Fuel cell current control method and system of fuel cell vehicle and vehicle

Abstract

The invention discloses a fuel cell current control method and system of a fuel cell vehicle and the vehicle. The fuel cell current control method of the fuel cell vehicle comprises the steps that single cell voltage data are collected, and the single cell voltage data comprise average single cell voltage and real-time minimum single cell voltage; obtaining a first current upper limit value according to the single battery voltage data and the minimum allowable average single battery voltage first quadratic term coefficient; obtaining a difference value between the average monomer voltage and the real-time minimum monomer voltage, and obtaining a second current upper limit value according to the difference value; and determining a final current according to the current requested by the current instruction, the first current upper limit value and the second current upper limit value, and controlling the current of the fuel cell according to the final current. By adopting the application, the over-low voltage of the single body is avoided, so that irreversible damage of the membrane electrode is prevented, and the service life of the galvanic pile is effectively prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to a fuel cell current control method and system for a fuel cell vehicle and the vehicle. BACKGROUND

[0002] The fuel cell system controls the power by adjusting the stack output current through the DCDC converter. The service life of the stack is extremely dependent on the operating conditions, and avoiding excessively low single cell voltage is the key to preventing irreversible damage to the membrane electrode. The prior art usually adopts fixed current limit or conservative strategy based on temperature, pressure and other macro parameters. These methods have the following defects: Inability to adapt to state changes: fixed limits cannot respond to performance degradation of the stack over time (such as catalyst activity decline), nor can they cope with consistency deterioration caused by transient conditions (such as water management disorders). This results in excessive current being applied when the state is poor, or premature restriction when the state is good, and the system's potential cannot be realized. Lack of predictive control capability: passive response to the current state only, unable to predict the near-term risk based on current performance trends and take preventive measures, with a protection lag. System installation difficulties: some solutions aim to predict the long-term service life (RUL) of the stack. Such methods are computationally complex, although they have higher accuracy, but cannot be directly used for real-time current control with high response frequency. SUMMARY

[0003] Therefore, it is necessary to provide a fuel cell current control method and system for a fuel cell vehicle and the vehicle to prevent irreversible damage to the membrane electrode and effectively improve the service life of the stack.

[0004] In a first aspect, a fuel cell current control method for a fuel cell vehicle is provided, comprising: collecting single cell voltage data, the single cell voltage data including average single cell voltage and real-time minimum single cell voltage; obtaining a first current upper limit value according to the single cell voltage data, a minimum allowable average single cell voltage and a quadratic coefficient, wherein the minimum allowable average single cell voltage is pre-stored, and the quadratic coefficient is read from a pre-stored stack reference fitting curve; obtaining a difference between the average single cell voltage and the real-time minimum single cell voltage, and obtaining a second current upper limit value according to the difference; determining a final current according to a current requested by a current instruction, the first current upper limit value and the second current upper limit value, and controlling the fuel cell current according to the final current.

[0005] In some examples, the obtaining the first current upper limit value according to the single cell voltage data and the lowest allowed average single cell voltage first quadratic coefficient comprises: reading out a second quadratic coefficient and a third quadratic coefficient from a stack fitting curve according to the single cell voltage data; solving the first current upper limit value according to the first quadratic coefficient, the second quadratic coefficient and the third quadratic coefficient.

[0006] In some examples, the obtaining the second current upper limit value according to the difference between the average single cell voltage and the real-time lowest single cell voltage comprises: obtaining a gain coefficient; solving the second current upper limit value according to the gain coefficient and the difference between the average single cell voltage and the real-time lowest single cell voltage.

[0007] In some examples, before solving the second current upper limit value according to the gain coefficient and the difference between the average single cell voltage and the real-time lowest single cell voltage, the method further comprises: obtaining a safety threshold value; calculating a safety difference between the difference between the average single cell voltage and the real-time lowest single cell voltage and the safety threshold value; the solving the second current upper limit value according to the gain coefficient and the difference between the average single cell voltage and the real-time lowest single cell voltage comprises: solving the second current upper limit value according to the gain coefficient and the safety difference.

[0008] In some examples, the determining the final current according to the current requested by the current instruction, the first current upper limit value and the second current upper limit value, and controlling the fuel cell current according to the final current comprises: taking the minimum value among the current requested by the current instruction, the first current upper limit value and the second current upper limit value as the final current; controlling the current output upper limit of the fuel cell according to the final current.

