A battery thermal safety threshold testing system

Abstract

This invention discloses a battery thermal safety threshold testing system, including a chamber and a hierarchical testing module, an aging testing module, and a safety testing CNC module disposed therein. The hierarchical testing module performs battery thermal safety tests on cells, modules, and battery packs in a hierarchical order. The aging testing module performs cyclic aging tests and calendar aging tests on the batteries to obtain aged battery test samples. The safety testing CNC module is communicatively connected to the hierarchical testing module and the aging testing module, and is used to arrange the test process according to the hierarchical order of cells, modules, and battery packs, control the operation of the hierarchical testing module and the aging testing module, collect and analyze test data to calculate the battery thermal safety threshold, and generate alarm and warning responses based on the obtained battery thermal safety threshold. This invention achieves closed-loop testing of cells, modules, and battery packs, with high data consistency and traceable thresholds across levels.

Description

Technical Field

[0001] This invention relates to the field of battery safety performance testing technology, and in particular to a battery thermal safety threshold testing system. Background Technology

[0002] With the rapid development of the new energy industry, the safety performance of batteries, as the core component of energy storage and supply, has attracted much attention. Existing battery safety performance testing systems typically adopt a decentralized, independent testing mode. Cell insulation testing, electrical performance limit testing, module thermal runaway testing, and overall system verification are usually completed on different equipment and in different locations. The testing environment and data acquisition and control benchmarks at each level of the cell, module, and battery pack are not uniform, resulting in poor consistency of test data. The obtained safety thresholds are not traceable across levels, making it difficult to adapt to the actual thermal safety management requirements of high-voltage series-connected battery systems. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a battery thermal safety threshold testing system to solve the technical problems of poor consistency of test data and lack of traceability of safety thresholds across different levels caused by the inconsistency of test environments and data acquisition and control benchmarks at different levels in the existing battery safety performance testing.

[0004] To solve the above-mentioned technical problems, the objective of this invention is achieved through the following technical solution: A battery thermal safety threshold testing system is provided, comprising a chamber, a hierarchical testing module, an aging testing module, and a safety testing CNC module. The hierarchical testing module is disposed in the chamber and is used to perform battery thermal safety tests on the cells, modules, and battery packs sequentially according to their hierarchical order. The aging testing module is disposed in the chamber and is used to perform cyclic aging tests and calendar aging tests on the batteries respectively, obtaining aged battery test samples for the hierarchical testing module to perform battery thermal safety tests on these samples. The safety testing CNC module is disposed in the chamber and is communicatively connected to the hierarchical testing module and the aging testing module. It is used to arrange the test process according to the hierarchical order of the cells, modules, and battery packs, control the operation of the hierarchical testing module and the aging testing module, collect and analyze test data to calculate the battery thermal safety threshold, and provide alarm and warning responses based on the obtained battery thermal safety threshold.

[0005] Its further technical solution is as follows: The safety test CNC module includes a data acquisition unit, a data analysis unit, a main control module, and an alarm and early warning linkage execution unit. The main control module is communicatively connected to the data acquisition unit, the data analysis unit, the alarm and early warning linkage execution unit, the hierarchical test module, and the aging test module. It is used to arrange the test process according to the hierarchical order of cells, modules, and battery packs, send control signals and control parameters to the data acquisition unit, the data analysis unit, the alarm and early warning linkage execution unit, the hierarchical test module, and the aging test module, and receive corresponding status feedback; the data acquisition... The data acquisition unit is used to respond to the control of the main control module and acquire test data using sensors deployed on the cells, modules, and battery packs with a unified timestamp. The data analysis unit is connected to the data acquisition unit and is used to receive the test data acquired by the data acquisition unit, preprocess it, and calculate the battery thermal safety threshold to obtain the threshold parameter. The alarm and warning linkage execution unit is connected to the main control module, the data acquisition unit, and the data analysis unit and is used to receive the test data acquired by the data acquisition unit and the threshold parameter obtained by the data analysis unit, and perform alarm and warning hierarchical linkage control based on the test data and the threshold parameter.

[0006] The further technical solution is as follows: the data acquisition unit adopts a 128-channel synchronous acquisition instrument.

[0007] The further technical solution is as follows: the alarm and early warning linkage execution unit includes a BMS linkage verification module, a thermal management control module, a fire-fighting linkage module, an exhaust gas purification module, and an emergency ventilation module. The main control module is connected to the BMS linkage verification module, the thermal management control module, the fire-fighting linkage module, the exhaust gas purification module, and the emergency ventilation module, respectively. The BMS linkage verification module is used to compare the received test data with threshold parameters and send a corresponding early warning signal to the main control module according to the comparison result, so that the main control module controls the operation of the thermal management control module, the fire-fighting linkage module, the exhaust gas purification module, and the emergency ventilation module according to the corresponding early warning signal.

[0008] The further technical solution is as follows: The BMS linkage verification module obtains the corresponding aging compensation coefficient based on the aging compensation coefficient matrix between the battery health status and the threshold in the received threshold parameters, combined with the current battery health status, and dynamically corrects the warning trigger threshold, thermal management control threshold, and fire linkage threshold for each level. This results in the corrected warning trigger threshold, thermal management control threshold, and fire linkage threshold for each level. The module then synchronously compares the received test data with the corrected warning trigger thresholds for each level, obtains the highest value corresponding to the level of warning trigger threshold satisfied by the test data, and sends a warning signal corresponding to the highest value to the main control module. This allows the main control module to control the operation of the thermal management control module, the fire linkage module, the exhaust gas purification module, and the emergency ventilation module based on the corresponding warning signal.

