A battery pack health status detection system, method and equipment based on EIS

Abstract

This invention relates to the field of battery performance testing technology, and particularly to a battery pack health status testing system, method, and device based on EIS. The system includes: a battery pack assembly, an excitation signal generation module, a voltage adaptive module, a signal acquisition and processing module, and an EIS detection component. The excitation signal generation module inputs an AC excitation signal into the battery pack. The voltage adaptive module is connected to the measurement circuit connection port and performs voltage reduction processing on the AC / DC hybrid response signal generated by the battery pack to obtain a low-voltage AC response signal. The signal acquisition and processing module acquires the low-voltage AC response signal and performs noise filtering processing to obtain a target AC response signal. The EIS detection component is connected to the signal acquisition and processing module and detects the target AC response signal to obtain the equivalent impedance response characteristics of the entire battery pack at different frequencies. The technical solution of this invention can improve the EIS detection efficiency of batteries and realize the health status evaluation of battery packs.

Description

Technical Field

[0001] This invention relates to the field of battery performance testing technology, and in particular to a system, method and device for testing the health status of a whole battery pack based on EIS. Background Technology

[0002] Currently, with the increasing scale and installed capacity of energy storage power stations, the energy storage testing technology industry has emerged and entered a period of rapid development. Existing battery testing methods suffer from low testing efficiency and difficulty in meeting the rapid on-site testing needs of power stations.

[0003] Therefore, those skilled in the art urgently need to develop a whole-pack battery health status detection system, method, and equipment based on EIS to solve the above-mentioned technical problems. Summary of the Invention

[0004] This invention provides a battery pack health status detection system, method, and device based on EIS, which can improve the EIS detection efficiency of batteries and realize the health status evaluation of battery packs.

[0005] In a first aspect, the present invention provides a battery pack health status detection system based on EIS, comprising: The battery pack to be tested includes the excitation signal generation module, voltage adaptive module, signal acquisition and processing module, and EIS detection component. The battery pack assembly includes an excitation circuit connection port, a measurement circuit connection port, and a battery pack connected between the excitation circuit connection port and the measurement circuit connection port; The excitation signal generation module is connected to the excitation loop connection port and the EIS detection component respectively, and is used to convert the drive signal generated by the EIS detection component into an AC excitation signal, and input the AC excitation signal into the battery pack; The voltage adaptive module is connected to the measurement circuit connection port and is used to step down the AC / DC hybrid response signal generated by the battery pack based on the AC excitation signal to obtain a low-voltage AC response signal. The signal acquisition and processing module is connected to the voltage adaptive module and is used to acquire the low-voltage AC response signal and perform noise filtering to obtain the target AC response signal. The EIS detection component is connected to the signal acquisition and processing module and is used to detect the target AC response signal to obtain the equivalent impedance response characteristics of the battery pack at different frequencies, so as to realize the health status detection of the battery pack.

[0006] Secondly, the present invention provides a method for detecting the overall health status of a battery pack based on EIS, applied to the system described in the first aspect of the present invention, comprising: The excitation signal generation module converts the drive signal generated by the EIS detection component into an AC excitation signal, and inputs the AC excitation signal to the excitation circuit connection port of the entire battery pack assembly. The voltage adaptive module performs a step-down process on the AC / DC hybrid response signal generated by the battery pack based on the AC excitation signal to obtain a low-voltage AC response signal. The low-voltage AC response signal is subjected to noise filtering by the signal acquisition and processing module to obtain the target AC response signal. The EIS detection component detects the target AC response signal to obtain the equivalent impedance response characteristics of the battery pack at different frequencies, thereby realizing the health status detection of the battery pack.

[0007] Thirdly, the present invention provides an EIS-based device for detecting the health status of a whole battery pack, including the system, housing, and fixture described in the first aspect of the present invention; The EIS-based whole-pack battery health status detection system is located inside the housing, and the fixture is used to connect the housing and the EIS-based whole-pack battery health status detection system.

