CN116047303B - Method for comprehensively analyzing uniformity of commercial-size proton exchange membrane fuel cell - Google Patents
Method for comprehensively analyzing uniformity of commercial-size proton exchange membrane fuel cell Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 60
- 239000012528 membrane Substances 0.000 title claims abstract description 28
- 230000010287 polarization Effects 0.000 claims abstract description 29
- 238000012544 monitoring process Methods 0.000 claims abstract description 13
- 238000004458 analytical method Methods 0.000 claims abstract description 7
- 238000011065 in-situ storage Methods 0.000 claims abstract description 7
- 230000008569 process Effects 0.000 claims description 23
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 21
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 19
- 239000007789 gas Substances 0.000 claims description 19
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- 229910052760 oxygen Inorganic materials 0.000 claims description 19
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 9
- 239000001257 hydrogen Substances 0.000 claims description 9
- 229910052739 hydrogen Inorganic materials 0.000 claims description 9
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- 230000004913 activation Effects 0.000 claims description 5
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- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
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Abstract
The invention discloses a method for comprehensively analyzing uniformity of a commercial-size proton exchange membrane fuel cell, which comprises the steps of firstly, rapidly and qualitatively analyzing in-plane uniformity through a multi-point voltage monitoring method; then, a current distribution model established through a multipoint voltage monitoring result is combined with an in-situ temperature monitoring method to analyze a redistribution mechanism of current and voltage; finally, the sensitivity of the individual polarization losses to the current density in the different cell regions was analyzed by a multipoint impedance method and a distribution of relaxation times. The scheme provides a comprehensive analysis framework for analyzing the in-plane uniformity of the proton exchange membrane commercial-size fuel cell aiming at the condition of non-uniform gas distribution of the commercial-size fuel cell, is suitable for the commercial-size graphite plate fuel cell, and realizes quantitative evaluation of the in-plane uniformity by deep research on internal polarization and corresponding loss of the fuel cell.
Description
Technical Field
The invention relates to the technical field of state analysis of commercial-size fuel cells for traffic power systems, in particular to a method for comprehensively analyzing uniformity of commercial-size proton exchange membrane fuel cells
Background
Proton Exchange Membrane Fuel Cells (PEMFCs) are receiving a great deal of attention for their non-pollution and high efficiency. However, the high cost and insufficient durability limit the popularization and commercial application of fuel cells. The performance of fuel cells is closely related to the simultaneous multiple internal transport processes such as membrane hydration, proton transport, oxygen transport and heat transport, which results in an uneven distribution of species on the activated surface.
Uneven distribution of species across the activated surface can cause undesirable phenomena such as current collection, poor fuel cell performance, and even reduced durability. This problem is exacerbated as the activation area increases, particularly in commercial-sized fuel cells. Therefore, monitoring and studying internal critical polarization dynamics and mitigating in-plane non-uniformities are critical to the development of high power fuel cell stacks. And in-plane heterogeneity becomes more pronounced with an increase in active area and significantly affects the life of the fuel cell. In order to promote commercialization of fuel cells, an evaluation method of a commercial fuel cell stack is urgently required. Many methods have been provided in the art to analyze fuel cell heterogeneity, but there is a technical gap in the comprehensive heterogeneity assessment of commercial fuel cell stacks.
First, the method relying on single point monitoring cannot provide dimensional information describing the complex in-plane heterogeneity of commercial size fuel cells, and most in-situ test methods cannot be directly applied to commercial fuel cell stacks. Then, it is difficult to obtain a current density distribution in the fuel cell due to the lack of advanced in-situ internal measurement methods. It is also challenging to separately study the non-uniform electrochemical reaction rates inside the fuel cell by conventional modeling methods. Third, quantitative losses in the internal polarization process were obtained by conventional Electrochemical Impedance Spectroscopy (EIS) and relaxation time distribution methods (DRT), but these studies were mainly conducted on laboratory-scale fuel cells. Moreover, based on the anisometric assumption of graphite bipolar plates, it is challenging to apply conventional methods to quantitative heterogeneity assessment.
Therefore, it is needed to provide a comprehensive in-plane heterogeneity evaluation method for commercial fuel cells, so as to facilitate migration to practical systems, and have higher application value.
