System and method for analyzing and processing sensitivity and consistency of fuel cell stack operation parameters based on multi-channel impedance

Abstract

The invention relates to a system for analyzing and processing sensitivity and consistency of fuel cell stack operation parameters based on multichannel impedance, which comprises a fuel cell stack, an analysis system, a direct current load and an alternating current load, and is characterized in that the fuel cell stack is used for supplying reaction gas and controlling temperature through a peripheral stack test bench; the direct-current load is connected with the fuel cell stack, the power output of the fuel cell stack is controlled through constant current or constant voltage, the alternating-current load is connected with the fuel cell stack, the input end of the analysis system is connected with the fuel cell stack, and the analysis system is connected with the alternating-current load. By adopting the system, the method, the device, the processor and the computer readable storage medium for realizing sensitivity and consistency analysis processing on the fuel cell stack operation parameters based on multi-channel impedance, quantitative acquisition of polarization process parameters of multiple channels of a full-size stack can be realized; a more comprehensive sensitivity analysis effect of the operation parameters is achieved, and a more comprehensive consistency analysis effect can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of fixed power supplies and vehicle-mounted transportation, and in particular to the field of proton exchange membrane fuel cells, and specifically refers to a system, method, device, processor and computer-readable storage medium thereof for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance. Background Art

[0002] Proton exchange membrane fuel cell (PEMFC) stacks have shown significant development prospects in the fields of stationary power and on-board transportation, mainly due to their high power density, energy conversion efficiency, zero emissions, and high dynamic response. However, the commercial application of fuel cell stacks in vehicles is still limited by high costs and durability issues. At present, the operating life of fuel cell stacks under on-board conditions is generally less than 2000 hours. Due to frequent load fluctuations, insufficient air intake, and inadequate water management and thermal management, stack failures may occur frequently, including membrane drying, flooding, and starvation, which ultimately lead to rapid performance degradation in a short period of time. If not diagnosed and controlled in time, this may lead to irreversible performance degradation, such as membrane degradation, carbon corrosion, catalyst loss, and material degradation, thereby accelerating the deterioration of service life. Therefore, accurate identification of internal states and timely control are crucial to improve the service life of on-board fuel cell stacks. The basic premise for the realization of this function is to accurately obtain the parameters of the internal polarization process of the stack and explore the sensitivity and consistency between the operating conditions and the polarization process.

[0003] CN116047303A discloses a comprehensive analysis method for the uniformity of commercial-sized proton exchange membrane fuel cells: a rapid qualitative analysis of the in-plane uniformity is performed through a multi-point voltage monitoring method; then, the current distribution model established by the multi-point voltage monitoring results is combined with an in-situ temperature monitoring method to analyze the redistribution mechanism of current and voltage; finally, the sensitivity of each polarization loss to current density in different battery regions is analyzed through a multi-point impedance method and the distribution of relaxation time. This invention is an analysis method for the operation and sensitivity of the entire surface of a single-chip battery, which is mainly used in the development and design stage of fuel cells. It does not systematically analyze the consistency between the chips of a commercial battery stack and the sensitivity of the operating parameters of each chip.

[0004] CN117423864A discloses a method for evaluating the uncertainty and sensitivity of fuel cell equivalent circuit model parameters: AC impedance spectrum data of the battery under three water management states: normal, flooded and membrane dry; establishing an equivalent circuit model and determining the vector of the parameters to be identified; using a variational Bayesian algorithm based on the automatic differential variation principle to evaluate the uncertainty of the model parameters to be identified, combined with the Sobol global sensitivity analysis method, to quantitatively evaluate the degree of influence of the changes in the parameters to be identified under different water management states on the output of the equivalent circuit model. This invention mainly provides the accuracy analysis of the impedance spectrum fitting parameters based on the equivalent circuit model, and does not yet provide the problem of analyzing the sensitivity and consistency of the operating parameters of the stack based on the identified parameters.

[0005] At present, the evaluation of the sensitivity and consistency of the operating parameters of fuel cell stacks is mainly based on voltage or single-channel impedance or a combination of the two parameters. No systematic analysis method for the difference in parameter sensitivity and consistency between stack cells is given, making it difficult to accurately obtain the internal polarization process parameters of the stack and their influencing factors. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and to provide a system, method, device, processor and computer-readable storage medium thereof that can realize sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance, which can meet the requirements of comprehensive analysis, accurate results and a wide range of applications.

[0007] In order to achieve the above objectives, the system, method, device, processor and computer-readable storage medium thereof for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance of the present invention are as follows:

[0008] The system for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance has the following main features: the system includes a fuel cell stack, an analysis system, a DC load and an AC load; the fuel cell stack is supplied with required reaction gas and temperature controlled through an external stack test bench; the DC load is connected to the fuel cell stack and controls the power output of the fuel cell stack through constant current or constant voltage; the AC load is connected to the fuel cell stack; the input end of the analysis system is connected to the fuel cell stack; and the output end of the analysis system is connected to the AC load.

