Method and device for controlling fuel cell air system

Abstract

The present invention relates to the technical field of fuel cells. Disclosed are a method and a device for controlling a fuel cell air system. The method of the present invention comprises: on the basis of the overall power required by a vehicle, determining a target stack power of a fuel cell; on the basis of the target stack power, determining a target inlet air humidity; on the basis of the target stack power and a stack high-frequency impedance, determining an actual stack internal humidity; on the basis of the target inlet air humidity and the actual stack internal humidity, determining a humidity adjustment valve control opening degree; and on the basis of the humidity adjustment valve control opening degree, controlling an opening degree of a humidity adjustment valve of an air system, such that the actual stack internal humidity reaches the target inlet air humidity. Since the target inlet air humidity is the optimal stack internal humidity for maximizing the load capacity of the fuel cell under the target stack power, an appropriate internal humidity within the fuel cell can be achieved, thereby improving the load capacity of the fuel cell.

Description

Fuel cell air system control method and device Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a method and device for controlling a fuel cell air system. Background Art

[0002] The humidity of a fuel cell's proton exchange membrane directly affects its performance. When the membrane is moderately humid, the fuel cell's internal resistance is low and its load capacity is high. When the membrane is too dry, the internal resistance increases and its load capacity decreases. Excessive moisture in the membrane can lead to cathode flooding, degrading fuel cell system performance and shortening its lifespan. Currently, fuel cell system humidity control is open-loop, resulting in poor control accuracy and an inability to maintain a moderate internal humidity within the fuel cell.

[0003] Summary of the Invention

[0004] The present invention solves the technical problem of how to maintain moderate humidity inside a fuel cell by providing a fuel cell air system control method and device.

[0005] On the one hand, the present invention provides the following technical solutions:

[0006] A fuel cell air system control method, comprising:

[0007] Obtaining the required power of the entire vehicle, and determining the target stack power of the fuel cell according to the required power of the entire vehicle;

[0008] Determining the target air intake humidity corresponding to the target stack power according to a preset correspondence relationship between stack power and air intake humidity;

[0009] Obtain the high-frequency impedance of the fuel cell stack;

[0010] Determining the actual humidity inside the stack corresponding to the high-frequency impedance of the stack according to the preset correspondence relationship between the stack impedance and the humidity inside the stack at the target stack power;

[0011] Determining a humidity control valve opening according to the target air intake humidity and the actual humidity inside the fuel cell stack;

[0012] The opening of the air system humidity control valve is controlled according to the humidity control valve opening control, so that the actual humidity inside the fuel cell stack reaches the target air intake humidity.

[0013] Preferably, obtaining the high-frequency impedance of the fuel cell stack includes:

[0014] Applying AC excitation of different frequencies to the DC step-up transformer of the fuel cell;

[0015] Obtaining the stack output voltage and stack output current under each of the AC excitations;

[0016] extracting a voltage component from each of the battery stack output voltages and a current component from each of the battery stack output currents;

[0017] Calculating the ratio of the voltage component to the current component corresponding to each AC excitation to obtain the impedance corresponding to the AC excitation;

[0018] The impedance analysis method is used to analyze the multiple impedances corresponding to the multiple AC excitations to obtain the high-frequency impedance of the battery stack.

[0019] Preferably, determining the humidity control valve opening according to the target air intake humidity and the actual humidity inside the fuel cell stack includes:

[0020] The deviation between the target air intake humidity and the actual humidity inside the fuel cell stack is input into a humidity PID controller, and the humidity control valve opening is output.

[0021] Preferably, after obtaining the vehicle power demand and determining the target stack power of the fuel cell according to the vehicle power demand, and before controlling the opening of the air system humidity control valve according to the humidity control valve opening control, the method further includes:

[0022] Determining the target humidity control valve opening corresponding to the target stack power according to a preset correspondence relationship between the stack power and the humidity control valve opening;

[0023] Input the target humidity control valve opening into the humidity feedforward controller, and output the humidity control valve feedforward opening;

[0024] The method of controlling the opening of the humidity control valve of the air system according to the humidity control valve opening control further includes:

[0025] If the sum of the humidity control valve control opening and the humidity control valve feedforward opening is lower than a first opening threshold, the humidity control valve opening is controlled to be the sum of the humidity control valve control opening and the humidity control valve feedforward opening;

[0026] If the sum of the humidity control valve control opening and the humidity control valve feedforward opening is higher than a first opening threshold, the humidity control valve opening is controlled to be the first opening threshold.

