Control method of hydrogen fuel cell air supply system and related device

Abstract

The invention relates to a control method of a hydrogen fuel cell air supply system and a related device. The control method comprises the following steps: acquiring real-time current information when the hydrogen fuel cell system runs, an air compressor feedforward rotating speed under the current condition executed by an air compressor, and a back pressure valve feedforward opening under the current condition executed by a back pressure valve; actual air flow and actual air pressure are obtained; respectively calculating air flow deviation and air pressure deviation; and performing air supply flow control and air supply pressure control according to the calculated deviation value. In the adjusting process, the actual air pressure always approaches to or is equal to the target air pressure, the actual air flow is adjusted along with the target air flow, gradually approaches to or is equal to the target air flow and is stable, and the problem that when the air compressor and the back pressure valve are adjusted at the same time, output of the air compressor and output of the back pressure valve interfere with each other and are coupled is solved. Therefore, responsiveness and stability of air flow and pressure control of the hydrogen fuel cell system are improved, stability of the system is improved, and service life of the system is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a control method and related devices for a hydrogen fuel cell air supply system. Background Art

[0002] CN110085891B discloses a method and related device for regulating the air pressure at the inlet of a fuel cell stack. The patent proposes a control based on model feedforward, and at the same time corrects the opening of the electronic throttle through PID control, so as to achieve air pressure control at the inlet of the fuel cell stack by controlling the opening of the electronic throttle. By using air pressure as the only control variable, the air flow cannot be kept constant for a long time, and the effect of this method is unstable in practical application.

[0003] CN115483419A discloses an air flow and back pressure control method for a fuel cell system. The method uses the air compressor speed at different air flow rates and the back pressure valve opening at different back pressures as feedforward, divides the working conditions according to the flow deviation and the back pressure deviation, selects the regulating device with the best comprehensive adjustability as the target regulating device, and each working condition corresponds to a regulating device (air compressor or back pressure valve). Within a control cycle, only the regulating device corresponding to the current working condition is controlled to perform corresponding regulating operations, so as to avoid mutual interference and coupling between the outputs of the air compressor and the back pressure valve. The method can meet the system requirements for flow deviation and pressure deviation, but there are too many calibration parameters and it is too complicated in practical applications.

[0004] Therefore, it is urgent to design a control method and related devices for a hydrogen fuel cell air supply system to solve the problems existing in the above-mentioned prior art. Summary of the invention

[0005] In view of this, the present invention provides a control method and related devices for a hydrogen fuel cell air supply system, with the aim of collaboratively controlling the flow and pressure of the air supply system of the hydrogen fuel cell system, thereby improving the responsiveness and stability of the air flow and pressure control of the hydrogen fuel cell system, and further improving the stability and life of the hydrogen fuel cell system.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A control method for a hydrogen fuel cell air supply system comprises the following steps:

[0008] S1. By performing open-loop control on the air compressor and the back pressure valve, calibrate the air compressor feedforward speed and the back pressure valve feedforward opening when the hydrogen fuel cell system is running under different current conditions, and make a current-air compressor feedforward speed table and a current-back pressure valve feedforward opening table respectively;

[0009] S2. Obtain the real-time current information of the hydrogen fuel cell system during operation, the air compressor executes the air compressor feedforward speed under the current condition, and the back pressure valve executes the back pressure valve feedforward opening under the current condition; obtain the actual air flow and actual air pressure; calculate the air flow deviation and air pressure deviation respectively; and perform air supply flow control and air supply pressure control respectively according to the calculated deviation values.

