from the 2nd to the 8th columns to the BMIC, and finally store the voltage value across each pressure sensing unit into the corresponding data register inside the BMIC.

[0050] Optionally, the BMIC may include 64 data registers, each storing the voltage value across a pressure sensing unit, thereby storing the voltage values ​​across pressure sensing units a11 to a88 in the pressure sensor 70. The data registers within the BMIC may be arranged in a matrix. Please refer to [link / reference]. Figure 14 , Figure 14 This is a schematic diagram of the data register matrix provided in this application. For example... Figure 14 As shown, taking pressure sensor 70, which includes 8 rows and 8 columns of pressure sensing units, as an example, the arrangement of each pressure sensing unit can be referred to the above. Figure 9 Correspondingly, the data register matrix inside the BMIC can also include 8 rows of data registers and 8 columns of data registers. The 8 data registers in the first row are used to store the voltage values ​​across pressure sensing units a11 to a81, and so on.

[0051] Once the voltage values ​​across each pressure sensing unit are stored in the corresponding data register within the BMIC, the MCU in the BCU can read the voltage values ​​stored in the BMIC's internal data register and obtain the expansion force data of multiple cells in the corresponding battery module based on the voltage values ​​across each pressure sensing unit. Here, when the BMIC receives the expansion force detection command from the MCU in the BCU, the BMIC can sequentially execute the control operations of each GPIO port and the acquisition operations of the ADC port. This eliminates the need for the MCU to frequently send control operation commands to each GPIO port of the BMIC, reducing the load rate of communication between the MCU and the bridge chip, as well as the load rate of communication between the bridge chip and the BMIC, and improving the efficiency of expansion force data acquisition.

[0052] In some feasible implementations, the pressure sensor includes multiple pressure sensing unit sets, each set comprising multiple pressure sensing units, all arranged in the same plane perpendicular to the first direction. Further, the multiple pressure sensing units are arranged in a matrix configuration; see [link to relevant documentation]. Figure 15 , Figure 15 This is another structural schematic diagram of the pressure sensor provided in this application. (See diagram below.) Figure 15 As shown, the pressure sensor 70 includes multiple pressure sensing unit sets, such as pressure sensing unit sets 71 to 74, a total of four pressure sensing unit sets. Each pressure sensing unit set includes multiple pressure sensing units arranged in a matrix. Taking pressure sensing unit set 71 as an example, pressure sensing unit set 71 includes x rows of pressure sensing units and y columns of pressure sensing units, that is, it includes a total of x×y pressure sensing units. For each row of pressure sensing units, the first row includes pressure sensing units a11 to a1y, a total of y pressure sensing units, and the second to xth rows also include y pressure sensing units. For each column of pressure sensing units, the first column includes pressure sensing units a11 to ax1, a total of x pressure sensing units, and the second to yth columns also include x pressure sensing units. In the aforementioned x×y pressure sensing units, the resistance, capacitance, or voltage across each pressure sensing unit changes with the compressive force applied in the first direction; in other words, it changes with the expansion force of the multiple cells.

[0053] Furthermore, in the aforementioned pressure sensing unit set 71, x pressure sensing units in each column are connected in series, and the first ends of the pressure sensing units in column y are connected to the BMU via a physical wiring connection, and the second ends of the pressure sensing units in column y are connected to the BMU via a physical wiring connection. For example, pressure sensing units a11 to ax1 in the first column are connected in series, and similarly, x pressure sensing units in columns 2 to y are connected in series. The first ends of the series-connected pressure sensing units in columns 1 to y are connected to the BMU via a physical wiring connection. In other words, pressure sensing units a11 to a1y in the first row are connected to the BMU via a physical wiring connection. After being connected in series, the pressure sensing units in the first column and the second end of the pressure sensing units in the yth column are connected to the BMU through a physical wiring. In other words, the pressure sensing units ax1 and axy in the xth row are connected to the BMU through a physical wiring. Thus, x×y pressure sensing units are connected to the corresponding BMU in a series and then parallel manner through two physical wirings.

