A high-precision testing system for electrical performance parameters of power battery cells

Abstract

This application relates to the field of power battery testing technology and discloses a high-precision testing system for the electrical performance parameters of power battery cells. The system acquires the terminal clamping status information of the cell under test, executes forward and reverse micropulse pre-excitation and collects voltage and current response results, extracts contact response characteristics, and generates contact stability judgment results, calibration validity judgment results, and test release results by combining zero-point drift results and link compensation results. After test release, the system executes main pulse testing, generates cell electrical performance parameter results and anomaly verification results, and outputs re-clamping or recalibration instructions. The system can distinguish between contact-side anomalies and test channel-side anomalies, improving the stability of cell electrical performance parameter test results and test processing efficiency.

Description

Technical Field

[0001] This application relates to the field of power battery testing technology, and more specifically, to a high-precision testing system for the electrical performance parameters of power battery cells. Background Technology

[0002] With the widespread application of power batteries in new energy vehicles, energy storage equipment, and secondary utilization scenarios, the open-circuit voltage, internal resistance, and impulse response electrical performance parameters of battery cells are usually tested during factory screening, grouping, maintenance re-inspection, and life assessment. The test results of electrical performance parameters are not only related to the quality judgment of individual battery cells, but also to the subsequent group consistency evaluation, remaining performance assessment, and operational safety analysis. Therefore, high requirements are placed on the accuracy of power battery cell electrical performance parameter testing, the stability of test results, and the efficiency of anomaly handling.

[0003] Existing power battery cell electrical performance parameter testing systems typically include clamping fixtures, test channels, sampling circuits, and control circuits. During testing, the cell under test is first clamped onto the test station, and then the test channel applies test excitation to the cell under test and collects response data such as voltage and current, thereby calculating the corresponding electrical performance parameters. To improve testing accuracy, existing solutions typically optimize aspects such as fixture conduction status, sampling accuracy, channel calibration, link compensation, and test process control to reduce the impact of contact-related errors, channel drift errors, and link errors on the test results.

[0004] However, in actual testing, on the one hand, the contact state between the cell terminal and the clamping component is easily affected by factors such as clamping position, contact coverage, clamping force, contact surface condition, and consistency of repeated clamping; on the other hand, the test channel itself may also produce measurement deviations due to zero-point drift, link compensation deviation, or changes in calibration status. Before formal testing, existing solutions usually lack a processing mechanism to separately determine the contact state and the test channel state, making it difficult to effectively distinguish between the additional error on the contact side and the measurement error on the test channel side before entering formal testing. After formal testing, when there are large fluctuations in parameter results, poor consistency of repeated testing, or abnormal responses, there is usually no processing mechanism to further verify the test results and select the corresponding correction path according to the source of the anomaly. As a result, test anomalies are mostly handled uniformly by repeated testing, re-clamping, or recalibration. This not only increases the number of invalid tests, but also makes the correction actions in the test process lack specificity, thereby affecting the stability of the cell's electrical performance parameters and the overall test processing efficiency.

[0005] Therefore, how to distinguish between contact-side anomalies and test channel-side anomalies during the testing of the electrical performance parameters of power battery cells, while ensuring the accuracy of formal testing, and how to select the corresponding correction path after anomalies occur, so as to improve the stability of the test results and the efficiency of test processing, has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] To overcome the aforementioned deficiencies of the prior art, this application provides the following technical solution: By performing clamping status identification, pre-excitation sampling, contact response feature extraction, test release judgment, main pulse testing, anomaly verification, and anomaly shunt control on the battery cell under test, a continuous processing chain is formed, encompassing pre-test judgment, parameter generation during testing, and anomaly shunt control after testing. This improves the accuracy, stability, and testing efficiency of the battery cell's electrical performance parameter test results. This application discloses a high-precision testing system for the electrical performance parameters of power battery cells, including: Clamping identification unit, used to acquire the terminal clamping status information of the battery cell under test; The pre-excitation execution unit is used to apply positive and reverse micropulses to the cell under test and to collect the corresponding voltage and current response results. The feature extraction unit is used to extract the initial instantaneous voltage drop difference, recovery slope difference, and repetitive pulse deviation based on the terminal clamping status information, voltage response results, and current response results, and to generate contact response feature results. The judgment unit is used to generate contact stability judgment results, calibration validity judgment results, and test release results based on the contact response characteristic results and the zero drift results and link compensation results in the most recent calibration reference. The formal test unit is used to perform the main pulse test and generate the cell electrical performance parameters when the test release result is a release result; The anomaly verification unit is used to generate anomaly verification results based on the cell's electrical performance parameters and the consistency results of adjacent responses during the main pulse test. The shunt control unit is used to output a re-clamping command or a recalibration command based on the contact stability judgment result and the calibration validity judgment result when the test release result is a non-release result or the abnormal review result meets the shunt conditions.

[0007] Furthermore, the methods for acquiring the corresponding voltage response and current response results include: Before applying positive and reverse micropulses to the cell under test, the terminal voltage of the cell under test and the current of the test channel are continuously collected to generate the voltage baseline and the current baseline before pre-excitation. Based on the application time of the positive and negative micropulses, the terminal voltage and channel current are synchronously collected before the start of each micropulse, during its duration, and during its recovery. Based on the pre-excitation voltage baseline, pre-excitation current baseline and sampling data corresponding to each micropulse, timing correction is performed to generate voltage response results and current response results that correspond one-to-one with the voltage response results. By establishing a unified baseline before and after the application of micropulse and performing time-series correction on the sampled data at each stage, the response data corresponding to micropulses of different polarities can be placed under a consistent comparison caliber, thereby providing a unified data foundation for subsequent contact response feature extraction.

[0008] Furthermore, methods for generating contact response characteristic results include: The effective response range is determined based on the terminal clamping status information, voltage response results, and current response results. Based on the effective response range, the normalized initial voltage drop corresponding to the first positive micropulse and the first negative micropulse is determined, and the two are directionally rounded and the difference is calculated to obtain the initial voltage drop difference; The forward recovery slope and the reverse recovery slope are determined based on the effective response interval, and the two are directionally rounded and the difference is calculated to obtain the recovery slope difference; The positive repetition bias and the negative repetition bias are determined based on the effective response range, and the repetition pulse bias is obtained based on the positive repetition bias and the negative repetition bias. Based on the initial instantaneous pressure drop difference, recovery slope difference, and repetitive pulse deviation, contact response characteristic results are generated; By combining the pole clamping status information to filter the pre-excitation response data and extracting the differences in the initial response, the recovery process, and the repeated response, the influence of the clamping contact state on the test response can be converted into comparable contact response features, thus providing a basis for contact side anomaly identification.

[0009] Furthermore, methods for generating contact stability determination results include: Read the initial voltage drop difference, recovery slope difference, and repetitive pulse deviation from the contact response characteristic results; compare the initial voltage drop difference, recovery slope difference, and repetitive pulse deviation with the contact characteristic reference range corresponding to the current cell type and the current test channel, respectively; When the initial instantaneous voltage drop difference, recovery slope difference, and repetitive pulse deviation are all within the corresponding allowable range, the contact stability judgment result is generated as a contact release state. When any feature quantity is outside the corresponding allowable range, the resulting contact stability determination is that the contact cannot be released. By comparing the contact response characteristic results with the corresponding contact characteristic reference range, the current clamping contact state can be determined before the formal test, thereby reducing the possibility of unstable clamping contact entering the formal test.

[0010] Furthermore, methods for generating calibration validity determination results include: Read the zero-point drift results and link compensation results from the most recent calibration reference; Compare the zero-point drift result with the allowable zero-point drift range corresponding to the current test channel, and compare the link compensation result with the allowable link compensation range corresponding to the current test channel; When the zero-point drift result is within the allowable range of zero-point drift and the link compensation result is within the allowable range of link compensation, the calibration validity judgment result is generated as calibration release status. When the zero-point drift result is outside the allowable range of zero-point drift or the link compensation result is outside the allowable range of link compensation, the calibration validity judgment result is generated as calibration cannot be released. By incorporating the zero-point drift results and link compensation results into the pre-test judgment process, the current state of the test channel can be independently verified, thereby distinguishing the test channel side error from the clamping contact side error.

[0011] Furthermore, methods for generating test release results include: Read the contact stability assessment results and calibration validity assessment results; The results of the contact stability assessment and the calibration validity assessment are combined for judgment. When the contact stability determination result is that the contact is ready for release and the calibration validity determination result is that the calibration is ready for release, the test release result is generated as the release result. When the contact stability determination result is that the contact is not releaseable, or the calibration validity determination result is that the calibration is not releaseable, the generated test release result is a non-release result. By combining the results of contact stability assessment and calibration validity assessment, formal testing can be initiated only when both the contact state and the test channel state meet the requirements, thereby improving the data reliability during the formal testing phase.