[0027] Preferably, after obtaining the required power of the entire vehicle and determining the target stack power of the fuel cell according to the required power of the entire vehicle, the method further includes:

[0028] Determining a target stack air flow rate corresponding to the target stack power according to a preset correspondence relationship between stack power and stack air flow rate;

[0029] Obtain the actual air flow rate entering the air system;

[0030] The deviation between the target air flow rate and the actual air flow rate is input into a flow PID controller, and the air compressor speed is output;

[0031] The speed of the air compressor of the air system is controlled according to the air compressor control speed, so that the actual stack air flow rate reaches the target stack air flow rate.

[0032] Preferably, the controlling the speed of the air compressor of the air system according to the air compressor speed control comprises:

[0033] Controlling the rotation speed of the air compressor is the air compressor control rotation speed.

[0034] Preferably, after determining the target stack air flow corresponding to the target stack power according to the preset correspondence between the stack power and the stack air flow, and before controlling the speed of the air compressor of the air system according to the air compressor speed control, the method further includes:

[0035] Determining a target air compressor speed corresponding to the target stack air flow rate based on a preset correspondence between the stack air flow rate and the air compressor speed rate;

[0036] The target air compressor speed is input into a flow feedforward controller, and the air compressor feedforward speed is output;

[0037] The controlling of the speed of the air compressor of the air system according to the air compressor speed control comprises:

[0038] If the sum of the air compressor control speed and the air compressor feedforward speed is lower than the speed threshold, the speed of the air compressor is controlled to be the sum of the air compressor control speed and the air compressor feedforward speed;

[0039] If the sum of the air compressor control speed and the air compressor feedforward speed is higher than a speed threshold, the speed of the air compressor is controlled to be the speed threshold.

[0040] Preferably, after obtaining the required power of the entire vehicle and determining the target stack power of the fuel cell according to the required power of the entire vehicle, the method further includes:

[0041] Determining the target stack air pressure corresponding to the target stack power according to a preset correspondence relationship between stack power and stack air pressure;

[0042] Obtain the actual air pressure entering the air system;

[0043] The deviation between the target air pressure and the actual air pressure is input into a pressure PID controller, and the back pressure valve opening is output;

[0044] The opening of the air system back-pressure valve is controlled according to the back-pressure valve opening control degree, so that the actual stack-inlet air pressure reaches the target stack-inlet air pressure.

[0045] Preferably, controlling the opening of the back-pressure valve of the air system according to the back-pressure valve opening control includes:

[0046] Controlling the opening of the back-pressure valve is referred to as the back-pressure valve controlled opening.

[0047] Preferably, after determining the target stack air pressure corresponding to the target stack power according to the preset correspondence between the stack power and the stack air pressure, and before controlling the opening of the air system backpressure valve according to the backpressure valve control opening, the method further includes:

[0048] Determining a target back-pressure valve opening corresponding to the target stack-inlet air pressure according to a preset correspondence relationship between the stack-inlet air pressure and the back-pressure valve opening;

[0049] Input the target back-pressure valve opening into a pressure feedforward controller, and output the back-pressure valve feedforward opening;

[0050] Controlling the opening of the back-pressure valve of the air system according to the back-pressure valve control opening includes:

[0051] If the sum of the back-pressure valve control opening and the back-pressure valve feedforward opening is lower than a second opening threshold, controlling the opening of the back-pressure valve to be the sum of the back-pressure valve control opening and the back-pressure valve feedforward opening;

[0052] If the sum of the back-pressure valve control opening and the back-pressure valve feedforward opening is higher than a second opening threshold, the back-pressure valve opening is controlled to be the second opening threshold.

[0053] Preferably, after obtaining the actual air pressure of the air system entering the stack, the method further includes:

[0054] If the actual air pressure entering the stack is higher than the safety threshold, the relief valve of the air system is opened.

[0055] Preferably, after obtaining the actual air pressure of the air system entering the stack, the method further includes:

[0056] If the actual air pressure entering the stack is higher than the pressure value corresponding to the actual air flow entering the stack, the relief valve of the air system is opened;

[0057] If the actual air pressure entering the stack is lower than the pressure value corresponding to the actual air flow entering the stack, the relief valve is closed.