[0054] Understandably, the arrangement and connection of pressure sensing units in other pressure sensing unit sets within pressure sensor 70 are the same as those in pressure sensing unit set 71 described above, and will not be repeated here. By using the above... Figure 15 The medium pressure sensor 70 includes multiple pressure sensing units divided into multiple pressure sensing unit sets. The multiple pressure sensing units in each pressure sensing unit set are connected to the corresponding BMU in a series and then parallel manner. Compared with the two ends of each pressure sensing unit being connected to the BMU through independent physical wiring, this greatly reduces the number of wiring and the number of BMU ports required.

[0055] Furthermore, the BMU includes a data selector and a control unit. The multiple pressure sensing units within the pressure sensor 70 can be connected to the control unit in the BMU via the data selector. See again. Figure 15 Each pressure sensing unit set in the pressure sensor 70 has two physical wires leading out and connected to the MUX. The MUX is connected to the ADC port and GPIO port of the control unit. The GPIO port of the control unit is used to send a selection signal to the data selector MUX. In response to the selection signal output by the control unit, the MUX sends the voltage values ​​across the y-column pressure sensing units in one of the multiple pressure sensing unit sets connected to it to the ADC port of the control unit. Thus, the control unit can receive the voltage values ​​across the multiple pressure sensing units in the multiple pressure sensing unit sets to obtain the expansion force data of multiple cells in the battery module corresponding to the pressure sensor 70.

[0056] In some feasible implementations, the above Figure 15 The MUX shown includes a signal selection terminal, an output terminal, and multiple input terminals. The control unit includes a control terminal and input terminals. Specifically, the signal selection terminal S of the MUX is used to connect to the control terminal of the control unit, i.e., the GPIO port of the control unit. One input terminal of the MUX is used to connect to a DC power supply (…). Figure 15 (Not shown) and the first end of the pressure sensing unit in column y of a pressure sensing unit set. Since the pressure sensor 70 includes 4 pressure sensing unit sets, the MUX1 can include 4 input terminals from input terminal IN1 to input terminal IN4. The output terminal OUT of the MUX is used to connect to the input terminal of the control unit, that is, the ADC port of the control unit. The second end of the pressure sensing unit in column y of each pressure sensing unit set is grounded.

[0057] During the process of the BMU acquiring the expansion force data output by the pressure sensor 70, the GPIO port of the control unit is used to output multiple selection signals, and each selection signal corresponds to an input terminal of a MUX. The MUX is used to electrically connect the target pressure sensing unit to the input terminal of the control unit based on any selection signal received at the signal selection terminal S, so that the input terminal of the control unit receives the voltage value across the target pressure sensing unit. The target pressure sensing unit is the pressure sensing unit in column y of a pressure sensing unit set connected to the input terminal corresponding to any selection signal. For example, when the signal selection terminal S of the MUX receives the selection signal corresponding to the input terminal IN1 of the MUX, the MUX responds to this selection signal and connects the pressure sensing unit set 71 connected to the input terminal IN1 to the output terminal OUT. Since the first terminal of the pressure sensing unit in column y of the pressure sensing unit set 71 is connected to the ADC port of the control unit through the MUX and the second terminal is grounded, the ADC port of the control unit can then obtain the voltage across the pressure sensing unit in column y of the pressure sensing unit set 71. Similarly, when the control unit sends different selection signals to the signal selection terminal of the MUX, the MUX responds to the different selection signals to connect the pressure sensing units in column y of different pressure sensing unit sets to the ADC port of the control unit. This allows the ADC port of the control unit to receive the voltage values ​​across all pressure sensing units in the pressure sensor 70 to obtain the expansion force data of multiple cells in the battery module. This significantly reduces the number of ports while ensuring that the control unit receives the voltage values ​​of all pressure sensing units to obtain the expansion force data.