[0009] Preferably, the analysis system includes a collection unit, an excitation signal unit, an impedance spectrum measurement unit, an impedance spectrum analysis unit and an analysis unit, the input end of the collection unit is connected to the fuel cell stack, the input end of the impedance spectrum measurement unit is connected to the collection unit, the input end of the impedance spectrum analysis unit is connected to the impedance spectrum measurement unit, the input end of the analysis unit is connected to the impedance spectrum analysis unit, the input end of the excitation signal unit is connected to the impedance spectrum measurement unit, and the output end of the excitation signal unit is connected to the AC load.

[0010] Preferably, the excitation signal unit receives instructions from the impedance spectrum measurement unit, controls the AC load, superimposes an AC excitation of corresponding amplitude and frequency on the DC output of the DC load, and injects the AC excitation into the fuel cell stack; the acquisition unit synchronously acquires the voltage of multiple channels of the fuel cell stack and the total current at the output end of the fuel cell stack, and the acquisition unit sends the acquired multi-channel voltage and current signals to the impedance spectrum measurement unit for impedance calculation, calculates the impedance of the fuel cell stack, and sends them to the impedance spectrum analysis unit; the impedance spectrum analysis unit analyzes the polarization resistance information in the impedance spectrum through DRT, and sends the polarization resistance information to the analysis unit, and the analysis unit performs sensitivity and consistency analysis of the stack operating parameters through a multivariate stepwise regression method and a variance mean method according to the values ​​of each polarization resistance under different operating conditions.

[0011] The method for realizing sensitivity and consistency analysis of fuel cell stack operating parameters based on multi-channel impedance using the above system is mainly characterized in that the method includes a processing process for realizing sensitivity analysis of fuel cell stack operating parameters based on multi-channel impedance, specifically including the following steps:

[0012] (1) Connect equipment for multi-channel impedance measurement and develop tests under different operating parameters;

[0013] (2) Determine the types of operating parameters for impedance measurement, formulate the change value of each operating parameter, and conduct multi-channel impedance spectrum test according to different operating parameter points;

[0014] (3) Analyze the polarization process of DRT impedance spectrum and identify the dependent variables;

[0015] (4) Normalize the standard operating conditions according to the range of the independent variable;

[0016] (5) Evaluate the sensitivity of operating parameters based on stepwise regression analysis;

[0017] (6) Analyze the sensitivity results of various operating parameters of polarization resistance;

[0018] Preferably, the step (2) specifically comprises the following steps:

[0019] (2.1) Perform wide spectrum measurement of fuel cell impedance spectrum under steady-state conditions;

[0020] (2.2) Perform DRT fitting on the impedance spectrum and calculate the polarization resistance contained in the impedance spectrum;

[0021] (2.3) Calculate the characteristic frequency distribution range and logarithmic frequency interval of the DRT peak;

[0022] (2.4) Determine the frequency range of impedance spectrum measurement based on the characteristic frequency range, and determine the minimum number of multiple frequency points based on the minimum logarithmic frequency interval;

[0023] (2.5) Determine the types of operating parameters for impedance measurement and set the change value of each operating parameter;

[0024] (2.6) Perform multi-channel impedance spectroscopy tests under different operating parameter points.

[0025] Preferably, the step (3) specifically comprises the following steps:

[0026] (3.1) Setting the characteristic frequency resolution ΔIogf and regularization parameter λ of the DRT method;

[0027] (3.2) Calculate the characteristic frequency and peak area of ​​each DRT characteristic peak;

[0028] (3.3) Polarization processes are assigned to each DRT peak based on its characteristic frequency and peak area.

[0029] Preferably, the normalization process is performed in step (4), specifically:

[0030] Normalization is performed according to the following formula:

[0031] x , =(xx stand ) / (x max -x min );

[0032] Among them, x , is the normalized value, x is the actual value, and x stand is the standard operating parameter value, x max is the maximum value of the operation change, x min is the minimum value of the operating parameter change.

[0033] Preferably, the step (5) specifically comprises the following steps:

[0034] (5.1) The sensitivity of the operating parameters of each polarization resistor of each channel is analyzed separately using a stepwise backward selection method;

[0035] (5.2) Determine whether the P value of the independent variable is greater than or equal to 0.05. If so, delete the independent variable and continue with step (5.1); otherwise, continue with step (5.3);

[0036] (5.3) Confirm the analysis model parameters and record the P value and t statistic value of each operating parameter;

[0037] (5.4) The quality of model fit is judged by comprehensive scoring based on the Bayesian Information Criterion;

[0038] (5.5) Analyze the goodness of fit of the regression model and adjust R 2 , evaluate model capabilities;

[0039] (5.6) Check for multicollinearity and determine the independence of the independent variables using the variance inflation factor.

[0040] Preferably, the step (6) specifically comprises the following steps:

[0041] (6.1) Calculate the P value and t-statistic value of the polarization resistance operation sensitivity under each channel;

[0042] (6.2) Determine whether the P values ​​of the polarization resistance of all channels to the operating parameters are less than 0.05. If so, the polarization resistance is completely related to the operating condition; otherwise, proceed to step (6.3);

[0043] (6.3) Determine whether the P values ​​of the polarization resistance of all channels to the operating parameters are greater than or equal to 0.05. If so, the polarization resistance is locally correlated with the operating condition; otherwise, the polarization resistance is conditionally correlated with the operating condition.