[0012] Furthermore, methods for generating cell electrical performance parameter results include: When the test release result is a release result, the main pulse test is performed on the cell under test, and the voltage sampling sequence and current sampling sequence corresponding to each main pulse are collected to generate the main pulse response result; Based on the main pulse response results, determine the test start voltage, ohmic internal resistance, average continuous response, and recovery slope corresponding to each main pulse. Based on the test start voltage, ohmic internal resistance, average continuous response and recovery slope corresponding to each main pulse, the cell electrical performance parameters are generated. By performing a main pulse test after the test is released, and extracting multiple electrical performance characteristics based on the main pulse response results, the battery cell electrical performance parameters can be generated based on the pre-determined contact state and test channel state, thereby improving the stability of the parameter results.

[0013] Furthermore, methods for generating anomaly review results include: Read the open-circuit voltage parameter, ohmic internal resistance parameter, and polarization response parameter from the battery cell electrical performance parameter results, and compare the open-circuit voltage parameter, ohmic internal resistance parameter, and polarization response parameter with the corresponding allowable ranges to generate parameter verification results; The consistency results of adjacent responses are compared with the upper limit of the consistency allowance to generate a consistency review result; Based on the parameter verification results and consistency verification results, generate anomaly verification results; By combining parameter result verification with test process consistency verification, abnormal states after formal testing can be reconfirmed, thereby reducing misjudgments caused by relying solely on single parameter results for anomaly assessment.

[0014] Furthermore, methods for outputting reclamping or recalibration commands include: The diversion trigger result is generated based on the test release result and the anomaly review result; When the shunt trigger result is a triggered shunt state, the shunt judgment is made based on the contact stability judgment result and the calibration validity judgment result; When the calibration validity determination result is that the calibration cannot be released, a recalibration command is output. When the calibration validity determination result is that the calibration is ready for release and the contact stability determination result is that the contact is not ready for release, a re-clamping command is output. By diverting abnormal states based on contact stability and calibration effectiveness results, abnormalities from different sources can be directed to corresponding correction paths, thereby improving the targeted nature of abnormality handling.

[0015] Furthermore, methods for generating consistent results for adjacent responses include: Extract two adjacent main pulses of the same polarity and amplitude from the main pulse response results in the order of testing to form an adjacent response comparison group; Consistency deviation is generated based on the difference in ohmic internal resistance, the difference in average sustained response, and the difference in recovery slope corresponding to each adjacent response comparison group. Generate consistency results for adjacent responses based on each consistency deviation. By quantifying the response difference between two adjacent main pulses of the same polarity and amplitude, the stability of repeated responses during formal testing can be characterized, thus providing a basis for the consistency of the testing process for anomaly verification.

[0016] Compared with related technologies, this application has the following advantages: Before the formal main pulse test, this application does not simply use unidirectional micropulses to obtain a single pre-test response. Instead, it first obtains the terminal clamping status information of the cell under test, then applies forward and reverse micropulses to the cell under test, and collects the corresponding voltage and current response results. Subsequently, it obtains the normalized initial instantaneous voltage drop, forward recovery slope, and reverse recovery slope corresponding to the first forward and reverse micropulses, respectively, and performs direction correction and difference calculation. Through this comparative sampling method under opposite current directions, it is possible to separate directional contact anomalies caused by terminal clamping offset, uneven clamping coverage, or differences in clamping force from the pre-excitation response, thereby improving the ability to identify contact anomalies before testing and reducing the mixing of contact-side anomalies with the normal response of the cell body.

[0017] This application does not use a general contact resistance value to judge the contact state as a single index. Instead, it combines the pre-excitation sampling results to extract the initial voltage drop difference, recovery slope difference, and repetitive pulse deviation, and generates contact response characteristic results. Among them, the initial voltage drop difference is used to characterize the difference in contact additional voltage drop at the moment the pulse enters, the recovery slope difference is used to characterize the difference in recovery speed after the pulse is removed, and the repetitive pulse deviation is used to characterize the difference in response stability under repeated excitation under the same conditions. By jointly characterizing the transient response, recovery response, and repetitive consistency, the current contact state can be more completely described, thereby improving the reliability of the contact stability judgment results and providing a basis for subsequently separating the contact side state from the test channel side state and incorporating them into the pre-test judgment process.

[0018] This application combines the contact response characteristic results with the zero-point drift results and link compensation results from the most recent calibration benchmark to generate contact stability judgment results and calibration validity judgment results, respectively. Then, based on the two, a test release result is generated, and the main pulse test is only executed when both the contact state and the calibration state are in a state where testing can continue. Through the pre-release processing method of contact-side judgment + test channel-side judgment, the situation of directly entering the formal test under the condition of unstable contact or calibration failure can be reduced, the probability of invalid test and repeated test is reduced, and the execution stability and test resource utilization efficiency of the formal test stage are improved.

[0019] After formal testing, this application not only generates cell electrical performance parameter results, but also extracts two adjacent main pulses of the same polarity and amplitude from the main pulse response results in the test order as adjacent response comparison groups. Based on the difference in ohmic internal resistance, the difference in average sustained response, and the difference in recovery slope corresponding to each adjacent response comparison group, it generates adjacent response consistency results. Since the subsequent consistency comparison is limited to adjacent, same polarity, and same amplitude main pulses, it is possible to observe response fluctuations under formal test load while maintaining consistent main test conditions. Combined with the cell electrical performance parameter results, it generates anomaly verification results. This not only further confirms whether the current test results are abnormal, but also further distinguishes between contact anomalies and test channel anomalies, reducing the risk of misjudgment caused by judging based on only a single parameter result.

[0020] This application, when the test release result is a non-release result or the abnormality review result meets the shunting conditions, outputs a re-clamping command or a recalibration command based on the contact stability judgment result and the calibration validity judgment result, so that the test abnormality can enter the corresponding correction path according to the source of the abnormality; at the same time, by constructing a continuous processing chain between pre-test judgment, formal test, post-test review and abnormality shunting processing, the judgment link, review link and correction link form a closed cooperation relationship, thereby improving the accuracy, stability and test processing efficiency of the power battery cell electrical performance parameter test results. Attached Figure Description

[0021] Figure 1 A schematic diagram of the overall process of a high-precision testing system for the electrical performance parameters of a power battery cell provided in this application; Figure 2 A data processing flowchart for the pre-excitation execution and contact response characteristics provided in this application; Figure 3 The data processing flowchart provided for this application includes judgment, formal testing, anomaly review, and diversion control. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] Please see Figure 1As shown, this embodiment provides a high-precision testing system for the electrical performance parameters of a power battery cell, including a clamping and identification unit, a pre-excitation execution unit, a feature extraction unit, a judgment unit, a formal testing unit, an anomaly verification unit, and a current shunting control unit. Each unit is connected by wires and / or wirelessly to realize data transmission between units.

[0024] The clamping identification unit is used to acquire the terminal clamping status information of the battery cell under test. Its purpose is to identify the clamping relationship between the battery cell under test and the positive and negative clamping components in the current test station, and generate the terminal clamping status information to be called by the subsequent pre-excitation execution unit and feature extraction unit, so that the subsequent micro-pulse application position, sampling position and response interpretation caliber all correspond to the current clamping status.

[0025] In some implementations, the clamping identification unit includes the following steps: Step 101: Determine the current clamping correspondence between the cell under test and the clamping components. Specifically, read the cell under test in the current test station and determine the positive and negative terminals of the cell under test; at the same time, read the positive clamping component used to clamp the positive terminal and the negative clamping component used to clamp the negative terminal in the current test station to generate the current clamping correspondence; the current clamping correspondence is used to collect clamping status data in step 102.

[0026] Step 102: Acquire clamping status data according to the current clamping correspondence. Specifically, based on the current clamping correspondence, acquire image data of the positive and negative electrode regions, and acquire displacement data of the positive and negative electrode clamping components. When the clamping mechanism is equipped with a force detection element, simultaneously acquire clamping force data of the positive and negative electrode clamping components to generate clamping status data. The clamping status data includes at least image data, displacement data, and clamping force data or force data reflected by the displacement data. The clamping status data is used to generate electrode clamping status information in step 103.