[0009] In some examples, before obtaining the first current upper limit value according to the single cell voltage data and the lowest allowed average single cell voltage first quadratic coefficient, the method further comprises: performing a standard polarization curve test under a stack health state to obtain a plurality of data points from a low current to a limit current, wherein each data point comprises a current and an average single cell voltage; According to the plurality of groups of data points, a least square method is used to fit them into a non-linear function, wherein the non-linear function represents the stack reference fitting curve.

[0010] In a second aspect, a fuel cell current control system of a fuel cell vehicle is provided, comprising: a collecting module configured to collect cell voltage data, the cell voltage data comprising an average cell voltage and a real-time lowest cell voltage; a first upper limit determining module configured to obtain a first current upper limit value according to the cell voltage data, a lowest allowable average cell voltage, and a first quadratic coefficient, wherein the lowest allowable average cell voltage is pre-stored, and the first quadratic coefficient is read from a pre-stored stack reference fitting curve; a second upper limit determining module configured to obtain a difference between the average cell voltage and the real-time lowest cell voltage, and obtain a second current upper limit value according to the difference; a control module configured to determine a final current according to a current requested by a current instruction, the first current upper limit value, and the second current upper limit value, and control the fuel cell current according to the final current.

[0011] In a third aspect, a vehicle is provided, comprising the fuel cell current control system of the fuel cell vehicle according to the second aspect described above.

[0012] In a fourth aspect, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the fuel cell current control method of the fuel cell vehicle according to the first aspect and any possible implementation manner of the first aspect.

[0013] In a fifth aspect, a computer readable storage medium is provided, having a computer program stored thereon, wherein the program is executable on a processor to implement the steps of the fuel cell current control method of the fuel cell vehicle according to the first aspect and any possible implementation manner of the first aspect.

[0014] In a sixth aspect, a computer program product is provided, having a computer program stored thereon, wherein the program is executable on a processor to implement the steps of the fuel cell current control method of the fuel cell vehicle according to the first aspect and any possible implementation manner of the first aspect.

[0015] By using the embodiments of the present application, the comprehensive performance state of the stack can be evaluated in real time, on line, and accurately, and the fuel cell current of the fuel cell vehicle can be dynamically and adaptively adjusted accordingly, so as to avoid excessively low cell voltage and prevent irreversible damage of the membrane electrode, thereby effectively improving the service life of the stack. BRIEF DESCRIPTION OF DRAWINGS

[0016] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 A flowchart of a fuel cell current control method for a fuel cell vehicle provided in an embodiment of this application; Figure 2 This is another flowchart of the fuel cell current control method for a fuel cell vehicle provided in the embodiments of this application; Figure 3 This is a schematic diagram illustrating the calculation of the first upper limit of current based on the prediction of fuel cell performance degradation. Figure 4 This is a structural block diagram of the fuel cell current control system for a fuel cell vehicle provided in an embodiment of this application; Figure 5 A structural block diagram of a computer device provided in an embodiment of this application. Detailed Implementation

[0017] The present application will now be described in further detail with reference to the embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the application. Furthermore, it should be noted that, for ease of description, only the parts relevant to the application are shown in the accompanying drawings.

[0018] It should be noted that, unless otherwise specified, the embodiments and features of the embodiments in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0019] The following describes in detail, with reference to the accompanying drawings, a fuel cell current control method, system, and vehicle for a fuel cell vehicle according to embodiments of this application.

[0020] Figure 1 This is a flowchart of a fuel cell current control method for a fuel cell vehicle according to an embodiment of this application. Figure 1 As shown, the fuel cell current control method for a fuel cell vehicle according to an embodiment of this application includes the following steps: S101: Collect individual cell voltage data, which includes average cell voltage and real-time minimum cell voltage.

[0021] S102: Based on the single cell voltage data and the first quadratic term coefficient of the minimum allowable average single cell voltage, the first current upper limit value is obtained, wherein the minimum allowable average single cell voltage is pre-stored, and the first quadratic term coefficient is read from the pre-stored stack reference fitting curve.