[0009] The further technical solution is as follows: the hierarchical testing module includes a cell testing unit, which includes an accelerating calorimeter, a charge / discharge cabinet, a high and low temperature test chamber, a camera, and a multi-component gas sensor; the charge / discharge cabinet is used to control the remaining charge of the cell fixed to the clamp of the accelerating calorimeter; the accelerating calorimeter is used to control the temperature rise of the cell according to a preset heating rate, and to obtain the cell's self-heating initiation temperature, diaphragm closure temperature, explosion-proof valve opening temperature, and thermal runaway trigger temperature; by moving the cell into the high and low temperature test chamber, and in conjunction with the charge / discharge cabinet, the cell is subjected to overcharge and over-discharge tests, and the voltage surge threshold and current surge threshold are output; the camera is used to capture the transient process of thermal runaway; the multi-component gas sensor is used to collect carbon monoxide concentration, hydrogen concentration, and hydride concentration.

[0010] The further technical solution is as follows: The hierarchical testing module includes a module testing unit, which includes an explosion-proof test chamber and a thermal management testing component. After the tested battery cells and heating elements are assembled into a module, they are moved into the explosion-proof test chamber. The liquid cooling interface of the module is connected to the liquid cooling pipeline system. The liquid cooling flow range, coolant temperature range, and liquid cooling pipeline system pressure range are set through the thermal management testing component. The heating elements of the module are controlled by the safety test CNC module to trigger thermal runaway, and the internal temperature difference, temperature rise rate, and heat spread rate parameters of the module are output. The safety test CNC module sends an early warning trigger signal to the thermal management testing module to verify the response time of the thermal management system.

[0011] The further technical solution is as follows: The hierarchical testing module includes a battery pack testing unit, which includes a high-power charging and discharging cabinet, a high-voltage control unit, and a BMS threshold calibration unit. After the tested modules are assembled into a battery pack, they are connected to the high-voltage control unit and the BMS threshold calibration unit respectively. The high-power charging and discharging cabinet simulates the high-voltage series operation of the battery pack through the high-voltage control unit, and then performs a full-condition charging and discharging test on the battery pack. The BMS threshold calibration unit continuously collects the BMS operation data of the battery pack to verify the alarm and warning triggering logic, thermal management control strategy, and fire linkage execution logic of different levels.

[0012] The further technical solution is as follows: the aging test module includes a cyclic aging chamber. By placing the battery cell to be tested into the cyclic aging chamber, the cyclic aging chamber performs a preset number of cycles on the battery cell to be tested to obtain a battery test sample after cyclic aging, so that the hierarchical test module can perform battery thermal safety testing on the battery test sample after cyclic aging.

[0013] The further technical solution is as follows: the aging test module includes a high-temperature storage box. By placing the battery cell to be tested into the high-temperature storage box and leaving it at a preset aging temperature for a preset time, a battery test sample after calendar aging is obtained, which is then used by the hierarchical test module to perform battery thermal safety testing on the battery test sample after calendar aging.

[0014] The beneficial technical effects of this invention are as follows: The battery thermal safety threshold testing system of this invention arranges the test process according to the hierarchical order of cells, modules, and battery packs through a safety test CNC module to control the operation of the hierarchical test module. It can control the application of the same temperature boundary and synchronous charge and discharge, realizing closed-loop testing and verification of cells, modules, and battery packs. In conjunction with the chamber, it ensures that the testing of cells, modules, and battery packs is carried out in the same environment, and the test data is collected and analyzed uniformly through the safety test CNC module. By using synchronous acquisition under a unified benchmark, the consistency of test data is improved, solving the problem of inconsistent test environments and acquisition control benchmarks at different levels of existing battery safety performance testing, and the problem of poor test data consistency caused by the fragmentation of the test link. This makes the obtained battery thermal safety threshold traceable across levels. Moreover, the aging test module obtains aged battery test samples, which are then used by the hierarchical test module to perform battery thermal safety tests on the aged battery test samples to obtain the parameter change law throughout the entire life cycle. This enables adaptive adjustment of the battery thermal safety threshold according to the battery health status, avoiding the problem of traditional fixed thresholds failing after battery aging, and improving system reliability. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. 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.

[0016] Figure 1 This is a schematic diagram of the framework of the battery thermal safety threshold testing system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the hierarchical testing module of the battery thermal safety threshold testing system provided in an embodiment of the present invention. Detailed Implementation

[0017] 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 only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Please see Figure 1 , Figure 1 This is a schematic diagram of the framework of a battery thermal safety threshold testing system provided in an embodiment of the present invention. The battery thermal safety threshold testing system 10 includes a chamber 11, a hierarchical testing module 12, an aging testing module 13, and a safety testing CNC module 14. The hierarchical testing module 12 is disposed in the chamber 11 and is used to perform battery thermal safety tests on the cells, modules, and battery packs in a hierarchical order. The aging testing module 13 is disposed in the chamber 11 and is used to perform cycle aging tests and calendar aging tests on the battery to obtain... The aged battery test samples are used by the hierarchical testing module 12 to perform battery thermal safety tests on the aged battery test samples; the safety test CNC module 14 is set in the cabin 11 and is communicatively connected to the hierarchical testing module 12 and the aging test module 13. It is used to arrange the test process according to the hierarchical order of cells, modules and battery packs, control the operation of the hierarchical testing module 12 and the aging test module 13, collect and analyze test data to calculate the battery thermal safety threshold, and perform alarm warning response based on the obtained battery thermal safety threshold.

