Electrochemical impedance spectroscopy testing methods, devices, equipment and media for new energy batteries

Abstract

The present invention provides a method, device, equipment, and medium for testing electrochemical impedance spectroscopy of new energy batteries, and relates to the technical field of electrochemical impedance spectroscopy of new energy batteries. The method comprises: using a preset generalized S transform to process a one-dimensional time-series signal of output voltage and a one-dimensional time-series signal of output current to obtain a two-dimensional time-frequency matrix of output voltage and a two-dimensional time-frequency matrix of output current; determining a target frequency response function estimation method based on the minimum value of the average current noise level and the average voltage noise level; when it is determined that the noise comes from voltage, calculating a weight matrix based on the energy of the measured current signal to obtain a target impedance value; when it is determined that the noise comes from current, calculating a weight matrix based on the energy of the measured voltage signal to obtain a target impedance value. The energy-weighted frequency response function estimation technology of the present invention extracts effective harmonic information from the two-dimensional time-frequency matrix, and accurately obtains the electrochemical impedance spectrum by giving priority to the more contributing frequency components.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical impedance spectroscopy of new energy batteries, and in particular to a method, device, equipment and medium for testing electrochemical impedance spectroscopy of new energy batteries. Background Art

[0002] The principle of electrochemical impedance spectroscopy (EIS) testing is to use a low-amplitude AC excitation signal to perturb an electrochemical system in equilibrium or under certain stable DC polarization conditions. Signal processing and analysis based on the measured excitation and response are then performed to study the relationship between the electrochemical system's AC impedance and frequency. EIS can accurately characterize the internal health state and dynamic behavior of a battery, providing key data support for battery performance evaluation and health monitoring.

[0003] Integrating electrochemical impedance spectroscopy (EIS) testing into power electronics enables online measurements without the need for additional peripheral equipment. Selecting an excitation signal rich in effective harmonics significantly reduces measurement time and improves test efficiency. However, the limitations of small impedance values ​​and low signal-to-noise ratios severely impact the accuracy and stability of impedance measurements. Therefore, improving the noise immunity of EIS measurements and more efficiently extracting reliable impedance data from noisy signals present significant challenges.

[0004] However, there is currently no technical solution that can solve the above technical problems, and there is no new energy battery electrochemical impedance spectroscopy testing method, device, equipment and medium. Summary of the Invention

[0005] The present invention provides a method, device, equipment and medium for testing the electrochemical impedance spectroscopy of a new energy battery. The frequency response function estimation technology based on energy weight extracts effective information of a two-dimensional time-frequency matrix, thereby accurately obtaining the electrochemical impedance spectrum of the new energy battery.

[0006] In a first aspect, the present invention provides a method for testing electrochemical impedance spectroscopy of a new energy battery, comprising:

[0007] Using a preset generalized S transform to process the output voltage one-dimensional time series signal and the output current one-dimensional time series signal, to obtain the output voltage two-dimensional time-frequency matrix and the output current two-dimensional time-frequency matrix;

[0008] Determine the current average noise level according to the output current signal and the frequency group to be measured, determine the voltage average noise level according to the output voltage signal and the frequency group to be measured, and determine the target frequency response function estimation method according to the minimum value of the current average noise level and the voltage average noise level;

[0009] When it is determined that the noise comes from voltage, a weight matrix based on the energy of the measured current signal is calculated, and the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix are processed according to a frequency response function estimation method based on the current energy weight matrix to obtain a target impedance value;

[0010] When it is determined that the noise comes from current, a weight matrix based on the energy of the measured voltage signal is calculated, and the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix are processed according to a frequency response function estimation method based on the voltage energy weight matrix to obtain the target impedance value.

[0011] According to the electrochemical impedance spectroscopy testing method for new energy batteries provided by the present invention, before using a preset generalized S transform to process the output voltage one-dimensional time series signal and the output current one-dimensional time series signal, the method further includes:

[0012] During the excitation and response phases of electrochemical impedance spectroscopy measurement of new energy batteries, the output voltage one-dimensional time series signal and the output current one-dimensional time series signal are collected.

[0013] According to the electrochemical impedance spectroscopy testing method for new energy batteries provided by the present invention, the method uses a preset generalized S transform to process the output voltage one-dimensional time series signal and the output current one-dimensional time series signal to obtain the output voltage two-dimensional time-frequency matrix and the output current two-dimensional time-frequency matrix, including:

[0014] ;

[0015] in, is the two-dimensional time-frequency matrix of output voltage, is the two-dimensional time-frequency matrix of the output current, is the time factor, is the harmonic frequency.