[0044] Preferably, the method further comprises a process for realizing consistency analysis of fuel cell stack operating parameters based on multi-channel impedance, which specifically comprises the following steps:

[0045] (2-1) Connect equipment for multi-channel impedance measurement and develop tests under different operating parameters;

[0046] (2-2) Determine the type of operating parameters for impedance measurement, formulate the change value of each operating parameter, and perform multi-channel impedance spectrum test according to different operating parameter points;

[0047] (2-3) performing DRT fitting on the measured multi-channel impedance spectra to obtain the polarization process information contained in the impedance spectra of each channel under different operating parameters;

[0048] (2-4) Calculate the variance and mean of the polarization resistance of each channel under different operating parameters;

[0049] (2-5) calculating the change of each polarization resistance variance under different operating parameter conditions, and setting each polarization resistance variance threshold;

[0050] (2-6) According to the threshold and polarization resistance variance values, the consistency-based operating parameter boundaries are given.

[0051] The device for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance is mainly characterized in that the device comprises:

[0052] a processor configured to execute computer-executable instructions;

[0053] A memory stores one or more computer executable instructions. When the computer executable instructions are executed by the processor, the various steps of the method for performing sensitivity and consistency analysis on fuel cell stack operating parameters based on multi-channel impedance are implemented.

[0054] The processor for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance has the main feature that the processor is configured to execute computer executable instructions. When the computer executable instructions are executed by the processor, the various steps of the above-mentioned method for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance are realized.

[0055] The main feature of the computer-readable storage medium is that a computer program is stored thereon, and the computer program can be executed by a processor to implement the various steps of the above-mentioned method for performing sensitivity and consistency analysis and processing on fuel cell stack operating parameters based on multi-channel impedance.

[0056] The system, method, device, processor and computer-readable storage medium thereof for realizing sensitivity and consistency analysis and processing for fuel cell stack operating parameters based on multi-channel impedance of the present invention can realize quantitative acquisition of polarization process parameters of multiple channels of full-size stack, realize synchronous acquisition of multi-channel impedance spectrum by synchronously collecting multi-channel voltage and current of stack, realize quantitative analysis of each polarization process information based on DRT method, thereby obtaining richer polarization process information of stack. The present invention can realize more comprehensive sensitivity analysis effect of operating parameters, analyze the operating parameter sensitivity of each polarization resistor of each channel respectively by stepwise backward selection method, calculate P value and t statistic value of operating sensitivity of each polarization resistor under each channel, and divide the correlation between polarization resistor and operating parameter into three categories: complete correlation, local correlation and uncorrelation. The main operating parameters affecting each polarization process and the main causes of local inconsistency can be further analyzed, providing basis for design and strategy optimization of stack. The present invention can achieve a more comprehensive consistency analysis effect. By calculating the variance and mean of each polarization resistance in each channel under different operating parameters, compared with the existing variance and mean of only the channel monomer voltage, a more detailed method and mean of activation resistance, ohmic resistance, and mass transfer resistance are achieved, laying the foundation for consistency-based operating parameter boundary identification and parameter optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a structural schematic diagram of the system for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance of the present invention.

[0058] Figure 2 It is a multi-channel connection schematic diagram of the system for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance of the present invention.

[0059] Figure 3 The present invention is a flow chart of a method for implementing sensitivity and consistency analysis processing for fuel cell stack operating parameters based on multi-channel impedance.

[0060] Figure 4 It is a flow chart of multi-channel impedance measurement and independent variable identification under different operating parameters of the present invention.

[0061] Figure 5 This is a flow chart of the DRT-based impedance spectrum polarization process analysis and dependent variable identification of the present invention.

[0062] Figure 6 It is a flow chart based on stepwise regression analysis and model evaluation of the present invention.

[0063] Figure 7The flowchart of the analysis of the sensitivity results of the polarization resistor to various operating parameters of the present invention.

[0064] Figure 8 The present invention is a flow chart of the fuel cell stack consistency analysis method based on multi-channel impedance.

[0065] Reference numerals:

[0066] 10Fuel cell stack

[0067] 20Sensitivity and consistency analysis system

[0068] 30 DC load

[0069] 40AC load DETAILED DESCRIPTION

[0070] In order to more clearly describe the technical content of the present invention, further description is given below in conjunction with specific embodiments.

[0071] The system of the present invention for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance includes a fuel cell stack 10, an analysis system 20, a DC load 30 and an AC load 40. The fuel cell stack 10 is supplied with required reaction gases and temperature controlled by an external stack test bench. The DC load 30 is connected to the fuel cell stack 10 and controls the power output of the fuel cell stack by constant current or constant voltage. The AC load 40 is connected to the fuel cell stack 10. The input end of the analysis system 20 is connected to the fuel cell stack 10, and the output end of the analysis system 20 is connected to the AC load 40.

[0072] As a preferred embodiment of the present invention, the analysis system 20 includes a collection unit, an excitation signal unit, an impedance spectrum measurement unit, an impedance spectrum analysis unit and an analysis unit, the input end of the collection unit is connected to the fuel cell stack 10, the input end of the impedance spectrum measurement unit is connected to the collection unit, the input end of the impedance spectrum analysis unit is connected to the impedance spectrum measurement unit, the input end of the analysis unit is connected to the impedance spectrum analysis unit, the input end of the excitation signal unit is connected to the impedance spectrum measurement unit, and the output end of the excitation signal unit is connected to the AC load 40.

