A control method and system for a fuel cell air supply system

Abstract

This invention discloses a control method for a fuel cell air supply system. It acquires nominal models describing the air compressor speed to air flow rate and the back pressure valve opening to cathode pressure under various operating conditions. It obtains expected data for each operating condition using the required current value of the fuel cell under each condition and switches between different models and controllers in the fuel cell air supply device based on the current operating condition. It obtains a flow deviation feedback value using the first nominal model and the output value of the fuel cell air supply system, and uses this feedback value to achieve closed-loop control of the air compressor. It also obtains a cathode pressure deviation feedback value using the second nominal model and the output value of the fuel cell air supply system, and uses this feedback value to achieve closed-loop control of the back pressure valve. In other words, this invention simultaneously achieves closed-loop control of the air compressor and back pressure valve based on the actual output of the fuel cell air supply system using the corresponding nominal model, controller, and expected data.

Description

Technical Field

[0001] This invention relates to the field of fuel cell control, and more particularly to a control method and system for a fuel cell air supply system. Background Technology

[0002] Proton exchange membrane fuel cells (PEMFCs), as an energy conversion device, have attracted widespread attention in recent years due to their advantages such as high efficiency, zero pollution, and low operating temperature. When operating under complex conditions, fuel cells and their subsystems need to possess good dynamic characteristics to respond quickly to demands, especially air supply systems, which are prone to dynamic response lag and significant disturbance effects. Existing control algorithms for fuel cell air supply systems rarely balance robustness with controller complexity. Common control algorithms include PID control and model predictive control. While PID control is simple in structure, its robustness is poor. Model predictive control, although possessing better robustness and control performance, requires high model accuracy, involves large computational loads, and has relatively high operating costs, thus limiting its practical application. Summary of the Invention

[0003] To improve the accuracy and stability of fuel cell air supply system control, this invention proposes a control method for fuel cell air supply systems, which is applied to a flow internal model controller G. IMC_m A model describing the mapping relationship between air compressor speed and air flow rate; and a pressure internal model controller G. IMC_P A fuel cell air supply device used to describe the mapping relationship model from back pressure valve opening to cathode pressure and the signal processing module; the control method includes:

[0004] The mapping relationship model describing the air compressor speed to air flow rate under various operating conditions was obtained through experimental identification methods and designated as the first nominal model. The model describing the mapping relationship between the back pressure valve opening and the cathode pressure is the second nominal model.

[0005] The signal processing module utilizes the required current value I of the fuel cell under various operating conditions. set Obtain the expected data corresponding to each operating condition; the expected data includes: expected airflow m ref_i Expected value of cathode pressure P ref_i Expected speed n of air compressor i and the desired opening θ of the back pressure valve i The first nominal model in the fuel cell air supply unit is switched based on the current operating conditions. Second nominal model Flow internal model controller G IMC_m and pressure internal mold controller G IMC_PWhere (i = 1, ..., N), N represents the number of working conditions;

[0006] Obtain the first nominal model Output flow difference Δm mod The actual flow rate m output by the fuel cell air supply system sys The difference is the flow deviation feedback value. The flow deviation feedback value and the expected airflow value m are then obtained. ref_i The difference is input into the flow internal model controller G. IMC_m Through the flow internal model controller G IMC_m Calculate the air compressor speed correction value and input it into the first nominal model. Simultaneously obtain the desired air compressor speed n i The sum of the air compressor speed correction value and the speed control value is the speed control value. The air compressor in the fuel cell air supply system is controlled by the speed control value, thereby realizing the closed-loop control of the air compressor.

[0007] Obtain the second nominal model Output cathode pressure difference ΔP mod The actual cathode pressure P output by the fuel cell air supply system sys The difference is the cathode pressure deviation feedback value. The cathode pressure deviation feedback value and the expected cathode pressure P are then obtained. ref_i The difference is input into the pressure internal mold controller G. IMC_P Through the pressure internal mold controller G IMC_P Calculate the back pressure valve opening correction value and input it into the second nominal model. Simultaneously obtain the desired opening θ of the back pressure valve. i The sum of the back pressure valve opening correction value and the back pressure valve opening control value is the back pressure valve opening control value. The back pressure valve in the fuel cell air supply system is controlled by the back pressure valve opening, thereby realizing the closed-loop control of the back pressure valve.