[0058] In some feasible implementations, Figure 15The control unit in the BMU shown can be an MCU, and the MUX can include two MUXs, each MUX being used to connect to the two pressure sensing unit sets in the pressure sensor 70. Please refer to [link to relevant documentation]. Figure 16 , Figure 16 This is another structural schematic diagram of the pressure sensor provided in this application. (See diagram below.) Figure 16 As shown, MUXa includes input terminals INa1 and INa2. Input terminal INa1 is connected to the DC power supply VCC via resistor R and to the first terminal of the pressure sensing unit in column y of pressure sensing unit set 71. Input terminal INa2 is connected to the DC power supply VCC via resistor R and to the first terminal of the pressure sensing unit in column y of pressure sensing unit set 72. MUXb includes input terminals INb1 and INb2. Input terminal INb1 is connected to the DC power supply VCC via resistor R and to the first terminal of the pressure sensing unit in column y of pressure sensing unit set 73. Input terminal INb2 is connected to the DC power supply VCC via resistor R and to the first terminal of the pressure sensing unit in column y of pressure sensing unit set 74. The second terminal of the pressure sensing unit in column y of each pressure sensing unit set is grounded. The signal selection terminal Sa of MUXa and the signal selection terminal Sb of MUXb are used to connect to the GPIO port of the MCU. The output terminal OUTa of MUXa is used to connect to the ADC1 port of the MCU, and the output terminal OUTb of MUXb is used to connect to the ADC2 port of the MCU.

[0059] During the process of the BMU acquiring the expansion force data output by the pressure sensor 70, the MCU's GPIO port is used to output multiple selection signals, and each selection signal corresponds to one input terminal of MUXa and MUXb. For example, when the selection signal is "0", it can correspond to the input terminal INa1 of MUXa and the input terminal INb1 of MUXb. Therefore, MUXa responds to the selection signal and connects the pressure sensing unit set 71 connected to the input terminal INa1 to the output terminal OUTa, while MUXb responds to the selection signal and connects the pressure sensing unit set 73 connected to the input terminal INb1 to the output terminal OUTb. Since the first end of the pressure sensing unit in column y of pressure sensing unit set 71 is connected to the ADC1 port of the MCU through MUXa and the second end is grounded, and the first end of the pressure sensing unit in column y of pressure sensing unit set 73 is connected to the ADC2 port of the MCU through MUXb and the second end is grounded, the ADC1 port of the MCU can obtain the voltage across the two ends of the pressure sensing unit in column y of pressure sensing unit set 71, and the ADC2 port can obtain the voltage across the two ends of the pressure sensing unit in column y of pressure sensing unit set 73. Similarly, when the selection signal is "1", this selection signal corresponds to the input terminal INa2 of MUXa and the input terminal INb2 of MUXb. Therefore, MUXa responds to the selection signal and connects the pressure sensing unit set 72 connected to the input terminal INa2 to the output terminal OUTa, while MUXb responds to the selection signal and connects the pressure sensing unit set 74 connected to the input terminal INb2 to the output terminal OUTb. At this time, the ADC1 port of the MCU can obtain the voltage across the pressure sensing units in column y of pressure sensing unit set 72, and the ADC2 port can obtain the voltage across the pressure sensing units in column y of pressure sensing unit set 74. Thus, the ADC1 and ADC2 ports of the MCU receive the voltage values ​​across all pressure sensing units in pressure sensor 70 to obtain the expansion force data of multiple cells in the battery module. This significantly reduces the number of ports while ensuring that the control unit receives the voltage values ​​of all pressure sensing units to obtain the expansion force data.

[0060] Optionally, the MCU in the BMU may include two GPIO ports. The signal selection terminals Sa of MUXa and Sb of MUXb can be used to connect to one GPIO port of the MCU. The two GPIO ports of the MCU are used to output multiple selection signals, so that MUXa and MUXb respond to the selection signals output by the corresponding GPIO ports to connect the pressure sensing units in column y of the corresponding pressure sensing unit set to the ADC1 port and ADC2 port of the MCU.