[0073] As a preferred embodiment of the present invention, the excitation signal unit receives instructions from the impedance spectrum measurement unit, controls the AC load 40, superimposes an AC excitation of corresponding amplitude and frequency on the DC output of the DC load 30, and injects the AC excitation of the fuel cell stack; the acquisition unit synchronously acquires the voltage of multiple channels of the fuel cell stack and the total current at the output end of the fuel cell stack, and the acquisition unit sends the acquired multi-channel voltage and current signals to the impedance spectrum measurement unit for impedance calculation, calculates the impedance of the fuel cell stack, and sends it to the impedance spectrum analysis unit; the impedance spectrum analysis unit analyzes the polarization resistance information in the impedance spectrum through DRT, and sends the polarization resistance information to the analysis unit, and the analysis unit performs sensitivity and consistency analysis of the stack operating parameters through a multivariate stepwise regression method and a variance mean method according to the values ​​of each polarization resistance under different operating conditions.

[0074] The method of the present invention uses the above system to realize sensitivity and consistency analysis of fuel cell stack operating parameters based on multi-channel impedance, wherein the method comprises a process of realizing sensitivity analysis of fuel cell stack operating parameters based on multi-channel impedance, specifically comprising the following steps:

[0075] (1) Connect equipment for multi-channel impedance measurement and develop tests under different operating parameters;

[0076] (2) Determine the types of operating parameters for impedance measurement, formulate the change value of each operating parameter, and conduct multi-channel impedance spectrum test according to different operating parameter points;

[0077] (3) Analyze the polarization process of DRT impedance spectrum and identify the dependent variables;

[0078] (4) Normalize the standard operating conditions according to the range of the independent variable;

[0079] (5) Evaluate the sensitivity of operating parameters based on stepwise regression analysis;

[0080] (6) Analyze the sensitivity results of various operating parameters of polarization resistance;

[0081] As a preferred embodiment of the present invention, the step (2) specifically comprises the following steps:

[0082] (2.1) Perform wide spectrum measurement of fuel cell impedance spectrum under steady-state conditions;

[0083] (2.2) Perform DRT fitting on the impedance spectrum and calculate the polarization resistance contained in the impedance spectrum;

[0084] (2.3) Calculate the characteristic frequency distribution range and logarithmic frequency interval of the DRT peak;

[0085] (2.4) Determine the frequency range of impedance spectrum measurement based on the characteristic frequency range, and determine the minimum number of multiple frequency points based on the minimum logarithmic frequency interval;

[0086] (2.5) Determine the types of operating parameters for impedance measurement and set the change value of each operating parameter;

[0087] (2.6) Perform multi-channel impedance spectroscopy tests under different operating parameter points.

[0088] As a preferred embodiment of the present invention, the step (3) specifically comprises the following steps:

[0089] (3.1) Setting the characteristic frequency resolution ΔIogf and regularization parameter λ of the DRT method;

[0090] (3.2) Calculate the characteristic frequency and peak area of ​​each DRT characteristic peak;

[0091] (3.3) Polarization processes are assigned to each DRT peak based on its characteristic frequency and peak area.

[0092] As a preferred embodiment of the present invention, the normalization process is performed in step (4), specifically:

[0093] Normalization is performed according to the following formula:

[0094] x , =(xx stand ) / (x max -x min );

[0095] Among them, x , is the normalized value, x is the actual value, and x stand is the standard operating parameter value, x max is the maximum value of the operation change, x min is the minimum value of the operating parameter change.

[0096] As a preferred embodiment of the present invention, the step (5) specifically comprises the following steps:

[0097] (5.1) The sensitivity of the operating parameters of each polarization resistor of each channel is analyzed separately using a stepwise backward selection method;

[0098] (5.2) Determine whether the P value of the independent variable is greater than or equal to 0.05. If so, delete the independent variable and continue with step (5.1); otherwise, continue with step (5.3);

[0099] (5.3) Confirm the analysis model parameters and record the P value and t statistic value of each operating parameter;

[0100] (5.4) The quality of model fit is judged by comprehensive scoring based on the Bayesian Information Criterion;

[0101] (5.5) Analyze the goodness of fit of the regression model and adjust R 2 , evaluate model capabilities;

[0102] (5.6) Check for multicollinearity and determine the independence of the independent variables using the variance inflation factor.

[0103] As a preferred embodiment of the present invention, the step (6) specifically comprises the following steps:

[0104] (6.1) Calculate the P value and t-statistic value of the polarization resistance operation sensitivity under each channel;

[0105] (6.2) Determine whether the P values ​​of the polarization resistance of all channels to the operating parameters are less than 0.05. If so, the polarization resistance is completely related to the operating condition; otherwise, proceed to step (6.3);

[0106] (6.3) Determine whether the P values ​​of the polarization resistance of all channels to the operating parameters are greater than or equal to 0.05. If so, the polarization resistance is locally correlated with the operating condition; otherwise, the polarization resistance is conditionally correlated with the operating condition.