[0008] Furthermore, the first nominal model The formula for obtaining it is:

[0009] Second nominal model The formula for obtaining it is:

[0010] In the formula, s is the complex frequency; Δn, Δθ, Δm, and ΔP represent the design values ​​of the speed difference, back pressure valve opening difference, flow rate difference, and cathode pressure difference under the corresponding operating conditions when the experiment is conducted through the experimental identification method, respectively.

[0011] Furthermore, the flow internal model controller G IMC_m The corresponding formula expression is:

[0012]

[0013] The pressure internal mold controller G IMC_P The corresponding formula expression is:

[0014]

[0015] In the formula, T m and T P Both represent the filter time constant, f m (s) and f P (s) are all filters.

[0016] The present invention also proposes a control system for a fuel cell air supply system, which is applied to a flow internal model controller G. IMC_m A model describing the mapping relationship between air compressor speed and air flow rate; and a pressure internal model controller G. IMC_P A fuel cell air supply device used to describe the mapping relationship model from back pressure valve opening to cathode pressure and the signal processing module; the control system includes:

[0017] The experimental module is used to obtain, through experimental identification methods, the mapping relationship model describing the air compressor speed to air flow rate under various operating conditions, which is the first nominal model. The model describing the mapping relationship between the back pressure valve opening and the cathode pressure is the second nominal model.

[0018] The expected data acquisition module is used to utilize the required current value I of the fuel cell under various operating conditions through the signal processing module. set Obtain the expected data corresponding to each operating condition; the expected data includes: expected airflow m ref_i Expected value of cathode pressure P ref_i Expected speed n of air compressor i and the desired opening θ of the back pressure valve i The first nominal model in the fuel cell air supply unit is switched based on the current operating conditions. Second nominal model Flow internal model controller G IMC_m and pressure internal mold controller G IMC_P Where (i = 1, ..., N), N represents the number of working conditions;

[0019] The air compressor closed-loop control module is used to obtain the first nominal model. Output flow difference Δm mod The actual flow rate m output by the fuel cell air supply system sys The difference is the flow deviation feedback value. The flow deviation feedback value and the expected airflow value m are then obtained. ref_i The difference is input into the flow internal model controller G.IMC_m Through the flow internal model controller G IMC_m Calculate the air compressor speed correction value and input it into the first nominal model. Simultaneously obtain the desired air compressor speed n i The sum of the air compressor speed correction value and the speed control value is the speed control value. The air compressor in the fuel cell air supply system is controlled by the speed control value, thereby realizing the closed-loop control of the air compressor.

[0020] The back pressure valve closing control module is used to obtain the second nominal model. Output cathode pressure difference ΔP mod The actual cathode pressure P output by the fuel cell air supply system sys The difference is the cathode pressure deviation feedback value. The cathode pressure deviation feedback value and the expected cathode pressure P are then obtained. ref_i The difference is input into the pressure internal mold controller G. IMC_P Through the pressure internal mold controller G IMC_P Calculate the back pressure valve opening correction value and input it into the second nominal model. Simultaneously obtain the desired opening θ of the back pressure valve. i The sum of the back pressure valve opening correction value and the back pressure valve opening control value is the back pressure valve opening control value. The back pressure valve in the fuel cell air supply system is controlled by the back pressure valve opening, thereby realizing the closed-loop control of the back pressure valve.

[0021] Furthermore, the first nominal model The formula for obtaining it is: Second nominal model The formula for obtaining it is: In the formula, s is the complex frequency; Δn, Δθ, Δm, and ΔP represent the design values ​​of the speed difference, back pressure valve opening difference, flow rate difference, and cathode pressure difference under the corresponding operating conditions when the experiment is conducted through the experimental identification method, respectively.

[0022] Furthermore, the flow internal model controller G IMC_m The corresponding formula expression is:

[0023]

[0024] The pressure internal mold controller G IMC_P The corresponding formula expression is:

[0025]

[0026] In the formula, T m and T P Both represent the filter time constant, f m (s) and f P (s) are all filters.