[0010] Further, the step S1 is as follows:

[0011] S1-1. According to the requirements of the air supply flow rate and air supply pressure for the optimal working conditions of the fuel cell stack, determine the target air flow rate and target air pressure corresponding to the hydrogen fuel cell system under different current conditions;

[0012] S1-2. By performing open-loop control on the air compressor and the back pressure valve, the corresponding air compressor speed and back pressure valve opening are calibrated when the hydrogen fuel cell system reaches the target air flow and the target air pressure under different current conditions. The air compressor speed at this time is used as the air compressor feedforward speed under the current condition, and the back pressure valve opening at this time is used as the back pressure valve feedforward opening under the current condition;

[0013] S1-3. According to the data obtained in step S1-2, a current-air compressor feedforward speed table and a current-back pressure valve feedforward opening table are respectively prepared.

[0014] Furthermore, the air supply flow control in step S2 is specifically as follows:

[0015] According to the real-time current information of the hydrogen fuel cell system during operation, the target air flow and the air compressor feedforward speed corresponding to the current condition are determined;

[0016] The air compressor executes the air compressor feedforward speed under the current condition, and obtains the actual air flow through the air flow meter set in the hydrogen fuel cell air supply system;

[0017] Calculate the difference between the actual air flow and the target air flow to obtain the air flow deviation;

[0018] According to the air flow deviation, the PI closed-loop control method is used to control the air supply flow.

[0019] Furthermore, the air supply pressure control in step S2 is specifically as follows:

[0020] According to the real-time current information of the hydrogen fuel cell system during operation, the target air pressure and the back pressure valve feedforward opening corresponding to the current condition are determined;

[0021] The back pressure valve performs the back pressure valve feedforward opening under the current condition, and obtains the actual air pressure through the pressure sensor arranged in the air supply system of the hydrogen fuel cell;

[0022] Calculate the difference between the actual air pressure and the target air pressure to obtain the air pressure deviation;

[0023] According to the air pressure deviation, the air supply pressure is controlled by PID closed-loop control.

[0024] Furthermore, the PI closed-loop control method uses segmented control according to different currents. First, the air compressor speed P parameter and the air compressor speed I parameter at different current points are calibrated to make a current-air compressor speed P parameter table and a current-air compressor speed I parameter table; when the hydrogen fuel cell system is underloaded, the air compressor speed P parameter and the air compressor speed I parameter are relatively large, the P / I control loop adjusts quickly, and the speed adjustment changes quickly; when the hydrogen fuel cell system is overloaded, the air compressor speed P parameter and the air compressor speed I parameter are relatively small, the P / I control loop adjusts slowly, and the speed adjustment changes little; in the air supply flow rate adjustment process, an allowable deviation value between the actual air flow rate and the target air flow rate is set. When the actual air flow rate is within the allowable deviation range of the target air flow rate, the air compressor does not adjust the speed.

[0025] Furthermore, the hydrogen fuel cell system is also provided with air flow meter fault identification. When an air flow meter fault is identified, the air compressor only executes the feedforward speed under the current current conditions to ensure that the hydrogen fuel cell system can be used normally for a short time.

[0026] Furthermore, the PID closed-loop control method first calibrates the back-pressure valve opening P parameter, the back-pressure valve opening I parameter, and the back-pressure valve opening D parameter at different current points; adopts incremental PID control, and the adjustment speed is fast when the air pressure deviation is large, and the adjustment speed decreases when the air pressure deviation is small, and it is smoothly adjusted to a steady state; in the process of adjusting the air supply pressure, an allowable deviation value between the actual air pressure and the target air pressure is set, and when the actual air pressure is within the allowable deviation range of the target air pressure, the back-pressure valve does not adjust the opening.

[0027] Furthermore, it is characterized in that the fuel cell controller FCU sends a controller signal to the air compressor controller, the air compressor controller controls the operation of the air compressor, and the air compressor speed is controlled by the air compressor controller, and the air compressor controller adopts CAN control mode; the fuel cell controller FCU directly controls the operation of the back pressure valve, and analog signals are used for the control / feedback of the back pressure valve; the data sending and receiving cycle of the air compressor controller for controlling the air compressor is longer than the data sending and receiving cycle of the fuel cell controller FCU for controlling the back pressure valve.