[0058] On the other hand, the present invention also provides the following technical solutions:

[0059] A fuel cell air system control device, comprising:

[0060] The first determination module is configured to obtain the required power of the entire vehicle and determine the target stack power of the fuel cell according to the required power of the entire vehicle;

[0061] a second determining module, configured to determine a target air intake humidity corresponding to the target stack power according to a preset correspondence relationship between stack power and air intake humidity;

[0062] An acquisition module, used to obtain the high-frequency impedance of the fuel cell stack;

[0063] a third determining module, configured to determine the actual humidity inside the stack corresponding to the high-frequency impedance of the stack according to a preset correspondence between the stack impedance and the humidity inside the stack at the target stack power;

[0064] a fourth determining module, configured to determine a control opening of the humidity control valve according to the target air intake humidity and the actual humidity inside the fuel cell stack;

[0065] The humidity control valve control module is used to control the opening of the air system humidity control valve according to the humidity control valve opening control degree, so that the actual humidity inside the fuel cell stack reaches the target air intake humidity.

[0066] On the other hand, the present invention also provides the following technical solutions:

[0067] An electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, any of the above-mentioned fuel cell air system control methods is implemented.

[0068] On the other hand, the present invention also provides the following technical solutions:

[0069] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements any of the above-mentioned fuel cell air system control methods.

[0070] One or more technical solutions provided by the present invention have at least the following technical effects or advantages:

[0071] The present invention determines a target stack power for the fuel cell based on the required power of the entire vehicle, determines a target air intake humidity based on the target stack power, determines the actual humidity inside the stack based on the target stack power and the high-frequency impedance of the stack, determines a humidity control valve opening based on the target air intake humidity and the actual humidity inside the stack, and controls the opening of the air system humidity control valve based on the humidity control valve opening to ensure that the actual humidity inside the stack reaches the target air intake humidity. Since the target air intake humidity is the internal humidity of the stack that optimizes the fuel cell load capacity at the target stack power, the internal humidity of the fuel cell can be moderated, thereby improving the load capacity of the fuel cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. 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 any creative work.

[0073] FIG1 is a schematic diagram of a partial structure of a fuel cell according to an embodiment of the present invention;

[0074] FIG2 is a flow chart of a fuel cell air system control method according to an embodiment of the present invention;

[0075] FIG3 is a schematic diagram of a fuel cell air system control device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0076] The embodiments of the present invention solve the technical problem of how to maintain a moderate humidity inside a fuel cell by providing a fuel cell air system control method and device.

[0077] In order to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0078] As shown in Figure 1, the fuel cell of this embodiment includes a fuel cell stack, an air system and a DC step-up transformer. The air system includes an air compressor, a humidity control valve, a back pressure valve and a discharge valve. The air outlet of the air compressor is respectively connected to the discharge valve and the air inlet of the fuel cell stack through the humidity control valve. The air outlet of the fuel cell stack is connected to the back pressure valve, and the DC step-up transformer connects the fuel cell stack and the high-voltage system of the whole vehicle. Among them, the air compressor is configured to control the flow rate of air entering the stack, the humidity control valve is configured to adjust the humidity of the air entering the stack, the back pressure valve and the discharge valve jointly control the pressure of the air entering the stack, and the DC step-up transformer is configured to boost the output voltage of the fuel cell stack to the bus voltage of the whole vehicle to provide power for the whole vehicle. Under normal circumstances, the discharge valve is in a closed state.

[0079] As shown in FIG2 , the fuel cell air system control method of this embodiment includes:

[0080] Step S1, obtaining the required power of the entire vehicle, and determining the target stack power of the fuel cell according to the required power of the entire vehicle;

[0081] Step S2, determining a target air intake humidity corresponding to the target stack power according to a preset correspondence relationship between stack power and air intake humidity;

[0082] Step S3, obtaining the high-frequency impedance of the fuel cell stack;

[0083] Step S4, determining the actual humidity inside the stack corresponding to the high-frequency impedance of the stack based on the correspondence between the stack impedance and the humidity inside the stack at a preset target stack power;

[0084] Step S5, determining the humidity control valve opening according to the target air intake humidity and the actual humidity inside the fuel cell stack;

[0085] Step S6: Control the opening of the humidity control valve of the air system according to the humidity control valve opening control, so that the actual humidity inside the fuel cell stack reaches the target air intake humidity.

[0086] In step S1, the required power of the entire vehicle determines the stack power. The relationship between the required power of the entire vehicle and the target stack power is: target stack power = required power of the entire vehicle / stack energy conversion efficiency.

[0087] In step S2, the correspondence between the stack power and the air intake humidity can be a table, which records the air intake humidity corresponding to each stack power, indicating the most appropriate air intake humidity under the stack power.