[0022] In one embodiment of this application, obtaining a first current upper limit value based on the individual cell voltage data and the first quadratic term coefficient of the minimum allowable average individual cell voltage includes: substituting the individual cell voltage data into the stack fitting curve to read the second quadratic term coefficient and the third quadratic term coefficient from the stack fitting curve; and solving for the first current upper limit value based on the first quadratic term coefficient, the second quadratic term coefficient, and the third quadratic term coefficient.

[0023] Before obtaining the first upper limit value of current based on the individual cell voltage data and the coefficients of the first quadratic term of the minimum allowable average individual cell voltage, the process further includes: performing a standard polarization curve test under the healthy state of the fuel cell stack to obtain multiple sets of data points from low current to the limiting current, wherein each set of data points includes the current and the average individual cell voltage. Based on the multiple sets of data points, a least squares method is used to fit them into a nonlinear function, wherein the nonlinear function characterizes the fuel cell stack reference fitting curve.

[0024] S103: Obtain the difference between the average cell voltage and the real-time lowest cell voltage, and obtain the second current upper limit value based on the difference.

[0025] In one embodiment of this application, obtaining the difference between the average cell voltage and the real-time lowest cell voltage, and obtaining a second current upper limit value based on the difference, includes: obtaining a gain coefficient; and solving for the second current upper limit value based on the gain coefficient and the difference between the average cell voltage and the real-time lowest cell voltage.

[0026] In this example, before determining the second current upper limit value based on the gain coefficient and the difference between the average cell voltage and the real-time minimum cell voltage, the method further includes: obtaining a safety threshold; and calculating the safety difference between the difference between the average cell voltage and the real-time minimum cell voltage and the safety threshold.

[0027] Based on this, the step of obtaining the second current upper limit value based on the gain coefficient and the difference between the average single-cell voltage and the real-time lowest single-cell voltage includes: obtaining the second current upper limit value based on the gain coefficient and the safety difference.

[0028] S104: Determine the final current based on the current requested by the current command, the first current upper limit value, and the second current upper limit value, and control the fuel cell current based on the final current.

[0029] In one embodiment of this application, a final current is determined based on the current requested by the current command, the first current upper limit value, and the second current upper limit value, and the current of the fuel cell is controlled based on the final current, including: taking the minimum value among the current requested by the current command, the first current upper limit value, and the second current upper limit value as the final current; and controlling the current output upper limit of the fuel cell based on the final current.

[0030] In the fuel cell current control method for a fuel cell vehicle according to embodiments of this application, the fuel cell system of the fuel cell vehicle includes a fuel cell stack, a DC-DC converter, a main controller (FCCU), and a dedicated cell voltage monitoring module (CVM). The CVM module is responsible for high-precision acquisition of all cell voltages and transmitting them to the FCCU via a communication bus. The fuel cell current control method for the fuel cell vehicle can be executed by the FCCU, specifically as follows... Figure 2 As shown, it includes: S1: Baseline data acquisition and storage.

[0031] Under healthy stack conditions, standard polarization curve testing was performed to obtain multiple sets of data points (I_ref_i, V_avg_ref_i) from low current to limiting current. The data were then fitted to a nonlinear function, such as a quadratic function, using the least squares method. V_avg_ref = f_ref(I) = a_ref * I² + b_ref ​​* I + c_ref.

[0032] The corresponding minimum allowable average cell voltage V_min is recorded. The function coefficients a_ref and V_min are pre-stored in the non-volatile memory of the FCCU.

[0033] S2: Real-time data acquisition and processing.

[0034] During operation, the FCCU receives all individual cell voltage data sent by the CVM and calculates the real-time average individual cell voltage V_avg_real and the real-time minimum individual cell voltage V_min_real. When the system is operating in steady state at different power levels (the criteria are: the temperature and pressure of the stack cathode, anode, and cooling circuit are within the set range and the current fluctuation is less than the set threshold; if there is a fault diagnosis system, it means that it is in a fault-free state), it automatically records multiple sets of valid real-time data points (I_fbk_j, V_avg_real_j) and stores them in a fixed-length buffer queue, with new data replacing old data.

[0035] S3: The calculation of the first current limit value I_limit1 is based on the real-time evaluation and prediction of the overall output performance.

[0036] The system provides real-time assessment of the current state of the overall output performance of the fuel cell stack and predicts the current when it reaches the lower voltage limit.