Disclosure of Invention
The invention provides a method for comprehensively analyzing uniformity of a commercial-size proton exchange membrane fuel cell in order to overcome the defects in the prior art.
The invention is realized by adopting the following technical scheme: a method for comprehensively analyzing uniformity of commercial-size proton exchange membrane fuel cells comprises the following steps:
Step S1, obtaining a plurality of polarization curves of a single cell through multipoint voltage monitoring to obtain voltage distribution in the cell, so as to evaluate the uniformity of the fuel cell with commercial size;
S2, constructing a current distribution model to represent the interrelation and redistribution process of voltage and current in the fuel cell, wherein the current distribution model is formed by combining a gas dynamic model and a voltage model with in-situ temperature measurement, and qualitatively evaluating the uniformity;
And step S3, researching internal polarization and corresponding loss of the fuel cell based on a multipoint electrochemical impedance monitoring and relaxation time distribution calculating method, and quantitatively evaluating in-plane uniformity.
Further, in the step S2, according to the collected voltage information of the plurality of positions, the current distribution model is built by the discretization concept in combination with the inlet flow, pressure and relative humidity information of the anode of the fuel cell.
Further, in the step S2, the current distribution model describes the aerodynamic process of the inlet and outlet by applying the principles of conservation of oxygen, nitrogen, hydrogen and water vapor mass in the cathode/anode channels, and regards all substances as ideal gases.
Further, in the step S2, the fuel cell adopts a cathode-anode cross air supply mode.
Further, in the step S2, during the current distribution model construction, the fuel cell is divided into innumerable equipotential body portions, the component concentrations on the divided equipotential bodies are uniformly distributed, and the current and voltage values on the equipotential bodies are decided, and there is a slight difference in the component concentrations between each equipotential body and results in the current and voltage values on each equipotential body, and the current difference between the equipotential bodies needs to be balanced by a lateral current, and thus a potential difference in the bipolar plate is induced.
Further, the gas dynamic model is divided into four cavity models of a cathode inlet, an anode outlet, a cathode outlet and an anode inlet.
Further, in the step S1, the positions of the multi-point voltage acquisition points are arbitrarily selected.
Compared with the prior art, the invention has the advantages and positive effects that:
(1) The scheme does not need to arrange a complex sensor system in the battery, such as a PCB board to acquire current distribution; the current distribution can be calculated only by acquiring conventional battery parameters;
(2) The cathode and the anode are comprehensively considered, a gas dynamic model is built, the reaction characteristics of the anode, the cathode and the exchange membrane can be covered, and compared with other methods, the method has better precision; the built model can reflect the change process of current and voltage in the dynamic process;
(3) By utilizing the multi-point voltage method, the non-uniformity of the fuel cell with commercial size can be rapidly evaluated without destructive modification of the fuel cell, and in theory, the fuel cell can be divided into a plurality of parts by a plurality of voltage acquisition points;
(4) The method for measuring the multi-point impedance is used for the first time to quantitatively analyze the non-uniformity of the fuel cell, and the method for analyzing the polarization loss causing potential difference is combined with the Pearson correlation analysis method to quantitatively evaluate the polarization loss.
Drawings
FIG. 1 is a flow chart of a comprehensive analysis method according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a multi-point voltage sampling according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a half-cell hypothesis according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a model prediction result according to an embodiment of the present invention;
fig. 5 is a schematic diagram of a multi-point impedance quantitative analysis according to an embodiment of the present invention.
Detailed Description
In order that the above objects, features and advantages of the invention will be more readily understood, a further description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced otherwise than as described herein, and therefore the present invention is not limited to the specific embodiments disclosed below.