[0016] ;

[0017] in, and They are and Gaussian window function The Fourier transform of is a frequency domain variable, corresponding to a time domain variable , Represents the one-dimensional time series signal of output voltage and output current, e is a natural constant, j is an imaginary unit, d is the total differential symbol, is pi.

[0018] According to the electrochemical impedance spectroscopy testing method for new energy batteries provided by the present invention, determining the current average noise level according to the output current signal and the frequency group to be measured, and determining the voltage average noise level according to the output voltage signal and the frequency group to be measured, includes:

[0019] It is beneficial to process all output current signals in the frequency group to be measured by Fourier transform to obtain all converted current values, and after summing all converted current values ​​in the frequency group to be measured, take the average value to obtain the current average noise level;

[0020] It is beneficial to process all output voltage signals in the frequency group to be measured by Fourier transform to obtain all converted voltage values. After summing all converted voltage values ​​in the frequency group to be measured, the average value is taken to obtain the voltage average noise level.

[0021] According to the electrochemical impedance spectroscopy testing method for new energy batteries provided by the present invention, the target frequency response function estimation method is determined according to the minimum value of the current average noise level and the voltage average noise level, including:

[0022] When the current average noise level is less than the voltage average noise level, determining that the noise is caused by the voltage;

[0023] When the current average noise level is greater than the voltage average noise level, it is determined that the noise is derived from the current.

[0024] According to the electrochemical impedance spectroscopy testing method for new energy batteries provided by the present invention, a weight matrix based on the energy of the measured current signal and a weight matrix based on the energy of the measured voltage signal are calculated, including:

[0025] ;

[0026] in, is the weight matrix, is the frequency vector of the signal harmonics, represents the index of the time factor, is the number of moments used for impedance calculation, is the time factor corresponding to the moment m, is the current, is the voltage, is a frequency response function estimation method based on the current energy weight matrix, It is a frequency response function estimation method based on the voltage energy weight matrix.

[0027] According to the electrochemical impedance spectroscopy testing method for new energy batteries provided by the present invention, the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix are processed according to a frequency response function estimation method based on the current energy weight matrix to obtain a target impedance value; the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix are processed according to a frequency response function estimation method based on the voltage energy weight matrix to obtain the target impedance value, including:

[0028] ;

[0029] in, is the target impedance value, is the cross density spectrum of voltage and current, is the autopower spectrum of the current, is the autopower spectrum of the voltage, wherein the cross density spectrum of the voltage and current is jointly determined based on the output voltage two-dimensional time-frequency matrix and the output current two-dimensional time-frequency matrix, the autopower spectrum of the current is determined based on the output current two-dimensional time-frequency matrix, and the autopower spectrum of the voltage is determined based on the output voltage two-dimensional time-frequency matrix.

[0030] In a second aspect, a new energy battery electrochemical impedance spectroscopy testing device is provided, comprising:

[0031] an acquisition unit, configured to process the one-dimensional time series signal of the output voltage and the one-dimensional time series signal of the output current using a preset generalized S transform to acquire a two-dimensional time-frequency matrix of the output voltage and a two-dimensional time-frequency matrix of the output current;

[0032] a determining unit configured to determine an average current noise level based on the output current signal and the frequency group to be measured, determine an average voltage noise level based on the output voltage signal and the frequency group to be measured, and determine a target frequency response function estimation method based on a minimum value between the average current noise level and the average voltage noise level;

[0033] a first calculation unit, configured to, when it is determined that the noise originates from voltage, calculate a weight matrix based on the energy of the measured current signal, and process the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix according to a frequency response function estimation method based on the current energy weight matrix to obtain a target impedance value;

[0034] The second calculation unit is used to calculate a weight matrix based on the energy of the measured voltage signal when it is determined that the noise comes from the current, and process the weight matrix, the output voltage two-dimensional time-frequency matrix and the output current two-dimensional time-frequency matrix according to a frequency response function estimation method based on the voltage energy weight matrix to obtain the target impedance value.

[0035] In a third aspect, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the electrochemical impedance spectroscopy testing method for new energy batteries when executing the program.

[0036] In a fourth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a calculation program. When the calculation program is executed by a processor, the processor implements the new energy battery electrochemical impedance spectroscopy testing method.