[0027] Step 103: Generate electrode clamping status information based on clamping status data. Specifically, read the clamping status data generated in step 102; first, extract the edges of the positive electrode outline, negative electrode outline, positive electrode clamping component contact boundary, and negative electrode clamping component contact boundary in the image data, and then perform region closure processing on the positive electrode outline, negative electrode outline, positive electrode clamping component contact boundary, and negative electrode clamping component contact boundary respectively to obtain the positive electrode projection area, negative electrode projection area, positive electrode clamping projection area, and negative electrode clamping projection area; then calculate the positive electrode projection area, negative electrode projection area, positive electrode clamping projection area, and negative electrode clamping projection area respectively. The geometric center positions of the projection area, the negative pole projection area, the positive pole clamping projection area, and the negative pole clamping projection area are defined. The center distance between the geometric center positions of the positive pole and the positive pole clamping is defined as the positive pole clamping position, and the center distance between the geometric center positions of the negative pole and the negative pole clamping is defined as the negative pole clamping position. The center distance can be calculated by calculating the spatial distance based on the difference in the lateral and longitudinal coordinates of the two corresponding geometric center positions.

[0028] After obtaining the positive electrode projection area, negative electrode projection area, positive electrode clamping projection area, and negative electrode clamping projection area, calculate the ratio of the overlap area between the positive electrode clamping projection area and the positive electrode projection area to the area of ​​the positive electrode projection area, and determine the ratio as the positive electrode clamping coverage amount; calculate the ratio of the overlap area between the negative electrode clamping projection area and the negative electrode projection area to the area of ​​the negative electrode projection area, and determine the ratio as the negative electrode clamping coverage amount.

[0029] After obtaining displacement data and clamping force data, when clamping force data exists, the clamping force values ​​corresponding to multiple consecutive sampling points within the clamping closure stabilization phase are averaged to generate the positive terminal clamping force and the negative terminal clamping force, respectively. When clamping force data does not exist, the current displacement data is read, and the pre-established displacement-force correspondence is called to perform interpolation calculations between the two standard displacement points corresponding to the current displacement data interval, generating the positive terminal clamping force and the negative terminal clamping force, respectively.

[0030] The clamping position of the positive terminal, the clamping position of the negative terminal, the clamping coverage of the positive terminal, the clamping coverage of the negative terminal, the clamping force of the positive terminal, and the clamping force of the negative terminal are summarized to generate terminal clamping status information; the terminal clamping status information is used by the pre-excitation execution unit and the feature extraction unit.

[0031] The relationship between displacement and force can be established as follows: For the current clamping mechanism, the corresponding standard force values ​​are collected at multiple clamping displacement positions to form a correspondence between displacement and force; subsequently, the current clamping force is obtained by calling the correspondence based on the current displacement data.

[0032] In some implementations, to illustrate the process of generating pole clamping status information based on clamping status data, for example: For the current battery cell under test, the positive terminal clamping position is calculated to be 0.21 mm based on the positive terminal projection area and the positive terminal clamping projection area, and the negative terminal clamping position is calculated to be 0.18 mm based on the negative terminal projection area and the negative terminal clamping projection area. Furthermore, based on the overlap ratio of the positive terminal clamping projection area and the positive terminal projection area, the positive terminal clamping coverage is 94.4%, and based on the overlap ratio of the negative terminal clamping projection area and the negative terminal projection area, the negative terminal clamping coverage is 93.1%. When the clamping force values ​​continuously collected by the positive terminal clamping component during the clamping closure stabilization phase are 41.8 N, 42.3 N, and 42.1 N, respectively, an average calculation is performed to obtain the positive terminal clamping force as 42.1 N; when the clamping force values ​​continuously collected by the negative terminal clamping component during the clamping closure stabilization phase are 40.9 N, 41.2 N, and 41.1 N, respectively, an average calculation is performed to obtain the negative terminal clamping force as 41.1 N; the positive terminal clamping position, negative terminal clamping position, positive terminal clamping coverage, negative terminal clamping coverage, positive terminal clamping force, and negative terminal clamping force are summarized to generate the terminal clamping status information corresponding to the current cell under test, which is then used in step 201.

[0033] The pre-excitation execution unit is used to apply positive and reverse micropulses to the cell under test and collect the corresponding voltage and current response results. The purpose is to establish a stable pre-excitation connection relationship for the cell under test based on the terminal clamping status information generated by the clamping identification unit before the formal main pulse test. Then, positive and reverse micropulses for contact identification are applied, and the corresponding terminal voltage response and channel current response are collected to generate voltage and current response results for the feature extraction unit to continue to use.

[0034] In some implementations, see Figure 2 As shown, the implementation steps of the pre-excitation execution unit include: Step 201: Determine the current access direction and voltage sampling direction of the current test channel based on the terminal clamping status information, and generate pre-excitation access information; specifically, read the terminal clamping status information generated in step 103, and extract the positive terminal clamping position, negative terminal clamping position, positive terminal clamping coverage, negative terminal clamping coverage, positive terminal clamping force, and negative terminal clamping force from the terminal clamping status information; first, compare the positive terminal clamping position with the preset upper limit of allowable position, compare the positive terminal clamping coverage with the preset lower limit of allowable coverage, and compare the positive terminal clamping force with the preset allowable force range; when When the positive terminal clamping position does not exceed the preset upper limit, the positive terminal clamping coverage is not lower than the preset lower limit, and the positive terminal clamping force is within the preset allowable range, the positive terminal clamping component corresponding to the positive terminal is determined to be the effective positive terminal. Then, the negative terminal clamping position, negative terminal clamping coverage, and negative terminal clamping force are compared in the same way. When the negative terminal clamping position does not exceed the preset upper limit, the negative terminal clamping coverage is not lower than the preset lower limit, and the negative terminal clamping force is within the preset allowable range, the negative terminal clamping component corresponding to the negative terminal is determined to be the effective negative terminal.

[0035] After determining the effective positive and negative terminals, connect the current output terminal of the test channel to the effective positive terminal, connect the current return terminal of the test channel to the effective negative terminal, connect the positive voltage sampling terminal of the test channel to the voltage sampling node corresponding to the effective positive terminal, and connect the negative voltage sampling terminal of the test channel to the voltage sampling node corresponding to the effective negative terminal to determine the current input direction and voltage sampling direction corresponding to the positive micropulse. Then, connect the current output terminal of the test channel to the effective negative terminal, connect the current return terminal of the test channel to the effective positive terminal, and keep the positive voltage sampling terminal corresponding to the effective positive terminal and the negative voltage sampling terminal corresponding to the effective negative terminal to determine the current input direction and voltage sampling direction corresponding to the reverse micropulse.

[0036] Finally, the current access direction corresponding to the positive micropulse, the current access direction corresponding to the negative micropulse, the voltage sampling direction corresponding to the positive micropulse, and the voltage sampling direction corresponding to the negative micropulse are summarized to generate pre-excitation access information; the pre-excitation access information is used as the pre-excitation pulse sequence configured in step 202.

[0037] The preset upper limit of position, the preset lower limit of coverage, and the preset allowable force range can be set in the following ways: The data is based on historical clamping data of the same type of battery cell under qualified clamping conditions. The upper limit of position is used to limit the maximum allowable offset between the clamping center and the terminal post center. The lower limit of coverage is used to limit the minimum allowable coverage ratio of the clamping component on the terminal post surface. The allowable force range is used to limit the allowable force range during the clamping process.

[0038] Step 202: Configure forward and reverse micropulses based on the pre-excitation access information to generate a pre-excitation pulse sequence; specifically, read the pre-excitation access information generated in step 201, and read the rated capacity range, rated voltage range, and range configuration of the current test channel for the cell under test; determine the amplitude of the forward and reverse micropulses based on the rated capacity range and range configuration, determine the duration of a single micropulse based on the rated voltage range and the sampling period of the test channel, determine the interval duration between adjacent micropulses based on the time requirement for the cell under test to recover to near the voltage baseline before pre-excitation after pre-excitation, and determine the number of repetitions of the same polarity micropulses based on the minimum number of repetitions required for the consistency determination of the repetitive response.

[0039] The determination of the amplitude of the forward and reverse micropulses can be achieved by selecting a current amplitude that allows the change in terminal voltage to exceed the minimum resolvable voltage change of the test channel, without causing the cell under test to enter the formal charging and discharging condition. The determination of the duration of a single micropulse can be achieved by covering at least the initial response sampling interval and the recovery sampling interval within a single micropulse. The determination of the interval between adjacent micropulses can be achieved by ensuring that after the previous micropulse ends, the terminal voltage returns to the allowable fluctuation range of the pre-excitation voltage baseline before entering the next micropulse.