[0088] Before step S4, this embodiment controls the stack power to be at different values. At each stack power, a large amount of stack impedance data of the fuel cell and the internal humidity data of the stack when each stack impedance is detected are obtained. Based on the large amount of stack impedance-internal humidity data at each stack power, a corresponding relationship between the stack impedance and the internal humidity of the stack at that stack power is established. In this way, a corresponding relationship between the stack impedance and the internal humidity of the stack at each stack power can be obtained. In this way, after step S1 determines the target stack power and step S3 obtains the high-frequency impedance of the fuel cell stack, the actual internal humidity of the stack corresponding to the high-frequency impedance of the stack can be determined based on the corresponding relationship between the stack impedance and the internal humidity of the stack at the target stack power.

[0089] Step S6 controls the opening of the air system humidity control valve according to the humidity control valve opening control so that the actual humidity inside the fuel cell stack reaches the target air intake humidity. Since the target air intake humidity is the internal humidity of the fuel cell stack that optimizes the fuel cell load capacity under the target fuel cell stack power, this can make the internal humidity of the fuel cell moderate and improve the load capacity of the fuel cell.

[0090] In this embodiment, step S3 may include: applying AC excitation of different frequencies to the DC boost transformer of the fuel cell; obtaining the stack output voltage and stack output current under each AC excitation; extracting the voltage component in each stack output voltage and the current component in each stack output current; calculating the ratio of the voltage component to the current component corresponding to each AC excitation to obtain the impedance corresponding to the AC excitation; and using the impedance analysis method to analyze multiple impedances corresponding to multiple AC excitations to obtain the high-frequency impedance of the stack.

[0091] The DC boost transformer includes an internal resistance detection module, an output current sensor, an output voltage sensor, and a boost DC-DC module. The internal resistance detection module provides AC excitation disturbances for fuel cell internal resistance detection. This AC excitation acts on the boost circuit of the boost DC-DC module, changing the input current of the boost DC-DC module. The output current sensor detects the stack output current, and the output voltage sensor detects the stack output voltage. An AC signal extraction algorithm can be used to extract the voltage component of the stack output voltage and the current component of the stack output current at each frequency. The impedance at the excitation frequency is calculated as follows: the voltage component corresponding to the excitation frequency / the current component corresponding to the excitation frequency. By continuously changing the frequency of the AC excitation, the impedance at different excitation frequencies can be determined. Using impedance analysis, the multiple impedances corresponding to multiple AC excitations can be analyzed to determine the high-frequency impedance of the stack.

[0092] In this embodiment, step S5 may include inputting the deviation between the target air intake humidity and the actual humidity inside the fuel cell stack into a humidity PID controller, which then outputs the humidity control valve opening control value. PID control is a mature technology. Because the humidity control valve opening control value is determined through PID control, PID control is a closed-loop control method with high control accuracy, making the humidity control valve opening control value more precise.

[0093] It is understood that if the opening of the air system humidity control valve is controlled to the humidity control valve controlled opening, the actual humidity inside the fuel cell stack will gradually approach the target air intake humidity and stabilize near the target air intake humidity. Therefore, to ensure that the actual humidity inside the fuel cell stack reaches the target air intake humidity, controlling the opening of the air system humidity control valve according to the humidity control valve controlled opening in step S6 may include: controlling the opening of the humidity control valve to the humidity control valve controlled opening.

[0094] Here, there is also provided a method for controlling the opening of the air system humidity control valve according to the humidity control valve control opening. After step S1 and before step S6, the fuel cell air system control method of this embodiment includes: determining the target humidity control valve opening corresponding to the target stack power according to the preset correspondence relationship between the stack power-air intake humidity-humidity control valve opening; inputting the target humidity control valve opening into the humidity feedforward controller, and outputting the humidity control valve feedforward opening. In step S6, the opening of the air system humidity control valve is controlled according to the humidity control valve control opening, and further includes: if the sum of the humidity control valve control opening and the humidity control valve feedforward opening is lower than the first opening threshold, then controlling the humidity control valve opening to be the sum of the humidity control valve control opening and the humidity control valve feedforward opening; if the sum of the humidity control valve control opening and the humidity control valve feedforward opening is higher than the first opening threshold, then controlling the humidity control valve opening to be the first opening threshold.

[0095] The humidity control valve control opening is obtained through PID control, and the humidity control valve feedforward opening is obtained through feedforward control. PID control is closed-loop control, and feedforward control is open-loop control. The humidity control valve opening is controlled to be the sum of the humidity control valve control opening and the humidity control valve feedforward opening. Closed-loop control and open-loop control can collaborate to improve the control accuracy of the actual humidity inside the fuel cell stack, making the humidity inside the fuel cell more moderate. If the sum of the humidity control valve control opening and the humidity control valve feedforward opening is higher than the first opening threshold, indicating that the sum of the humidity control valve control opening and the humidity control valve feedforward opening exceeds the maximum opening allowed or achievable by the humidity control valve, the humidity control valve opening is controlled to be the maximum opening allowed or achievable by the humidity control valve.