[0037] Constraint fitting: Using a function isomorphic to the baseline model, V = a_ref * I² + b * I + c. With the quadratic coefficient a_ref representing the curve curvature fixed, and using real-time data points from the buffer queue, a weighted least squares method (with higher weights assigned to high-current points) is employed to fit the linear coefficient b_real and the constant term c_real for the current state, thus obtaining the polarization curve function for the current state. V_avg_real(I) = a_ref * I² + b_real * I + c_real.

[0038] Extrapolation calculation: such as Figure 2 As shown, solve the equation a_ref * I² + b_real * I + c_real = V_min. The resulting positive real solution is the first upper limit of current, I_limit1, which represents the current corresponding to the estimated average voltage dropping to the minimum safe limit based on the current overall performance state.

[0039] S4: The calculation of the second current limit value I_limit2 is based on real-time evaluation and dynamic correction of voltage consistency.

[0040] Real-time assessment of the internal voltage consistency of the fuel cell stack to address immediate deterioration issues.

[0041] Calculate the difference between the average cell voltage and the lowest cell voltage: X = V_avg_real - V_min_real (unit: mV). This difference X is a key indicator for evaluating voltage consistency.

[0042] Based on the difference X, the second upper limit of the current is calculated using a preset linear correction formula: I_limit2 = I_feedback - k * (X - X0).

[0043] Where k is a gain coefficient greater than 0 (e.g., 2), and X0 is a preset safety threshold (e.g., 50mV). When X>X0, it indicates that the voltage consistency has deteriorated, and the formula will negatively correct the current command. The larger the difference, the more severe the restriction.

[0044] S5: Final current command generation and output.

[0045] The FCCU compares the raw current command I_cmd_raw requested by the upper-level controller, the calculated first current limit value I_limit1, and the second current limit value I_limit2. The minimum of these three values ​​is taken as the final current command I_cmd sent to the DC-DC converter. I_cmd=min(I_cmd_raw,I_limit1,I_limit2).

[0046] By collecting data from multiple current operating points and using a fitting model with a fixed curvature (a_ref), the current value (I_limit1) at which the voltage will drop to a dangerous level (V_min) if this trend continues can be predicted in advance.

[0047] It can calculate the risk boundary and apply restrictions before the average voltage of the fuel cell stack reaches the dangerous value, thereby achieving "predictive protection" and reducing the damage to fuel cell stack performance caused by excessive load current when the performance is poor.

[0048] The source of adaptability (I_limit1): The value of I_limit1 is not fixed; it changes dynamically with the fitting parameters b_real and c_real. When the fuel cell stack performance degrades, the fitted curve shifts downward, and the calculated I_limit1 value automatically decreases, resulting in stricter limitations. When the fuel cell stack performance is good (such as a new stack or one that has just undergone maintenance), the I_limit1 value automatically increases, removing unnecessary restrictions. This is the meaning of "adaptive."

[0049] The source of accuracy (I_limit2): I_limit2 specifically handles instantaneous, local consistency issues that I_limit1 cannot cover. Even if the overall performance is acceptable (I_limit1 value is large), if a single cell suddenly deteriorates (X value increases), I_limit2 will respond immediately and accurately to the situation, forcibly reducing the current to protect the weakest cell.

[0050] "Dynamically calculated I_limit1" ensures that the limiting strategy changes with the stack state, while "consistently consistent I_limit2" ensures comprehensive protection. The minimum selection logic (min function) of both ultimately ensures that the system operates at the safest current under any circumstances, while also releasing maximum performance when conditions are favorable.

[0051] This application proposes to fix the higher-order coefficients (e.g., a_ref) representing the nonlinear curvature, and only refit the lower-order coefficients (b_real, c_real) representing the voltage offset.

[0052] The operation of "fixing a_ref" greatly simplifies the complexity and computational cost of the fitting process (requiring only the solution of a system of two linear equations), enabling it to be completed within milliseconds. Simultaneously, by fixing the shape of the health curve, the physical meaning of the fitting and extrapolation results is clear, avoiding the large errors that may occur with purely mathematical fitting. This means that this application achieves near-complex model accuracy by employing an extremely ingenious engineering simplification method, resolving the contradiction between limited onboard computing power and high model accuracy requirements.