[0028] Furthermore, the closed-loop PID regulation speed of the air supply pressure is set higher than the closed-loop PI regulation speed of the air supply flow rate, that is, the regulation time required for the air pressure to reach a stable state is less than the regulation time required for the air flow rate to reach a stable state.

[0029] The present invention also provides a hydrogen fuel cell air supply system, which is used to execute the control method of the above-mentioned hydrogen fuel cell air supply system, and the hydrogen fuel cell air supply system includes: an air filter, an air flow meter, an air compressor, an intercooler, a humidifier, a pressure sensor and a back pressure valve; the pressure sensor is arranged at the inlet of the hydrogen fuel cell stack, and the pressure sensor is used to measure the air supply pressure; the air flow meter is used to measure the air supply flow rate; after passing through the air filter, air flow meter, air compressor, intercooler, and humidifier in sequence, the air enters the stack from the air inlet to participate in the reaction, and after the reaction, the tail exhaust gas is discharged from the air outlet of the stack, then enters the humidifier, and is discharged outside the hydrogen fuel cell system.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) By collaboratively controlling the flow and pressure of the air supply system of the hydrogen fuel cell system, the air compressor controller is used to control the operation of the air compressor, and the fuel cell controller FCU is used to directly control the operation of the back pressure valve. The data sending and receiving cycle of the air compressor is longer than the data sending and receiving cycle of the back pressure valve. At the same time, the air supply pressure closed-loop PID adjustment speed is set higher than the air supply flow closed-loop PI adjustment speed. During the adjustment process of the back pressure valve and the air compressor, the actual air pressure always approaches or is equal to the target air pressure, and the actual air flow is adjusted according to the target air flow, gradually approaches or is equal to the target air flow and stabilizes, avoiding the problem of mutual interference and coupling between the outputs of the air compressor and the back pressure valve when they are adjusted at the same time. This improves the responsiveness and stability of the air flow and pressure control of the hydrogen fuel cell system, thereby improving the stability and life of the hydrogen fuel cell system.

[0032] (2) During the air supply flow rate regulation process, by setting the allowable deviation value between the actual air flow rate and the target air flow rate, it is possible to prevent the air compressor speed from being continuously adjusted due to the flow fluctuation caused by the vibration of the air compressor's own speed, and to prevent the air compressor and the back pressure valve from interfering with each other due to the fluctuation of the flow and pressure before the air compressor and the back pressure valve are adjusted to the target value, so that both the air compressor and the back pressure valve cannot quickly reach a stable state; during the air supply pressure regulation process, by setting the allowable deviation value between the actual air pressure and the target air pressure, it is possible to prevent the pressure fluctuation caused by the vibration of the back pressure valve opening and the continuous adjustment of the back pressure valve opening, and to prevent the pressure and flow fluctuation caused by the back pressure valve and the air compressor from interfering with each other before the back pressure valve and the air compressor are adjusted to the target value.

[0033] Other features and advantages of the present invention will be described in the following description, and partly become obvious from the description, or be understood by implementing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A schematic structural diagram of an air supply system for a hydrogen fuel cell according to an embodiment of the present invention is shown.

[0036] In the figure: 1. Air filter; 2. Air flow meter; 3. Air compressor; 4. Intercooler; 5. Humidifier; 6. Pressure sensor; 7. Battery stack; 8. Back pressure valve. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The embodiment of the present invention provides a control method for a hydrogen fuel cell air supply system. Figure 1 As shown, the control method comprises the following steps:

[0039] S1. By performing open-loop control on the air compressor and the back pressure valve, calibrate the air compressor feedforward speed and the back pressure valve feedforward opening when the hydrogen fuel cell system is running under different current conditions, and make a current-air compressor feedforward speed table and a current-back pressure valve feedforward opening table respectively;

[0040] S2. Obtain the real-time current information of the hydrogen fuel cell system during operation, the air compressor executes the air compressor feedforward speed under the current condition, and the back pressure valve executes the back pressure valve feedforward opening under the current condition; obtain the actual air flow and actual air pressure; calculate the air flow deviation and air pressure deviation respectively; and perform air supply flow control and air supply pressure control respectively according to the calculated deviation values.