[0096] This embodiment requires not only controlling the internal humidity of the fuel cell to a moderate level, but also controlling the actual inlet air flow of the air system to a moderate level to improve the fuel cell's load capacity. Therefore, after step S1, the fuel cell air system control method of this embodiment further includes: determining a target inlet air flow corresponding to a target stack power based on a preset relationship between stack power and inlet air flow; obtaining the actual inlet air flow of the air system; inputting the deviation between the target inlet air flow and the actual inlet air flow into a flow PID controller, outputting an air compressor control speed; and controlling the speed of the air system compressor based on the air compressor control speed to ensure that the actual inlet air flow reaches the target inlet air flow.

[0097] Similarly, the correspondence between stack power and air flow rate can be a table, which records the air flow rate corresponding to each stack power, indicating the most appropriate air flow rate for the stack power. PID control is a mature technology. It is understandable that if the speed of the air system compressor is controlled to be the compressor control speed, the actual air flow rate of the air system will gradually approach the target air flow rate and stabilize near the target air flow rate. The speed of the air system compressor is controlled according to the compressor control speed. Since the compressor control speed is obtained through PID control, PID control is a closed-loop control with high control accuracy. It can make the actual air flow rate closer to the target air flow rate, and the actual air flow rate of the air system can be moderate.

[0098] As mentioned above, if the air system compressor speed is controlled to the compressor control speed, the actual inlet air flow of the air system will gradually approach the target inlet air flow and stabilize near the target inlet air flow. Therefore, controlling the speed of the air system compressor based on the compressor control speed may include: controlling the air compressor speed to the compressor control speed.

[0099] Here, there is also provided a method for controlling the speed of the air compressor of the air system according to the air compressor control speed. After determining the target stack air flow corresponding to the target stack power according to the preset correspondence between the stack power and the stack air flow, and before controlling the speed of the air compressor of the air system according to the air compressor control speed, the fuel cell air system control method of this embodiment may also include: determining the target air compressor speed corresponding to the target stack air flow according to the preset correspondence between the stack air flow and the air compressor speed; inputting the target air compressor speed into the flow feedforward controller, and outputting the air compressor feedforward speed. Controlling the speed of the air compressor of the air system according to the air compressor control speed may include: if the sum of the air compressor control speed and the air compressor feedforward speed is lower than the speed threshold, then controlling the speed of the air compressor to be the sum of the air compressor control speed and the air compressor feedforward speed; if the sum of the air compressor control speed and the air compressor feedforward speed is higher than the speed threshold, then controlling the speed of the air compressor to be the speed threshold.

[0100] The compressor control speed is achieved through PID control, and the compressor feedforward speed is achieved through feedforward control. PID control is a closed-loop control, while feedforward control is an open-loop control. The controlled compressor speed is the sum of the compressor control speed and the compressor feedforward speed. Closed-loop and open-loop control work together to improve the control accuracy of the actual air flow entering the stack, making the actual air flow entering the stack more moderate. If the sum of the compressor control speed and the compressor feedforward speed exceeds the speed threshold, indicating that the sum exceeds the maximum speed allowed or achievable by the compressor, the controlled compressor speed is then set to the maximum speed allowed or achievable by the compressor.

[0101] This embodiment requires not only controlling the internal humidity of the fuel cell to a moderate level, but also controlling the actual inlet air pressure of the air system to a moderate level to improve the fuel cell's load capacity. Therefore, after step S1, the fuel cell air system control method of this embodiment further includes: determining a target inlet air pressure corresponding to a target stack power based on a preset relationship between stack power and inlet air pressure; obtaining the actual inlet air pressure of the air system; inputting the deviation between the target inlet air pressure and the actual inlet air pressure into a pressure PID controller, which outputs a backpressure valve control opening; and controlling the opening of the air system backpressure valve based on the backpressure valve control opening to ensure that the actual inlet air pressure reaches the target inlet air pressure.

[0102] Similarly, the correspondence between the stack power and the air pressure entering the stack can be a table, which records the air pressure entering the stack corresponding to each stack power, indicating the most appropriate air pressure entering the stack under the stack power. PID control is a mature technology. It is understandable that if the opening of the back-pressure valve of the air system is controlled to be the back-pressure valve control opening, the actual air pressure entering the stack of the air system will gradually approach the target air pressure entering the stack and stabilize near the target air pressure entering the stack. The opening of the back-pressure valve of the air system is controlled according to the back-pressure valve control opening. Since the back-pressure valve control opening is obtained through PID control, PID control is a closed-loop control with high control accuracy. It can make the actual air pressure entering the stack closer to the target air pressure entering the stack, and can make the actual air pressure entering the stack of the air system moderate.