[0027] Compared with the prior art, the present invention has at least the following beneficial effects:

[0028] (1) This invention obtains a nominal model for describing the air compressor speed to air flow rate and the back pressure valve opening to cathode pressure under various operating conditions; and utilizes the required current value I of the fuel cell under various operating conditions. set Obtain the expected data corresponding to each operating condition, and switch the various models and controllers in the fuel cell air supply device based on the current operating condition; obtain the first nominal model. Output flow difference Δm mod The actual flow rate m output by the fuel cell air supply system sys The difference is the flow deviation feedback value, which is used in conjunction with the expected airflow value m. ref_i and the expected speed n of the air compressor i To achieve closed-loop control of the air compressor; and to obtain the second nominal model. Output cathode pressure difference ΔP mod The actual cathode pressure P output by the fuel cell air supply system sys The difference is the cathode pressure deviation feedback value. Using the cathode pressure deviation feedback value and the expected cathode pressure P... ref_i With the desired opening θ of the back pressure valve i The invention achieves closed-loop control of the back pressure valve by using the corresponding nominal model and controller, as well as the expected data, based on the actual output of the fuel cell air supply system. The control structure is simple, and the corresponding model and controller are switched according to different operating conditions, which greatly improves the accuracy and effect of the control.

[0029] (2) The fuel cell air supply device of the present invention has the advantages of simple structure, intuitive design, no need for precise object model, and easy adjustment, which can effectively meet the actual use needs;

[0030] (3) This invention achieves control of flow and pressure in the air supply system of a fuel cell with low coupling between cathode pressure and flow, while ensuring rapid dynamic response and taking into account the requirements of robustness and simple controller structure. Attached Figure Description

[0031] Figure 1 This is a structural diagram of a fuel cell air supply device;

[0032] Figure 2 This is a control system module diagram for a fuel cell air supply system. Detailed Implementation

[0033] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0034] Example 1

[0035] To improve the accuracy and stability of fuel cell air supply system control, this invention proposes a control method for fuel cell air supply systems, applicable to, for example... Figure 1 The diagram shows the flow internal model controller G. IMC_m A model describing the mapping relationship between air compressor speed and air flow rate; and a pressure internal model controller G. IMC_P A fuel cell air supply device used to describe the mapping relationship model from back pressure valve opening to cathode pressure and the signal processing module; the control method includes:

[0036] The first nominal model is obtained by using the M-sequence experimental identification method to identify the mapping relationship between air compressor speed and air flow under various operating conditions. The model describing the mapping relationship between the back pressure valve opening and the cathode pressure is the second nominal model.

[0037] First nominal model The formula for obtaining it is:

[0038] Second nominal model The formula for obtaining it is:

[0039] In the formula, s is the complex frequency; Δn, Δθ, Δm, and ΔP represent the design values ​​of the speed difference, back pressure valve opening difference, flow rate difference, and cathode pressure difference under the corresponding operating conditions when the experiment is conducted through the experimental identification method, respectively.

[0040] It needs to be explained that the design value of the speed difference Δn is specifically the difference between the air compressor speed designed based on the target and operating conditions identified by the parameters and the preset value obtained by experimental calibration under the corresponding operating conditions (at the linearized equilibrium point); the design value of the back pressure valve opening difference Δθ is specifically the difference between the back pressure valve opening designed based on the target and operating conditions identified by the parameters and the preset value obtained by experimental calibration under the corresponding operating conditions; the experimental value of the flow rate difference Δm is specifically the difference between the air compressor flow rate designed based on the target and operating conditions identified by the parameters and the preset value obtained by experimental calibration under the corresponding operating conditions; and the experimental value of the cathode pressure difference ΔP is specifically the difference between the cathode pressure designed based on the target and operating conditions identified by the parameters and the preset value obtained by experimental calibration under the corresponding operating conditions.

[0041] The flow internal model controller G IMC_m The corresponding formula expression is:

[0042]

[0043] The pressure internal mold controller G IMC_P The corresponding formula expression is:

[0044]

[0045] In the formula, T m and T P Both represent the filter time constant, f m (s) and f P (s) are all filters.

[0046] The signal processing module utilizes the required current value I of the fuel cell under various operating conditions. set Obtain the expected data corresponding to each operating condition; the expected data includes: expected airflow m ref_i Expected value of cathode pressure P ref_i Expected speed n of air compressor i and the desired opening θ of the back pressure valve i The first nominal model in the fuel cell air supply unit is switched based on the current operating conditions. Second nominal model Flow internal model controller G IMC_m and pressure internal mold controller G IMC_P Where (i = 1, ..., N), N represents the number of working conditions;

[0047] It should be noted that, in order to improve the accuracy of control, the nominal model corresponding to each operating condition is obtained through experimental identification methods. The purpose is to switch the nominal model and internal model controller in the fuel cell air supply device to the nominal model and internal model controller corresponding to the current operating condition under different operating conditions, so as to improve the control accuracy.