[0019] Cyclic aging refers to capacity loss during charge-discharge cycles, specifically the irreversible capacity loss that occurs in lithium-ion batteries during these cycles. Calendar aging refers to capacity degradation during battery storage, specifically the slow decrease in capacity as the battery is stored for longer periods without undergoing charge-discharge cycles. Hierarchical testing module 12 is used to obtain test data for all stages of thermal runaway development. The battery thermal safety threshold testing system 10 uses a safety test CNC module 14 to arrange the test process according to the hierarchical order of cells, modules, and battery packs to control the operation of the hierarchical test module 12. This allows for control over the application of the same temperature boundary and synchronous charge / discharge, achieving closed-loop testing and verification of cells, modules, and battery packs. Combined with the housing 11, this ensures that the testing of cells, modules, and battery packs is conducted in the same environment. Test data is uniformly collected and analyzed through the safety test CNC module 14, utilizing synchronous acquisition under a unified benchmark to improve test data consistency. This addresses the problem of inconsistent test environments and acquisition control benchmarks at different levels in existing battery safety performance testing, leading to poor test data consistency due to fragmented test links. The system ensures that the obtained battery thermal safety thresholds are traceable across levels. Furthermore, the aging test module 13 acquires aged battery test samples for the hierarchical test module to perform battery thermal safety tests on these samples, obtaining the parameter change patterns throughout the entire life cycle. This enables adaptive adjustment of the battery thermal safety threshold based on the battery's health status, avoiding the failure of traditional fixed thresholds after battery aging and improving system reliability.

[0020] Combination Figure 2Specifically, the hierarchical testing module 12 includes a cell testing unit 121, which includes an accelerating rate calorimeter (ARC), a charge / discharge cabinet, a high / low temperature test chamber, a camera, and a multi-component gas sensor. The charge / discharge cabinet is used to control the remaining state of charge (SoC) of the cell fixed to the clamp of the accelerating rate calorimeter. The accelerating rate calorimeter is used to control the temperature rise of the cell according to a preset heating rate, and to obtain the cell's self-heating initiation temperature, diaphragm pore closure temperature, explosion-proof valve opening temperature, and thermal runaway trigger temperature. By moving the cell into the high / low temperature test chamber and cooperating with the charge / discharge cabinet, overcharge and over-discharge tests are performed on the cell, and voltage and current surge thresholds are output. The camera is used to capture the transient process of thermal runaway. The multi-component gas sensor is used to collect carbon monoxide, hydrogen, and hydride concentrations. The preset heating rate can be 0.5℃ / min, and the camera is a high-speed camera. The charge / discharge cabinet controls the remaining charge of the battery cells fixed to the clamp of the accelerating calorimeter to be in five gradient states: 0%, 25%, 50%, 75%, and 100%. The basic thermal safety parameters of the battery cells can be obtained through the battery cell testing unit 121. These parameters include the self-heating initiation temperature, diaphragm closure temperature, explosion-proof valve opening temperature, thermal runaway trigger temperature, and single-cell thermal safety boundary parameters. The single-cell thermal safety boundary parameters include the overcharge voltage mutation threshold, over-discharge voltage mutation threshold, short-circuit current peak value, and various gas evolution concentration thresholds.

[0021] Specifically, the hierarchical testing module 12 includes a module testing unit 122, which comprises an explosion-proof test chamber and a thermal management testing component. After the tested battery cells and heating elements are assembled into a module, it is moved into the explosion-proof test chamber. The module's liquid cooling interface is connected to the liquid cooling pipeline system. The thermal management testing component sets the liquid cooling flow rate range, coolant temperature range, and liquid cooling pipeline system pressure range. The safety test CNC module controls the module's heating elements to trigger thermal runaway, providing a thermal propagation test environment for the module. It outputs the module's internal temperature difference, temperature rise rate, and thermal propagation speed parameters. The safety test CNC module sends an early warning trigger signal to the thermal management testing module to verify the thermal management system's response time. The module testing unit 122 can obtain the module's thermal propagation and temperature control parameters, including the module's maximum internal temperature difference, maximum temperature rise rate, thermal propagation speed, cooling rate at different flow rates, and thermal management system response time.

[0022] The thermal management system is a liquid cooling circuit system integrated into the module or battery pack itself. A liquid cooling pipeline system is installed inside the housing 11, running through the interior of the housing 11. It is physically connected to the liquid cooling interfaces of the cells, modules, and battery packs under test within the housing 11 via waterproof aviation connectors. The liquid cooling flow rate can be set from 0 to 20 L / min, the coolant temperature from 5 to 45°C, and the liquid cooling pipeline system pressure from 0 to 0.8 MPa. The thermal management test assembly serves as a calibration test platform for the module's thermal management performance. The thermal management test assembly includes an adjustable-speed coolant circulation pump, a high-precision constant-temperature chiller, a proportional pressure regulating valve group, a flow meter, inlet and outlet high-precision temperature sensors, inlet and outlet pressure sensors, and a data acquisition interface. An adjustable-speed coolant circulation pump provides circulation power for the liquid-cooled piping system. A high-precision constant-temperature chiller controls the temperature of the coolant in the liquid-cooled piping system. A proportional pressure regulating valve group is used to adjust the working pressure of the liquid-cooled piping system. Flow meters, inlet and outlet high-precision temperature sensors, and inlet and outlet pressure sensors collect the flow, temperature, and pressure parameters of the liquid-cooled piping system in real time. All collected data is uploaded to the data acquisition unit 141 in real time through the data acquisition interface. The thermal management test component is used to perform full-parameter range traversal testing, covering all possible actual operating conditions, and realizing comprehensive testing of the complete performance boundaries of the thermal management system. The thermal management test component achieves continuous adjustment of the flow rate range from 0 to 20 L / min through the adjustable-speed circulation pump, which can calibrate the cooling rate and response time at different flow rates; it achieves precise control of the coolant temperature range from 5 to 45°C through the high-precision constant-temperature chiller, which can simulate the temperature control limits under different ambient temperatures; and it achieves continuous adjustment of the liquid-cooled piping system pressure range from 0 to 0.8 MPa through the proportional pressure regulating valve group, which can verify the heat exchange efficiency and piping reliability under different pressures.