[0040] After determining the amplitude of the forward micropulse, the amplitude of the reverse micropulse, the duration of a single micropulse, the interval between adjacent micropulses, and the number of repetitions of micropulses of the same polarity, the micropulses are arranged in the following order: first forward micropulse - repetitive forward micropulse - first reverse micropulse - repetitive reverse micropulse to generate a pre-excitation pulse sequence. The pre-excitation pulse sequence includes at least the access direction, pulse amplitude, start time, duration, and interval duration corresponding to each micropulse. The pre-excitation pulse sequence is used in step 203 to apply the pre-excitation pulse and collect the response.

[0041] Step 203: Apply positive and reverse micropulses according to the pre-excitation pulse sequence to generate voltage response results and current response results; specifically, read the pre-excitation pulse sequence generated in step 202, and continuously sample the terminal voltage and test channel current of the cell under test before executing the pre-excitation pulse sequence to determine the voltage baseline and current baseline before pre-excitation respectively; then, according to the access direction, pulse amplitude, start time and duration of each micropulse in the pre-excitation pulse sequence, apply the first positive micropulse, the first positive repeating micropulse, the first reverse micropulse and the reverse repeating micropulse to the cell under test in sequence, and synchronously collect the terminal voltage and channel current within the preset sampling duration, duration and recovery duration before the start of each micropulse.

[0042] After all micro-pulse sampling is completed, the sampling sequence is rectified according to the pre-excitation voltage baseline, the pre-excitation current baseline, and the sampling data corresponding to each micro-pulse, based on the sampling interval before the micro-pulse start, the micro-pulse continuous sampling interval, and the micro-pulse recovery sampling interval. The rectified terminal voltage sampling sequences corresponding to the first positive micro-pulse, the positive repeating micro-pulse, the first reverse micro-pulse, and the reverse repeating micro-pulse are summarized to generate the voltage response result. The channel current sampling sequences corresponding one-to-one with the above terminal voltage sampling sequences are summarized to generate the current response result.

[0043] The voltage response results include at least the first positive micro-pulse voltage sampling sequence, the forward repeating micro-pulse voltage sampling sequence, the first reverse micro-pulse voltage sampling sequence, and the reverse repeating micro-pulse voltage sampling sequence; the current response results include at least the current sampling sequences that correspond one-to-one with the above voltage sampling sequences. The voltage and current response results are available for use by the feature extraction unit.

[0044] The pre-excitation voltage baseline and pre-excitation current baseline can be generated in the following ways: Before executing the first micropulse, the terminal voltage and channel current are continuously collected within multiple sampling cycles. The average of the multiple sampling points is calculated to obtain the pre-excitation voltage baseline and the pre-excitation current baseline.

[0045] Furthermore, to illustrate the process of generating voltage and current response results based on the pre-excitation pulse sequence, for example: For the battery cell under test with a rated capacity range of 50 Ah to 60 Ah, based on the current test channel range configuration, the forward micropulse amplitude can be set to +1.0 Ampere, the reverse micropulse amplitude to -1.0 Ampere, the duration of a single micropulse to 40 ms, the interval between adjacent micropulses to 200 ms, and the number of repetitions of the same polarity micropulse to 2. Before executing the first micropulse, multiple sampling points are continuously collected, with corresponding terminal voltages of 3.7123 V, 3.7125 V, 3.7124 V, 3.7124 V, and 3.7124 V, respectively. After averaging these values, the pre-excitation is obtained. The baseline voltage is 3.7124 volts; the corresponding channel currents are 0.000 amp, 0.001 amp, 0.000 amp, -0.001 amp and 0.000 amp respectively. After averaging these values, the baseline current before pre-excitation is 0.000 amp. Subsequently, the first positive micropulse, the first positive repeating micropulse, the first negative micropulse and the second negative repeating micropulse are applied sequentially according to the pre-excitation pulse sequence. The terminal voltage and channel current corresponding to each micropulse are synchronously acquired. After timing correction, the voltage response result and current response result corresponding to each micropulse are generated and used in steps 301 to 304.

[0046] The feature extraction unit is used to extract the initial instantaneous voltage drop difference, recovery slope difference, and repetitive pulse deviation based on the electrode clamping status information, voltage response results, and current response results, and to generate contact response feature results. The purpose is to convert the electrode clamping status information and the voltage response results and current response results obtained from the pre-excitation acquisition into quantitative features that can characterize the current contact state, and generate contact response feature results that can be used by the subsequent determination unit.

[0047] In some implementations, see Figure 2 As shown, the feature extraction unit implementation steps include: Step 301: Determine the effective response interval based on the terminal clamping status information, voltage response result, and current response result. Specifically, read the terminal clamping status information generated in step 103 and the voltage response result and current response result generated in step 203; determine the start interval and recovery interval corresponding to each micropulse based on the start and end times of the micropulse in the voltage response result; and then, in combination with the clamping position amount, clamping coverage amount, and clamping force in the terminal clamping status information, eliminate response segments where the number of consecutive missing sampling points exceeds the preset missing sampling upper limit, the clamping position change amount exceeds the preset position change upper limit, the clamping coverage amount is lower than the preset coverage lower limit, or the clamping force change amount exceeds the preset force change upper limit, thereby generating the effective response interval.

[0048] The preset upper limit for missing samples, the preset upper limit for position changes, the preset lower limit for coverage, and the preset upper limit for force changes can be set by: determining them based on the statistical fluctuation range of the clamped stable samples in historical pre-excitation tests; the effective response interval is used to extract contact response features in steps 302 to 304.

[0049] Step 302: Extract the initial voltage drop difference based on the effective response interval; specifically, read the effective voltage sampling sequence and effective current sampling sequence corresponding to the first positive micropulse, and the effective voltage sampling sequence and effective current sampling sequence corresponding to the first reverse micropulse; and determine the pulse start time and the first stable sampling time after the pulse start from their respective effective response intervals.

[0050] First, read the pre-excitation voltage baseline and pre-excitation current baseline before the start of the first positive micropulse. Then, read the voltage and current values ​​at the first stable sampling moment corresponding to the first positive micropulse. The difference between the pre-excitation voltage baseline and the voltage value at the first stable sampling moment is determined as the positive first instantaneous voltage change, and the difference between the pre-excitation current baseline and the current value at the first stable sampling moment is determined as the positive first instantaneous current change. When the positive first instantaneous current change is not zero, divide the positive first instantaneous voltage change by the positive first instantaneous current change to obtain the positive normalized first instantaneous voltage drop.

[0051] Then, in the same manner, read the pre-excitation voltage baseline and pre-excitation current baseline before the start of the first reverse micropulse, as well as the voltage and current values ​​at the first stable sampling moment corresponding to the first reverse micropulse; determine the difference between the pre-excitation voltage baseline and the voltage value at the first stable sampling moment as the reverse first instantaneous voltage change, and determine the difference between the pre-excitation current baseline and the current value at the first stable sampling moment as the reverse first instantaneous current change; when the reverse first instantaneous current change is not zero, divide the reverse first instantaneous voltage change by the reverse first instantaneous current change to obtain the reverse normalized first instantaneous voltage drop.

[0052] After obtaining the forward normalized initial instantaneous pressure drop and the reverse normalized initial instantaneous pressure drop, the two are directionally normalized according to a preset polarity normalization rule so that the forward normalized initial instantaneous pressure drop and the reverse normalized initial instantaneous pressure drop are represented under the same pressure drop direction. Then, the difference between the directional normalized forward normalized initial instantaneous pressure drop and the reverse normalized initial instantaneous pressure drop is calculated to generate the initial instantaneous pressure drop difference. The initial instantaneous pressure drop difference is used as the contact response characteristic result generated in step 305.

[0053] The method for determining the first stable sampling time can be as follows: Among multiple consecutive sampling points after the pulse starts, the sampling moment when the current change first enters the preset sampling stability range and remains at least the preset number of sampling points is selected as the first stable sampling moment.

[0054] The implementation method of the preset polarity reduction rule can be as follows: The direction of the voltage drop formed when the current flows from the positive terminal to the negative terminal is taken as the positive voltage drop direction; when the direction of the normalized initial voltage drop is consistent with the positive voltage drop direction, the original sign is maintained; when the direction of the normalized initial voltage drop is opposite to the positive voltage drop direction, the sign of the normalized initial voltage drop is converted.

[0055] Step 303: Extract the recovery slope difference based on the effective response interval; specifically, read the effective voltage sampling sequence after the end of the first positive micropulse and the effective voltage sampling sequence after the end of the first reverse micropulse respectively, and determine the recovery start time and recovery end time from their respective effective response intervals; arrange the sampling time and voltage value corresponding to multiple consecutive sampling points between the recovery start time and the recovery end time in chronological order to form the positive recovery sampling point sequence and the reverse recovery sampling point sequence.