[0037] The present invention utilizes the generalized S transform to more precisely capture the temporal changes of the signal by improving the temporal resolution. While improving the temporal resolution, it also enhances the retrieval and expression of harmonic information under multiple harmonic components, supports fast calculation, and improves the retrievability and distinguishability of harmonic information. The one-dimensional time series signal is transformed into a two-dimensional time-frequency matrix, which enhances the expression of harmonic information and enables more efficient processing and analysis of signals with multiple harmonic components. The frequency response function estimation technology based on energy weighting extracts effective harmonic information from the two-dimensional time-frequency matrix, and accurately obtains the electrochemical impedance spectrum by prioritizing the more contributing frequency components. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 This is one of the flow charts of the electrochemical impedance spectroscopy testing method for new energy batteries provided by the present invention;

[0040] Figure 2 This is the second flow chart of the electrochemical impedance spectroscopy testing method for new energy batteries provided by the present invention;

[0041] Figure 3 This is the third flow chart of the electrochemical impedance spectroscopy testing method for new energy batteries provided by the present invention;

[0042] Figure 4 It is the electrochemical impedance spectroscopy result provided by the present invention;

[0043] Figure 5 is the real part of the impedance result provided by the present invention;

[0044] Figure 6 is the result of the imaginary part of impedance provided by the present invention;

[0045] Figure 7 This is a schematic structural diagram of the electrochemical impedance spectroscopy testing device for new energy batteries provided by the present invention;

[0046] Figure 8 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0047] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0048] Based on the generalized S-transform, the present invention transforms a one-dimensional time series with multiple harmonic components, including voltage and current signals, into a two-dimensional time-frequency matrix to enhance the retrievability and distinguishability of harmonic information. For the retrieved information, the energy-weighted frequency response function estimation technology is applied to calculate the electrochemical impedance spectroscopy.

[0049] Figure 1 This is one of the flow diagrams of the electrochemical impedance spectroscopy testing method for new energy batteries provided by the present invention, which includes:

[0050] Step 101: Use a preset generalized S transform to process the one-dimensional time series signal of the output voltage and the one-dimensional time series signal of the output current to obtain a two-dimensional time-frequency matrix of the output voltage and a two-dimensional time-frequency matrix of the output current;

[0051] Step 102: determining a current average noise level based on the output current signal and the frequency group to be measured, determining a voltage average noise level based on the output voltage signal and the frequency group to be measured, and determining a target frequency response function estimation method based on the minimum value of the current average noise level and the voltage average noise level;

[0052] Step 103: When it is determined that the noise comes from voltage, a weight matrix based on the energy of the measured current signal is calculated, and the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix are processed according to a frequency response function estimation method based on the current energy weight matrix to obtain a target impedance value;

[0053] Step 104: When it is determined that the noise comes from the current, a weight matrix based on the energy of the measured voltage signal is calculated, and the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix are processed according to a frequency response function estimation method based on the voltage energy weight matrix to obtain the target impedance value.

[0054] In step 101, before using a preset generalized S transform to process the one-dimensional time series signal of the output voltage and the one-dimensional time series signal of the output current, the method further includes:

[0055] During the excitation and response phases of electrochemical impedance spectroscopy measurement of new energy batteries, the output voltage one-dimensional time series signal and the output current one-dimensional time series signal are collected.

[0056] Optionally, during the excitation and response phases of electrochemical impedance spectroscopy measurements of new energy batteries, collect the one-dimensional time series signal of the battery output voltage. and the output current one-dimensional timing signal of the output current .

[0057] Optionally, the step of processing the one-dimensional time series signal of the output voltage and the one-dimensional time series signal of the output current by using a preset generalized S transform to obtain a two-dimensional time-frequency matrix of the output voltage and the two-dimensional time-frequency matrix of the output current includes:

[0058] ;

[0059] in, is the two-dimensional time-frequency matrix of output voltage, is the two-dimensional time-frequency matrix of the output current, is the time factor, is the mathematical form of the generalized S-transform of harmonic frequencies It is given by:

[0060]

[0061] in, and They are and Gaussian window function The Fourier transform of is a frequency domain variable, corresponding to a time domain variable , Represents the one-dimensional time series signal of output voltage and output current, e is a natural constant, j is an imaginary unit, d is the total differential symbol, is pi.

[0062] Optionally, the generalized S transform involved transforms a one-dimensional time series signal with multiple harmonic components into a two-dimensional time-frequency matrix to enhance the retrievability and distinguishability of harmonic information, where the time axis is derived from the time scale of the one-dimensional time series, and the frequency axis corresponds to the effective harmonic components contained in the one-dimensional time series.

[0063] Gaussian window function Determined by the following formula:

[0064] ;

[0065] in, is the Gaussian window function The time domain standard deviation.