[0023] Specifically, the hierarchical testing module 12 includes a battery pack testing unit 123, which comprises a high-power charging and discharging cabinet, a high-voltage control unit, and a BMS (Battery Management System) threshold calibration unit. After the tested modules are assembled into a battery pack, they are connected to the high-voltage control unit and the BMS threshold calibration unit. The high-power charging and discharging cabinet, via the high-voltage control unit, simulates high-voltage series operation of the battery pack, and then performs a full-condition charging and discharging test. The BMS threshold calibration unit continuously collects the battery pack's BMS operating data to verify different levels of alarm triggering logic, thermal management control strategies, and fire-fighting linkage execution logic. The battery pack testing unit 123 provides system-level parameters for the battery pack, including overall voltage consistency deviation, overall temperature distribution, high-voltage circuit disconnection response time, multi-level alarm triggering delay, and linkage protection execution timeliness.

[0024] Among them, qualified modules that have passed module testing and verification can be assembled into a complete battery pack according to the 1P104S architecture. The high-voltage interface of the battery pack is connected to the high-voltage control module, and the BMS communication interface of the battery pack is connected to the BMS threshold calibration unit to simulate the high-voltage series operation of 1P104S. In 1P104S, P stands for Parallel. In a battery module, the parallel connection is to connect the positive terminals of multiple battery cells to each other and the negative terminals to each other to form a parallel circuit. 1P indicates that in this module, only one set of battery cells is connected in parallel. Therefore, the battery cells in this module are composed of multiple individuals connected in series rather than in parallel. The number of parallel connections is 1, so no additional parallel layers are added. In 1P104S, "S" stands for Series, meaning connected in series. "104S" indicates that this module has 104 battery cells connected in series. The series connection method involves connecting the positive terminal of one battery to the negative terminal of the next, and so on, forming a long chain to increase the total voltage of the battery pack. The total voltage of the series-connected battery pack is the sum of the voltages of each individual battery cell. Assembling a battery pack with a 1P104S architecture can meet specific voltage and capacity requirements. The high series number can provide a higher operating voltage, suitable for applications requiring high voltage input or output. The high-voltage output terminal of the high-power charge / discharge cabinet is connected to the input terminal of the high-voltage control module, and the output terminal of the high-voltage control module is connected to the battery pack, forming a complete high-voltage test circuit. The high-voltage control module is used for circuit on / off control, insulation monitoring, and safety protection. The high-power charge / discharge cabinet provides the power excitation required for testing. The BMS threshold calibration unit is a calibration and verification unit used to write the threshold parameters to be verified into the battery pack's BMS and to collect the operating status and warning signals of the battery pack's BMS. Full-condition charge-discharge testing was conducted. The high-power charge-discharge cabinet performed full-range charge-discharge cycles at different rates and with varying remaining battery capacity, according to the typical vehicle operating condition curves specified in national standards. During the test, the BMS threshold calibration unit continuously collected the battery pack's BMS operating data. By simulating first-level warning trigger conditions such as voltage anomalies and temperature differences, the accuracy of the first-level warning logic and the response effect of the thermal management cooling strategy were verified. Extreme temperature zone testing was conducted. The chamber 11 was subjected to -40℃ low-temperature environment, 25℃ normal temperature environment, and 85℃ high-temperature environment, with repeated charge-discharge cycles performed under each temperature condition to verify the applicability of the warning threshold at different temperature boundaries and the adaptability of the thermal management heating and cooling strategies. Abuse scenario testing was conducted. By simulating extreme abuse conditions such as overcharging and over-discharging, the accuracy of second-level and third-level warning triggers was verified. Simultaneously, the linkage execution logic of high-voltage circuit disconnection, fire suppression system activation, exhaust gas purification, and emergency ventilation was verified.Throughout the testing process, the safety test CNC module directly collects data in real time from the temperature sensors, voltage sensors, and current sensors deployed on the battery pack body. The BMS threshold calibration unit continuously verifies the alarm and warning triggering logic, thermal management control strategy, and fire linkage execution logic of different levels in all test scenarios to ensure the accuracy and reliability of the thresholds under all operating conditions, temperature ranges, and multiple scenarios.

[0025] Specifically, the aging test module includes a cyclic aging chamber. By placing the battery cell to be tested into the cyclic aging chamber and performing a preset number of cycles on the battery cell to be tested in the cyclic aging chamber, an aged battery test sample is obtained, which is then used by the hierarchical test module 12 to perform battery thermal safety testing on the aged battery test sample.

[0026] In this single-cycle test, the battery cell under test is charged at a constant current and constant voltage according to the current corresponding to the battery's rated capacity until the cell voltage reaches the charging cutoff voltage. After a preset resting time, the cell is discharged at a constant current according to the current corresponding to the battery's rated capacity until the cell voltage reaches the discharge quiescent voltage. The preset number of cycles includes four gradients: 500, 1000, 1500, and 2000. The aged battery test samples undergo battery thermal safety testing through a hierarchical testing module according to the hierarchical order of cell, module, and battery pack. Of course, in other embodiments, the number of cycles can be set according to actual needs.

[0027] Specifically, the aging test module includes a high-temperature storage box. By placing the battery cell to be tested into the high-temperature storage box and letting it stand at a preset aging temperature for a preset time, a battery test sample after calendar aging is obtained, which is then used by the hierarchical test module 12 to perform battery thermal safety testing on the battery test sample after calendar aging.