[0107] As a preferred embodiment of the present invention, the method further includes a process for realizing consistency analysis of fuel cell stack operating parameters based on multi-channel impedance, which specifically includes the following steps:

[0108] (2-1) Connect equipment for multi-channel impedance measurement and develop tests under different operating parameters;

[0109] (2-2) Determine the type of operating parameters for impedance measurement, formulate the change value of each operating parameter, and perform multi-channel impedance spectrum test according to different operating parameter points;

[0110] (2-3) performing DRT fitting on the measured multi-channel impedance spectra to obtain the polarization process information contained in the impedance spectra of each channel under different operating parameters;

[0111] (2-4) Calculate the variance and mean of the polarization resistance of each channel under different operating parameters;

[0112] (2-5) calculating the change of each polarization resistance variance under different operating parameter conditions, and setting each polarization resistance variance threshold;

[0113] (2-6) According to the threshold and polarization resistance variance values, the consistency-based operating parameter boundaries are given.

[0114] The device for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance of the present invention comprises:

[0115] a processor configured to execute computer-executable instructions;

[0116] A memory stores one or more computer executable instructions. When the computer executable instructions are executed by the processor, the various steps of the method for performing sensitivity and consistency analysis on fuel cell stack operating parameters based on multi-channel impedance are implemented.

[0117] The processor of the present invention is used to implement sensitivity and consistency analysis processing for fuel cell stack operating parameters based on multi-channel impedance, wherein the processor is configured to execute computer executable instructions, and when the computer executable instructions are executed by the processor, the various steps of the above-mentioned method for implementing sensitivity and consistency analysis processing for fuel cell stack operating parameters based on multi-channel impedance are implemented.

[0118] The computer-readable storage medium of the present invention stores a computer program thereon, and the computer program can be executed by a processor to implement the various steps of the above-mentioned method for performing sensitivity and consistency analysis and processing on fuel cell stack operating parameters based on multi-channel impedance.

[0119] In a specific embodiment of the present invention, a multi-channel impedance measurement and analysis system for sensitivity and consistency is proposed. In addition to multi-channel synchronous measurement, the system also includes sensitivity and consistency analysis algorithms integrated into the system to realize a system specifically for sensitivity and consistency analysis of fuel cell stack operating parameters.

[0120] The fuel cell stack operating parameter sensitivity and consistency analysis system based on multi-channel impedance of the present invention includes a fuel cell stack 10; a sensitivity and consistency analysis system 20, wherein the analysis system 20 includes an acquisition unit, an excitation signal unit, a multi-channel impedance spectrum measurement unit, a multi-channel impedance spectrum analysis unit and an analysis unit; a DC load 30; and an AC load 40.

[0121] First, the fuel cell stack 10 supplies the required reaction gas and controls the temperature through its peripheral stack test bench. The DC load 30 is connected to the fuel cell stack 10, and uses constant current or constant voltage to control the power output of the fuel cell stack. In addition, when starting the sensitivity and consistency analysis of the fuel cell stack operating parameters, the excitation signal unit of the analysis system 20 receives the instruction of the multi-channel impedance spectrum measurement unit, controls the AC load 40, and superimposes the AC excitation of the corresponding amplitude and frequency on the DC output of the DC load 30 to realize the injection of AC excitation of the fuel cell stack.

[0122] The voltage of the multi-channel of the fuel cell stack and the total current of the output end of the fuel cell stack are synchronously collected by the collection unit of the analysis system 20. The collection unit of the analysis system 20 sends the collected multi-channel voltage and current signals to the multi-channel impedance spectrum measurement unit for impedance calculation, calculates the impedance of the fuel cell stack, and sends it to the multi-channel impedance spectrum analysis unit of the analysis system 20. The multi-channel impedance spectrum analysis unit analyzes the polarization resistance information in the impedance spectrum by the DRT method, and then sends each polarization resistance information to the analysis unit of the analysis system 20. The analysis unit performs sensitivity and consistency analysis of the stack operating parameters according to the values ​​of each polarization resistance under different operating conditions by the multivariate stepwise regression method and the variance mean method.

[0123] The flow chart of the fuel cell stack operating parameter sensitivity analysis method based on multi-channel impedance is as follows: Figure 3 As shown, first, according to Figure 2 The schematic diagram is used to connect the equipment for multi-channel impedance measurement and formulate experiments under different operating parameters (S1). Next, the types of operating parameters for impedance measurement are determined, such as the stack intake temperature, the relative humidity of hydrogen or air intake, pressure, and stoichiometric ratio, and the change value of each operating parameter is formulated, such as the stack intake temperature from 50 to 90°C, with an operating parameter point every 10°C; the multi-channel impedance measurement scheme under different operating parameter points is determined, and the multi-channel impedance spectrum test experiment under the above-mentioned different operating parameter points is carried out (S2). The measured multi-channel impedance spectrum is fitted by DRT to obtain the polarization process information contained in the impedance spectrum of each channel under different operating parameters, such as activation resistance, mass transfer resistance, and ohmic resistance (S3); then, the standard operating conditions are normalized according to the range of variation of the independent variable (S4), and the formula is shown below.

[0124] x , =(xx stand ) / (x max -x min )

[0125] In the formula, x , is the normalized value, x is the actual value, and x stand is the standard operating parameter value, x max is the maximum value of the operation change, x min is the minimum value of the operating parameter change.