[0053] This application does not require any hardware changes. CVM and FCCU are standard configurations in modern fuel cell systems. No additional hardware costs are required; deployment on existing mass-produced products is possible solely through software upgrades. The industrialization threshold is extremely low, promotion is easy, and marginal costs are virtually zero, making it highly commercially valuable and practical.

[0054] For example, baseline data is established. Polarization profiles are scanned on a fuel cell stack under standard conditions (specific temperature, pressure, and humidity) from 0A to 500A (limiting current, corresponding to an average voltage of 0.60V). Select 10 key current points (e.g., 0, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500A) and their corresponding average voltage values; Using a quadratic function for fitting, a baseline curve (assuming) is obtained: V_avg_ref = (-0.001) * I² + (-0.22) * I + 850 That is: a_ref = -0.001, b_ref ​​= -0.22, c_ref = 850; Set V_min = 600mV; Write a_ref, b_ref, c_ref, and V_min into the FCCU's Flash memory.

[0055] Real-time operation and data acquisition (FCCU executes in a loop).

[0056] In each operating cycle (10ms), the FCCU receives 300 individual cell voltage data V_cell[1..300] from the CM via the CAN bus; Calculate V_avg_real = average(V_cell[1..300]); Calculate V_min_real = min(V_cell[1..300]); Read the current I_feebback; Steady-state determination: If the following conditions are met simultaneously: ① the stack temperature is 6±5°C; ② the anode-cathode voltage difference is stable; ③ the I_feedback fluctuation is less than ±10A in the past second, then it is determined to be in steady state; If the state is steady, the current data point (I_feedback, V_avg_real) is added to a circular queue of length 10, and the oldest data is discarded.

[0057] Calculate I_limit1 (triggered whenever there is new data in the queue).

[0058] Suppose there are 5 data points in the current queue: (30, 844), (50, 817), (100, 769), (200, 723), (300, 684); Constraint fitting: Fix a = a_ref = -0.001. Use weighted least squares (giving higher weights to points at 200A and 300A) to fit only b_real and c_real; Assuming the fitted values ​​are: b_real = -0.2417, c_real = 828.95, then the current state curve is: V_avg_real(I) = (-0.001) * I² + (-0.2417) * I +828.95 Extrapolation calculation: Solve for (-0.001) * I² + (-0.2417) * I + 828.95 = 600 Solving the equation and taking the positive root, we get I_limit1 = 372.675 A. (That is, when the predicted current is 372.675 A, the average voltage will drop to the lower limit of 600 mV.) Calculate I_limit2 (calculate for each cycle).

[0059] Calculate the difference X = V_avg_real – V_min_real. Assuming V_avg_real = 700 mV and V_min_real = 640 mV, then X = 60 mV. Substituting into the formula (assuming k=2, X0=50 mV): I_limit2 = I_feedback - 2 * (60 - 50) = I_feedback - 2 * 10= I_feedback -20; (That is, if the current cell stack has poor consistency, the current will be reduced by 20A. Conversely, if X < X0, the result is obviously I_feedback plus a certain value. k does not need to be a fixed value. It can be set to obtain different k values ​​based on the cell voltage difference from a table. This way, the higher the cell voltage difference, the stronger the limiting ability, and the reduction of the current limitation when X < X0.) Current comparison and command output.

[0060] Assume I_limit1 = 350 A, I_limit2 = 315 A, I_cmd_raw = 320 A; Therefore, I_cmd = min(350,315,320) = 315 A. (That is, the current is currently limited by I_limit2.) The fuel cell current control method for fuel cell vehicles according to the embodiments of this application can evaluate the overall performance status of the fuel cell stack in real time, online and accurately, and adjust the fuel cell current of the fuel cell vehicle dynamically and adaptively accordingly, thereby avoiding excessively low cell voltage, preventing irreversible damage to the membrane electrode assembly, and effectively improving the service life of the fuel cell stack.

[0061] Figure 4 This is a structural block diagram of a fuel cell current control system for a fuel cell vehicle according to an embodiment of this application. Figure 4 As shown, the fuel cell current control system for a fuel cell vehicle according to an embodiment of this application includes: a data acquisition module 410, a first upper limit determination module 420, a second upper limit determination module 430, and a control module 430, wherein: The acquisition module 410 is used to acquire individual cell voltage data, which includes average cell voltage and real-time minimum cell voltage. The first upper limit determination module 420 is used to obtain a first current upper limit value based on the single cell voltage data and the first quadratic term coefficient of the minimum allowable average single cell voltage, wherein the minimum allowable average single cell voltage is pre-stored and the first quadratic term coefficient is read from the pre-stored stack reference fitting curve. The second upper limit determination module 430 is used to obtain the difference between the average single-cell voltage and the real-time lowest single-cell voltage, and to obtain the second current upper limit value based on the difference. The control module 440 is used to determine the final current based on the current requested by the current command, the first current upper limit value and the second current upper limit value, and to control the fuel cell current based on the final current.