[0056] First, denoising is performed on the voltage values ​​in the forward recovery sampling point sequence. Then, taking the recovery start time as the time zero point, each sampling time in the forward recovery sampling point sequence is converted into a relative recovery time. Linear fitting is performed with the relative recovery time as the independent variable and the corresponding voltage value as the dependent variable to obtain the forward voltage recovery fitting line. The slope of the forward voltage recovery fitting line is determined as the forward recovery slope.

[0057] The voltage values ​​in the reverse recovery sampling point sequence are then denoised in the same way, and the sampling time in the reverse recovery sampling point sequence is converted into a relative recovery time with the recovery start time as the time zero point. Then, a linear fitting is performed with the relative recovery time as the independent variable and the corresponding voltage value as the dependent variable to obtain the reverse voltage recovery fitting line. The slope of the reverse voltage recovery fitting line is determined as the reverse recovery slope.

[0058] After obtaining the forward recovery slope and the reverse recovery slope, the two are oriented and oriented according to the preset polarity oriented ...

[0059] The noise reduction process can be implemented in the following ways: The voltage values ​​in the recovered sampling point sequence are processed by moving average in the sampling order to obtain the denoised voltage value sequence.

[0060] The linear fitting can be implemented in the following ways: The least squares fitting method is used to obtain the fitting line of voltage relative to time for multiple consecutive sampling points in the recovered sampling point sequence, and the slope of the fitting line is used as the recovery slope.

[0061] The implementation method of the preset polarity reduction rule can be as follows: The direction of the terminal voltage regressing towards the pre-excitation voltage baseline is defined as the positive recovery direction; when the direction of the fitted slope is consistent with the positive recovery direction, the original slope sign is maintained; when the direction of the fitted slope is opposite to the positive recovery direction, the sign of the fitted slope is changed.

[0062] Step 304: Extract the repetitive pulse deviation based on the effective response interval; specifically, read the effective voltage sampling sequence and effective current sampling sequence corresponding to the first micropulse and the repetitive micropulse under the same polarity respectively; wherein, the first positive micropulse and the positive repetitive micropulse constitute a positive repetitive comparison group, and the first negative micropulse and the negative repetitive micropulse constitute a negative repetitive comparison group.

[0063] First, the positive repetitive comparison group is processed: the pre-excitation voltage baseline, voltage and current values ​​at the first stable sampling moment, recovery interval sampling points, and pulse duration interval sampling points corresponding to the first positive micropulse and the positive repetitive micropulse are read; the normalized initial voltage drop of the first positive micropulse and the normalized initial voltage drop of the positive repetitive micropulse are obtained according to the method in step 302; the recovery slope of the first positive micropulse and the recovery slope of the positive repetitive micropulse are obtained according to the method in step 303; the voltage values ​​corresponding to the sampling points of the pulse duration interval of the first positive micropulse are averaged to obtain the average response of the first positive micropulse, and the average response of the positive repetitive micropulse is obtained in the same way; then the differences between the normalized initial voltage drop of the first positive micropulse and the normalized initial voltage drop of the positive repetitive micropulse, the differences between the recovery slope of the first positive micropulse and the recovery slope of the positive repetitive micropulse, and the differences between the average response of the first positive micropulse and the average response of the positive repetitive micropulse are calculated respectively, and the three differences are weighted and summarized to generate the positive repetition deviation.

[0064] The reverse repeating comparison group was then processed in the same way to obtain the reverse repeating bias.

[0065] After obtaining the positive and negative repetition biases, the positive and negative repetition biases are summarized to generate the repetition pulse bias. The summarization method can be: taking the average of the positive and negative repetition biases, or taking the larger of the two as the repetition pulse bias. The repetition pulse bias is used as the contact response characteristic result generated in step 305.

[0066] The method for determining the sampling points within the pulse duration interval can be as follows: After the first stable sampling moment following the start of the micropulse, multiple consecutive sampling points within a preset duration are extracted as sampling points for the pulse duration interval.

[0067] The weighted aggregation can be implemented in the following ways: Preset weights are set for the difference in normalized initial voltage drop, the difference in recovery slope, and the difference in average response, respectively. The three are then weighted and summed to obtain the repeatability deviation under the corresponding polarity. The preset weights are determined based on the degree of influence of each feature on repeatability consistency in historical stable clamping samples.

[0068] Step 305: Generate contact response characteristic results based on the initial instantaneous voltage drop difference, recovery slope difference, and repetitive pulse deviation; summarize the initial instantaneous voltage drop difference, recovery slope difference, and repetitive pulse deviation to generate contact response characteristic results. The contact response characteristic results include at least three quantitative features: initial instantaneous voltage drop difference, recovery slope difference, and repetitive pulse deviation; the contact response characteristic results are available for further use by the determination unit.

[0069] The reason for adopting the above-mentioned pre-excitation and feature extraction method in this embodiment is as follows: The technical purpose of the pre-excitation in this embodiment is not merely to obtain a single pre-test response before testing, but to generate normalized initial voltage drop, forward recovery slope, and reverse recovery slope corresponding to the first positive and first reverse micropulses, respectively, through forward and reverse micropulses. After direction normalization, the difference is calculated to further generate the initial voltage drop difference and recovery slope difference. By constructing comparable response pairs under opposite current directions, the response differences of the contact interface under different current directions can be revealed. If only unidirectional micropulses are used, only a unidirectional response can be obtained, which cannot form the initial voltage drop difference and recovery slope difference, and it is also difficult to separate directional contact anomalies caused by clamping offset, uneven clamping coverage, or differences in clamping force from the pre-excitation response. Therefore, it is not conducive to the generation of subsequent contact stability judgment results.

[0070] Furthermore, this embodiment does not use the general contact resistance value for single-index judgment on the contact side. Instead, it combines the pre-excitation sampling results to extract the initial voltage drop difference, recovery slope difference, and repetitive pulse deviation, and the three are used together to generate the contact response characteristic result. Among them, the initial voltage drop difference is used to characterize the difference in additional voltage drop at the moment the pulse enters, the recovery slope difference is used to characterize the difference in recovery speed after the pulse is removed, and the repetitive pulse deviation is used to characterize the difference in repetitive stability of the contact response under the same conditions. Since the general contact resistance value can only reflect the overall resistivity at a certain moment, it is difficult to simultaneously characterize directional symmetry, recovery dynamic characteristics, and repetitive stability. Therefore, this embodiment uses the initial voltage drop difference, recovery slope difference, and repetitive pulse deviation to jointly characterize the current contact state, so as to improve the pertinence and reliability of the contact stability judgment result.

[0071] In some embodiments, to illustrate the process of generating contact response characteristic results based on voltage response results and current response results, for example: Based on the pre-excitation voltage baseline of 3.7124 V and the pre-excitation current baseline of 0.000 A, at the first stable sampling moment of the first positive micropulse, the voltage value is read as 3.7001 V and the current value as 1.000 A. Therefore, the initial positive voltage change is 0.0123 V and the initial positive current change is 1.000 A, resulting in a normalized initial positive voltage drop of 12.3 milliohms. At the first stable sampling moment of the first reverse micropulse, the voltage value is read as 3.7242 V and the current value as -1.000 A. Therefore, the initial reverse voltage change is -0.0118 V and the initial reverse current change is -1.000 A. After polarity correction, the normalized initial reverse voltage drop is obtained. The value is 11.8 milliohms, thus generating the initial instantaneous voltage drop difference. Further, fitting processing is performed on the recovery sampling points corresponding to the first positive micropulse and the first negative micropulse, respectively, to obtain the positive recovery slope and the negative recovery slope. After direction normalization and difference calculation, the recovery slope difference is generated. Then, the normalized initial instantaneous voltage drop difference, recovery slope difference, and average response difference in the positive and negative repeating comparison groups are weighted and summarized to obtain the positive repeating deviation and the negative repeating deviation, and further generate the repeating pulse deviation. Finally, the initial instantaneous voltage drop difference, recovery slope difference, and repeating pulse deviation are summarized to generate the contact response characteristic result, which is then used in step 402.

[0072] The judgment unit is used to generate contact stability judgment results, calibration validity judgment results, and test release results based on the contact response characteristic results and the zero-point drift results and link compensation results in the most recent calibration reference. The purpose is to incorporate the contact response characteristic results on the contact side and the most recent calibration reference on the test channel side into the judgment process before the current test, generate contact stability judgment results and calibration validity judgment results respectively, and then generate test release results from the two judgment results, so that the subsequent formal test can only be performed when both the current contact state and the current calibration state are in a testable state.