[0061] Optional, Figure 16In this configuration, MUXa and MUXb can be single-pole double-throw (SPDT) switches. The input terminals INa1 of MUXa and INb1 of MUXb can be normally closed terminals of the SPDT switches, while the input terminals INa2 of MUXa and INb2 of MUXb can be normally open terminals. The output terminals OUTa of MUXa and OUTb of MUXb can be the common terminals of the SPDT switches. Specifically, before the selection signal, the output terminals OUTa and INa1 of MUXa and INb1 of MUXb are always connected. At this time, the MCU's ADC1 port can obtain the voltage across the pressure sensing units in column y of pressure sensing unit set 71, and the ADC2 port can obtain the voltage across the pressure sensing units in column y of pressure sensing unit set 73. Next, when the output terminals OUTa and OUTb of MUXa and MUXb receive the selection signal from the GPIO port of the MCU, the output terminal OUTa of MUXa switches to be connected to the input terminal INa2, and the output terminal OUTb of MUXb switches to be connected to INb2. At this time, the MCU's ADC1 port can obtain the voltage across the pressure sensing units in column y of pressure sensing unit set 72, and the ADC2 port can obtain the voltage across the pressure sensing units in column y of pressure sensing unit set 74. This allows the MCU's ADC1 and ADC2 ports to receive the voltage values ​​across all pressure sensing units in pressure sensor 70 to obtain the expansion force data of multiple cells in the battery module. This significantly reduces the number of ports while ensuring that the control unit receives the voltage values ​​of all pressure sensing units to obtain expansion force data.

[0062] In some feasible implementations, the control unit in the BMU can be a BMIC; see [link to relevant documentation]. Figure 17 , Figure 17 This is another structural schematic diagram of the pressure sensor provided in this application. (See diagram below.) Figure 17 As shown, taking the example of a MUX comprising two MUXs, each MUX being used to connect two pressure sensing unit sets in pressure sensor 70, the connection methods between MUXa and MUXb and their corresponding pressure sensing unit sets can be referred to the above. Figure 16The description of the above will not be repeated here. The signal selection terminals Sa and Sb of MUXa and MUXb are used to connect to the GPIO ports of the BMIC. The output terminal OUTa of MUXa is used to connect to the ADC1 port of the BMIC, and the output terminal OUTb of MUXb is used to connect to the ADC2 port of the BMIC. The BMIC is also connected to the MCU in the BCU via a bridge chip. Furthermore, the MCU in the BCU can send the control operations of the BMIC's GPIO ports and the acquisition operations of the ADC ports to the BMIC via the bridge chip. The bridge chip can translate the control operations and acquisition operation commands output by the MCU into a communication protocol that the BMIC can recognize. Therefore, based on the received control operation commands, the BMIC controls the GPIO1 port to send multiple selection signals to MUXa and MUXb, and controls the ADC1 and ADC2 ports to receive the expansion force data from the pressure sensor 70 based on the received acquisition operation commands. The specific process by which the BMIC acquires expansion force data based on the control operations of the GPIO ports and the acquisition operations of the ADC ports can be referred to the above. Figure 16 The description of how the MCU acquires expansion force data is not repeated here.

Claims

1. A battery pack, characterized in that, The battery pack includes a housing, multiple battery modules, a pressure sensor, and a battery management unit. The housing includes a liquid-cooled base plate, side plates, end plates, and a cover plate. The housing has an accommodating space, and the multiple battery modules are placed within the accommodating space. There is a gap between two adjacent battery modules. The battery module includes multiple battery cells, which are stacked side by side on the liquid-cooled base plate along a first direction. The pressure sensor is attached to the side of any one of the multiple battery cells that is perpendicular to the first direction. The pressure sensor is provided with physical wiring, which is used to lead out from the gap between two adjacent battery modules and connect to the battery management unit. The battery management unit is used to receive expansion force data of multiple cells in the battery module from the pressure sensor through the physical wiring.