[0103] As mentioned above, if the opening of the air system backpressure valve is controlled to the backpressure valve control opening, the actual inlet air pressure of the air system will gradually approach the target inlet air pressure and stabilize near the target inlet air pressure. Therefore, controlling the opening of the air system backpressure valve based on the backpressure valve control opening can include: controlling the opening of the backpressure valve to the backpressure valve control opening.

[0104] A method for controlling the opening of the air system backpressure valve according to the backpressure valve control opening is also provided. After determining the target stack air pressure corresponding to the target stack power according to the preset correspondence between the stack power and the stack air pressure, and before controlling the opening of the air system backpressure valve according to the backpressure valve control opening, the fuel cell air system control method of this embodiment may also include: determining the target backpressure valve opening corresponding to the target stack air pressure according to the preset correspondence between the stack air pressure and the backpressure valve opening; inputting the target backpressure valve opening into the pressure feedforward controller, and outputting the backpressure valve feedforward opening. Controlling the opening of the air system backpressure valve according to the backpressure valve control opening includes: if the sum of the backpressure valve control opening and the backpressure valve feedforward opening is lower than a second opening threshold, controlling the backpressure valve opening to be the sum of the backpressure valve control opening and the backpressure valve feedforward opening; if the sum of the backpressure valve control opening and the backpressure valve feedforward opening is higher than the second opening threshold, controlling the backpressure valve opening to be the second opening threshold.

[0105] The backpressure valve control opening is obtained through PID control, and the backpressure valve feedforward opening is obtained through feedforward control. PID control is a closed-loop control, while feedforward control is an open-loop control. The controlled backpressure valve opening is the sum of the backpressure valve control opening and the backpressure valve feedforward opening. Closed-loop and open-loop control can be used to collaboratively improve the control accuracy of the actual air pressure entering the stack, making the actual air pressure entering the stack more moderate. If the sum of the backpressure valve control opening and the backpressure valve feedforward opening exceeds the second opening threshold, indicating that the sum of the backpressure valve control opening and the backpressure valve feedforward opening exceeds the maximum opening allowed or achievable by the backpressure valve, the backpressure valve opening is controlled to the maximum opening allowed or achievable by the backpressure valve.

[0106] Taking into account the safety risk posed by excessive actual air pressure entering the stack of the air system, in this embodiment, after obtaining the actual air pressure entering the stack of the air system, the fuel cell air system control method may further include: if the actual air pressure entering the stack is higher than the safety threshold, opening the air system's bleed valve; if the actual air pressure entering the stack is higher than the pressure value corresponding to the actual air flow entering the stack, opening the air system's bleed valve; if the actual air pressure entering the stack is lower than the pressure value corresponding to the actual air flow entering the stack, closing the bleed valve.

[0107] As shown in FIG3 , a fuel cell air system control device according to this embodiment includes:

[0108] The first determination module is used to obtain the required power of the entire vehicle and determine the target stack power of the fuel cell according to the required power of the entire vehicle;

[0109] A second determination module is used to determine the target air intake humidity corresponding to the target stack power according to a preset correspondence relationship between the stack power and the air intake humidity;

[0110] An acquisition module, used to obtain the high-frequency impedance of the fuel cell stack;

[0111] A third determination module is used to determine the actual humidity inside the stack corresponding to the high-frequency impedance of the stack according to the corresponding relationship between the stack impedance and the humidity inside the stack at a preset target stack power;

[0112] A fourth determination module is used to determine the humidity control valve opening according to the target air intake humidity and the actual humidity inside the fuel cell stack;

[0113] The humidity control valve control module is used to control the opening of the air system humidity control valve according to the humidity control valve control opening, so that the actual humidity inside the fuel cell stack reaches the target air intake humidity.

[0114] Based on the same inventive concept as the fuel cell air system control method described above, this embodiment also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of any one of the fuel cell air system control methods described above are implemented.

[0115] Among them, the bus architecture (represented by the bus), the bus can include any number of interconnected buses and bridges, and the bus links together various circuits including one or more processors represented by the processor and memory represented by the memory. The bus can also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are all well known in the art and therefore will not be described further herein. The bus interface provides an interface between the bus and the receiver and transmitter. The receiver and transmitter can be the same component, namely a transceiver, which provides a unit for communicating with various other devices on a transmission medium. The processor is responsible for managing the bus and general processing, while the memory can be used to store data used by the processor when performing operations.