[0008] This invention provides an EIS-based system, method, and device for detecting the health status of an entire battery pack. It can detect an unopened battery pack based on EIS detection technology, divide the voltage generated by the high-voltage battery pack, and achieve the purpose of using a dedicated EIS measurement chip with a voltage of up to 5V for detection, thereby improving the EIS detection efficiency of the battery and realizing the health status evaluation of the battery pack. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of a battery pack health status detection system based on EIS provided in an embodiment of the present invention; Figure 2 It is based on Figure 1 The diagram shows a surge protection module and an excitation signal generation module. Figure 3 It is based on Figure 1 The diagram shows a structural schematic of a voltage adaptive module and a signal acquisition and processing module. Figure 4 It is based on Figure 1 The diagram shows a schematic of a battery pack health status detection device based on EIS.

[0011] Figure label: 10-Complete battery pack 11-Excitation signal generation module 12-Voltage Adaptive Module 13-Signal Acquisition and Processing Module; 14-Surge protection module; 40-LCD touchscreen; 41-Slave communication interface; 42-Host communication interface; 43-CAN communication interface; 44 - Battery charging port; 45 - Connecting terminal; 46 - Power switch; 47 - Power indicator light; 48-French mouth; 49 - Round handle. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0013] Please refer to Figures 1-3 This invention provides an EIS-based whole battery pack health status detection system, including: a whole battery pack assembly 10 to be detected, an excitation signal generation module 11, a voltage adaptive module 12, a signal acquisition and processing module 13, and an EIS detection component; The battery pack 10 includes an excitation circuit connection port, a measurement circuit connection port, and a battery pack connected between the excitation circuit connection port and the measurement circuit connection port; The excitation signal generation module 11 is connected to the excitation loop connection port and the EIS detection component respectively, and is used to convert the drive signal generated by the EIS detection component into an AC excitation signal and input the AC excitation signal into the battery pack; The voltage adaptive module 12 is connected to the measurement circuit connection port and is used to step down the AC / DC hybrid response signal generated by the battery pack based on the AC excitation signal to obtain a low-voltage AC response signal. The signal acquisition and processing module 13 is connected to the voltage adaptive module 12 and is used to acquire the low-voltage AC response signal and perform noise filtering to obtain the target AC response signal. The EIS detection component is connected to the signal acquisition and processing module 13 and is used to detect the target AC response signal to obtain the equivalent impedance response characteristics of the battery pack at different frequencies, so as to realize the health status detection of the battery pack.

[0014] In this embodiment of the invention, the health status of the entire battery pack is rapidly detected based on electrochemical impedance spectroscopy (EIS). The entire battery pack to be tested is connected to the excitation signal generation module 11, the voltage adaptive module 12, and the signal acquisition and processing module 13 via four-wire connection terminals (i.e., excitation circuit connection port and measurement circuit connection port). The excitation circuit connection port is connected to the excitation signal generation module 11, which converts the drive signal generated by the EIS detection component into an AC excitation signal and inputs it into the battery pack. The battery pack generates a response signal based on the AC excitation signal, which includes an AC response signal and a DC response signal, i.e., a mixed AC / DC response signal. Since the DC response signal voltage value generated by the battery pack is usually relatively large (typically 200-800V), it is difficult to match the testing range of the EIS detection component. Therefore, the voltage adaptive module 12 performs voltage reduction processing on the mixed AC / DC response signal to obtain a low-voltage AC response signal. The voltage adaptive module 12 incorporates a voltage divider circuit to divide the mixed AC / DC response signal. The resulting low-voltage AC response signal undergoes noise filtering in the signal acquisition and processing module 13 to obtain the target AC response signal. The EIS detection component detects the target AC response signal to obtain the equivalent impedance response characteristics of the battery pack at different frequencies, thereby acquiring the health status detection results. These results include battery health parameters such as SOC, SOH, and internal temperature. The EIS detection component is typically a dedicated test chip in EIS technology, possessing functions such as generating the AC excitation signal, adaptively adjusting the voltage divider resistor in the voltage divider circuit, and analyzing the response signal to obtain the health status detection results.