[0048] Obtain the first nominal model Output flow difference Δm mod The actual flow rate m output by the fuel cell air supply system sys The difference is the flow deviation feedback value. The flow deviation feedback value and the expected airflow value m are then obtained. ref_i The difference is input into the flow internal model controller G. IMC_m Through the flow internal model controller G IMC_m Calculate the air compressor speed correction value and input it into the first nominal model. Simultaneously obtain the desired air compressor speed n i The sum of the air compressor speed correction value and the speed control value is the speed control value. The air compressor in the fuel cell air supply system is controlled by the speed control value, thereby realizing the closed-loop control of the air compressor.

[0049] Obtain the second nominal model Output cathode pressure difference ΔP mod The actual cathode pressure P output by the fuel cell air supply system sys The difference is the cathode pressure deviation feedback value. The cathode pressure deviation feedback value and the expected cathode pressure P are then obtained. ref_i The difference is input into the pressure internal mold controller G. IMC_P Through the pressure internal mold controller G IMC_P Calculate the back pressure valve opening correction value and input it into the second nominal model. Simultaneously obtain the desired opening θ of the back pressure valve. i The sum of the back pressure valve opening correction value and the back pressure valve opening control value is the back pressure valve opening control value. The back pressure valve in the fuel cell air supply system is controlled by the back pressure valve opening, thereby realizing the closed-loop control of the back pressure valve.

[0050] This invention obtains nominal models describing the air compressor speed to air flow rate and the back pressure valve opening to cathode pressure under various operating conditions; and utilizes the required current value I of the fuel cell under each operating condition. set Obtain the expected data corresponding to each operating condition, and switch the various models and controllers in the fuel cell air supply device based on the current operating condition; obtain the first nominal model. Output flow difference Δm mod The actual flow rate m output by the fuel cell air supply system sys The difference is the flow deviation feedback value, which is used in conjunction with the expected airflow value m. ref_i and the expected speed n of the air compressor i To achieve closed-loop control of the air compressor; and to obtain the second nominal model. Output cathode pressure difference ΔP mod The actual cathode pressure P output by the fuel cell air supply system sys The difference is the cathode pressure deviation feedback value. Using the cathode pressure deviation feedback value and the expected cathode pressure P... ref_i With the desired opening θ of the back pressure valve i This invention achieves closed-loop control of the back pressure valve by utilizing the corresponding nominal model and controller, along with expected data, based on the actual output of the fuel cell air supply system. The control structure is simple, and the corresponding model and controller are switched according to different operating conditions, which greatly improves the accuracy and effectiveness of the control.

[0051] Example 2

[0052] like Figure 2 As shown, the present invention also proposes a control system for a fuel cell air supply system, which is applied to a flow internal model controller G. IMC_mA model describing the mapping relationship between air compressor speed and air flow rate; and a pressure internal model controller G. IMC_P A fuel cell air supply device used to describe the mapping relationship model from back pressure valve opening to cathode pressure and the signal processing module; the control system includes:

[0053] The experimental module is used to obtain, through experimental identification methods, the mapping relationship model describing the air compressor speed to air flow rate under various operating conditions, which is the first nominal model. The model describing the mapping relationship between the back pressure valve opening and the cathode pressure is the second nominal model.

[0054] First nominal model The formula for obtaining it is: Second nominal model The formula for obtaining it is: In the formula, s is the complex frequency; Δn, Δθ, Δm, and ΔP represent the design values ​​of the speed difference, back pressure valve opening difference, flow rate difference, and cathode pressure difference under the corresponding operating conditions when the experiment is conducted using the experimental identification method, respectively. The flow rate internal model controller G... IMC_m The corresponding formula expression is:

[0055]

[0056] The pressure internal mold controller G IMC_P The corresponding formula expression is:

[0057]

[0058] In the formula, T m and T P Both represent the filter time constant, f m (s) and f P (s) are all filters.