[0041] Specifically, the step S1 is as follows:

[0042] S1-1. According to the requirements of the air supply flow rate and air supply pressure for the optimal working conditions of the fuel cell stack, determine the target air flow rate and target air pressure corresponding to the hydrogen fuel cell system under different current conditions;

[0043] S1-2. By performing open-loop control on the air compressor and the back pressure valve, the corresponding air compressor speed and back pressure valve opening are calibrated when the hydrogen fuel cell system reaches the target air flow and the target air pressure under different current conditions. The air compressor speed at this time is used as the air compressor feedforward speed under the current condition, and the back pressure valve opening at this time is used as the back pressure valve feedforward opening under the current condition;

[0044] S1-3. According to the data obtained in step S1-2, a current-air compressor feedforward speed table and a current-back pressure valve feedforward opening table are respectively prepared.

[0045] The air supply flow rate control in step S2 is specifically as follows:

[0046] According to the real-time current information of the hydrogen fuel cell system during operation, the target air flow and the air compressor feedforward speed corresponding to the current condition are determined;

[0047] The air compressor executes the air compressor feedforward speed under the current condition, and obtains the actual air flow through the air flow meter set in the hydrogen fuel cell air supply system;

[0048] Calculate the difference between the actual air flow and the target air flow to obtain the air flow deviation;

[0049] According to the air flow deviation, the PI closed-loop control method is used to control the air supply flow. The deviation between the actual air flow and the target air flow is made as small as possible or there is no deviation, thereby realizing the control of the air supply flow.

[0050] The PI closed-loop control method uses segmented control according to different currents. First, the air compressor speed P parameter and the air compressor speed I parameter at different current points are calibrated to prepare a current-air compressor speed P parameter table and a current-air compressor speed I parameter table. When the hydrogen fuel cell system is under low load, the air compressor speed P parameter and the air compressor speed I parameter are relatively large, the P / I control loop is adjusted quickly, and the speed adjustment changes quickly, so that the speed of the required flow rate can be reached quickly, shortening the adjustment time. When the hydrogen fuel cell system is under high load, the air compressor speed P parameter and the air compressor speed I parameter are relatively small, the P / I control loop is adjusted slowly, and the speed adjustment changes little, so that the flow fluctuation is small when the required flow rate is reached, thereby improving the system stability.

[0051] The hydrogen fuel cell system is also equipped with air flow meter fault identification. When an air flow meter fault is detected, the air compressor only executes the feedforward speed under the current current conditions to ensure that the hydrogen fuel cell system can be used normally for a short time.

[0052] In the process of adjusting the air compressor speed, the air compressor is set with an operating speed range [v min ,v max ], to ensure that the air compressor can work normally when the air compressor speed is within this range, where v min is the minimum speed of the air compressor, v max The maximum speed of the air compressor. The air compressor is set with a minimum speed to prevent the air compressor from surging or malfunctioning due to the air compressor speed being too low during the adjustment process; the air compressor is set with a maximum speed to prevent the air compressor from overspeeding during the adjustment process.

[0053] During the air supply flow rate adjustment process, an allowable deviation value is set between the actual air flow rate and the target air flow rate. When the actual air flow rate is within the allowable deviation range of the target air flow rate, the air compressor does not adjust the speed. Setting the allowable deviation value can prevent the air compressor's own speed jitter from causing flow fluctuations and causing the air compressor speed to be adjusted continuously. It can also prevent the air compressor and the back pressure valve from interfering with each other due to fluctuations in flow and pressure before the air compressor and the back pressure valve adjust to the target value, so that the air compressor and the back pressure valve cannot quickly reach a stable state.