[0015] The aforementioned excitation signal generation module 11, voltage adaptive module 12, and signal acquisition and processing module 13 are deployed on the measurement board, while the EIS detection component is deployed on the main control board. The measurement board and the main control board communicate via a serial port. The measurement board and the main control board share a set of 10-cell 18650 battery packs for power supply, and the power supply module supplies power to the various hardware circuits of the board itself.

[0016] In one embodiment of the present invention, it further includes: a surge protection module 14; Surge protection module 14 is used to absorb surge voltage generated by the battery pack.

[0017] In this embodiment, the surge protection module 14 is located at the front end of the test circuit and is used to suppress voltage spikes and surges at the moment of connection.

[0018] In one embodiment of the present invention, the surge protection module 14 includes a varistor U1, a Zener diode D1, a gas discharge tube U3, a normally closed relay K2 and a normally closed relay K3, and the excitation circuit connection port includes a FORCE+ terminal and a FORCE- terminal. The varistor U1 is connected in parallel with the Zener diode D1, and the anode of the Zener diode D1 is connected in series with one end of the gas discharge tube U3; The common terminal of normally closed relay K2 is connected to the FORCE+ terminal, the normally closed contact of normally closed relay K2 is connected to the cathode of Zener diode D1, the common terminal of normally closed relay K3 is connected to the FORCE- terminal, and the normally closed contact of normally closed relay K3 is connected to the other end of gas discharge tube U3. The surge protection module 14 is connected in parallel with the excitation signal generation module 11 through normally closed relays K2 and K3, respectively.

[0019] In this embodiment, as Figure 2 As shown, the surge protection module is placed at the input of the excitation signal generation module 11, i.e., the FORCE+ / FORCE- terminal. It consists of a varistor U1 connected in parallel with a Zener diode D1, which is then connected in series with a gas discharge tube U3 to form a surge absorption circuit. The surge absorption circuit is connected in parallel with the loads R2 and R3 on the excitation signal generation module 11 via normally closed relays K2 and K3, ensuring that the battery pack under test is preferentially connected to the surge absorption circuit, thus protecting the back-end circuitry of the measurement board.

[0020] In one embodiment of the present invention, the excitation signal generation module 11 includes a MOSFET U2, an inductor L1, a diode D2, a filter capacitor C1, a filter voltage regulator resistor R4, a current limiting resistor R1, a load switching resistor R2, a load switching resistor R3, a switching relay K4, and a switching relay K5. The drive signal output pin of the EIS detection component is connected to the gate of MOSFET U2, the drain of MOSFET U2 is connected to the FORCE- terminal, and the source of MOSFET U2 is connected to the switching contact of switching relay K4 and the switching contact of switching relay K5 respectively. The switching contacts of switching relay K4 and switching relay K5 are connected in parallel. The common terminal of switching relay K4 is connected to one end of load switching resistor R2. The common terminal of switching relay K5 is connected to one end of load switching resistor R3. The other ends of load switching resistor R2 and load switching resistor R3 are connected in parallel and then connected to normally closed relay K2. Inductor L1 and diode D2 are connected in parallel. The anode of diode D2 is connected to the cathode of Zener diode D1. The cathode of diode D2 is connected to one end of current-limiting resistor R1. The other end of current-limiting resistor R1 is connected to filter capacitor C1 and filter voltage regulator resistor R4 respectively. Filter capacitor C1 and filter voltage regulator resistor R4 are connected in parallel to the FORCE- terminal.

[0021] In this embodiment, the excitation signal generation module 11 excites the battery pack to generate an excitation current (AC / DC hybrid response signal) through the switching load switching resistors R2 and R3 of the MOSFET U2. The drive signal output pin EIS VSW CTRL of the EIS detection component generates a square wave signal with a frequency range of 10kHz to 0.01Hz to control the switching frequency of the MOSFET U2, reaching the high, medium, and low frequency ranges in most EIS curves.