[0066] Gaussian window function The time domain standard deviation is defined as Function:

[0067] ;

[0068] Among them, h, p, and r are adjustable parameters used to control the shape.

[0069] Parameter tuning is usually optimized by the degree of energy concentration, which often involves a huge amount of calculation. The principle of selecting the time domain standard deviation in this invention is to concentrate the main energy of the Gaussian window to be convolved in the period of the harmonic, widening the energy concentration range to obtain higher time resolution:

[0070]

[0071] in, is the specified energy concentration interval, n is no less than 3, and is a parameter that measures the width of the energy concentration interval. To reduce optimization time and adapt to online applications, the hyperparameters h, p, and r are tuned according to the energy concentration interval. The optimization process is independent of the generalized S-transform.

[0072] The present invention obtains better time resolution by selecting an energy concentration interval of 4 times the time domain standard deviation:

[0073] ;

[0074] in, is the specified energy concentration interval, n is no less than 3, and is a parameter that measures the width of the energy concentration interval. To reduce optimization time and adapt to online applications, the hyperparameters h, p, and r are tuned according to the energy concentration interval. The optimization process is independent of the generalized S-transform.

[0075] Furthermore, we know that:

[0076] ;

[0077] Right now , , , the tuning is independent of the generalized S-transform. It is worth noting that this embodiment only demonstrates this one selection scheme for improving the time resolution of the transformation result, and the combination of the selection of other parameters can also have such an effect.

[0078] According to the above formula, the generalized S transform regards the signal and exponential terms in the integral term as a whole and introduces a Gaussian window to be convolved, which can perform fast calculations and thus reduce the computational complexity:

[0079]

[0080] in, and They are and Gaussian window function The Fourier transform of is a frequency domain variable, corresponding to a time domain variable .

[0081] Output voltage and output current The two-dimensional time-frequency matrix does not have acceptable accuracy for all time instants. The electrochemical impedance spectroscopy is calculated using the frequency response function estimation technique. Estimation and It is estimated that it is applicable to the case where the system output noise and input noise are more obvious. For new energy batteries that implement electrochemical impedance spectroscopy measurement, the system input is the output current , the system output is the output voltage .

[0082] In step 102, determining the current average noise level according to the output current signal and the frequency group to be measured, and determining the voltage average noise level according to the output voltage signal and the frequency group to be measured, includes:

[0083] It is beneficial to process all output current signals in the frequency group to be measured by Fourier transform to obtain all converted current values, and after summing all converted current values ​​in the frequency group to be measured, take the average value to obtain the current average noise level;

[0084] It is beneficial to process all output voltage signals in the frequency group to be measured by Fourier transform to obtain all converted voltage values. After summing all converted voltage values ​​in the frequency group to be measured, the average value is taken to obtain the voltage average noise level.

[0085] Optionally, the noise caused by the voltage or current measurement channel and equipment is measured based on the Fourier transform result of the steady-state DC. In actual application scenarios, the stable DC output current is measured first. or output voltage The signal is then transformed into and Finally, according to the frequency group to be measured of the electrochemical impedance spectroscopy Calculating the average noise level :

[0086]

[0087] in, is the frequency group to be measured The number of frequencies in the range. The output voltage with lower average noise level or output current , select the estimation method of the frequency response function.

[0088] Optionally, determining the target frequency response function estimation method according to the minimum value of the current average noise level and the voltage average noise level includes:

[0089] When the current average noise level is less than the voltage average noise level, it is determined that the noise comes from the voltage. In this case, step 103 is selected for execution. When the current average noise level is greater than the voltage average noise level, it is determined that the noise comes from the current. In this case, step 104 is selected for execution.

[0090] Optionally, a weight matrix based on the energy of the measured current signal is calculated, and a weight matrix for measuring the voltage signal is calculated, including:

[0091]

[0092] in, is the weight matrix, is the frequency vector of the signal harmonics, represents the index of the time factor, is the number of moments used for impedance calculation, is the time factor corresponding to the moment m, is the current, is the voltage, is a frequency response function estimation method based on the current energy weight matrix, It is a frequency response function estimation method based on the voltage energy weight matrix.

[0093] Optionally, the signal energy is expressed as a weight in Estimated Represented as the weight matrix of the measured current signal, Estimated It is represented as a weight matrix of the measured voltage signal. By assigning weights to the cross-power spectrum and the auto-power spectrum, the distortion interference of the low-energy frequency components on the time axis can be reduced.