[0054] The air supply pressure control in step S2 is specifically as follows:

[0055] According to the real-time current information of the hydrogen fuel cell system during operation, the target air pressure and the back pressure valve feedforward opening corresponding to the current condition are determined;

[0056] The back pressure valve performs the back pressure valve feedforward opening under the current condition, and obtains the actual air pressure through the pressure sensor arranged in the air supply system of the hydrogen fuel cell;

[0057] Calculate the difference between the actual air pressure and the target air pressure to obtain the air pressure deviation;

[0058] According to the air pressure deviation, the PID closed-loop control method is used to control the air supply pressure. The deviation between the actual air pressure and the target air pressure is made as small as possible or there is no deviation, so as to realize the control of the air supply pressure.

[0059] The PID closed-loop control method first calibrates the back-pressure valve opening P parameter, the back-pressure valve opening I parameter, and the back-pressure valve opening D parameter at different current points; and adopts incremental PID control. When the air pressure deviation is large, the adjustment speed is fast, and when the air pressure deviation is small, the adjustment speed decreases, and the air pressure is smoothly adjusted to a steady state, which ensures both the responsiveness of the air pressure regulation and the accuracy of the regulation.

[0060] In the process of adjusting the air supply pressure, the allowable deviation value between the actual air pressure and the target air pressure is set. When the actual air pressure is within the allowable deviation range of the target air pressure, the back pressure valve does not adjust the opening. Setting the allowable deviation value can prevent the back pressure valve opening from jittering and causing pressure fluctuations, which leads to continuous adjustment of the back pressure valve opening. It can also prevent the back pressure valve and the air compressor from interfering with each other due to fluctuations in pressure and flow before the back pressure valve and the air compressor are adjusted to the target value.

[0061] The fuel cell controller FCU sends a controller signal to the air compressor controller, and the air compressor controller controls the operation of the air compressor; the air compressor speed is controlled by the air compressor controller, and the air compressor controller adopts CAN control mode.

[0062] The fuel cell controller FCU directly controls the operation of the back pressure valve; analog signals are used for back pressure valve control / feedback, and the data transmission rate is determined by the hardware circuit and software developers, usually at the ms level.

[0063] The data sending and receiving cycle of the air compressor controller used to control the air compressor is longer than the data sending and receiving cycle of the fuel cell controller FCU used to control the back pressure valve. In the process of adjusting the air compressor speed once, the back pressure valve has been adjusted multiple times.

[0064] Preferably, the air compressor controller is used to control the air compressor with a message cycle of 100ms, that is, the data sending and receiving cycle is 100ms. In data transmission, after sending an air compressor speed request, the feedback result can be obtained 100ms later, and the calculation for the feedback value and the target value is started to adjust the speed.

[0065] Preferably, the fuel cell controller FCU is used to control the analog signal data sending and receiving cycle of the back pressure valve is 10ms.

[0066] At the same time, the air supply pressure closed-loop PID adjustment speed is set to be higher than the air supply flow closed-loop PI adjustment speed, that is, the adjustment time required for the air pressure to reach a stable state is less than the adjustment time required for the air flow to reach a stable state, thereby achieving that during the adjustment process of the back-pressure valve and the air compressor, the actual air pressure always approaches or is equal to the target air pressure, and the actual air flow is adjusted following the target air flow, gradually approaches or is equal to the target air flow and stabilizes, avoiding the problem of mutual interference and coupling between the outputs of the air compressor and the back-pressure valve when the two are adjusted at the same time.