[0022] In addition, the excitation signal generation module 11 also includes a sampling resistor R5 and a comparator U24. The current of the excitation signal generation module 11 is sampled by the comparator U24 and entered into the MCU for current monitoring via CURRENT_SENSING, serving as an independent protection circuit to monitor abnormal current in real time.

[0023] In one embodiment of the present invention, the voltage adaptive module 12 includes voltage divider resistors R9, R22, R15, variable resistor R64, a first active low-pass filter, and a first follower amplifier. The measurement circuit connection port includes a SENSE+ terminal and a SENSE- terminal. The SENSE+ terminal, voltage divider resistors R22, R9, and R15, and one end of variable resistor R64 are connected in series, and the other end of variable resistor R64 is grounded. The two input terminals of the first active low-pass filter are connected in parallel with the two ends of the voltage divider resistor R9, the output terminal of the first active low-pass filter is connected to the input terminal of the first follower amplifier, and the output terminal of the first follower amplifier is connected to the voltage adaptive adjustment pin of the EIS detection component.

[0024] In this embodiment, as Figure 2 As shown, voltage divider resistors R9, R22, and R15, along with variable resistor R64, constitute a voltage divider circuit. The battery voltage monitoring adaptive range adjustment circuit is placed at the measurement loop input. The MCU monitors voltage fluctuations in real time. Resistor R9 serves as the voltage sampling resistor. The signal VOLTAGE_SENSING, processed by the first follower amplifier, is acquired and used to adjust variable resistor R64 to achieve adaptive adjustment.

[0025] In one embodiment of the present invention, the first active low-pass filter includes an operational amplifier U6, an input resistor R13, a feedback resistor R14, and a feedback capacitor C8. One end of the input resistor R13 is connected to the connection node between the voltage divider resistors R9 and R22, and the other end is connected to the non-inverting input terminal of the operational amplifier U6. The feedback resistor R14 and the feedback capacitor C8 are connected in parallel to the inverting input terminal of the operational amplifier U6; The output of operational amplifier U6 is connected to the input of the first follower amplifier.

[0026] In this embodiment, one end of the input resistor R13 is connected to the node between the voltage divider resistors R9 and R22 to extract the measured signal after voltage division. The other end of the input resistor R13 is connected to the non-inverting input of the operational amplifier U6, serving as the main input path for the filtered signal. The feedback resistor R14 and the feedback capacitor C8 are connected in parallel across the inverting input and output of the operational amplifier U6, forming a typical first-order active low-pass filter structure. The output of the operational amplifier U6 is connected to the input of the first follower amplifier, further buffering and impedance matching the filtered signal to ensure the accuracy and stability of the signal when transmitted to subsequent processing units.

[0027] In one embodiment of the present invention, the signal acquisition and processing module 13 includes a second active filter and a second follower amplifier; The two input terminals of the second active filter are connected in parallel with the two ends of the voltage divider resistor R15, the output terminal of the second active filter is connected to the input terminal of the second follower amplifier, and the output terminal of the second follower amplifier is connected to the signal acquisition and analysis pin of the EIS detection component.

[0028] In this embodiment, comparator U7 and its peripheral circuitry constitute a second active filter. The response signal generated inside the battery pack, triggered by the excitation signal generation module 11, is attenuated by the second active filter to remove the DC component of the battery pack under test. Then, it enters the second follower amplifier to amplify the weak AC component. The resulting signal, EIS_VCH, is then filtered and sampled by the dedicated EIS measurement chip. The first active low-pass filter has a cutoff frequency of 0.001 Hz. The second active filter removes high-frequency noise and interference components from the response signal. The second follower amplifier enhances the signal's driving capability and achieves impedance matching, ensuring the signal remains stable and accurate when transmitted to the EIS detection component. The output of the second follower amplifier is connected to the signal acquisition and analysis pin of the EIS detection component, sending the processed target AC response signal to the EIS detection component for analysis and status assessment.