[0094] Optionally, the step of processing the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix according to a frequency response function estimation method based on the current energy weight matrix to obtain the target impedance value; and processing the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix according to a frequency response function voltage estimation method based on the voltage energy weight matrix to obtain the target impedance value includes:

[0095]

[0096] in, is the target impedance value, is the cross density spectrum of voltage and current, is the autopower spectrum of the current, is the autopower spectrum of voltage, is the frequency vector of the signal harmonics, represents the index of the time factor, is the number of moments available for impedance calculation. is a weighting factor of the time-frequency matrix, wherein the cross density spectrum of the voltage and current is jointly determined based on the output voltage two-dimensional time-frequency matrix and the output current two-dimensional time-frequency matrix, the autopower spectrum of the current is determined based on the output current two-dimensional time-frequency matrix, and the autopower spectrum of the voltage is determined based on the output voltage two-dimensional time-frequency matrix.

[0097] Optional, output voltage and output current The two-dimensional time-frequency matrix contains both time and frequency information. Due to differences in the distribution of signal harmonic power along the time axis and the influence of noise, not all information at all moments has acceptable accuracy. To effectively utilize the limited power in the signal harmonics, the electrochemical impedance spectroscopy is calculated using frequency response function estimation techniques.

[0098] The main difference between the frequency response function estimation techniques lies in the assumptions about the source or location of the random noise. Estimation and The estimation is applicable to the case where the output noise and input noise are more obvious. or output current , select the frequency response function estimation method. Cross density spectrum of voltage and current , the autopower spectrum of the current , the autopower spectrum of voltage They can be calculated by the following formulas:

[0099]

[0100]

[0101]

[0102] in, and They are two-dimensional time-frequency matrices and About Time The frequency domain vector of and are their conjugates respectively.

[0103] Because the time-frequency matrix obtained by retrieving impedance information using the generalized S-transform can distinguish differences in energy information, frequency-labeled impedance can be determined by compressing the time axis. The energy screening problem of the two-dimensional time-frequency matrix at each moment is converted into an energy-based weighted representation, allowing the impedance to be expressed directly in terms of frequency characteristics using time-frequency information.

[0104] In an optional embodiment, the electrochemical impedance spectrum of the hydrogen fuel cell is tested online. Due to the small impedance value characteristics and noise influence, the voltage response obtained by the current excitation has a lower signal-to-noise ratio for each harmonic component. moment, choose Estimated impedance calculation, Estimation and The estimation does not circumvent the extraction of information at a single moment; accurate identification of step moments is still required to improve computational accuracy. Because the time-frequency matrix obtained by retrieving impedance information using the generalized S-transform can distinguish differences in energy information, the impedance labeled by frequency can be determined by compressing the time axis. The energy screening problem of the two-dimensional time-frequency matrix at each moment is converted into an energy-based weighted representation, allowing the impedance to be expressed directly in terms of frequency characteristics using time-frequency information. By assigning weights to the cross-power spectrum and auto-power spectrum, the distortion interference of low-energy frequency components on the time axis can be reduced.

[0105] The present invention utilizes the generalized S transform to more precisely capture the temporal changes of the signal by improving the temporal resolution. While improving the temporal resolution, it also enhances the retrieval and expression of harmonic information under multiple harmonic components, supports fast calculation, and improves the retrievability and distinguishability of harmonic information. The one-dimensional time series signal is transformed into a two-dimensional time-frequency matrix, which enhances the expression of harmonic information and enables more efficient processing and analysis of signals with multiple harmonic components. The frequency response function estimation technology based on energy weighting extracts effective harmonic information from the two-dimensional time-frequency matrix, and accurately obtains the electrochemical impedance spectrum by prioritizing the more contributing frequency components.

[0106] Figure 2This is the second flow chart of the electrochemical impedance spectroscopy testing method for new energy batteries provided by the present invention. First, a one-dimensional time series including the output voltage and output current of the new energy battery is collected, and then the one-dimensional time series is transformed into a two-dimensional time-frequency matrix using the generalized S transform; energy-based weights are designed according to the main sources of noise, and the frequency response function estimation technology scheme is selected according to the main sources of noise. Finally, the electrochemical impedance spectrum of the new energy battery is calculated.