[0073] In some implementations, see Figure 3 As shown, the steps of the determination unit implementation method include: Step 401: Extract zero-point drift results and link compensation results based on the most recent calibration benchmark. Specifically, read the most recent calibration benchmark corresponding to the current test channel and extract the zero-point drift results and link compensation results from the most recent calibration benchmark. The zero-point drift results are the voltage zero-point offset and current zero-point offset obtained during the most recent no-load calibration, and the link compensation results are the compensation amount obtained during the most recent standard component calibration, used to correct additional errors in the test leads, clamping components, and sampling paths. The zero-point drift results and link compensation results are used to generate contact stability determination results and calibration validity determination results in step 402.

[0074] Step 402: Generate contact stability judgment results and calibration validity judgment results based on contact response characteristic results, zero-point drift results, and link compensation results. Specifically, read the contact response characteristic results generated in step 305, and compare the initial instantaneous voltage drop difference, recovery slope difference, and repetitive pulse deviation with the contact characteristic reference ranges corresponding to the current cell type and the current test channel, respectively. When the initial instantaneous voltage drop difference is within the allowable range of the initial instantaneous voltage drop difference, the recovery slope difference is within the allowable range of the recovery slope difference, and the repetitive pulse deviation is within the allowable range of the repetitive pulse deviation, the contact stability judgment result is generated as a contact release state. When any characteristic quantity is outside the corresponding allowable range, the contact stability judgment result is generated as a contact non-release state.

[0075] Simultaneously, the zero-point drift result is compared with the allowable zero-point drift range corresponding to the current test channel, and the link compensation result is compared with the allowable link compensation range corresponding to the current test channel. When the zero-point drift result is within the allowable zero-point drift range and the link compensation result is within the allowable link compensation range, a calibration validity judgment result is generated as calibration is allowed. When the zero-point drift result is outside the allowable zero-point drift range or the link compensation result is outside the allowable link compensation range, a calibration validity judgment result is generated as calibration is not allowed. The contact stability judgment result and the calibration validity judgment result are used by step 403 and by subsequent shunting control.

[0076] The contact feature reference range can be formed in the following ways: Select standard test samples where the clamping position, clamping coverage, and clamping force are all in a qualified state, and repeatedly perform pre-excitation tests in a calibrated test channel. Statistically analyze the historical distribution ranges of the initial instantaneous voltage drop difference, recovery slope difference, and repetitive pulse deviation. Subsequently, for the current cell type and the current test channel, call up the corresponding historical distribution range to form the contact characteristic reference range used for the current judgment.

[0077] The allowable range for zero-point drift and the allowable range for link compensation can be determined as follows: Based on the no-load calibration results and standard part calibration results of the current test channel in multiple historical calibration cycles, the stable fluctuation ranges of zero-point offset and compensation are calculated respectively; subsequently, the stable fluctuation ranges corresponding to the current test channel model, range configuration and sampling path are called to form the allowable range for the current judgment.

[0078] Step 403: Generate a test release result based on the contact stability determination result and the calibration validity determination result. Specifically, the contact stability determination result and the calibration validity determination result are combined for judgment. When the contact stability determination result is in a contact release state and the calibration validity determination result is in a calibration release state, a test release result is generated as a release result. When the contact stability determination result is in a contact non-release state or the calibration validity determination result is in a calibration non-release state, a test release result is generated as a non-release result. The test release result is used for subsequent formal testing and subsequent shunting control.

[0079] Step 404: Output the set of judgment results; specifically, output the contact stability judgment result, the calibration validity judgment result, and the test release result; among which, the test release result is for the formal test unit to read, and the contact stability judgment result and the calibration validity judgment result are for the subsequent flow control to continue reading after the anomaly review; the test release result is used as the object called by the subsequent formal test.

[0080] Furthermore, to illustrate the process of generating test release results based on contact stability assessment results and calibration validity assessment results, for example: When the initial instantaneous voltage drop difference, recovery slope difference, and repetitive pulse deviation generated in step 305 are all within the contact characteristic reference range corresponding to the current cell type and the current test channel, a contact stability judgment result can be generated as a contact release state. At the same time, when the zero-point drift result and link compensation result in the most recent calibration reference are both within the allowable range corresponding to the current test channel, a calibration validity judgment result can be generated as a calibration release state. Based on this, the contact stability judgment result and the calibration validity judgment result are combined for judgment to generate a test release result as a release result, and the test release result is used for further use in step 501.

[0081] The formal testing unit is used to execute the main pulse test and generate cell electrical performance parameter results when the test release result is a release result. Its purpose is to execute the main pulse test on the cell under test when the test release result generated in step 404 is a release result, to obtain cell electrical performance parameter results that characterize the current electrical performance state of the cell under test, and to simultaneously generate adjacent response consistency results in the main pulse test process for the anomaly verification unit to continue to call.

[0082] In some implementations, see Figure 3 As shown, the formal test unit implementation steps include: Step 501: Configure the main pulse test sequence based on the test release result; specifically, read the test release result generated in step 404; when the test release result is a release result, read the rated capacity range, rated voltage range, current test channel range configuration, and current test ambient temperature of the cell under test; based on the rated capacity range, rated voltage range, range configuration, and test ambient temperature, determine the forward main pulse amplitude, reverse main pulse amplitude, duration of a single main pulse, interval duration between adjacent main pulses, number of repetitions of the same polarity main pulse, and main pulse test sequence in the main pulse test, and generate the main pulse test sequence.

[0083] The determination of the amplitude of the forward main pulse and the amplitude of the reverse main pulse can be as follows: under the premise of not exceeding the safe output range of the current test channel and the allowable test range of the cell under test, select the current amplitude that can make the terminal voltage response significantly higher than the sampling resolution of the test channel; the determination of the duration of a single main pulse can be as follows: cover the main pulse start response interval, the continuous response interval and the recovery response interval; the determination of the duration of the interval between adjacent main pulses can be as follows: make the terminal voltage return to the allowable fluctuation range of the baseline before the main pulse after the end of the previous main pulse.

[0084] The main pulse test sequence includes at least the polarity, amplitude, start time, duration and interval of each main pulse; the main pulse test sequence is used as the main pulse test to be performed in the next step.

[0085] Step 502: Perform the main pulse test according to the main pulse test sequence and generate the main pulse response result; specifically, read the main pulse test sequence generated in step 501; before executing the first main pulse, continuously sample the terminal voltage of the cell under test and the test channel current to generate the voltage baseline and current baseline before the main pulse; then apply each positive main pulse and each negative main pulse to the cell under test in sequence according to the main pulse test sequence, and synchronously collect the terminal voltage and channel current before, during and after the application of each main pulse.

[0086] After all main pulse sampling is completed, the sampling sequence is adjusted according to the voltage baseline before the main pulse, the current baseline before the main pulse, and the sampling data corresponding to each main pulse, based on the sampling interval before the start of the main pulse, the continuous sampling interval of the main pulse, and the recovery sampling interval of the main pulse, to generate the main pulse response result. The main pulse response result includes at least the voltage sampling sequence, current sampling sequence, baseline before the main pulse, and recovery interval sampling sequence corresponding to each main pulse. The main pulse response result is used in the next step to generate the cell electrical performance parameter results and the consistency results of adjacent responses.

[0087] Step 503: Generate cell electrical performance parameter results and adjacent response consistency results based on the main pulse response results; specifically, read the main pulse response results; first, extract the main pulse pre-pulse voltage baseline, main pulse pre-pulse current baseline, voltage and current values ​​at the first stable sampling moment, sampling points of the main pulse duration interval, and sampling points of the recovery interval corresponding to each main pulse from the main pulse response results; perform the following processing on each main pulse: The voltage baseline before the main pulse is used as the test start voltage corresponding to the main pulse; the voltage and current values ​​at the first stable sampling moment are read, the difference between the voltage baseline before the main pulse and the voltage value at the first stable sampling moment is calculated, and this difference is divided by the difference between the current baseline before the main pulse and the current value at the first stable sampling moment to obtain the ohmic internal resistance corresponding to the main pulse; the voltage values ​​corresponding to the sampling points in the main pulse duration interval are averaged to obtain the average continuous response corresponding to the main pulse; the same fitting process as in step 303 is performed on the sampling points in the recovery interval to obtain the recovery slope corresponding to the main pulse.

[0088] After obtaining the test start voltage, ohmic internal resistance, average continuous response, and recovery slope corresponding to each main pulse, the test start voltage corresponding to all main pulses is averaged to generate open-circuit voltage parameters; the ohmic internal resistance corresponding to all main pulses is averaged to generate ohmic internal resistance parameters; the average continuous response and recovery slope corresponding to all main pulses are weighted and summarized according to preset parameter combination rules to generate polarization response parameters; finally, the open-circuit voltage parameters, ohmic internal resistance parameters, and polarization response parameters are summarized to generate the cell electrical performance parameters.