[0029] Furthermore, this invention provides a method for detecting the overall health status of a battery pack based on EIS, applicable to an EIS-based overall battery pack health status detection system. The method includes: The excitation signal generation module converts the drive signal generated by the EIS detection component into an AC excitation signal, and inputs the AC excitation signal to the excitation circuit connection port of the entire battery pack assembly. The voltage adaptive module is used to step down the AC / DC hybrid response signal generated by the battery pack based on the AC excitation signal to obtain a low-voltage AC response signal. The low-voltage AC response signal is noise filtered by the signal acquisition and processing module to obtain the target AC response signal; The EIS detection component is used to detect the target AC response signal to obtain the equivalent impedance response characteristics of the battery pack at different frequencies, thereby realizing the health status detection of the battery pack.

[0030] In one embodiment of the present invention, it further includes: The surge protection module absorbs the surge voltage generated by the battery pack.

[0031] In this embodiment, an EIS-based method for detecting the health status of a whole battery pack includes a self-test process, measurement signal processing, and protection mechanism design during the measurement process. Specifically, it includes: connecting the battery pack to be tested; after powering on the device, monitoring whether the bus voltage is normal; if normal, switching the relay in the surge protection module. Next, the self-test process begins, opening the relay at the voltage level, switching the self-test relay, and determining whether the excitation circuit current is normal. When the excitation circuit current is detected to be normal, the self-test relay is switched again. Next, the measurement signal processing stage begins, adjusting the variable resistor to configure the resistance value, opening the relay while simultaneously connecting the test signal, reading the voltage value, and determining whether the voltage value is normal. When no abnormal voltage fluctuations are detected, the user can start the impedance test using a one-click operation of the EIS dedicated test chip via the LCD touchscreen, and simultaneously display the processed measurement data on the LCD screen. During the test, the software simultaneously enables protection monitoring: one channel monitors the excitation circuit current acquisition, and another channel monitors current overcurrent triggering. When the detected current or voltage exceeds a preset value, all test circuits are shut down, and an abnormal situation is displayed on the LCD screen, terminating the test.

[0032] Furthermore, the present invention provides an EIS-based battery health status detection device, comprising an EIS-based battery health status detection system, a housing, and a fixture; The EIS-based overall battery health status detection system is located inside the housing, and the fixture is used to connect the housing and the EIS-based overall battery health status detection system.

[0033] In this embodiment, as Figure 4As shown, the outer casing features a lightweight design. Two types of fully enclosed insulated connection clamps are provided for connecting the battery under test: a thickened small 11cm pure copper clamp and a thickened large 16cm pure copper clamp, catering to most scenarios requiring quick connection. The main control board is located in the upper part of the casing, connecting to an external LCD touchscreen 40, a Type-C slave communication interface 41, a USB host communication interface 42, a CAN communication interface 43, and providing a 42V battery charging interface 44. The measurement board is located in the lower part of the casing. The device under test is connected to the measurement board's test circuit via a four-wire connection terminal, shown as terminal 45 in the diagram, for a total of four terminal ports. The upper part of the main unit features a 7-inch LCD capacitive touchscreen, with clamp connection ports, a power switch 46, a power indicator light 47, and a speaker 48 above the screen. The bottom of the casing has 10mm support feet, and the upper part has a circular handle 49.