[0067] An embodiment of the present invention also provides a hydrogen fuel cell air supply system, which is used to execute the control method of the above-mentioned hydrogen fuel cell air supply system, and the hydrogen fuel cell air supply system includes: an air filter 1, an air flow meter 2, an air compressor 3, an intercooler 4, a humidifier 5, a pressure sensor 6 and a back pressure valve 8; the pressure sensor 6 is arranged at the inlet of the hydrogen fuel cell stack 7, and the pressure sensor 6 is used to measure the air supply pressure; the air flow meter 2 is used to measure the air supply flow rate; after the air passes through the air filter 1, the air flow meter 2, the air compressor 3, the intercooler 4, and the humidifier 5 in sequence, it enters the stack 7 from the air inlet to participate in the reaction, and after the reaction, the tail exhaust gas is discharged from the air outlet of the stack 7, and then enters the humidifier 5, and then discharged outside the hydrogen fuel cell system.

[0068] The present invention coordinately controls the air flow and pressure of the air path of the hydrogen fuel cell system, uses the air compressor controller to control the operation of the air compressor, uses the fuel cell controller FCU to directly control the operation of the back pressure valve, and controls the data sending and receiving cycle of the air compressor to be longer than the data sending and receiving cycle of the back pressure valve, and at the same time sets the air supply pressure closed loop PID adjustment speed higher than the air supply flow closed loop PI adjustment speed. During the adjustment process of the back pressure valve and the air compressor, the actual air pressure always approaches or is equal to the target air pressure, and the actual air flow is adjusted following the target air flow, gradually approaches or is equal to the target air flow and is stable, avoiding the problem of mutual interference and coupling between the outputs of the air compressor and the back pressure valve when they are adjusted at the same time. Thereby improving the responsiveness and stability of the air flow and pressure control of the hydrogen fuel cell system, and further improving the stability and life of the hydrogen fuel cell system.

[0069] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for a hydrogen fuel cell air supply system, characterized in that: The control method comprises the following steps: S1. By performing open-loop control on the air compressor and the back pressure valve, calibrate the air compressor feedforward speed and the back pressure valve feedforward opening when the hydrogen fuel cell system is running under different current conditions, and make a current-air compressor feedforward speed table and a current-back pressure valve feedforward opening table respectively; S2. Acquire the real-time current information of the hydrogen fuel cell system when it is running, the air compressor executes the air compressor feedforward speed under the current condition, and the back pressure valve executes the back pressure valve feedforward opening under the current condition; Get the actual air flow and actual air pressure; The air flow deviation and the air pressure deviation are calculated respectively; and the air supply flow control and the air supply pressure control are performed respectively according to the calculated deviation values.

2. The control method of the hydrogen fuel cell air supply system according to claim 1, characterized in that: The step S1 is as follows: S1-1. According to the requirements of the air supply flow rate and air supply pressure for the optimal working conditions of the fuel cell stack, determine the target air flow rate and target air pressure corresponding to the hydrogen fuel cell system under different current conditions; S1-2. By performing open-loop control on the air compressor and the back pressure valve, the corresponding air compressor speed and back pressure valve opening are calibrated when the hydrogen fuel cell system reaches the target air flow and the target air pressure under different current conditions. The air compressor speed at this time is used as the air compressor feedforward speed under the current condition, and the back pressure valve opening at this time is used as the back pressure valve feedforward opening under the current condition; S1-3. According to the data obtained in step S1-2, a current-air compressor feedforward speed table and a current-back pressure valve feedforward opening table are respectively prepared.

3. The control method of the hydrogen fuel cell air supply system according to claim 2, characterized in that: The air supply flow rate control in step S2 is specifically as follows: According to the real-time current information of the hydrogen fuel cell system during operation, the target air flow and the air compressor feedforward speed corresponding to the current condition are determined; The air compressor executes the air compressor feedforward speed under the current condition, and obtains the actual air flow through the air flow meter set in the hydrogen fuel cell air supply system; Calculate the difference between the actual air flow and the target air flow to obtain the air flow deviation; According to the air flow deviation, the PI closed-loop control method is used to control the air supply flow.