[0089] Simultaneously, two adjacent main pulses of the same polarity and amplitude are extracted from the main pulse response results in the order of testing to form adjacent response comparison groups; for each adjacent response comparison group, the difference in ohmic internal resistance, the difference in average sustained response, and the difference in recovery slope are calculated, and weighted summaries are performed according to preset consistency combination rules to generate the consistency deviation amount corresponding to the group; then, the average calculation or the larger value is taken for all consistency deviation amounts to generate the adjacent response consistency results.

[0090] The implementation of the preset parameter combination rule can be as follows: set preset weights for the average continuous response and the recovery slope respectively, and perform weighted summation; the implementation of the preset consistency combination rule can be as follows: set preset weights for the difference in ohmic internal resistance, the difference in the average continuous response and the difference in the recovery slope respectively, and perform weighted summation.

[0091] The results of the cell's electrical performance parameters and the consistency results of adjacent responses are available for the anomaly verification unit to continue to use.

[0092] In this embodiment, the reason for adopting the above-mentioned method of generating consistent results for adjacent responses is that: this embodiment does not judge the contact state solely based on the pre-excitation results, but after the formal main pulse test, it further extracts two adjacent main pulses of the same polarity and amplitude from the main pulse response results as adjacent response comparison groups, and compares the difference in ohmic internal resistance, the difference in the average value of the continuous response, and the difference in the recovery slope to generate consistent results for adjacent responses; among them, "adjacent", "same polarity", and "same amplitude" are used together to ensure that the main test conditions between the comparison groups are consistent, so that the comparison results mainly reflect the changes in contact state or test channel state under the formal test load, without introducing additional effects caused by polarity differences, amplitude differences, or excessive time spans; if this consistency comparison method is not adopted, and the judgment is made solely based on whether the final cell electrical performance parameters are abnormal, it can only confirm that the result is abnormal, and it is difficult to further distinguish whether the abnormality comes from changes on the contact side or changes on the test channel side, and it is also not conducive to outputting re-clamping instructions or recalibration instructions based on the contact stability judgment results and calibration validity judgment results. Therefore, the consistency check in the latter part of this embodiment is used in conjunction with the contact determination in the former part to further distinguish the sources of abnormality.

[0093] In some implementations, to illustrate the process of generating cell electrical performance parameters and adjacent response consistency results based on the main impulse response results, for example: Three main pulses of the same polarity and amplitude are applied consecutively to the cell under test. The corresponding baseline voltages before the main pulses are 3.709 V, 3.710 V, and 3.708 V, respectively. The voltage values ​​of each main pulse at the first stable sampling moment are 3.519 V, 3.520 V, and 3.520 V, respectively, and the current values ​​are 10.0 A, 10.0 A, and 10.0 A, respectively. The corresponding generated internal resistances in ohms are 19.0 milliohms, 19.0 milliohms, and 18.8 milliohms, respectively. Furthermore, by averaging the voltage values ​​corresponding to the sampling points in the continuous interval of each main pulse, the average continuous response can be obtained. By performing fitting processing on the sampling points in the recovery interval of each main pulse, the recovery slope can be obtained. After obtaining the test starting voltage and resistance values ​​corresponding to each main pulse, the average response can be obtained. After calculating the internal resistance, average continuous response, and recovery slope, the test starting voltage corresponding to all main pulses is averaged to generate open-circuit voltage parameters; the ohmic internal resistance is averaged to generate ohmic internal resistance parameters; the average continuous response and recovery slope are weighted and summarized according to preset parameter combination rules to generate polarization response parameters, and further generate cell electrical performance parameters; at the same time, adjacent response comparison groups are extracted from two adjacent main pulses of the same polarity and amplitude, and the differences in ohmic internal resistance, average continuous response, and recovery slope corresponding to each group are weighted and summarized to generate consistency deviation; then, based on all consistency deviations, adjacent response consistency results are generated and used for further calls in steps 601 to 603.

[0094] The anomaly verification unit is used to generate anomaly verification results based on the cell electrical performance parameter results and the adjacent response consistency results during the main pulse test. Its purpose is to jointly verify the cell electrical performance parameter results and adjacent response consistency results generated in step 503, determine whether there is an anomaly in the current main pulse test results, and generate anomaly verification results for the shunt control unit to continue to call.

[0095] In some implementations, see Figure 3 As shown, the implementation steps of the anomaly review unit include: Step 601: Determine the parameter verification result based on the cell electrical performance parameter results. Specifically, read the cell electrical performance parameter results generated in step 503, and extract the open-circuit voltage parameter, ohmic internal resistance parameter, and polarization response parameter from the cell electrical performance parameter results. Compare the open-circuit voltage parameter with the allowable open-circuit voltage range corresponding to the current cell type, current test environment temperature, and current test state; compare the ohmic internal resistance parameter with the allowable ohmic internal resistance range corresponding to the current cell type, current test environment temperature, and current test state; compare the polarization response parameter with the allowable polarization response range corresponding to the current cell type, current test environment temperature, and current test state. When the open-circuit voltage parameter, ohmic internal resistance parameter, and polarization response parameter are all within their respective allowable ranges, a parameter verification result of normal parameter status is generated; when any parameter is outside its corresponding allowable range, a parameter verification result of abnormal parameter status is generated. The parameter verification result is used to generate the abnormal verification result in step 602.

[0096] The allowable ranges can be formed by statistically analyzing historical qualified samples of the same type of battery cell under corresponding test environment temperature and test conditions.

[0097] Step 602: Determine the consistency verification result based on the adjacent response consistency results. Specifically, read the adjacent response consistency results generated in step 503 and compare them with the consistency allowable upper limit corresponding to the current cell type and the current test sequence. When the adjacent response consistency results do not exceed the consistency allowable upper limit, a consistency verification result of normal consistency is generated; when the adjacent response consistency results exceed the consistency allowable upper limit, a consistency verification result of abnormal consistency is generated. The consistency verification result is used to generate the abnormal verification result in step 603.

[0098] The upper limit of consistency can be determined by: statistical results of consistency deviation obtained from repeated main pulse tests of the same type of battery cell under stable clamping and effective calibration conditions.

[0099] Step 603: Generate an abnormal review result based on the parameter review result and the consistency review result. Specifically, read the parameter review result generated in step 601 and the consistency review result generated in step 602. When the parameter review result indicates a normal parameter state and the consistency review result indicates a normal consistency state, generate an abnormal review result indicating that the traffic splitting conditions are not met. When the parameter review result indicates an abnormal parameter state, or the consistency review result indicates an abnormal consistency state, generate an abnormal review result indicating that the traffic splitting conditions are met. The abnormal review result is then used by the traffic splitting control unit.

[0100] Furthermore, to illustrate the process of generating anomaly verification results based on cell electrical performance parameters and adjacent response consistency results, for example: When the open-circuit voltage parameter, ohmic internal resistance parameter, and polarization response parameter generated in step 503 are all within the allowable range corresponding to the current cell type, current test environment temperature, and current test state, the parameter verification result is generated as normal. At the same time, when the consistency result of adjacent responses does not exceed the upper limit of consistency corresponding to the current cell type and current test sequence, the consistency verification result is generated as normal. Based on this, an abnormal verification result is generated as not meeting the shunting condition. As another example, when the parameter verification result is normal, but the consistency result of adjacent responses exceeds the corresponding upper limit of consistency, the consistency verification result is generated as abnormal, and an abnormal verification result is further generated as meeting the shunting condition, which can be called by step 701.

[0101] The shunt control unit is used to output a re-clamping command or a recalibration command based on the contact stability judgment result and the calibration validity judgment result when the test release result is a non-release result or the anomaly review result meets the shunt conditions. The purpose is to determine whether the current anomaly is more suitable to be handled by re-clamping or recalibration based on the contact stability judgment result and the calibration validity judgment result generated in step 402 when the test release result generated in step 403 is a non-release result or the anomaly review result generated in step 603 meets the shunt conditions, and output the corresponding re-clamping command or recalibration command.

[0102] In some implementations, see Figure 3 As shown, the implementation steps of the shunt control unit include: Step 701: Generate a shunting trigger result based on the test release result and the anomaly review result. Specifically, read the test release result generated in step 403 and the anomaly review result generated in step 603. When the test release result is a non-release result, generate a shunting trigger result in a shunting triggered state. When the test release result is a release result and the anomaly review result meets the shunting conditions, generate a shunting trigger result in a shunting triggered state. When the test release result is a release result and the anomaly review result does not meet the shunting conditions, generate a shunting trigger result in a non-shunting triggered state. The shunting trigger result is used to output a re-clamping command or a recalibration command in step 702.