[0107] Figure 3 This is the third flow chart of the electrochemical impedance spectroscopy test method for new energy batteries provided by the present invention. In such an embodiment, the present invention discloses an electrochemical impedance spectroscopy test method for new energy batteries such as energy storage batteries, hydrogen fuel cells and electrolytic cells. In the online test stage of electrochemical impedance spectroscopy, the excitation superimposed on a given working current is input into the converter controller as a reference signal, and the current excitation implements a broadband perturbation to obtain a voltage response of the corresponding frequency. The voltage signal and the current signal are collected as a one-dimensional time series to be processed in the new energy battery connected to the converter. The proposed generalized S transform transforms the one-dimensional time series into a two-dimensional time-frequency matrix, effectively improving the time resolution, so that the time-frequency information of multiple harmonic components can be retrieved and distinguished. Secondly, according to the noise level, the frequency response function estimation technology based on energy weight is applied to extract the effective information of the two-dimensional time-frequency matrix. The information retrieval and extraction method enhances the adaptability and robustness of impedance acquisition to complex signal environments, thereby improving the measurement accuracy of the electrochemical impedance spectrum.

[0108] Figure 4 The electrochemical impedance spectroscopy results provided by the present invention are used in the calculation of voltage and current collected during the electrochemical impedance spectroscopy test of a hydrogen fuel cell. The current and voltage signals are collected by injecting an excitation current with multiple harmonic components into the hydrogen fuel cell to obtain a response voltage. Figure 4 For the electrochemical impedance spectroscopy results obtained based on the proposed method and FFT, compared with the traditional FFT results, the proposed information retrieval and extraction method greatly alleviates the noise interference, smoothes the electrochemical impedance spectroscopy results, and improves its measurement accuracy. Figure 5 as well as Figure 6 The real and imaginary parts of the impedance are obtained based on the proposed method and FFT. No matter from the comparison of the real or imaginary part, the results of the proposed method are smoother and more accurate.

[0109] Figure 71 is a structural schematic diagram of the electrochemical impedance spectroscopy testing device for a new energy battery provided by the present invention. The electrochemical impedance spectroscopy testing device for a new energy battery includes an acquisition unit 1. The acquisition unit 1 is used to process the one-dimensional time series signal of the output voltage and the one-dimensional time series signal of the output current using a preset generalized S transform to obtain a two-dimensional time-frequency matrix of the output voltage and a two-dimensional time-frequency matrix of the output current. The working principle of the acquisition unit 1 can be referred to the aforementioned step 101 and will not be repeated here.

[0110] The new energy battery electrochemical impedance spectroscopy testing device also includes a determination unit 2, which is used to determine the current average noise level based on the output current signal and the frequency group to be measured, determine the voltage average noise level based on the output voltage signal and the frequency group to be measured, and determine the target frequency response function estimation method based on the minimum value of the current average noise level and the voltage average noise level. The working principle of the determination unit 2 can be referred to the aforementioned step 102 and will not be repeated here.

[0111] The new energy battery electrochemical impedance spectroscopy testing device also includes a first calculation unit 3, which is used to calculate a weight matrix based on the energy of the measured current signal when it is determined that the noise comes from the voltage, and process the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix according to a frequency response function estimation method based on the current energy weight matrix to obtain a target impedance value. The working principle of the first calculation unit 3 can be referred to the aforementioned step 103 and will not be repeated here.

[0112] The new energy battery electrochemical impedance spectroscopy testing device also includes a second calculation unit 4, which is used to calculate a weight matrix based on the energy of the measured voltage signal when it is determined that the noise comes from the current, and process the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix according to a frequency response function estimation method based on the pressure-flow energy weight matrix to obtain the target impedance value. The working principle of the second calculation unit 4 can be referred to the aforementioned step 104 and will not be repeated here.

[0113] The present invention utilizes the generalized S transform to more precisely capture the temporal changes of the signal by improving the temporal resolution. While improving the temporal resolution, it also enhances the retrieval and expression of harmonic information under multiple harmonic components, supports fast calculation, and improves the retrievability and distinguishability of harmonic information. The one-dimensional time series signal is transformed into a two-dimensional time-frequency matrix, which enhances the expression of harmonic information and enables more efficient processing and analysis of signals with multiple harmonic components. The frequency response function estimation technology based on energy weighting extracts effective harmonic information from the two-dimensional time-frequency matrix, and accurately obtains the electrochemical impedance spectrum by prioritizing the more contributing frequency components.