[0034] The main control board has a built-in storage unit for real-time local saving of test data; it features a master-slave communication interface, supporting PC viewing and data export; it also has remote data transmission capabilities, allowing data to be transferred to the cloud or mobile devices as needed; and it includes a touchscreen display for real-time monitoring of the test progress for easy on-site use. The measurement board incorporates surge absorption circuitry and relay protection circuitry to clamp and absorb energy from abnormal voltage transients, protecting the equipment from surges and voltage spikes. A battery voltage adaptive range adjustment circuit monitors the voltage of the tested battery pack in real time, automatically matching different battery pack numbers for flexible application in on-site testing scenarios. A non-injection excitation current circuit and a high-precision filtering sampling circuit enable safe and rapid EIS testing in high-voltage battery pack scenarios. It is primarily used for rapid health status detection of stepped batteries, improving battery safety and reliability. The main control board has communication and external device connection capabilities, located in the upper part of the casing. The main control board hardware circuitry is equipped with an SMT32F407 microcontroller, which can be directly operated by connecting to an external LCD touchscreen. The Bluetooth module DA14531 and the 4G module WH-GM800 enable remote communication, allowing data to be transmitted to the cloud or a mobile device as needed. It features a Type-C slave communication port, a USB master communication port, and a CAN communication port for device data exchange. The corresponding software design includes an LCD touchscreen UI that displays the test progress in real time. Upon power-up, the device automatically enters a self-test process. After detecting the battery pack connection voltage signal, the measurement process can be initiated with a single touch on the touchscreen. During the measurement process, the software performs real-time data processing and incorporates voltage and current protection mechanisms.

[0035] In summary, this invention provides an EIS-based system, method, and device for detecting the health status of a whole battery pack. Through a wide-voltage-range sampling circuit design, it can adapt to battery pack testing environments with an ultra-wide voltage range of 200-800V. By attenuating the DC component through a low-pass filter design in the hardware circuit, it achieves the goal of using dedicated EIS measurement chips up to 5V. The excitation current to the battery pack under test is extremely small, effectively reducing the impact on the state of charge (SOC) of the battery pack and minimizing interference with the battery pack's status during testing. A smaller current sampling design reduces power consumption during use. The device size is controlled within 21cm*15cm*12cm, and the plastic casing design fundamentally reduces weight, making it convenient for handheld use in the field.

[0036] It should be noted that, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0037] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A battery pack health status detection system based on EIS, characterized in that, include: The battery pack to be tested includes the excitation signal generation module, voltage adaptive module, signal acquisition and processing module, and EIS detection component. The battery pack assembly includes an excitation circuit connection port, a measurement circuit connection port, and a battery pack connected between the excitation circuit connection port and the measurement circuit connection port; The excitation signal generation module is connected to the excitation loop connection port and the EIS detection component respectively, and is used to convert the drive signal generated by the EIS detection component into an AC excitation signal, and input the AC excitation signal into the battery pack; The voltage adaptive module is connected to the measurement circuit connection port and is used to step down the AC / DC hybrid response signal generated by the battery pack based on the AC excitation signal to obtain a low-voltage AC response signal. The signal acquisition and processing module is connected to the voltage adaptive module and is used to acquire the low-voltage AC response signal and perform noise filtering to obtain the target AC response signal. The EIS detection component is connected to the signal acquisition and processing module and is used to detect the target AC response signal to obtain the equivalent impedance response characteristics of the battery pack at different frequencies, so as to realize the health status detection of the battery pack. The voltage adaptive module includes voltage divider resistors R9, R22, R15, variable resistor R64, a first active low-pass filter, and a first follower amplifier. The measurement circuit connection port includes a SENSE+ terminal and a SENSE- terminal. The SENSE+ terminal, one end of the voltage divider resistor R22, the voltage divider resistor R9, the voltage divider resistor R15 and the variable resistor R64 are connected in series, and the other end of the variable resistor R64 is grounded. The two input terminals of the first active low-pass filter are connected in parallel with the two ends of the voltage divider resistor R9, the output terminal of the first active low-pass filter is connected to the input terminal of the first follower amplifier, and the output terminal of the first follower amplifier is connected to the voltage adaptive adjustment pin of the EIS detection component.

2. The system according to claim 1, characterized in that, Also includes: Surge protection module; The surge protection module is used to absorb the surge voltage generated by the battery pack.