[0028] The preset aging temperature can be 45°C or 60°C, and the preset duration can be 6 months or 12 months. Of course, in other embodiments, the preset aging temperature and preset duration can be set according to actual needs.

[0029] It should be noted that the aged battery test samples, through the hierarchical testing module 12, obtain the basic thermal safety parameters of the aged cells, the thermal spread and temperature control parameters of the aged modules, and the system-level parameters of the aged battery pack. The safety test CNC module 14 compares the deviations of the initial battery parameter data with the parameter data of the aged battery test samples, calculates the deviation of each parameter as the battery health state decays, establishes a continuous functional relationship between the parameter deviations and the battery health state, and generates aging compensation coefficient matrices between the battery health state and thresholds at the cell, module, and battery pack levels, respectively, to achieve adaptive adjustment of the thresholds under different health states. By setting up a cyclic aging chamber and a high-temperature storage chamber in the aging test module 13 to achieve cyclic aging and calendar aging, the changing patterns of thermal safety parameters throughout the battery's life cycle are obtained, providing data support for dynamic threshold compensation.

[0030] Preferably, in some embodiments, the safety test CNC module 14 includes a data acquisition unit 141, a data analysis unit 142, a main control module 143, and an alarm and early warning linkage execution unit 144. The main control module 143 is communicatively connected to the data acquisition unit 141, the data analysis unit 142, the alarm and early warning linkage execution unit 144, the hierarchical test module 12, and the aging test module 13. It is used to arrange the test process according to the hierarchical order of cells, modules, and battery packs, send control signals and control parameters to the data acquisition unit 141, the data analysis unit 142, the alarm and early warning linkage execution unit 144, the hierarchical test module 12, and the aging test module 13, and receive corresponding status feedback. The data acquisition unit 141 is used to respond to the control of the main control module 143, and uses sensors deployed on the cells, modules and battery pack with a unified timestamp to acquire test data; the data analysis unit 142 is connected to the data acquisition unit 141, and is used to receive the test data acquired by the data acquisition unit 141, preprocess it and calculate the battery thermal safety threshold to obtain the threshold parameter; the alarm and early warning linkage execution unit 144 is connected to the main control module 143, the data acquisition unit 141 and the data analysis unit 142, and is used to receive the test data acquired by the data acquisition unit 141 and the threshold parameter obtained by the data analysis unit 142, and perform alarm and early warning hierarchical linkage control according to the test data and the threshold parameter.

[0031] The unified timestamp ensures synchronization of multiple parameters, avoiding feature loss caused by asynchronous acquisition. The main control module 143 executes control through a combination of industrial Ethernet and hard-wired triggering. The main control module 143 sends test scripts and control commands to the hierarchical test module 12 and aging test module 13 via industrial Ethernet; the main control module 143 sends millisecond-level synchronization trigger signals to the data acquisition unit 141 via hard-wired signals, and can also send emergency safety interlock signals to the hierarchical test module 12 and aging test module 13. When the main control module 143 detects any of the following trigger conditions: thermal runaway confirmation, internal short circuit confirmation, concentration exceeding the standard, abnormal door opening, communication interruption, and manual emergency stop, it immediately sends an emergency safety interlock signal to all associated module units via hard-wired signals. Upon receiving the emergency safety interlock signal, the corresponding module unit immediately executes a preset safety protection action; the main control module 143 has a built-in state machine engine, which is used to automatically arrange and execute the test process according to the order of cell testing, module testing, battery pack testing, aging testing to closed-loop verification. Sensors on the cells, modules, and battery packs include temperature sensors, voltage sensors, current sensors, and gas sensors. The hierarchical testing module 12 provides separate testing environments for the cells, modules, and battery packs, allowing for controlled testing within the same environment. The safety testing CNC module 14, through the setup of a data acquisition unit 141, a data analysis unit 142, a main control module 143, and an alarm and early warning linkage execution unit 144, achieves coordinated overall control scheduling, synchronous data acquisition, intelligent analysis, and linked execution. Furthermore, the alarm and early warning linkage execution unit 144 enables coordinated early warning, temperature control, and fire suppression, ensuring timely response.

[0032] Specifically, the data acquisition unit employs a 128-channel synchronous acquisition instrument. The sampling frequency of the data acquisition unit is not less than 1kHz, the time synchronization accuracy is ±1ms, the temperature accuracy is ±0.1℃, and the voltage accuracy is ±0.1mV. By limiting the sampling frequency to no less than 1kHz and the time synchronization accuracy to ±1ms, it is ensured that the weak transient characteristics of thermal runaway can be completely captured, avoiding feature loss.

[0033] Specifically, the data analysis unit 142 uses the Grubbs criterion to remove outliers from the data, and then performs noise reduction processing on the data after outlier removal using the 3σ or 6σ criterion. It further filters the noise-reduced data using moving average filtering and Kalman filtering to obtain preprocessed data. The data analysis unit 142 calculates the safety threshold based on the preprocessed data using box plot statistical methods and Weibull distribution fitting methods, and optimizes the threshold triggering conditions using ROC curves (receiver operating characteristic curves). The data analysis unit 142 also compares the deviations of the battery's initial parameter data with the parameter data of the aged battery test samples, calculates the deviation of each parameter as the battery's health status decays, establishes a continuous functional relationship between the parameter deviations and the battery's health status, and generates aging compensation coefficient matrices between the battery health status and the threshold at the cell level, module level, and battery pack level, respectively, to adaptively adjust the thresholds under different health states according to the corresponding aging compensation coefficients.