The embodiment provides a method for comprehensively analyzing uniformity of a commercial-size proton exchange membrane fuel cell, and it should be noted that the commercial size in this embodiment refers to an active area size of the commercial fuel cell, and is different from a small-size fuel cell used in a laboratory, and includes the following steps:
Step S1, obtaining a plurality of polarization curves of a single cell through multipoint voltage monitoring to obtain voltage distribution in the cell, so as to perform simple and rapid uniformity evaluation on a fuel cell with commercial size;
S2, constructing a current distribution model to represent the interrelation and redistribution process of voltage and current in the fuel cell, wherein the current distribution model is formed by combining a gas dynamic model and a voltage model with in-situ temperature measurement, and qualitatively evaluating the uniformity;
And S3, eliminating the difficulty of comprehensively evaluating the uniformity by means of a set of voltage monitors based on a multipoint electrochemical impedance monitoring and relaxation time distribution calculation method, deeply researching the internal polarization and corresponding loss of the fuel cell, and quantitatively evaluating the in-plane uniformity.
The method described in this embodiment provides a comprehensive and systematic framework for uniformity analysis of proton exchange membrane fuel cells, demonstrates how to incorporate dimensional information into uniformity assessment, can only obtain one-sided cell parameter information by means of single-point voltage sampling, and can learn about the differences existing in a single cell by means of multi-point voltage sampling, and incorporates the in-plane differences of the cells into an evaluation system in the process. Commercial fuel cells are discretely modeled to estimate current density distribution and combined with multi-point impedance to determine quantitative polarization loss, traditional Electrochemical Impedance Spectroscopy (EIS) and relaxation time distribution methods (DRT) obtain quantitative loss of internal polarization processes, by which quantitative in-plane differences can be determined. The results of the study are then applied to practical fuel cell system applications, which can further guide analysis of degradation mechanisms and cell optimization.
FIG. 1 is a flow chart of a method for evaluating the uniformity of a fuel cell system constructed in accordance with an embodiment of the present invention, specifically using the following technical solution;
s1, obtaining voltages at an anode outlet and an anode inlet of a large-area fuel cell;
The multiple polarization curves in the fuel cell unit are acquired at different positions of the battery through an external data acquisition card, the previous fuel cell state estimation only depends on voltage data acquired at a single position, two voltage data of the same battery at different sampling positions can be acquired by means of multi-point voltage, and the in-plane difference of the fuel cell can be rapidly evaluated through comparing the two voltage data. In the present embodiment, the anode inlet and the anode outlet are taken as examples, and the positions of the multipoint voltage collecting points may be arbitrarily selected as long as they are arbitrary two positions in the fuel cell.
As shown in fig. 2, two pieces of voltage information at the anode inlet and the anode outlet of the fuel cell are input, and the voltage data are taken as main parameters for estimating the current density, in this example, a graphite plate fuel cell with a certain commercial size is taken as an example, under various test conditions, the voltage information at two positions is obtained, and when the current density rises from 100mA/cm 2 to 2000mA/cm 2, the voltages at the two positions show a relatively obvious difference.
And step S2, an advanced current distribution model is provided to represent the mutual relation and redistribution process of the voltage and the current in the fuel cell, and the uniformity is qualitatively evaluated in combination with in-situ temperature measurement.
In step S2, an advanced current distribution model is established by discretizing the information of the inlet flow, pressure and relative humidity of the anode of the fuel cell provided by the fuel cell test bench according to the acquired voltage information of a plurality of positions, wherein the current distribution model describes the aerodynamic process of an inlet and an outlet by applying the principles of conservation of mass of oxygen, nitrogen, hydrogen and water vapor in a cathode/anode channel, and all substances are regarded as ideal gases. In which the fuel cell adopts a cathode-anode cross gas supply mode, the fuel cell is divided into innumerable equipotential body portions during a model building process, the distribution of the component concentration on the divided equipotential bodies is uniform, and current and voltage values on the equipotential bodies are determined, there is a slight difference in the component concentration between each equipotential body, and the current and voltage values on each equipotential body are caused, the current difference between the equipotential bodies needs to be balanced by a transverse current, and thus a potential difference in the bipolar plate is induced.
In step S2, the gas dynamic model is divided into four cavity models of a cathode inlet, an anode outlet, a cathode outlet and an anode inlet, as shown in fig. 3, the cathode inlet cavity 1 and the anode outlet cavity 4 together form one half cell, and the cathode outlet cavity 2 and the anode inlet cavity 3 together form the other half cell.