2. The battery pack according to claim 1, characterized in that, The pressure sensor includes multiple pressure sensing units, all of which are arranged on the same plane perpendicular to the first direction, and are arranged in a matrix form. The multiple pressure sensing units include m rows of pressure sensing units and n columns of pressure sensing units. The resistance, capacitance, or voltage across each pressure sensing unit changes with the expansion force of the multiple battery cells. The first ends of the n pressure sensing units in each row are connected and then connected to the battery management unit through a physical wiring connection. The second ends of the m pressure sensing units in each column are connected and then connected to the battery management unit through a physical wiring connection.

3. The battery pack according to claim 2, characterized in that, The battery management unit includes a data selector and a control unit. The data selector is used to send the voltage value across at least one of the plurality of pressure sensing units to the control unit in response to a selection signal output by the control unit.

4. The battery pack according to claim 3, characterized in that, The data selector includes a first data selector and a second data selector. The first data selector and the second data selector each include a signal selection terminal, an output terminal, and multiple input terminals. The control unit includes a control terminal and an input terminal. The signal selection terminals of the first data selector and the second data selector are respectively used to connect to the first control terminal and the second control terminal of the control unit. The first data selector includes m input terminals, and each input terminal is used to connect to the first terminal of n pressure sensing units in a row of pressure sensing units. The second data selector includes n input terminals, and each input terminal is used to connect to the second terminal of m pressure sensing units in a column of pressure sensing units. The output terminal of the first data selector is used to connect to the input terminal of the control unit and to a DC power supply through a resistor, and the output terminal of the second data selector is used to ground. The first data selector and the second data selector respond to the selection signals output by the first control terminal and the second control terminal of the control unit, respectively, to select one of the plurality of pressure sensing units and electrically connect it to the input terminal of the control unit, so that the control unit receives the voltage value across the pressure sensing unit.

5. The battery pack according to claim 3, characterized in that, The data selector includes a first data selector and a second data selector. The first data selector and the second data selector each include a signal selection terminal, an output terminal, and multiple input terminals. The control unit includes a control terminal and an input terminal. The signal selection terminals of the first data selector and the second data selector are respectively used to connect to the first control terminal and the second control terminal of the control unit. The first data selector includes m input terminals, and each input terminal is used to connect to the first terminal of n pressure sensing units in a row of pressure sensing units. The second data selector includes n input terminals, and each input terminal is used to connect to the second terminal of m pressure sensing units in a column of pressure sensing units. The battery pack also includes a differential sampling circuit. The output terminals of the first data selector and the second data selector are respectively used to connect to the first input terminal and the second input terminal of the differential sampling circuit. The output terminal of the differential sampling circuit is used to connect to the input terminal of the control unit through a resistor. The first data selector and the second data selector respond to the selection signals output by the first control terminal and the second control terminal of the control unit, respectively, to select one of the plurality of pressure sensing units and electrically connect it to the input terminal of the control unit, so that the control unit receives the voltage value across the pressure sensing unit.

6. The battery pack according to claim 4 or 5, characterized in that, The first control terminal of the control unit is used to output multiple first selection signals, and the second control terminal of the control unit is used to simultaneously output multiple second selection signals. Each first selection signal corresponds to an input terminal of a first data selector, and each second selection signal corresponds to an input terminal of a second data selector. When the first data selector receives any first selection signal at its signal selection terminal and the second data selector receives any second selection signal at its signal selection terminal, the first data selector and the second data selector together electrically connect the target pressure sensing unit to the input terminal of the control unit, so that the input terminal of the control unit receives the voltage value across the target pressure sensing unit, thereby enabling the input terminal of the control unit to receive the voltage value across the plurality of pressure sensing units to obtain the expansion force data of the plurality of cells in the battery module; The target pressure sensing unit is a pressure sensing unit that is connected to the input terminal of the first data selector corresponding to any first selection signal and the input terminal of the second data selector corresponding to any second selection signal.