[0126] According to the normalized independent variables and the polarization process information fitted by DRT, the sensitivity of the polarization resistance operating parameters of each channel was analyzed based on the multivariate stepwise regression method, and the goodness of fit of the regression model and the adjustment R 2, evaluate the model capability (S5). According to the results of S5, analyze whether the P value of the polarization resistance under all channels is less than 0.05, and divide the operating parameters of the polarization resistance into completely correlated, partially correlated, and completely uncorrelated (S6). Based on the results of S6, further analyze the main operating parameters affecting each polarization process and further analyze the main reasons for local inconsistency, providing a basis for the design and strategy optimization of the battery stack.

[0127] The above R 2 It is a statistic in regression analysis that is used to assess the explanatory power of a model while taking into account the number of independent variables used in the model. Compared to the ordinary R2, the adjusted R2 is more suitable for comparing models with different numbers of independent variables because it imposes a certain penalty on model complexity.

[0128] In order to determine the number and range of impedance spectrum measurement frequency points under different operating parameters, reduce unnecessary low-frequency measurement points, and improve the efficiency of impedance spectrum measurement, the multi-channel impedance measurement under different operating parameters is designed. Figure 4 As shown, first, a wide spectrum measurement of the fuel cell impedance spectrum is performed under steady-state conditions. The impedance spectrum needs to have high and low frequency intercepts (S21), which generally covers about 0.1Hz to 10kHz for fuel cells; the impedance spectrum is DRT fitted to calculate the polarization resistance (S3, which is also Figure 3 S3 in the figure), further calculate the characteristic frequency distribution range of the DRT peak and its logarithmic frequency interval (S22); according to the required polarization resistance information, for example, only ohmic resistance, activation resistance and mass transfer resistance are required, and the frequency range of the impedance spectrum measurement is determined according to the characteristic frequency range of the above process. In addition, the minimum number of multiple frequency points is determined according to the minimum logarithmic frequency interval, thereby avoiding unnecessary frequency measurement points (S23); determine the type of operating parameters for impedance measurement, such as the stack intake temperature, the relative humidity of hydrogen or air intake, pressure and stoichiometric ratio, and formulate the change value of each operating parameter, such as the stack intake temperature from 50 to 90°C, with an operating parameter point every 10°C (S24); carry out multi-channel impedance spectrum test experiments under the above different operating parameter points (S25).

[0129] In order to achieve accurate analysis of the impedance spectrum, the impedance spectrum polarization process analysis and dependent variable identification based on DRT are as follows: Figure 5As shown. First, the DRT method needs to be improved and the parameters need to be optimized. The two key parameters of the DRT method include the characteristic frequency resolution ΔIogf and the regularization parameter λ. In order to balance the DRT characteristic peak overlap problem and the accuracy problem, ΔIogf is set to less than 1 / 5 of the minimum logarithmic frequency interval; the regularization parameter λ is used to optimize the overfitting and underfitting problems. The principle of selection is that when the change in the λ value is less than a certain threshold value for the fitting residual deviation, the value is selected as the regularization parameter λ (S31). Then the characteristic frequency and peak area of ​​each DRT characteristic peak are calculated (S32), and the polarization process is assigned to each peak according to the characteristic frequency and peak area of ​​each DRT peak. Generally, from low frequency to high frequency, they are mass transfer process, charge transfer process, anode and catalyst layer proton transfer process, and ohmic process (S33).

[0130] Then, the sensitivity of the operating parameters was evaluated based on the stepwise regression analysis method, as shown in the flowchart. Figure 6 As shown. The stepwise backward selection method is used to analyze the sensitivity of the operating parameters of each polarization resistor of each channel (S41). When the P value of an independent variable is ≥ 0.05, the independent variable is deleted and the S41 process is repeated until the P values ​​of all variables are < 0.05 (S42); thereby confirming the analysis model parameters, recording the P value and t statistic of each operating parameter here (S43), where P value and t statistic are two important concepts in statistics for evaluating hypothesis testing; next, the goodness of model fitting is judged by the comprehensive score of the Bayesian information criterion (S44), and the goodness of fit of the regression model and the adjusted R 2 , evaluate model capability (S45); check for multicollinearity and determine the independence between independent variables through variance inflation factor (S46).

[0131] Finally, the analysis flow chart of the sensitivity results of the polarization resistance operating parameters is as follows: Figure 7 As shown. According to the method of S5, the P value and t statistic value (S41) of the operation sensitivity of each polarization resistor under each channel are calculated, and it is judged that when the P value of the polarization resistor of all channels to the operation parameter is <0.05, the polarization resistor is completely related to the operation condition; when the P value of the polarization resistor of all channels to the operation parameter is partially <0.05, the polarization resistor is partially related to the operation condition. When the P value of the polarization resistor of all channels to the operation parameter is all ≥0.05, the polarization resistor is irrelevant to the operation condition.