4. The control method of the hydrogen fuel cell air supply system according to claim 3, characterized in that: The air supply pressure control in step S2 is specifically as follows: According to the real-time current information of the hydrogen fuel cell system during operation, the target air pressure and the back pressure valve feedforward opening corresponding to the current condition are determined; The back pressure valve performs the back pressure valve feedforward opening under the current condition, and obtains the actual air pressure through the pressure sensor arranged in the air supply system of the hydrogen fuel cell; Calculate the difference between the actual air pressure and the target air pressure to obtain the air pressure deviation; According to the air pressure deviation, the air supply pressure is controlled by PID closed-loop control.

5. The control method of the hydrogen fuel cell air supply system according to claim 3, characterized in that: The PI closed-loop control method uses segmented control according to different currents. First, the air compressor speed P parameter and the air compressor speed I parameter at different current points are calibrated to make a current-air compressor speed P parameter table and a current-air compressor speed I parameter table; When the hydrogen fuel cell system is under low load, the air compressor speed parameter P and air compressor speed parameter I are large, the P / I control loop is adjusted quickly, and the speed adjustment changes quickly; when the hydrogen fuel cell system is under high load, the air compressor speed parameter P and air compressor speed parameter I are small, the P / I control loop is adjusted slowly, and the speed adjustment changes little; During the air supply flow rate adjustment process, an allowable deviation value between the actual air flow rate and the target air flow rate is set. When the actual air flow rate is within the allowable deviation range of the target air flow rate, the air compressor does not adjust the speed.

6. The control method of the hydrogen fuel cell air supply system according to claim 3, characterized in that: The hydrogen fuel cell system is also equipped with an air flow meter fault identification function. When an air flow meter fault is detected, the air compressor only executes the feedforward speed under the current conditions.

7. The control method of the hydrogen fuel cell air supply system according to claim 4, characterized in that: The PID closed-loop control method first calibrates the back-pressure valve opening P parameter, the back-pressure valve opening I parameter, and the back-pressure valve opening D parameter at different current points; adopts incremental PID control, and the adjustment speed is fast when the air pressure deviation is large, and the adjustment speed decreases when the air pressure deviation is small, and it is smoothly adjusted to a steady state; in the process of adjusting the air supply pressure, an allowable deviation value between the actual air pressure and the target air pressure is set, and when the actual air pressure is within the allowable deviation range of the target air pressure, the back-pressure valve does not adjust the opening.

8. The control method of the hydrogen fuel cell air supply system according to any one of claims 5 or 7, characterized in that: The fuel cell controller FCU sends a controller signal to the air compressor controller. The air compressor controller controls the operation of the air compressor and controls the air compressor speed through the air compressor controller. The air compressor controller adopts CAN control mode. The fuel cell controller FCU directly controls the operation of the back pressure valve and uses analog signals for back pressure valve control / feedback. The data sending and receiving cycle of the air compressor controller used to control the air compressor is longer than the data sending and receiving cycle of the fuel cell controller FCU used to control the back pressure valve.

9. The control method of the hydrogen fuel cell air supply system according to claim 8, characterized in that: The air supply pressure closed-loop PID adjustment speed is set higher than the air supply flow closed-loop PI adjustment speed, that is, the adjustment time required for the air pressure to reach a stable state is less than the adjustment time required for the air flow to reach a stable state.

10. A hydrogen fuel cell air supply system, used to execute the control method of the hydrogen fuel cell air supply system according to any one of claims 1 to 9, characterized in that: The hydrogen fuel cell air supply system includes: an air filter, an air flow meter, an air compressor, an intercooler, a humidifier, a pressure sensor and a back pressure valve; the pressure sensor is arranged at the inlet of the hydrogen fuel cell stack, and the pressure sensor is used to measure the air supply pressure; the air flow meter is used to measure the air supply flow; after passing through the air filter, air flow meter, air compressor, intercooler and humidifier in sequence, the air enters the stack from the air inlet to participate in the reaction, and after the reaction, the tail gas is discharged from the air outlet of the stack, then enters the humidifier, and is discharged outside the hydrogen fuel cell system.

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