[0103] Step 702: Generate a shunt control result based on the contact stability determination result and the calibration validity determination result. Specifically, when the shunt trigger result is in the shunt trigger state, read the contact stability determination result and the calibration validity determination result generated in step 402. When the calibration validity determination result is in the calibration non-release state, generate a shunt control result in the recalibration state. When the calibration validity determination result is in the calibration release state and the contact stability determination result is in the contact non-release state, generate a shunt control result in the re-clamping state. When the calibration validity determination result is in the calibration non-release state and the contact stability determination result is in the contact non-release state, still generate a shunt control result in the recalibration state.

[0104] The reason for prioritizing the generation of a recalibration state when both the contact stability judgment result and the calibration validity judgment result indicate that the test channel is not ready for release is that when the calibration status of the current test channel fails, the reliability of the contact judgment result obtained from the current test channel decreases. By restoring the calibration status of the test channel first and then re-entering the clamping identification process, the invalid clamping adjustment can be avoided under the condition of calibration failure.

[0105] When the shunt trigger result is in the shunt trigger state, the contact stability judgment result is in the contact release state, and the calibration validity judgment result is in the calibration release state, the generated shunt control result is in the recalibration state. This is because when the current contact side has been determined to be releaseable but the main pulse test still shows an anomaly, the anomaly is preferentially attributed to the test channel side. Restoring the test channel calibration state before re-entering the main pulse test is more conducive to eliminating the continuous impact of test channel drift on the test results. The shunt control result is used to output the corresponding shunt command in step 703.

[0106] Step 703: Output a re-clamping command or a recalibration command based on the shunt control result; specifically, read the shunt control result generated in step 702; when the shunt control result is in the re-clamping state, output a re-clamping command and return the current cell under test to the clamping identification process corresponding to the clamping identification unit; when the shunt control result is in the recalibration state, output a recalibration command and return the current test channel to the most recent calibration benchmark update process, and re-enter the judgment process corresponding to the judgment unit after updating the calibration benchmark.

[0107] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A high-precision testing system for the electrical performance parameters of a power battery cell, characterized in that, include: Clamping identification unit, used to acquire the terminal clamping status information of the cell under test; The pre-excitation execution unit is used to apply positive and reverse micropulses to the cell under test and to collect the corresponding voltage and current response results. The feature extraction unit is used to extract the initial instantaneous voltage drop difference, recovery slope difference, and repetitive pulse deviation based on the terminal clamping status information, voltage response results, and current response results, and to generate contact response feature results. The judgment unit is used to generate contact stability judgment results, calibration validity judgment results, and test release results based on the contact response characteristic results and the zero-point drift results and link compensation results in the most recent calibration reference. The formal test unit is used to perform the main pulse test and generate the cell electrical performance parameters when the test release result is a release result; The anomaly verification unit is used to generate anomaly verification results based on the cell's electrical performance parameters and the consistency results of adjacent responses during the main pulse test. The shunt control unit is used to output a re-clamping command or a recalibration command based on the contact stability judgment result and the calibration validity judgment result when the test release result is a non-release result or the abnormal review result meets the shunt conditions.

2. The high-precision testing system for the electrical performance parameters of a power battery cell according to claim 1, characterized in that, Methods for collecting the corresponding voltage and current response results include: Before applying positive and reverse micropulses to the cell under test, the terminal voltage of the cell under test and the current of the test channel are continuously collected to generate the voltage baseline and the current baseline before pre-excitation. Based on the application time of the positive and negative micropulses, the terminal voltage and channel current are synchronously collected before the start of each micropulse, during its duration, and during its recovery. Based on the pre-excitation voltage baseline, pre-excitation current baseline, and sampling data corresponding to each micro-pulse, timing correction is performed to generate voltage response results and current response results that correspond one-to-one with the voltage response results.

3. The high-precision testing system for the electrical performance parameters of a power battery cell according to claim 1, characterized in that, Methods for generating contact response characteristic results include: The effective response range is determined based on the terminal clamping status information, voltage response results, and current response results. Based on the effective response range, the normalized initial voltage drop corresponding to the first positive micropulse and the first negative micropulse is determined, and the two are directionally rounded and the difference is calculated to obtain the initial voltage drop difference; The forward recovery slope and the reverse recovery slope are determined based on the effective response interval, and the two are directionally rounded and the difference is calculated to obtain the recovery slope difference; The positive repetition bias and the negative repetition bias are determined based on the effective response range, and the repetition pulse bias is obtained based on the positive repetition bias and the negative repetition bias. Contact response characteristics are generated based on the initial pressure drop difference, recovery slope difference, and repetitive pulse deviation.

4. A high-precision testing system for the electrical performance parameters of a power battery cell according to claim 1 or 3, characterized in that, Methods for generating contact stability determination results include: Read the initial voltage drop difference, recovery slope difference, and repetitive pulse deviation from the contact response characteristic results; compare the initial voltage drop difference, recovery slope difference, and repetitive pulse deviation with the contact characteristic reference range corresponding to the current cell type and the current test channel, respectively; When the initial instantaneous voltage drop difference, recovery slope difference, and repetitive pulse deviation are all within the corresponding allowable range, the contact stability judgment result is generated as a contact release state. When any feature quantity is outside the corresponding allowable range, the contact stability determination result is a contact non-release state.

5. A high-precision testing system for the electrical performance parameters of a power battery cell according to claim 1, characterized in that, Methods for generating calibration validity determination results include: Read the zero-point drift results and link compensation results from the most recent calibration reference; Compare the zero-point drift result with the allowable zero-point drift range corresponding to the current test channel, and compare the link compensation result with the allowable link compensation range corresponding to the current test channel; When the zero-point drift result is within the allowable range of zero-point drift and the link compensation result is within the allowable range of link compensation, the calibration validity judgment result is generated as calibration release status. When the zero-point drift result is outside the allowable range of zero-point drift or the link compensation result is outside the allowable range of link compensation, the calibration validity judgment result is generated as calibration not allowed.

6. A high-precision testing system for the electrical performance parameters of a power battery cell according to claim 4, characterized in that, Methods for generating test release results include: Read the contact stability assessment results and calibration validity assessment results; The results of the contact stability assessment and the calibration validity assessment are combined for judgment. When the contact stability determination result is that the contact is ready for release and the calibration validity determination result is that the calibration is ready for release, the test release result is generated as the release result. When the contact stability determination result is that the contact is not releaseable, or the calibration validity determination result is that the calibration is not releaseable, the generated test release result is a non-release result.

7. The high-precision testing system for the electrical performance parameters of a power battery cell according to claim 1, characterized in that, Methods for generating cell electrical performance parameters include: When the test release result is a release result, the main pulse test is performed on the cell under test, and the voltage sampling sequence and current sampling sequence corresponding to each main pulse are collected to generate the main pulse response result; Based on the main pulse response results, determine the test start voltage, ohmic internal resistance, average continuous response, and recovery slope corresponding to each main pulse. Based on the test start voltage, ohmic internal resistance, average continuous response, and recovery slope corresponding to each main pulse, the cell electrical performance parameters are generated.

8. A high-precision testing system for the electrical performance parameters of a power battery cell according to claim 7, characterized in that, Methods for generating anomaly review results include: Read the open-circuit voltage parameter, ohmic internal resistance parameter, and polarization response parameter from the battery cell electrical performance parameter results, and compare the open-circuit voltage parameter, ohmic internal resistance parameter, and polarization response parameter with the corresponding allowable ranges to generate parameter verification results; The consistency results of adjacent responses are compared with the upper limit of the consistency allowance to generate a consistency review result; Based on the parameter verification results and consistency verification results, anomaly verification results are generated.

9. A high-precision testing system for the electrical performance parameters of a power battery cell according to claim 1, characterized in that, Methods for outputting reclamping or recalibration commands include: The diversion trigger result is generated based on the test release result and the anomaly review result; When the shunt trigger result is a triggered shunt state, the shunt judgment is made based on the contact stability judgment result and the calibration validity judgment result; When the calibration validity determination result is that the calibration cannot be released, a recalibration command is output. When the calibration validity determination result is that the calibration is ready for release and the contact stability determination result is that the contact is not ready for release, a re-clamping command is output.

10. A high-precision testing system for the electrical performance parameters of a power battery cell according to claim 8, characterized in that, Methods for generating consistent results for adjacent responses include: Extract two adjacent main pulses of the same polarity and amplitude from the main pulse response results in the order of testing to form an adjacent response comparison group; Consistency deviation is generated based on the difference in ohmic internal resistance, the difference in average sustained response, and the difference in recovery slope corresponding to each adjacent response comparison group. Generate consistency results for adjacent responses based on each consistency deviation.

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