[0114] Figure 8Schematic diagram of the structure of the electronic device provided by the present invention, such as Figure 8 As shown, the electronic device may include: a processor 110 , a communications interface 120 , a memory 130 and a communication bus 140 , wherein the processor 110 , the communications interface 120 and the memory 130 communicate with each other via the communication bus 140 . The processor 110 can call the logic instructions in the memory 130 to execute the electrochemical impedance spectroscopy testing method of the new energy battery, which includes: using a preset generalized S transform to process the output voltage one-dimensional time series signal and the output current one-dimensional time series signal to obtain the output voltage two-dimensional time-frequency matrix and the output current two-dimensional time-frequency matrix; determining the current average noise level according to the output current signal and the frequency group to be measured, determining the voltage average noise level according to the output voltage signal and the frequency group to be measured, and determining the target frequency response function estimation method according to the minimum value of the current average noise level and the voltage average noise level; when it is determined that the noise comes from voltage, calculating a weight matrix based on the energy of the measured current signal, processing the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix according to the frequency response function estimation method based on the current energy weight matrix, and obtaining the target impedance value; when it is determined that the noise comes from current, calculating a weight matrix based on the energy of the measured voltage signal, processing the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix according to the frequency response function estimation method based on the voltage energy weight matrix, and obtaining the target impedance value.

[0115] In addition, the logical instructions in the aforementioned memory 130 can be implemented in the form of software functional units and, when sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or the portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes various media that can store program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0116] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute a new energy battery electrochemical impedance spectroscopy test method provided by the above methods. The method includes: using a preset generalized S transform to process the output voltage one-dimensional time series signal and the output current one-dimensional time series signal to obtain the output voltage two-dimensional time-frequency matrix and the output current two-dimensional time-frequency matrix; determining the current average noise level according to the output current signal and the frequency group to be measured, determining the voltage average noise level according to the output voltage signal and the frequency group to be measured, and determining the voltage average noise level according to the output voltage signal and the frequency group to be measured. The target frequency response function estimation method is determined by the minimum value of the current average noise level and the voltage average noise level; when it is determined that the noise comes from the voltage, the weight matrix based on the measured current signal energy is calculated, and the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix are processed according to the frequency response function estimation method based on the current energy weight matrix to obtain the target impedance value; when it is determined that the noise comes from the current, the weight matrix based on the measured voltage signal energy is calculated, and the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix are processed according to the frequency response function estimation method based on the current energy weight matrix to obtain the target impedance value.

[0117] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the electrochemical impedance spectroscopy testing method for new energy batteries provided by the above methods, the method comprising: using a preset generalized S transform to process a one-dimensional time series signal of an output voltage and a one-dimensional time series signal of an output current to obtain a two-dimensional time-frequency matrix of an output voltage and a two-dimensional time-frequency matrix of an output current; determining a current average noise level according to the output current signal and a frequency group to be measured, determining a voltage average noise level according to the output voltage signal and the frequency group to be measured, and determining a target frequency response function estimation method according to the minimum value of the current average noise level and the voltage average noise level; when it is determined that the noise comes from voltage, calculating a weight matrix based on the energy of the measured current signal, processing the weight matrix, the two-dimensional time-frequency matrix of the output voltage, and the two-dimensional time-frequency matrix of the output current according to a frequency response function estimation method based on the current energy weight matrix, to obtain a target impedance value; when it is determined that the noise comes from current, calculating a weight matrix based on the energy of the measured voltage signal, processing the weight matrix, the two-dimensional time-frequency matrix of the output voltage, and the two-dimensional time-frequency matrix of the output current according to a frequency response function estimation method based on the voltage energy weight matrix, to obtain the target impedance value.

[0118] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0119] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A new energy battery electrochemical impedance spectroscopy test method, characterized in that: include: Using a preset generalized S transform to process the output voltage one-dimensional time series signal and the output current one-dimensional time series signal, to obtain the output voltage two-dimensional time-frequency matrix and the output current two-dimensional time-frequency matrix; All output current signals in the frequency group to be measured are processed using Fourier transform to obtain all converted current values, all converted current values ​​in the frequency group to be measured are summed and averaged to obtain an average current noise level; all output voltage signals in the frequency group to be measured are processed using Fourier transform to obtain all converted voltage values, all converted voltage values ​​in the frequency group to be measured are summed and averaged to obtain an average voltage noise level, and a target frequency response function estimation method is determined based on the minimum value between the average current noise level and the average voltage noise level; When it is determined that the noise comes from voltage, a weight matrix based on the energy of the measured current signal is calculated, and the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix are processed according to a frequency response function estimation method based on the current energy weight matrix to obtain a target impedance value; When it is determined that the noise comes from current, a weight matrix based on the energy of the measured voltage signal is calculated, and the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix are processed according to a frequency response function estimation method based on the voltage energy weight matrix to obtain the target impedance value.