[0116] Since the electronic device described in this embodiment is used to implement the fuel cell air system control method according to the embodiment of the present invention, those skilled in the art will be able to understand the specific implementation and various variations of the electronic device according to the embodiment of the present invention based on the fuel cell air system control method described in the embodiment of the present invention. Therefore, how the electronic device implements the method according to the embodiment of the present invention will not be described in detail here. As long as those skilled in the art can implement the electronic device used in the fuel cell air system control method according to the embodiment of the present invention, it falls within the scope of protection of the present invention.

[0117] Based on the same inventive concept as the above-mentioned fuel cell air system control method, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements any of the above-mentioned fuel cell air system control methods.

[0118] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0119] The present invention is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the function specified in one or more processes in the flowchart and / or one or more boxes in the block diagram. These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device, which implements the function specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0120] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0121] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0122] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A fuel cell air system control method, characterized in that: include: Obtaining the required power of the whole vehicle, and determining the target stack power of the fuel cell according to the required power of the whole vehicle; Determining the target air intake humidity corresponding to the target battery stack power according to a preset correspondence relationship between battery stack power and air intake humidity; Obtain the high-frequency impedance of the fuel cell stack; Determining the actual humidity inside the battery stack corresponding to the high-frequency impedance of the battery stack according to the corresponding relationship between the impedance of the battery stack and the humidity inside the battery stack at the preset target battery stack power; Determining a humidity control valve opening according to the target air intake humidity and the actual humidity inside the fuel cell stack; The opening of the air system humidity control valve is controlled according to the humidity control valve opening control, so that the actual humidity inside the fuel cell stack reaches the target air intake humidity.

2. The fuel cell air system control method according to claim 1, characterized in that: The obtaining of the high frequency impedance of the fuel cell stack includes: Applying AC excitation of different frequencies to the DC step-up transformer of the fuel cell; Obtaining the stack output voltage and stack output current under each of the AC excitations; Extracting a voltage component from each of the battery stack output voltages and a current component from each of the battery stack output currents; Calculating the ratio of the voltage component to the current component corresponding to each of the AC excitations to obtain the impedance corresponding to the AC excitation; The impedance analysis method is used to analyze the multiple impedances corresponding to the multiple AC excitations to obtain the high-frequency impedance of the battery stack.

3. The fuel cell air system control method according to claim 1, characterized in that: The step of determining the humidity control valve opening according to the target air intake humidity and the actual humidity inside the fuel cell stack includes: The deviation between the target air intake humidity and the actual humidity inside the fuel cell stack is input into a humidity PID controller, and the humidity control valve control opening is output.

4. The fuel cell air system control method according to claim 3, characterized in that: After obtaining the vehicle power demand, determining the target stack power of the fuel cell according to the vehicle power demand, and before controlling the opening of the air system humidity control valve according to the humidity control valve opening control, the method further includes: Determining the target humidity control valve opening corresponding to the target battery stack power according to a preset correspondence relationship between the battery stack power and the humidity control valve opening; Input the target humidity control valve opening into a humidity feedforward controller, and output the humidity control valve feedforward opening; The method of controlling the opening of the humidity control valve of the air system according to the humidity control valve control opening also includes: If the sum of the humidity control valve control opening and the humidity control valve feedforward opening is lower than the first opening threshold, the humidity control valve opening is controlled to be the sum of the humidity control valve control opening and the humidity control valve feedforward opening; If the sum of the humidity control valve control opening and the humidity control valve feedforward opening is higher than a first opening threshold, the humidity control valve opening is controlled to be the first opening threshold.

5. The fuel cell air system control method according to claim 1, characterized in that: After obtaining the vehicle power requirement and determining the target stack power of the fuel cell according to the vehicle power requirement, the method further includes: Determining a target stack air flow rate corresponding to the target stack power according to a preset correspondence relationship between stack power and stack air flow rate; Obtain the actual air flow rate of the air system into the reactor; The deviation between the target air flow rate and the actual air flow rate is input into a flow PID controller, and the air compressor control speed is output; The speed of the air compressor of the air system is controlled according to the air compressor control speed, so that the actual stack air flow rate reaches the target stack air flow rate.

6. The fuel cell air system control method according to claim 5, characterized in that: The controlling the speed of the air compressor of the air system according to the air compressor control speed includes: Controlling the rotation speed of the air compressor is controlling the rotation speed of the air compressor.