[0132] Figure 8 A flow chart of the fuel cell stack consistency analysis method based on multi-channel impedance is given. First, according to Figure 2The schematic diagram is used to connect the equipment for multi-channel impedance measurement and formulate tests under different operating parameters (S1). Next, the types of operating parameters for impedance measurement are determined, such as the stack intake temperature, the relative humidity of hydrogen or air intake, pressure, and stoichiometric ratio, and the change value of each operating parameter is formulated, such as the stack intake temperature from 50 to 90°C, with an operating parameter point every 10°C; the multi-channel impedance measurement scheme under different operating parameter points is determined, and the multi-channel impedance spectrum test experiment under the above different operating parameter points is carried out (S2). The measured multi-channel impedance spectrum is subjected to DRT fitting to obtain the polarization process information contained in the impedance spectrum of each channel under different operating parameters, such as activation resistance, mass transfer resistance and ohmic resistance (S3); the variance and mean of the polarization resistance under each channel under different operating parameters are calculated (S7), the change of the variance of each polarization resistance under different operating parameters is calculated, and the threshold value of the variance of each polarization resistance is set (S8); according to the threshold value and the polarization resistance variance value, the operating parameter boundary based on consistency is given, that is, when the polarization resistance variance value under the operating parameter is greater than the threshold value, the operating parameter is unreasonable.

[0133] The specific implementation scheme of this embodiment can refer to the relevant description in the above embodiment, which will not be repeated here.

[0134] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0135] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0136] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0137] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution device. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0138] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the corresponding program may be stored in a computer-readable storage medium, which, when executed, includes one of the steps of the method embodiment or a combination thereof.

[0139] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0140] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0141] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0142] The system, method, device, processor and computer-readable storage medium thereof for realizing sensitivity and consistency analysis and processing for fuel cell stack operating parameters based on multi-channel impedance of the present invention can realize quantitative acquisition of polarization process parameters of multiple channels of full-size stack, realize synchronous acquisition of multi-channel impedance spectrum by synchronously collecting multi-channel voltage and current of stack, realize quantitative analysis of each polarization process information based on DRT method, thereby obtaining richer polarization process information of stack. The present invention can realize more comprehensive sensitivity analysis effect of operating parameters, analyze the operating parameter sensitivity of each polarization resistor of each channel respectively by stepwise backward selection method, calculate P value and t statistic value of operating sensitivity of each polarization resistor under each channel, and divide the correlation between polarization resistor and operating parameter into three categories: complete correlation, local correlation and uncorrelation. The main operating parameters affecting each polarization process and the main causes of local inconsistency can be further analyzed, providing basis for design and strategy optimization of stack. The present invention can achieve a more comprehensive consistency analysis effect. By calculating the variance and mean of each polarization resistance in each channel under different operating parameters, compared with the existing variance and mean of only the channel monomer voltage, a more detailed method and mean of activation resistance, ohmic resistance, and mass transfer resistance are achieved, laying the foundation for consistency-based operating parameter boundary identification and parameter optimization.

[0143] In this specification, the present invention has been described with reference to specific embodiments thereof. However, it is apparent that various modifications and variations may be made without departing from the spirit and scope of the present invention. Therefore, the specification and drawings should be regarded as illustrative rather than restrictive.

Claims

1. A system for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance, characterized in that: The system includes a fuel cell stack, an analysis system, a DC load and an AC load. The fuel cell stack is supplied with required reaction gas and temperature controlled through an external stack test bench. The DC load is connected to the fuel cell stack and controls the power output of the fuel cell stack through constant current or constant voltage. The AC load is connected to the fuel cell stack. The input end of the analysis system is connected to the fuel cell stack, and the output end of the analysis system is connected to the AC load.

2. The system for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance according to claim 1, characterized in that: The analysis system comprises a collection unit, an excitation signal unit, an impedance spectrum measurement unit, an impedance spectrum analysis unit and an analysis unit. The input end of the collection unit is connected to the fuel cell stack, the input end of the impedance spectrum measurement unit is connected to the collection unit, the input end of the impedance spectrum analysis unit is connected to the impedance spectrum measurement unit, the input end of the analysis unit is connected to the impedance spectrum analysis unit, the input end of the excitation signal unit is connected to the impedance spectrum measurement unit, and the output end of the excitation signal unit is connected to the AC load.

3. The system for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance according to claim 2, characterized in that: The excitation signal unit receives instructions from the impedance spectrum measurement unit, controls the AC load, superimposes an AC excitation of corresponding amplitude and frequency on the DC output of the DC load, and injects the AC excitation into the fuel cell stack; the acquisition unit synchronously acquires the voltage of multiple channels of the fuel cell stack and the total current at the output end of the fuel cell stack, and the acquisition unit sends the acquired multi-channel voltage and current signals to the impedance spectrum measurement unit for impedance calculation, calculates the impedance of the fuel cell stack, and sends it to the impedance spectrum analysis unit; The impedance spectrum analysis unit analyzes the polarization resistance information in the impedance spectrum through DRT, and sends each polarization resistance information to the analysis unit. The analysis unit performs sensitivity and consistency analysis of the stack operating parameters through the multivariate stepwise regression method and the variance mean method according to the values ​​of each polarization resistance under different operating conditions.