2. The electrochemical impedance spectroscopy test method for new energy batteries according to claim 1, characterized in that: Before using the preset generalized S transform to process the output voltage one-dimensional time series signal and the output current one-dimensional time series signal, the method further includes: During the excitation and response phases of electrochemical impedance spectroscopy measurement of new energy batteries, the output voltage one-dimensional time series signal and the output current one-dimensional time series signal are collected.

3. The electrochemical impedance spectroscopy test method for new energy batteries according to claim 1, characterized in that: The method of using a preset generalized S transform to process the one-dimensional time series signal of the output voltage and the one-dimensional time series signal of the output current to obtain a two-dimensional time-frequency matrix of the output voltage and the two-dimensional time-frequency matrix of the output current includes: ； in, is the two-dimensional time-frequency matrix of output voltage, is the two-dimensional time-frequency matrix of the output current, is the time factor, is the harmonic frequency; ； in, and They are and Gaussian window function The Fourier transform of is a frequency domain variable, corresponding to a time domain variable , Represents the one-dimensional time series signal of output voltage and output current, e is a natural constant, j is an imaginary unit, d is the total differential symbol, is pi.

4. The electrochemical impedance spectroscopy test method for new energy batteries according to claim 1, characterized in that: The method of estimating the target frequency response function according to the minimum value of the current average noise level and the voltage average noise level includes: When the current average noise level is less than the voltage average noise level, determining that the noise is caused by the voltage; When the current average noise level is greater than the voltage average noise level, it is determined that the noise is derived from the current.

5. The electrochemical impedance spectroscopy testing method for new energy batteries according to claim 1, characterized in that: Calculating a weight matrix based on the energy of the measured current signal and calculating a weight matrix based on the energy of the measured voltage signal include: ； in, is the weight matrix, is the frequency vector of the signal harmonics, represents the index of the time factor, is the number of moments used for impedance calculation, is the time factor corresponding to the moment m, is the current, is the voltage, is a frequency response function estimation method based on the current energy weight matrix, It is a frequency response function estimation method based on the voltage energy weight matrix.

6. The electrochemical impedance spectroscopy testing method for new energy batteries according to claim 5, characterized in that: The target impedance value is obtained by processing the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix according to a frequency response function estimation method based on the current energy weight matrix; Processing the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix in a voltage manner according to a frequency response function based on a voltage energy weight matrix to obtain the target impedance value includes: ； in, is the target impedance value, is the cross density spectrum of voltage and current, is the autopower spectrum of the current, is the autopower spectrum of the voltage, wherein the cross density spectrum of the voltage and current is jointly determined based on the output voltage two-dimensional time-frequency matrix and the output current two-dimensional time-frequency matrix, the autopower spectrum of the current is determined based on the output current two-dimensional time-frequency matrix, and the autopower spectrum of the voltage is determined based on the output voltage two-dimensional time-frequency matrix.

7. A new energy battery electrochemical impedance spectroscopy testing device, characterized in that: include: an acquisition unit, configured to process the one-dimensional time series signal of the output voltage and the one-dimensional time series signal of the output current using a preset generalized S transform to acquire a two-dimensional time-frequency matrix of the output voltage and a two-dimensional time-frequency matrix of the output current; a determination unit configured to process all output current signals in the frequency group to be measured using a Fourier transform to obtain all converted current values, sum all converted current values ​​in the frequency group to be measured, take an average value, and obtain an average current noise level; process all output voltage signals in the frequency group to be measured using a Fourier transform to obtain all converted voltage values, sum all converted voltage values ​​in the frequency group to be measured, take an average value, and obtain an average voltage noise level; and determine a target frequency response function estimation method based on a minimum value between the average current noise level and the average voltage noise level; a first calculation unit, configured to, when it is determined that the noise originates from voltage, calculate a weight matrix based on the energy of the measured current signal, and process the weight matrix, the output voltage two-dimensional time-frequency matrix, and the output current two-dimensional time-frequency matrix according to a frequency response function estimation method based on the current energy weight matrix to obtain a target impedance value; The second calculation unit is used to calculate a weight matrix based on the energy of the measured voltage signal when it is determined that the noise comes from the current, and process the weight matrix, the output voltage two-dimensional time-frequency matrix and the output current two-dimensional time-frequency matrix according to a frequency response function estimation method based on the voltage energy weight matrix to obtain the target impedance value.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the electrochemical impedance spectroscopy testing method for new energy batteries as described in any one of claims 1 to 6 is implemented.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a calculation program. When the calculation program is executed by a processor, the processor implements the electrochemical impedance spectroscopy testing method for a new energy battery according to any one of claims 1 to 6.

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