[0062] The fuel cell current control system of the fuel cell vehicle according to the embodiments of this application can evaluate the overall performance status of the fuel cell stack in real time, online and accurately, and adjust the fuel cell current of the fuel cell vehicle dynamically and adaptively accordingly, thereby avoiding excessively low cell voltage, preventing irreversible damage to the membrane electrode, and effectively improving the service life of the fuel cell stack.

[0063] Specific limitations regarding the fuel cell current control system for fuel cell vehicles can be found in the above-described limitations on the fuel cell current control method for fuel cell vehicles, and will not be repeated here. Each module of the aforementioned fuel cell current control system for fuel cell vehicles can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0064] In one embodiment, a vehicle is provided, including: a fuel cell current control system for a fuel cell vehicle according to any of the above embodiments, wherein the vehicle is capable of real-time, online and accurate evaluation of the overall performance status of the fuel cell stack, and dynamically and adaptively adjusting the fuel cell current of the fuel cell vehicle accordingly, thereby avoiding excessively low cell voltage, thereby preventing irreversible damage to the membrane electrode assembly, and effectively improving the service life of the fuel cell stack.

[0065] Furthermore, other components and functions of the vehicle according to the embodiments of this application are known to those skilled in the art and will not be described in detail here.

[0066] In one embodiment, a computer device is provided. Figure 5 This is a structural block diagram of the computer device provided in the embodiments of this application, with reference to... Figure 5 The computer device includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the aforementioned embodiment of the fuel cell current control method for fuel cell vehicles. For example, it performs the following: collecting individual cell voltage data, which includes the average individual cell voltage and the real-time lowest individual cell voltage; Based on the individual cell voltage data and the first quadratic term coefficient of the minimum allowable average individual cell voltage, the first current upper limit value is obtained, wherein the minimum allowable average individual cell voltage is pre-stored, and the first quadratic term coefficient is read from the pre-stored stack reference fitting curve. The difference between the average cell voltage and the real-time lowest cell voltage is obtained, and a second current upper limit value is obtained based on the difference; The final current is determined based on the current requested by the current command, the first current upper limit value, and the second current upper limit value, and the fuel cell current is controlled based on the final current.

[0067] This application also provides a computer-readable storage medium storing a computer program. When the processor executes the computer program, it implements the aforementioned fuel cell current control method embodiment for fuel cell vehicles. For example, it performs the following: collecting individual cell voltage data, including average cell voltage and real-time minimum cell voltage; Based on the individual cell voltage data and the first quadratic term coefficient of the minimum allowable average individual cell voltage, the first current upper limit value is obtained, wherein the minimum allowable average individual cell voltage is pre-stored, and the first quadratic term coefficient is read from the pre-stored stack reference fitting curve. The difference between the average cell voltage and the real-time lowest cell voltage is obtained, and a second current upper limit value is obtained based on the difference; The final current is determined based on the current requested by the current command, the first current upper limit value, and the second current upper limit value, and the fuel cell current is controlled based on the final current.

[0068] This application provides a computer program product including instructions that, when executed, cause the method described in this application embodiment to be performed. For example, it can execute... Figure 1 The steps of the fuel cell current control method for the fuel cell vehicle shown are executed, for example: Collect individual cell voltage data, which includes average cell voltage and real-time minimum cell voltage; Based on the individual cell voltage data and the first quadratic term coefficient of the minimum allowable average individual cell voltage, the first current upper limit value is obtained, wherein the minimum allowable average individual cell voltage is pre-stored, and the first quadratic term coefficient is read from the pre-stored stack reference fitting curve. The difference between the average cell voltage and the real-time lowest cell voltage is obtained, and a second current upper limit value is obtained based on the difference; The final current is determined based on the current requested by the current command, the first current upper limit value, and the second current upper limit value, and the fuel cell current is controlled based on the final current.