[0059] The expected data acquisition module is used to utilize the required current value I of the fuel cell under various operating conditions through the signal processing module. set Obtain the expected data corresponding to each operating condition; the expected data includes: expected airflow m ref_i Expected value of cathode pressure P ref_i Expected speed n of air compressor i and the desired opening θ of the back pressure valve i The first nominal model in the fuel cell air supply unit is switched based on the current operating conditions. Second nominal model Flow internal model controller G IMC_m and pressure internal mold controller G IMC_PWhere (i = 1, ..., N), N represents the number of working conditions;

[0060] The air compressor closed-loop control module is used to obtain the first nominal model. Output flow difference Δm mod The actual flow rate m output by the fuel cell air supply system sys The difference is the flow deviation feedback value. The flow deviation feedback value and the expected airflow value m are then obtained. ref_i The difference is input into the flow internal model controller G. IMC_m Through the flow internal model controller G IMC_m Calculate the air compressor speed correction value and input it into the first nominal model. Simultaneously obtain the desired air compressor speed n i The sum of the air compressor speed correction value and the speed control value is the speed control value. The air compressor in the fuel cell air supply system is controlled by the speed control value, thereby realizing the closed-loop control of the air compressor.

[0061] The back pressure valve closing control module is used to obtain the second nominal model. Output cathode pressure difference ΔP mod The actual cathode pressure P output by the fuel cell air supply system sys The difference is the cathode pressure deviation feedback value. The cathode pressure deviation feedback value and the expected cathode pressure P are then obtained. ref_i The difference is input into the pressure internal mold controller G. IMC_P Through the pressure internal mold controller G IMC_P Calculate the back pressure valve opening correction value and input it into the second nominal model. Simultaneously obtain the desired opening θ of the back pressure valve. i The sum of the back pressure valve opening correction value and the back pressure valve opening control value is the back pressure valve opening control value. The back pressure valve in the fuel cell air supply system is controlled by the back pressure valve opening, thereby realizing the closed-loop control of the back pressure valve.

[0062] This invention enables the control of flow and pressure in a fuel cell air supply system with low coupling between cathode pressure and flow rate, while ensuring rapid dynamic response and balancing robustness with a simple controller structure.

[0063] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0064] Furthermore, in this invention, descriptions involving terms such as "first," "second," and "a" are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0065] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0066] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

Claims

1. A control method for an air supply system for a fuel cell, characterized in that, Its applications include flow internal model controllers G IMC_m A model describing the mapping relationship between air compressor speed and air flow rate; and a pressure internal model controller G. IMC_P A fuel cell air supply device used to describe the mapping relationship model from back pressure valve opening to cathode pressure and the signal processing module; the control method includes: The mapping relationship model describing the air compressor speed to air flow rate under various operating conditions was obtained through experimental identification methods and designated as the first nominal model. The model describing the mapping relationship between the back pressure valve opening and the cathode pressure is the second nominal model. The signal processing module utilizes the required current value I of the fuel cell under various operating conditions. set Obtain the expected data corresponding to each operating condition; the expected data includes: expected airflow m ref_i Expected value of cathode pressure P ref_i Expected speed n of air compressor i and the desired opening θ of the back pressure valve i The first nominal model in the fuel cell air supply unit is switched based on the current operating conditions. Second nominal model Flow internal model controller G IMC_m and pressure internal mold controller G IMC_P Where (i = 1, ..., N), N represents the number of working conditions; Obtain the first nominal model Output flow difference Δm mod The actual flow rate m output by the fuel cell air supply system sys The difference is the flow deviation feedback value. The flow deviation feedback value and the expected airflow value m are then obtained. ref_i The difference is input into the flow internal model controller G. IMC_m Through the flow internal model controller G IMC_m Calculate the air compressor speed correction value and input it into the first nominal model. Simultaneously obtain the desired air compressor speed n i The sum of the air compressor speed correction value and the speed control value is the speed control value. The air compressor in the fuel cell air supply system is controlled by the speed control value, thereby realizing the closed-loop control of the air compressor. Obtain the second nominal model Output cathode pressure difference ΔP mod The actual cathode pressure P output by the fuel cell air supply system sys The difference is the cathode pressure deviation feedback value. The cathode pressure deviation feedback value and the expected cathode pressure P are then obtained. ref_i The difference is input into the pressure internal mold controller G. IMC_P Through the pressure internal mold controller G IMC_P Calculate the back pressure valve opening correction value and input it into the second nominal model. Simultaneously obtain the desired opening θ of the back pressure valve. i The sum of the back pressure valve opening correction value and the back pressure valve opening control value is the back pressure valve opening control value. The back pressure valve in the fuel cell air supply system is controlled by the back pressure valve opening, thereby realizing the closed-loop control of the back pressure valve.