[0034] Specifically, the data analysis unit 142 is also used to verify the threshold parameters using the GRR (Gauge Repeatability and Reproducibility) analysis method, the confidence interval verification method, and the false alarm rate and false miss rate verification method. The verified threshold parameters are used as the early warning trigger thresholds for each level according to the corresponding level.

[0035] The study employed several methods to evaluate the reliability and consistency of the data acquisition unit 141. The GRR analysis method was used to calculate the repeatability and reproducibility of the measurement system, determine the GRR percentage, and ensure that the measurement error remained within acceptable limits. A confidence interval verification method was used to verify the reliability of the threshold statistics. Using preprocessed data as a sample and corresponding threshold parameters, the sample mean and standard deviation were calculated. A normal distribution was selected based on the sample size, and a 95% confidence interval was calculated to verify whether the calculated threshold parameters met the confidence interval. This ensured the statistical significance of the threshold statistics, eliminated biases caused by random factors, and improved the statistical reliability of the thresholds. The obtained threshold parameters were then substituted back into all historical test data to count the number of samples that triggered warnings and the number of samples that actually experienced thermal runaway. The false alarm rate and false alarm rate were calculated, and statistical analysis ensured that the false alarm rate was 0 and the false alarm rate was less than 0.1%. This verified the practical application effect of the threshold parameters. The false alarm rate was the percentage of samples that actually experienced thermal runaway but did not trigger a warning, and the false alarm rate was the percentage of samples that triggered a warning but did not actually experience thermal runaway.

[0036] Specifically, the alarm and early warning linkage execution unit 144 includes a BMS linkage verification module, a thermal management control module, a fire-fighting linkage module, an exhaust gas purification module, and an emergency ventilation module. The main control module 143 is connected to the BMS linkage verification module, the thermal management control module, the fire-fighting linkage module, the exhaust gas purification module, and the emergency ventilation module, respectively. The BMS linkage verification module is used to compare the received test data with threshold parameters and send a corresponding early warning signal to the main control module according to the comparison result, so that the main control module can control the operation of the thermal management control module, the fire-fighting linkage module, the exhaust gas purification module, and the emergency ventilation module according to the corresponding early warning signal.

[0037] The thermal management control module is used for temperature control to adjust cooling power and actively eliminate battery heat accumulation, thus blocking the path of thermal runaway. The thermal management control module is electrically connected to the liquid cooling pipeline system to control its operation. Multiple temperature sensors are installed inside the chamber 11 to collect temperature data in real time and feed it back to the thermal management control module, forming a closed-loop temperature control circuit. During operation, the thermal management control module receives control commands from the main control module 143 and precisely controls the coolant flow rate of the liquid cooling pipeline system by adjusting the opening of the electronic expansion valve. The coolant absorbs heat generated by the battery during its circulation within the pipeline of the chamber 11 for heat dissipation, achieving continuous temperature control. The fire-fighting linkage module is used to perform fire extinguishing, cooling, and reignition suppression operations. The module includes an extinguishing agent nozzle array and a water mist pipeline. The extinguishing agent nozzle array can be installed on the top of the chamber 11 to cover the entire test area. The extinguishing agent nozzle array can be a perfluorohexanone nozzle array, enabling rapid fire extinguishing. The water mist pipeline can be a high-pressure fine water mist pipeline, arranged around the bottom and sides of the chamber 11 to continuously cool and suppress reignition through the extinguishing agent nozzle array in conjunction with the water mist pipeline. The fire-fighting linkage module may also include a nitrogen purging pipeline connected to the air inlet of the chamber 11, allowing nitrogen to be purged into the chamber 11 to reduce the oxygen content inside, achieving inerting protection. The exhaust gas purification module is used to treat toxic and harmful gases such as carbon monoxide (CO), hydrogen fluoride (HF), and volatile organic compounds (VOCs) generated during thermal runaway, achieving compliant emissions. VOCs include formaldehyde, benzene, and toluene, which are organic compounds that readily volatilize at room temperature. The exhaust gas purification module's inlet is rigidly sealed to the exhaust outlet of chamber 11 via a flange, and the flange of the exhaust gas purification module is rigidly sealed to the exhaust outlet of the explosion-proof test chamber. The exhaust outlet is connected to the laboratory's centralized exhaust system. The exhaust gas purification module includes a primary filter unit, an activated carbon adsorption unit, a chemical scrubbing unit, and a catalytic combustion unit. Toxic and harmful gases generated during thermal runaway within chamber 11 enter the exhaust gas purification module through the exhaust outlet, sequentially passing through the primary filter unit to trap particulate matter, the activated carbon adsorption unit to neutralize acidic gases, the chemical scrubbing unit to adsorb organic gases, and the catalytic combustion unit for catalytic oxidation and decomposition treatment, ensuring that the gases emitted from the exhaust outlet of the exhaust gas purification module meet ambient air quality standards. The emergency ventilation module is used to quickly replace the gas inside compartment 11, reduce the concentration of flammable gases, and prevent explosions. The emergency ventilation module includes a high-power explosion-proof fan installed at the exhaust port on the top of compartment 11. An air intake port is located at the bottom of compartment 11, forming a convection path. By controlling the explosion-proof fan to start at full power, a negative pressure flow field is created inside compartment 11. Fresh air enters from the air intake port at the bottom of compartment 11, directing toxic and flammable gases towards the exhaust port at the top. The exhaust gas is then purified by the exhaust gas purification module.The emergency ventilation module can quickly replace all the gas inside compartment 11, effectively reducing the risk of explosion.