7. The fuel cell air system control method according to claim 5, characterized in that: After determining the target stack air flow corresponding to the target stack power according to the preset correspondence relationship between the stack power and the stack air flow, and before controlling the speed of the air compressor of the air system according to the air compressor control speed, the method further includes: Determine the target air compressor speed corresponding to the target air flow rate entering the stack according to the preset corresponding relationship between the air flow rate entering the stack and the air compressor speed; The target air compressor speed is input into a flow feedforward controller, and the air compressor feedforward speed is output; The controlling the speed of the air compressor of the air system according to the air compressor control speed includes: If the sum of the air compressor control speed and the air compressor feedforward speed is lower than the speed threshold, the speed of the air compressor is controlled to be the sum of the air compressor control speed and the air compressor feedforward speed; If the sum of the air compressor control speed and the air compressor feedforward speed is higher than a speed threshold, the speed of the air compressor is controlled to be the speed threshold.

8. The fuel cell air system control method according to claim 1, characterized in that: After obtaining the vehicle power requirement and determining the target stack power of the fuel cell according to the vehicle power requirement, the method further includes: Determining the target stack air pressure corresponding to the target stack power according to a preset correspondence relationship between stack power and stack air pressure; Obtain the actual air pressure entering the air system; The deviation between the target stack air pressure and the actual stack air pressure is input into a pressure PID controller, and the back pressure valve opening is output; The opening of the air system back-pressure valve is controlled according to the back-pressure valve control opening, so that the actual stack-inlet air pressure reaches the target stack-inlet air pressure.

9. The fuel cell air system control method according to claim 8, characterized in that: The step of controlling the opening of the back-pressure valve of the air system according to the back-pressure valve control opening comprises: Controlling the opening of the back pressure valve is the back pressure valve controlled opening.

10. The fuel cell air system control method according to claim 8, characterized in that: After determining the target stack air pressure corresponding to the target stack power according to the preset correspondence relationship between the stack power and the stack air pressure, and before controlling the opening of the air system back pressure valve according to the back pressure valve control opening, the method further includes: Determining the target back-pressure valve opening corresponding to the target stack-inlet air pressure according to a preset correspondence relationship between the stack-inlet air pressure and the back-pressure valve opening; Input the target back pressure valve opening into a pressure feedforward controller, and output the back pressure valve feedforward opening; The step of controlling the opening of the back-pressure valve of the air system according to the back-pressure valve control opening comprises: If the sum of the back-pressure valve control opening and the back-pressure valve feedforward opening is lower than a second opening threshold, the back-pressure valve opening is controlled to be the sum of the back-pressure valve control opening and the back-pressure valve feedforward opening; If the sum of the back-pressure valve control opening and the back-pressure valve feedforward opening is higher than a second opening threshold, the back-pressure valve opening is controlled to be the second opening threshold.

11. The fuel cell air system control method according to claim 8, characterized in that: After obtaining the actual air pressure of the air system, the method further includes: If the actual air pressure entering the stack is higher than the safety threshold, the relief valve of the air system is opened.

12. The fuel cell air system control method according to claim 8, characterized in that: After obtaining the actual air pressure of the air system, the method further includes: If the actual air pressure entering the stack is higher than the pressure value corresponding to the actual air flow entering the stack, the relief valve of the air system is opened; If the actual air pressure entering the stack is lower than the pressure value corresponding to the actual air flow entering the stack, the relief valve is closed.

13. A fuel cell air system control device, characterized in that: include: A first determination module is used to obtain the required power of the whole vehicle and determine the target stack power of the fuel cell according to the required power of the whole vehicle; A second determination module is used to determine the target air intake humidity corresponding to the target battery stack power according to a preset correspondence relationship between battery stack power and air intake humidity; An acquisition module, used for acquiring the high-frequency impedance of the fuel cell stack; A third determination module is used to determine the actual humidity inside the battery stack corresponding to the high-frequency impedance of the battery stack according to the corresponding relationship between the battery stack impedance and the humidity inside the battery stack at the preset target battery stack power; A fourth determination module determines a humidity control valve opening according to the target air intake humidity and the actual humidity inside the fuel cell stack; The humidity control valve control module is used to control the opening of the humidity control valve of the air system according to the humidity control valve control opening, so that the actual humidity inside the fuel cell stack reaches the target air intake humidity.

14. An electronic device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the fuel cell air system control method according to any one of claims 1 to 12 is implemented.

15. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the fuel cell air system control method according to any one of claims 1 to 12 is implemented.

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