4. A method for implementing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance using the system of claim 1, characterized in that: The method includes a process for realizing a fuel cell stack operating parameter sensitivity analysis based on multi-channel impedance, specifically comprising the following steps: (1) Connect equipment for multi-channel impedance measurement and develop tests under different operating parameters; (2) Determine the types of operating parameters for impedance measurement, formulate the change value of each operating parameter, and conduct multi-channel impedance spectrum test according to different operating parameter points; (3) Analyze the polarization process of DRT impedance spectrum and identify the dependent variables; (4) Normalize the standard operating conditions according to the range of the independent variable; (5) Evaluate the sensitivity of operating parameters based on stepwise regression analysis; (6) Analyze the sensitivity results of the polarization resistance to each operating parameter.

5. The method for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance according to claim 4, characterized in that: The step (2) specifically comprises the following steps: (2.1) Perform wide spectrum measurement of fuel cell impedance spectrum under steady-state conditions; (2.2) Perform DRT fitting on the impedance spectrum and calculate the polarization resistance contained in the impedance spectrum; (2.3) Calculate the characteristic frequency distribution range and logarithmic frequency interval of the DRT peak; (2.4) Determine the frequency range of impedance spectrum measurement based on the characteristic frequency range, and determine the minimum number of multiple frequency points based on the minimum logarithmic frequency interval; (2.5) Determine the types of operating parameters for impedance measurement and set the change value of each operating parameter; (2.6) Perform multi-channel impedance spectroscopy tests under different operating parameter points.

6. The method for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance according to claim 4, characterized in that: The step (3) specifically comprises the following steps: (3.1) Setting the characteristic frequency resolution ΔIogf and regularization parameter λ of the DRT method; (3.2) Calculate the characteristic frequency and peak area of ​​each DRT characteristic peak; (3.3) Polarization processes are assigned to each DRT peak based on its characteristic frequency and peak area.

7. The method for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance according to claim 4, characterized in that: The normalization process is performed in step (4), specifically: Normalization is performed according to the following formula: x , =(x-x stand ) / (x max -x min ); Among them, x , is the normalized value, x is the actual value, and x stand is the standard operating parameter value, x max is the maximum value of the operation change, x min is the minimum value of the operating parameter change.

8. The method for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance according to claim 4, characterized in that: The step (5) specifically comprises the following steps: (5.1) The sensitivity of the operating parameters of each polarization resistor of each channel is analyzed separately using a stepwise backward selection method; (5.2) Determine whether the P value of the independent variable is greater than or equal to 0.

05. If so, delete the independent variable and continue with step (5.1); otherwise, continue with step (5.3); (5.3) Confirm the analysis model parameters and record the P value and t statistic value of each operating parameter; (5.4) The quality of model fit is judged by comprehensive scoring based on the Bayesian Information Criterion; (5.5) Analyze the goodness of fit of the regression model and adjust R 2 , evaluate model capabilities; (5.6) Check for multicollinearity and determine the independence of the independent variables using the variance inflation factor.

9. The method for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance according to claim 4, characterized in that: The step (6) specifically comprises the following steps: (6.1) Calculate the P value and t-statistic value of the polarization resistance operation sensitivity under each channel; (6.2) Determine whether the P values ​​of the polarization resistance of all channels to the operating parameters are less than 0.

05. If so, the polarization resistance is completely related to the operating condition; otherwise, proceed to step (6.3); (6.3) Determine whether the P values ​​of the polarization resistance of all channels to the operating parameters are greater than or equal to 0.

05. If so, the polarization resistance is locally correlated with the operating condition; otherwise, the polarization resistance is conditionally correlated with the operating condition.

10. The method for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance according to claim 1, characterized in that: The method further includes a process for realizing a consistency analysis of fuel cell stack operating parameters based on multi-channel impedance, specifically comprising the following steps: (2-1) Connect equipment for multi-channel impedance measurement and develop tests under different operating parameters; (2-2) Determine the type of operating parameters for impedance measurement, formulate the change value of each operating parameter, and perform multi-channel impedance spectrum test according to different operating parameter points; (2-3) performing DRT fitting on the measured multi-channel impedance spectra to obtain the polarization process information contained in the impedance spectra of each channel under different operating parameters; (2-4) Calculate the variance and mean of the polarization resistance of each channel under different operating parameters; (2-5) calculating the change of each polarization resistance variance under different operating parameter conditions, and setting each polarization resistance variance threshold; (2-6) According to the threshold and polarization resistance variance values, the consistency-based operating parameter boundaries are given.

11. A device for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance, characterized in that: The device comprises: a processor configured to execute computer executable instructions; A memory storing one or more computer executable instructions, wherein when the computer executable instructions are executed by the processor, the steps of the method for performing sensitivity and consistency analysis on fuel cell stack operating parameters based on multi-channel impedance as described in any one of claims 4 to 10 are implemented.

12. A processor for realizing sensitivity and consistency analysis and processing of fuel cell stack operating parameters based on multi-channel impedance, characterized in that: The processor is configured to execute computer executable instructions. When the computer executable instructions are executed by the processor, the various steps of the method for performing sensitivity and consistency analysis and processing on fuel cell stack operating parameters based on multi-channel impedance as described in any one of claims 4 to 10 are implemented.

13. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and the computer program can be executed by a processor to implement the various steps of the method for performing sensitivity and consistency analysis processing on fuel cell stack operating parameters based on multi-channel impedance as described in any one of claims 4 to 10.

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