3. The system according to claim 2, characterized in that, The surge protection module includes a varistor U1, a Zener diode D1, a gas discharge tube U3, a normally closed relay K2, and a normally closed relay K3. The excitation circuit connection port includes a FORCE+ terminal and a FORCE- terminal. The varistor U1 is connected in parallel with the Zener diode D1, and the anode of the Zener diode D1 is connected in series with one end of the gas discharge tube U3; The common terminal of the normally closed relay K2 is connected to the FORCE+ terminal, the normally closed contact of the normally closed relay K2 is connected to the cathode of the Zener diode D1, the common terminal of the normally closed relay K3 is connected to the FORCE- terminal, and the normally closed contact of the normally closed relay K3 is connected to the other end of the gas discharge tube U3. The surge protection module is connected in parallel with the excitation signal generation module through the normally closed relay K2 and the normally closed relay K3, respectively.

4. The system according to claim 3, characterized in that, The excitation signal generation module includes a MOSFET U2, an inductor L1, a diode D2, a filter capacitor C1, a filter voltage regulator resistor R4, a current limiting resistor R1, a load switching resistor R2, a load switching resistor R3, a switching relay K4, and a switching relay K5. The drive signal output pin of the EIS detection component is connected to the gate of the MOS transistor U2, the drain of the MOS transistor U2 is connected to the FORCE- terminal, and the source of the MOS transistor U2 is connected to the switching contact of the switching relay K4 and the switching contact of the switching relay K5, respectively. The switching contacts of the switching relay K4 and the switching contacts of the switching relay K5 are connected in parallel. The common terminal of the switching relay K4 is connected to one end of the load switching resistor R2. The common terminal of the switching relay K5 is connected to one end of the load switching resistor R3. The other ends of the load switching resistor R2 and the other ends of the load switching resistor R3 are connected in parallel and then connected to the normally closed relay K1. The inductor L1 and the diode D2 are connected in parallel. The anode of the diode D2 is connected to the cathode of the Zener diode D1. The cathode of the diode D2 is connected to one end of the current-limiting resistor R1. The other end of the current-limiting resistor R1 is connected to the filter capacitor C1 and the filter voltage regulator resistor R4 respectively. The filter capacitor C1 and the filter voltage regulator resistor R4 are connected in parallel to the FORCE- terminal.

5. The system according to claim 1, characterized in that, The first active low-pass filter includes an operational amplifier U6, an input resistor R13, a feedback resistor R14, and a feedback capacitor C8; One end of the input resistor R13 is connected to the connection node between the voltage divider resistors R9 and R22, and the other end is connected to the non-inverting input terminal of the operational amplifier U6. The feedback resistor R14 and the feedback capacitor C8 are connected in parallel to the inverting input terminal of the operational amplifier U6; The output terminal of the operational amplifier U6 is connected to the input terminal of the first follower amplifier.

6. The system according to claim 1, characterized in that, The signal acquisition and processing module includes a second active filter and a second follower amplifier; The two input terminals of the second active filter are connected in parallel with the two ends of the voltage divider resistor R15, the output terminal of the second active filter is connected to the input terminal of the second follower amplifier, and the output terminal of the second follower amplifier is connected to the signal acquisition and analysis pin of the EIS detection component.

7. A method for detecting the overall health status of a battery pack based on EIS, characterized in that, The system applied to any one of claims 1-6 comprises: The excitation signal generation module converts the drive signal generated by the EIS detection component into an AC excitation signal, and inputs the AC excitation signal to the excitation circuit connection port of the entire battery pack assembly. The voltage adaptive module performs a step-down process on the AC / DC hybrid response signal generated by the battery pack based on the AC excitation signal to obtain a low-voltage AC response signal. The low-voltage AC response signal is subjected to noise filtering by the signal acquisition and processing module to obtain the target AC response signal. The target AC response signal is detected by the EIS detection component to obtain the equivalent impedance response characteristics of the battery pack at different frequencies, thereby realizing the health status detection of the battery pack.

8. The method according to claim 7, characterized in that, Also includes: The surge protection module absorbs the surge voltage generated by the battery pack.

9. A battery pack health status detection device based on EIS, characterized in that, Includes the system, housing, and fixture as described in any one of claims 1-6; The EIS-based whole-pack battery health status detection system is located inside the housing, and the fixture is used to connect the housing and the EIS-based whole-pack battery health status detection system.

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