2. The control method for a fuel cell air supply system according to claim 1, characterized in that, First nominal model The formula for obtaining it is: Second nominal model The formula for obtaining it is: In the formula, s is the complex frequency; Δn, Δθ, Δm, and ΔP represent the design values ​​of the speed difference, back pressure valve opening difference, flow rate difference, and cathode pressure difference under the corresponding operating conditions when the experiment is conducted through the experimental identification method, respectively.

3. The control method for a fuel cell air supply system according to claim 2, characterized in that, The flow internal model controller G IMC_m The corresponding formula expression is: The pressure internal mold controller G IMC_P The corresponding formula expression is: In the formula, T m and T P Both represent the filter time constant, f m (s) and f P (s) are all filters.

4. A control system for a fuel cell air supply system, characterized in that, Its applications include flow internal model controllers G IMC_m A model describing the mapping relationship between air compressor speed and air flow rate; and a pressure internal model controller G. IMC_P A fuel cell air supply device used to describe the mapping relationship model from back pressure valve opening to cathode pressure and the signal processing module; the control system includes: The experimental module is used to obtain, through experimental identification methods, the mapping relationship model describing the air compressor speed to air flow rate under various operating conditions, which is the first nominal model. The model describing the mapping relationship between the back pressure valve opening and the cathode pressure is the second nominal model. The expected data acquisition module is used to utilize the required current value I of the fuel cell under various operating conditions through the signal processing module. set Obtain the expected data corresponding to each operating condition; the expected data includes: expected airflow m ref_i Expected value of cathode pressure P ref_i Expected speed n of air compressor i and the desired opening θ of the back pressure valve i The first nominal model in the fuel cell air supply unit is switched based on the current operating conditions. Second nominal model Flow internal model controller G IMC_m and pressure internal mold controller G IMC_P Where (i = 1, ..., N), N represents the number of working conditions; The air compressor closed-loop control module is used to obtain the first nominal model. Output flow difference Δm mod The actual flow rate m output by the fuel cell air supply system sys The difference is the flow deviation feedback value. The flow deviation feedback value and the expected airflow value m are then obtained. ref_i The difference is input into the flow internal model controller G. IMC_m Through the flow internal model controller G IMC_m Calculate the air compressor speed correction value and input it into the first nominal model. Simultaneously obtain the desired air compressor speed n i The sum of the air compressor speed correction value and the speed control value is the speed control value. The air compressor in the fuel cell air supply system is controlled by the speed control value, thereby realizing the closed-loop control of the air compressor. The back pressure valve closing control module is used to obtain the second nominal model. Output cathode pressure difference ΔP mod The actual cathode pressure P output by the fuel cell air supply system sys The difference is the cathode pressure deviation feedback value. The cathode pressure deviation feedback value and the expected cathode pressure P are then obtained. ref_i The difference is input into the pressure internal mold controller G. IMC_P Through the pressure internal mold controller G IMC_P Calculate the back pressure valve opening correction value and input it into the second nominal model. Simultaneously obtain the desired opening θ of the back pressure valve. i The sum of the back pressure valve opening correction value and the back pressure valve opening control value is the back pressure valve opening control value. The back pressure valve in the fuel cell air supply system is controlled by the back pressure valve opening, thereby realizing the closed-loop control of the back pressure valve.

5. A control system for a fuel cell air supply system according to claim 4, characterized in that, First nominal model The formula for obtaining it is: Second nominal model The formula for obtaining it is: In the formula, s is the complex frequency; Δn, Δθ, Δm, and ΔP represent the design values ​​of the speed difference, back pressure valve opening difference, flow rate difference, and cathode pressure difference under the corresponding operating conditions when the experiment is conducted through the experimental identification method, respectively.

6. A control system for a fuel cell air supply system according to claim 5, characterized in that, The flow internal model controller G IMC_m The corresponding formula expression is: The pressure internal mold controller G IMC_P The corresponding formula expression is: In the formula, T m and T P Both represent the filter time constant, f m (s) and f P (s) are all filters.

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