For the cathode inlet chamber 1, the following equation of state is obtained:
for the cathode outlet chamber 2, the following equation of state is obtained:
Formulas (A1) - (B7) are mass conservation equations for oxygen and nitrogen. During this process, nitrogen is not consumed, but the oxygen consumption rate of the two chambers in series is different. Oxygen consumption can change oxygen concentration and affect nitrogen partial pressure, current density, and sampling voltage.
Where R is the ideal gas constant, M v is the vapor molar mass, and F is the Faraday constant.
I 1 is the current on the anode outlet half cell and i 2 is the current on the anode inlet half cell; i 1 and i 2 are parameters that need to be solved.
T fc is the cell temperature, V ca is the cathode cavity volume, k ca,in is the cathode inlet flow coefficient, k ca,out is the cathode outlet flow coefficient, these parameters being obtained by measurement or calibration.
Likewise, the principle of conservation of hydrogen mass is also applied to the anode channels to describe the aerodynamic process of the anode inlet and outlet chambers.
For the anode inlet chamber 3, the following equation of state is obtained:
for the anode outlet cavity 4, the following state equation is obtained:
Wherein V an is the volume of the anode cavity, which is obtained by measurement; k an,in is the anode inlet flow coefficient, k an,out is the anode outlet flow coefficient, obtained by calibration.
In addition, the membrane-spanning transport process of water is also considered in the model, and in general, the membrane hydration model generally comprises two main processes. First, electroosmosis, where water molecules pass through a membrane from an anode to a cathode by hydrogen protons. Second, the water concentration gradient across the membrane causes back diffusion of water, typically from the cathode to the anode. In combination with these two water transport mechanisms, assuming a linear distribution of water concentration gradients across the membrane, two main mechanisms can be expressed based on the water flux N w,mem described above.
Wherein C w,ca and C w,an are the membrane water molar concentrations on both sides of the anode and cathode, respectively; l m is the film thickness; n d is the electroosmotic resistance coefficient. All membrane hydration equations are as follows:
Where EW is the equivalent weight of the film, ρ mem is the density of the film, and L m is the thickness of the film, these parameters being obtained by calibration.
Thus, the mass flow of water through the different portions of a single cell can be calculated as follows.
Wherein the method comprises the steps ofFor the water mass flow through the anode outlet half cell,/>For the water mass flow through the anode inlet half cell, a is the equivalent activation area of the fuel cell and M w is the steam molar mass. Positive values of net membrane water flux indicate transfer from anode to cathode due to electroosmosis, negative values indicate back diffusion from cathode to anode due to concentration gradients.
In step S2, the gas dynamic model is introduced into the voltage model, and the current in the two half cells is calculated.
In the present invention, the cathode inlet chamber 1 and the anode outlet chamber 4 together form one half cell, and the cathode outlet chamber 2 and the anode inlet chamber 3 together form the other half cell. Thus, both the anode gas concentration variation and the cathode gas concentration variation result in redistribution of the current and voltage inside the fuel cell.
For this purpose, it is necessary to establish the relationship between the internal pressure, flow rate, temperature, current and voltage of the fuel cell, and the like, and the relationship between the oxygen partial pressure, the hydrogen partial pressure, the cell temperature, the oxygen concentration, the current and voltage is revealed:
Wherein, Is the open circuit voltage calculated by the Nernst equation, v act is the activation voltage loss, v ohm is the ohmic voltage loss caused by the resistance of the polymer membrane to the cells, and v conc is the concentration voltage loss caused by the concentration drop of the reactants as they are consumed in the reaction.
Is the battery temperature T fc, hydrogen partial pressure/>And oxygen partial pressure/>Is a function of (a).
Wherein a 1＝0.85×10-3,a2＝4.3085×10-5 is defined as the total number of the components,Given by (C1) and (D1)/>Given by (A1) and (B1).
The calculation method of the activation voltage loss v act is as follows.
Wherein,Is the dissolved oxygen concentration at the three-phase reaction interface of the cathode catalyst layer, given by (A5) and (B6), i is the current ,b1＝0.708,b2＝1.432×10-3,b3＝-1.572×10-4,b4＝1.043×10-4.