[0069] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0070] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A fuel cell current control method for a fuel cell vehicle, characterized in that, include: Collect individual cell voltage data, which includes average cell voltage and real-time minimum cell voltage; Based on the individual cell voltage data and the first quadratic term coefficient of the minimum allowable average individual cell voltage, the first current upper limit value is obtained, wherein the minimum allowable average individual cell voltage is pre-stored, and the first quadratic term coefficient is read from the pre-stored stack reference fitting curve. The difference between the average cell voltage and the real-time lowest cell voltage is obtained, and a second current upper limit value is obtained based on the difference; The final current is determined based on the current requested by the current command, the first current upper limit value, and the second current upper limit value, and the fuel cell current is controlled based on the final current.

2. The fuel cell current control method for a fuel cell vehicle according to claim 1, characterized in that, The step of obtaining the first current upper limit value based on the individual cell voltage data and the coefficient of the first quadratic term of the minimum allowable average individual cell voltage includes: The individual cell voltage data is input into the stack fitting curve to read the coefficients of the second quadratic term and the coefficients of the third quadratic term from the stack fitting curve. The first upper limit value of the current is obtained by solving based on the coefficients of the first quadratic term, the second quadratic term, and the third quadratic term.

3. The fuel cell current control method for a fuel cell vehicle according to claim 1, characterized in that, The step of obtaining the difference between the average cell voltage and the real-time lowest cell voltage, and obtaining the second current upper limit value based on the difference, includes: Obtain the gain coefficient; The second upper limit of current is obtained by solving the difference between the gain coefficient and the average single-cell voltage and the real-time lowest single-cell voltage.

4. The fuel cell current control method for a fuel cell vehicle according to claim 3, characterized in that, Before determining the second upper current limit value based on the gain coefficient and the difference between the average cell voltage and the real-time lowest cell voltage, the process further includes: Obtain the security threshold; Calculate the difference between the average cell voltage and the real-time lowest cell voltage and the safety difference between the safety threshold; The step of calculating the second upper limit of current based on the gain coefficient and the difference between the average single-cell voltage and the real-time lowest single-cell voltage includes: The second upper limit value of current is obtained by solving based on the gain coefficient and the safety difference.

5. The fuel cell current control method for a fuel cell vehicle according to claim 1, characterized in that, The step of determining the final current based on the current requested by the current command, the first current upper limit value, and the second current upper limit value, and controlling the fuel cell current based on the final current, includes: The minimum value among the current requested by the current command, the first current upper limit value, and the second current upper limit value is taken as the final current; The upper limit of the current output of the fuel cell is controlled based on the final current.

6. The fuel cell current control method for a fuel cell vehicle according to any one of claims 1-5, characterized in that, Before obtaining the first current upper limit value based on the individual cell voltage data and the coefficient of the first quadratic term of the minimum allowable average individual cell voltage, the process further includes: Under the healthy condition of the fuel cell stack, standard polarization curve tests are performed to obtain multiple sets of data points from low current to limit current. Each set of data points includes the current and average cell voltage. Based on the multiple sets of data points, the least squares method is used to fit them into a nonlinear function, wherein the nonlinear function characterizes the reference fitting curve of the fuel cell stack.

7. A fuel cell current control system for a fuel cell vehicle, characterized in that, include: The acquisition module is used to acquire individual cell voltage data, which includes average cell voltage and real-time minimum cell voltage. The first upper limit determination module is used to obtain the first current upper limit value based on the single cell voltage data and the first quadratic term coefficient of the minimum allowable average single cell voltage, wherein the minimum allowable average single cell voltage is pre-stored and the first quadratic term coefficient is read from the pre-stored stack reference fitting curve. The second upper limit determination module is used to obtain the difference between the average single-cell voltage and the real-time lowest single-cell voltage, and to obtain the second current upper limit value based on the difference. The control module is used to determine the final current based on the current requested by the current command, the first current upper limit value, and the second current upper limit value, and to control the fuel cell current based on the final current.

8. A vehicle, characterized in that, include: The fuel cell current control system for a fuel cell vehicle according to claim 7.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the fuel cell current control method for fuel cell vehicles according to any one of claims 1-6.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the fuel cell current control method for fuel cell vehicles according to any one of claims 1-6.

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