[0038] Preferably, the threshold parameters ultimately verified and output by the data analysis unit 142 include a first-level warning trigger threshold, a second-level warning trigger threshold, a third-level warning trigger threshold, a thermal management control threshold, a fire-fighting linkage threshold, and an aging compensation coefficient matrix between the battery health status and the thresholds. Specifically, the first-level warning trigger threshold includes the upper and lower voltage limits of a single cell, the voltage difference threshold of a single cell, the upper temperature limit, and the temperature difference threshold; the second-level warning trigger threshold includes the temperature rise rate threshold, the carbon monoxide concentration threshold, the hydrogen concentration threshold, the hydride concentration threshold, and the voltage drop threshold; the third-level warning trigger threshold includes the thermal runaway confirmation temperature threshold and the thermal runaway confirmation temperature rise rate threshold; the thermal management control threshold includes the cooling start / stop temperature, the heating start / stop temperature, and the maximum allowable temperature difference; and the fire-fighting linkage threshold includes the pre-fire-fighting activation trigger threshold, the fire-extinguishing activation trigger threshold, and the exhaust gas purification activation trigger threshold.

[0039] Preferably, the BMS linkage verification module obtains the corresponding aging compensation coefficient based on the aging compensation coefficient matrix between the battery health status and the threshold in the received threshold parameters, combined with the current battery health status, and dynamically corrects the warning trigger threshold, thermal management control threshold, and fire linkage threshold for each level. This results in corrected warning trigger thresholds, thermal management control thresholds, and fire linkage thresholds for each level. The module then synchronously compares the received test data with the corrected warning trigger thresholds for each level, obtains the highest value corresponding to the level of warning trigger threshold satisfied by the test data, and sends a warning signal corresponding to the highest value to the main control module 143. This allows the main control module 143 to control the operation of the thermal management control module, the fire linkage module, the exhaust gas purification module, and the emergency ventilation module based on the corresponding warning signal.

[0040] When the highest value of the level corresponding to the warning trigger threshold satisfied by the test data is 1, that is, the test data satisfies any one of the threshold conditions of the upper and lower limits of the voltage of a single cell, the voltage difference threshold of a single cell, the upper limit of the temperature, and the temperature difference threshold in the first-level warning trigger threshold, then a first-level warning signal is sent to the main control module 143, and the main control module 143 starts the liquid cooling pipeline system according to the thermal management control threshold.

[0041] When the highest value of the warning trigger threshold corresponding to the test data is 2, that is, when the test data meets any of the threshold conditions in the secondary warning trigger threshold, namely the temperature rise rate threshold, carbon monoxide concentration threshold, hydrogen concentration threshold, hydride carbon concentration threshold, and voltage drop threshold, a secondary warning signal is sent to the main control module 143. The main control module 143 starts the liquid cooling pipeline system according to the thermal management control threshold and controls it to operate at full power, and starts the pre-fire protection procedure according to the fire linkage threshold. The pre-fire protection procedure involves filling the explosion-proof test chamber with nitrogen for inerting treatment, reducing the oxygen content in the explosion-proof test chamber, and suppressing the risk of combustion and explosion of combustible gases.

[0042] When the highest value of the warning trigger threshold corresponding to the test data is 3, that is, the test data meets any one of the threshold conditions of the thermal runaway confirmation temperature threshold and the thermal runaway confirmation temperature rise rate threshold in the three-level warning trigger threshold, a three-level warning signal is sent to the main control module 143. The main control module 143 starts the liquid cooling pipeline system and controls it to work at maximum power according to the thermal management control threshold, starts the fire extinguishing procedure and starts the exhaust gas purification and emergency ventilation according to the fire linkage threshold.

[0043] In summary, the battery thermal safety threshold testing system of this invention arranges the test process according to the hierarchical order of cells, modules, and battery packs through a safety test CNC module to control the operation of the hierarchical test module. This allows for the application of the same temperature boundary and synchronous charge / discharge, achieving closed-loop testing and verification of cells, modules, and battery packs. Combined with the test chamber, this ensures that the testing of cells, modules, and battery packs is conducted in the same environment. Test data is uniformly collected and analyzed through the safety test CNC module, utilizing synchronous acquisition under a unified benchmark to improve test data consistency. This solves the problem of inconsistent test environments and acquisition control benchmarks at different levels in existing battery safety performance testing, leading to poor test data consistency due to fragmented test links. The obtained battery thermal safety thresholds are traceable across levels. Furthermore, the aging test module obtains aged battery test samples for the hierarchical test module to perform battery thermal safety tests on these samples, obtaining the parameter change patterns throughout the entire life cycle. This enables adaptive adjustment of the battery thermal safety threshold based on the battery health status, avoiding the failure of traditional fixed thresholds after battery aging and improving system reliability.

[0044] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A battery thermal safety threshold testing system, characterized in that, include: hull; A hierarchical testing module is installed in the cabin and is used to perform battery thermal safety tests on the cells, modules and battery packs in a hierarchical order according to the cell, module and battery pack. An aging test module, located in the chamber, is used to perform cycle aging tests and calendar aging tests on the battery respectively, and obtain battery test samples after aging, so that the hierarchical test module can perform battery thermal safety tests on the battery test samples after aging. A safety test CNC module, located in the cabin, is communicatively connected to the hierarchical test module and the aging test module. It is used to arrange the test process according to the hierarchical order of cells, modules and battery packs, control the operation of the hierarchical test module and the aging test module, collect and analyze test data to calculate the battery thermal safety threshold, and provide alarm and early warning responses based on the obtained battery thermal safety threshold.