According to ohm's law, the ohmic loss v ohm can be calculated as follows.
vohm(λmem,i,Tfc)＝i×Rm (7)
Where R m is the membrane resistance, L m is the proton exchange membrane thickness, c 1＝0.05139,c2＝0.00326,c1 =350.
At high current densities, mass transfer of the reactants or products is hindered, resulting in concentration overpotential. The concentration voltage loss v conc can be calculated as follows.
vconc(i)＝e1×exp(i) (9)
Wherein e 1＝5.389×10-10.
By inputting parameters, e.g. oxygen concentration in gas channelsAnd/>Hydrogen partial pressure/>And/>Partial pressure of oxygenAnd/>Film Water content/>And/>A voltage model is introduced as shown in equation (4). The relationship between the voltage and current of the anode inlet and outlet half cells is shown in equations (10) and (11), respectively.
Δi＝|i1-i2| (12)
Where V fc1 is the voltage of the anode outlet half cell and V fc2 is the voltage of the anode inlet half cell. Δi is the lateral current of the two half-cells, and the two sampled voltages (V fc1 and V fc2) of one cell obtained through experiments are boundary conditions of the above formula. From the two sampled voltages of the cell, the current distribution of the model can be obtained (the proposed current distribution model comprises two parts: a four-chamber gas dynamic model and a voltage model), as shown in fig. 4.
Step S3, providing a multipoint electrochemical impedance monitoring and relaxation time distribution calculating method, carrying out electrochemical impedance testing on different positions of a single cell, obtaining polarization and corresponding loss of different positions of the cell, calculating the polarization loss of different positions according to the multipoint impedance and relaxation time distribution method, and analyzing the correlation between the voltage difference in the single cell and the polarization loss of different positions by using a Pearson correlation analysis method.
The difficulty of comprehensively evaluating uniformity by means of a set of voltage monitors is eliminated by proposing a multipoint electrochemical impedance monitoring and relaxation time distribution calculation method. The internal polarization and corresponding loss of the fuel cell were studied in depth and the in-plane uniformity was quantitatively evaluated.
The impedance is mainly used for quantitative analysis of the fuel cell, and the difference can be quantitatively analyzed by utilizing a multi-point impedance method, and the method is specifically as follows:
In the initial phase of 100mA/cm 2, the intermediate and low frequency resistances are reflected by two overlapping arcs. At a subsequent stage of increasing the load to 1900mA/cm 2, the low and medium frequency arcs separate and increase significantly. This is mainly a result of more pronounced loading and mass transfer losses at high loads. In-plane heterogeneity of fuel cells varies significantly under different operating conditions, which is manifested in differences in impedance losses in different regions, which are directly related to complex internal electrochemical reaction processes and heterogeneous distribution of species.
In order to further study the electrochemical kinetics of the different region polarization processes, the invention introduces a DRT method to study the in-plane polarization process and the corresponding losses of the fuel cell. The DRT method can extract the relaxation time distribution of the electrochemical system through deconvolution technology and guide the electrochemical modeling of the electrochemical system. Assuming that the voltage response of the electrochemical system to the step current disturbance decays exponentially with a specific time scale distribution, the impedance of the electrochemical system can be written in the following form.
Where R 0 is the ohmic resistance of the electrochemical system, Z pol (f) is the polarization resistance, R pol is the polarization resistance, τ is the relaxation characteristic time, g (τ) is the distribution function of the relaxation time, i is the complex unit, and f is the frequency.
Equation (14) can be understood as the sum of ohmic resistance plus an infinite parallel RC element. The impedance spectrum is decomposed into three distinct peaks at different characteristic frequencies, indicating three distinct polarization dynamics in the stack. From the characteristic frequency of each polarization process and related studies, the polarization process can be expressed as: (1) proton transfer in a fuel cell; (2) oxygen reduction reaction of the cathode; (3) oxygen diffusion in the catalyst layer.