7. The battery pack according to claim 3, characterized in that, The data selector includes a signal selection terminal, an output terminal, and multiple input terminals. The control unit includes a control terminal and an input terminal. The signal selection terminal of the data selector is used to connect to the control terminal of the control unit. The control unit includes m input terminals, each of which is used to connect to the first end of n pressure sensing units in a row of pressure sensing units and to a DC power supply through a resistor. The data selector includes n input terminals, each of which is used to connect to the second end of m pressure sensing units in a column of pressure sensing units. The output terminal of the data selector is grounded. The data selector responds to the selection signal output by the control terminal of the control unit, selects one row of pressure sensing units from the plurality of pressure sensing units and electrically connects it to the input terminal of the control unit, so that the control unit receives the voltage value at both ends of the row of pressure sensing units.

8. The battery pack according to claim 7, characterized in that, The control terminal of the control unit is used to output multiple selection signals, and each selection signal corresponds to the input terminal of the data selector; The data selector is used to electrically connect the target pressure sensing unit to the input terminal of the control unit based on any selection signal when the signal selection terminal receives any selection signal, so that the input terminal of the control unit receives the voltage value across the target pressure sensing unit, thereby enabling the input terminal of the control unit to receive the voltage value across the plurality of pressure sensing units to obtain the expansion force data of the plurality of cells in the battery module. The target pressure sensing unit is m pressure sensing units in a column of pressure sensing units connected to the input terminal corresponding to any selection signal.

9. The battery pack according to claim 1, characterized in that, The pressure sensor includes multiple pressure sensing unit sets, each pressure sensing unit set including multiple pressure sensing units, and the multiple pressure sensing units are arranged on the same plane perpendicular to the first direction. The multiple pressure sensing units are arranged in a matrix form, wherein the multiple pressure sensing units include x rows of pressure sensing units and y columns of pressure sensing units. The resistance, capacitance or voltage across each pressure sensing unit changes with the expansion force of the multiple battery cells. Each column of pressure sensing units consists of x pressure sensing units connected in series, and the first ends of the y columns of pressure sensing units are connected to the battery management unit via a physical wiring connection. The second ends of the y columns of pressure sensing units are also connected to the battery management unit via a physical wiring connection.

10. The battery pack according to claim 9, characterized in that, The battery management unit includes a data selector and a control unit. The data selector is used to send the voltage value across the y-column pressure sensing unit in one of the multiple pressure sensing unit sets to the control unit in response to the selection signal output by the control unit.

11. The battery pack according to claim 10, characterized in that, The data selector includes a signal selection terminal, an output terminal, and multiple input terminals. The control unit includes a control terminal and an input terminal. The signal selection terminal of the data selector is used to connect to the control terminal of the control unit. One input terminal of the data selector is used to connect to the first terminal of the pressure sensing unit in the y-column of the pressure sensing unit set, and is connected to a DC power supply through a resistor. The output terminal of the data selector is used to connect to the input terminal of the control unit. The second terminal of the pressure sensing unit in the y-column of each pressure sensing unit set is grounded. The data selector responds to the selection signal output by the control terminal of the control unit, selects one pressure sensing unit set from the plurality of pressure sensing unit sets and electrically connects it to the input terminal of the control unit, so that the control unit receives the voltage values ​​across the y-column pressure sensing units in the one pressure sensing unit set.

12. The battery pack according to claim 11, characterized in that, The control terminal of the control unit is used to output at least one selection signal, and each selection signal corresponds to an input terminal of the data selector; The data selector is used to electrically connect the target pressure sensing unit to the input terminal of the control unit based on any selection signal when the signal selection terminal receives any selection signal, so that the input terminal of the control unit receives the voltage value across the target pressure sensing unit, thereby enabling the input terminal of the control unit to receive the voltage value across multiple pressure sensing units in the set of multiple pressure sensing units to obtain the expansion force data of multiple cells in the battery module. Wherein, the target pressure sensing unit is a pressure sensing unit in column y of the pressure sensing unit set connected to the input terminal corresponding to any selection signal.

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