2. The battery thermal safety threshold testing system according to claim 1, characterized in that, The safety testing CNC module includes a data acquisition unit, a data analysis unit, a main control module, and an alarm and early warning linkage execution unit. The main control module is communicatively connected to the data acquisition unit, the data analysis unit, the alarm and early warning linkage execution unit, the hierarchical testing module, and the aging testing module. It is used to arrange the test process according to the hierarchical order of cells, modules, and battery packs, and to send control signals and control parameters to the data acquisition unit, the data analysis unit, the alarm and early warning linkage execution unit, the hierarchical testing module, and the aging testing module, and to receive corresponding status feedback. The data acquisition unit responds to the control of the main control module by acquiring test data using sensors deployed on the cells, modules, and battery packs with a unified timestamp. The data analysis unit is connected to the data acquisition unit and receives the test data acquired by the data acquisition unit, preprocesses it, and calculates the battery thermal safety threshold to obtain threshold parameters. The alarm and warning linkage execution unit is connected to the main control module, the data acquisition unit, and the data analysis unit. It is used to receive test data acquired by the data acquisition unit and threshold parameters obtained by the data analysis unit, and to perform alarm and warning hierarchical linkage control based on the test data and threshold parameters.

3. The battery thermal safety threshold testing system according to claim 2, characterized in that, The data acquisition unit uses a 128-channel synchronous acquisition instrument.

4. The battery thermal safety threshold testing system according to claim 2, characterized in that, The alarm and early warning linkage execution unit includes a BMS linkage verification module, a thermal management control module, a fire-fighting linkage module, an exhaust gas purification module, and an emergency ventilation module. The main control module is connected to the BMS linkage verification module, the thermal management control module, the fire-fighting linkage module, the exhaust gas purification module, and the emergency ventilation module, respectively. The BMS linkage verification module is used to compare the received test data with threshold parameters and send corresponding early warning signals to the main control module according to the comparison results, so that the main control module can control the operation of the thermal management control module, the fire-fighting linkage module, the exhaust gas purification module, and the emergency ventilation module according to the corresponding early warning signals.

5. The battery thermal safety threshold testing system according to claim 4, characterized in that, The BMS linkage verification module, based on the aging compensation coefficient matrix between the battery health status and the threshold in the received threshold parameters, and combined with the current battery health status, obtains the corresponding aging compensation coefficient to dynamically correct the warning trigger threshold, thermal management control threshold, and fire linkage threshold for each level. This results in corrected warning trigger thresholds, thermal management control thresholds, and fire linkage thresholds for each level. The module then synchronously compares the received test data with the corrected warning trigger thresholds for each level, obtains the highest value corresponding to the level of warning trigger threshold satisfied by the test data, and sends a warning signal corresponding to that highest value to the main control module. This allows the main control module to control the operation of the thermal management control module, the fire linkage module, the exhaust gas purification module, and the emergency ventilation module based on the corresponding warning signal.

6. The battery thermal safety threshold testing system according to claim 1, characterized in that, The hierarchical testing module includes a cell testing unit, which comprises an accelerating calorimeter, a charge / discharge cabinet, a high / low temperature test chamber, a camera, and a multi-component gas sensor. The charge / discharge cabinet controls the remaining charge of the cell fixed to the clamp of the accelerating calorimeter. The accelerating calorimeter controls the temperature rise of the cell according to a preset heating rate, acquiring the cell's self-heating initiation temperature, diaphragm closure temperature, explosion-proof valve opening temperature, and thermal runaway trigger temperature. By moving the cell into the high / low temperature test chamber and using the charge / discharge cabinet, overcharge and over-discharge tests are performed on the cell, outputting voltage and current surge thresholds. The camera captures the transient thermal runaway process. The multi-component gas sensor collects carbon monoxide, hydrogen, and hydride concentrations.

7. The battery thermal safety threshold testing system according to claim 1, characterized in that, The hierarchical testing module includes a module testing unit, which comprises an explosion-proof test chamber and a thermal management testing component. After the tested battery cells and heating elements are assembled into a module, it is moved into the explosion-proof test chamber. The module's liquid cooling interface is connected to the liquid cooling pipeline system. The thermal management testing component sets the liquid cooling flow rate range, coolant temperature range, and liquid cooling pipeline system pressure range. The safety test CNC module controls the module's heating elements to trigger thermal runaway, outputting parameters such as the module's internal temperature difference, temperature rise rate, and heat spread rate. The safety test CNC module sends an early warning trigger signal to the thermal management testing module to verify the thermal management system's response time.

8. The battery thermal safety threshold testing system according to claim 1, characterized in that, The hierarchical testing module includes a battery pack testing unit, which comprises a high-power charging and discharging cabinet, a high-voltage control unit, and a BMS threshold calibration unit. After the tested modules are assembled into a battery pack, they are connected to the high-voltage control unit and the BMS threshold calibration unit. The high-power charging and discharging cabinet, via the high-voltage control unit, simulates high-voltage series operation of the battery pack, and then performs a full-condition charging and discharging test. The BMS threshold calibration unit continuously collects the battery pack's BMS operating data to verify different levels of alarm triggering logic, thermal management control strategies, and fire-fighting linkage execution logic.

9. The battery thermal safety threshold testing system according to claim 1, characterized in that, The aging test module includes a cyclic aging chamber. By placing the battery cell to be tested into the cyclic aging chamber, the battery cell to be tested is subjected to a preset number of cycles in the cyclic aging chamber to obtain a battery test sample after cyclic aging, which is then used by the hierarchical test module to perform battery thermal safety testing on the cyclically aged battery test sample.

10. The battery thermal safety threshold testing system according to claim 1, characterized in that, The aging test module includes a high-temperature storage box. By placing the battery cell to be tested into the high-temperature storage box and letting it stand at a preset aging temperature for a preset time, a battery test sample after calendar aging is obtained, which is then used by the hierarchical test module to perform battery thermal safety testing on the battery test sample after calendar aging.

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