In-plane heterogeneity (manifested as a voltage difference Δv in the bipolar plate) is mainly caused by maldistribution of species such as water, gas, heat, and current, and ultimately affects the output performance of the battery. Therefore, it is necessary to reveal the relationship between the heterogeneity (Δv) and the internal parameter distribution differences (water, gas, heat, and current). It is noted that the internal parameter state of the fuel cell is directly related to the polarization losses in the different regions. Thus, the present invention employs pearson correlation analysis to analyze the correlation between heterogeneity (Δv) and polarization resistance differences (Δi, Δr mt,ΔRct,ΔRpt).
Furthermore, it should be noted that the pearson correlation analysis method represents the correlation between the two sets of data by a factor r, which has a value of-1 to 1. The positive and negative signs of r represent positive and negative correlations, respectively, and the absolute value evaluates the strength of the correlation. The larger the value, the more correlated the two data sets. Furthermore, all data met a normal distribution prior to analysis.
The present invention is not limited to the above-mentioned embodiments, and any equivalent embodiments which can be changed or modified by the technical content disclosed above can be applied to other fields, but any simple modification, equivalent changes and modification made to the above-mentioned embodiments according to the technical substance of the present invention without departing from the technical content of the present invention still belong to the protection scope of the technical solution of the present invention.
Claims (2)
1. A method for comprehensively analyzing uniformity of a commercial-size proton exchange membrane fuel cell, comprising the steps of:
Step S1, obtaining a plurality of polarization curves of a single cell through multipoint voltage monitoring to obtain voltage distribution in the cell, so as to evaluate the uniformity of the fuel cell with commercial size;
S2, constructing a current distribution model to represent the interrelation and redistribution process of voltage and current in the fuel cell, wherein the current distribution model is formed by combining a gas dynamic model and a voltage model with in-situ temperature measurement, and qualitatively evaluating the uniformity;
The gas dynamic model is divided into four cavity models of a cathode inlet cavity 1, an anode outlet cavity 4, a cathode outlet cavity 2 and an anode inlet cavity 3, wherein the cathode inlet cavity 1 and the anode outlet cavity 4 form a half cell together, namely an anode inlet half cell, and the cathode outlet cavity 2 and the anode inlet cavity 3 form another half cell together, namely an anode outlet half cell; then calculating the key parameters of the hydrogen pressure of the anode inlet cavity 3 and the anode outlet cavity 4, and the key parameters of the oxygen pressure and the dissolved oxygen concentration of the cathode inlet cavity 1 and the cathode outlet cavity 2;
in addition, the current distribution model also takes the transmembrane transport process of water into consideration, builds a membrane hydration model, and calculates key parameters of the membrane water content;
finally, according to the key parameters obtained by calculation of the gas dynamic model and the membrane hydration model, a voltage model is established:
Wherein, Is the open circuit voltage calculated by the Nernst equation,/>Is the activation voltage loss,/>Is the ohmic voltage loss caused by the resistance of the polymer film to the cells,/>Is the concentration voltage loss caused by the concentration drop of the reactant during the consumption of the reaction;
By introducing the cathode into the dissolved oxygen concentration of the cavity 1 And oxygen pressure/>Dissolved oxygen concentration in the cathode outlet chamber 2And oxygen pressure/>Hydrogen pressure of anode inlet chamber 3/>And hydrogen pressure of anode outlet cavity 4/>Membrane water content/>, of the anode outlet half cellAnd membrane water content of the anode inlet half cell/>Introducing a voltage model to calculate the sampling voltage/>, of the anode outlet half-cellAnd sample voltage of anode inlet half cell/>；
Obtaining current distribution of a model according to two sampling voltages of the battery, namely obtaining a current distribution model;
Wherein, Is the battery temperature,/>And/>The parameters to be solved are respectively represented as currents on the anode outlet half cell and the anode inlet half cell;
And S3, carrying out electrochemical impedance tests at different positions of the single cell based on a multipoint electrochemical impedance monitoring and relaxation time distribution calculating method, obtaining polarization and corresponding loss at different positions of the cell, and quantitatively evaluating in-plane uniformity by researching internal polarization and corresponding loss of the fuel cell and utilizing a Pearson correlation analysis method.
2. The method for comprehensive analysis of uniformity of a commercial-size proton exchange membrane fuel cell according to claim 1, wherein: in the step S1, the positions of the multipoint voltage acquisition points are arbitrarily selected.
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