Anti-surge method of hydrogen fuel cell air compressor and air system

Abstract

The invention discloses an anti-surge method of a hydrogen fuel cell air compressor and an air system, and belongs to the field of hydrogen fuel cells. According to the anti-surge method, characteristic parameters of the air compressor are collected in advance to form a data set A related to the flow of the air compressor and the pressure loss of the front end and the rear end of the compressor; then, according to the corresponding current air inlet flow value of the air compressor in each sampling period, the data set A and a preset working compression ratio equation, calculating to obtain an actual corresponding working compression ratio in the period, and selecting a corresponding air compressor working mode by comparing the working compression ratio with a corresponding compression ratio protection value; therefore, different anti-surge control strategies can be implemented. According to collection, calculation and comparison of the working parameters of the air compressor, the real-time operation conditions of the air compressor under different working conditions can be rapidly and accurately judged, then the anti-surge control strategy is dynamically adjusted, the adaptability of the strategy and the air compressor is good, and the ideal anti-surge effect can be achieved.

Description

Technical Field

[0001] The invention belongs to the field of hydrogen fuel cells, and in particular relates to an anti-surge method and an air system for a hydrogen fuel cell air compressor. Background Art

[0002] As an on-board new energy power supply system or battery energy storage system, the hydrogen fuel cell system uses the battery stack to cause an electrochemical reaction between hydrogen and oxygen in the air under the action of a catalyst, generating electricity through the electrochemical reaction. It can be used as an energy storage device, mobile power supply, vehicle drive power supply, etc.

[0003] In hydrogen fuel cell systems, the air system plays a vital role. It is responsible for sending a large amount of air to the cathode side to participate in the hydrogen-oxygen reduction reaction, and ensuring that the temperature, pressure, humidity and flow rate on the cathode side of the fuel cell stack are within a relatively comfortable range. Since the air compressor inside the hydrogen fuel cell system is in a dynamic operating state during actual use, it will be affected by changes in environmental conditions, operating conditions, rapid load changes, actuator reaction rate, etc., resulting in unstable operation and surge. And because the efficient operating point of the fuel cell is often close to this area, surge is very common in the operation of hydrogen fuel cells. However, the surge of the air compressor will not only affect the power output efficiency of the fuel cell, reduce the operating stability, efficiency and life of the engine, but may also cause irreversible damage to the fuel cell system, which is very harmful.

[0004] The current control strategies for setting up anti-surge for air compressors mainly include improving the performance of air compressors to expand the safe working range of air compressors, or adjusting the air compressor intake flow or air compressor outlet pressure to prevent the air compressor from entering the surge area. However, due to the complex operating conditions of automotive fuel cells, these two methods cannot stably control the airflow or intake flow, pressure and other parameter values ​​of the air compressor, and have poor adaptability to air compressors, making it difficult to achieve the ideal anti-surge effect. Therefore, there is an urgent need to provide an anti-surge method and air system for hydrogen fuel cell air compressors that can solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a method and air system for preventing surge of a hydrogen fuel cell air compressor in view of the above shortcomings, and to solve the problem that the current anti-surge strategy is poorly adaptable to the air compressor and the anti-surge effect is not ideal. To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A method for preventing surge of a hydrogen fuel cell air compressor comprises the following steps:

[0007] Platform construction steps: Build a hydrogen fuel cell working platform, preset the sampling period T, and set the compression ratio protection value CR of the air compressor in the hydrogen fuel cell at different speeds R保 ;

[0008] Data set construction steps: According to the working conditions of the hydrogen fuel cell at different working powers, the corresponding air compressor front end pressure loss value P under different air compressor intake flow values ​​GS is obtained. 前损 And the pressure loss value P at the rear end of the air compressor 后损 , and then form n groups of GS values, P 前损 Value and P 后损 A data set A with one-to-one correspondence between values;

[0009] Collection steps: Whenever a new sampling cycle is entered, the current compressor speed R and compressor intake flow value GS of the current hydrogen fuel cell are recollected. 当前 , environmental pressure value P 环 And the stack pressure value P of the built-in stack of the hydrogen fuel cell 堆 ;

[0010] Calculation steps:

[0011] J1: According to the current air compressor intake flow value GS 当前 And data set A, construct the front loss function f(x) and rear loss function f'(x) corresponding to the current air compressor intake flow, and calculate the current air compressor intake flow value GS 当前 The corresponding air compressor front end pressure loss value P 前损 And the pressure loss value P at the rear end of the air compressor 后损 ;

[0012] J2: According to the preset working compression ratio CR 工 The actual working compression ratio CR of the air compressor in the current sampling period is calculated by the formula 工 ; Among them, CR 工 The specific formula is expressed as:

[0013]

[0014] Control steps: The CR obtained in the current sampling period T 工 CR corresponding to the current air compressor speed R 保 The values ​​are compared; then, the working mode that the air compressor should enter is selected according to the comparison results; and then, the corresponding anti-surge control strategy is adopted for the tail exhaust valve provided for the hydrogen fuel cell according to different working modes.

[0015] Furthermore, the data set construction steps are specifically as follows:

[0016] S1: Make the hydrogen fuel cell operate at a preset initial power P 工 Normal start; the initial working power value P 工 Set to the maximum output power P of the hydrogen fuel cellmax 5%, that is, P 工 =5%×P max ;

[0017] S2: Make the hydrogen fuel cell work stably for a preset time at the current working power; then, obtain and record the ambient pressure value P at the current working power. 环 , air compressor intake flow value GS, air compressor speed value R, air compressor intake pressure value P 进 , the pressure value of the air compressor outlet p 出 , the stack pressure value P of the built-in stack of the hydrogen fuel cell 堆 ; Then calculate the pressure loss value P at the front end of the air compressor 前损 And the pressure loss value P at the rear end of the air compressor 后损 ;

[0018] S3: Determine whether the current working power is the maximum output power P max If not reached, let P 工 =P 工 +5%×P max , then return to step S2; if the current working power is the maximum output power P max , then proceed to step S4;

[0019] S4: Compare the obtained air intake flow value GS of each air compressor with its corresponding air compressor front end pressure loss value P 前损 And the pressure loss value P at the rear end of the air compressor 后损 to form n groups including GS value, P 前损 Value and P 后损 A data set A with three types of data in one-to-one correspondence.

[0020] Furthermore, in the step S2, the air intake pressure loss value P at the front end of the air compressor is calculated. 前损 The specific formula is P 前损 =P 进 -P 环 , calculate the intake pressure loss value P at the rear end of the air compressor 后损 The specific formula is P 后损 =P 出 -P 堆 .

[0021] Furthermore, the J1 step specifically includes:

[0022] Data calling steps: Call the two sets of data sets A that are closest to the current air compressor intake flow value GS 当前 Data A x and A x+1 , and in A x Medium, G.S.x <GS 当前 , while in A x+1 Medium, G.S. x+1 >GS 当前 ;

[0023] The steps of constructing the compression function are as follows: x and A x+1 Construct the air compressor intake flow value GS about the air compressor front end pressure loss value P 前损 The changing front loss function f(x) and the air compressor inlet flow value GS are related to the air compressor rear pressure loss value P 后损 The variable loss function f'(x), where f(x) and f'(x) are both linear functions;

[0024] Pressure loss calculation steps: The current air compressor intake flow value GS is calculated by constructing the front loss function f(x) and the rear loss function f'(x). 当前 The corresponding air compressor front end pressure loss value P 前损 And the pressure loss value P at the rear end of the air compressor 后损 .

[0025] Furthermore, in the control step, the specific steps for selecting the working mode of the hydrogen fuel cell are:

[0026] When CR 工 ≥CR 保 When the hydrogen fuel cell is judged to have surge risk, the air compressor is put into anti-surge working mode;

[0027] When 0.9×CR 保 <CR 工 <CR 保 When the hydrogen fuel cell is detected, it is judged that there is a possibility of surge risk, and the air compressor enters the protection working mode;

[0028] When CR 工 ≤0.9×CR 保 When the hydrogen fuel cell is judged to be operating normally, the air compressor enters the normal working mode.

[0029] Furthermore, in the anti-surge working mode, the control strategy for the tail exhaust valve is specifically: controlling the tail exhaust valve to open at a preset maximum opening rate v max Increase valve opening.

[0030] Furthermore, in the anti-surge working mode, the maximum opening rate v of the tail exhaust valve is max The setting steps are as follows:

[0031] The hydrogen fuel cell is started normally with the tail valve closed, i.e., the tail valve opening K = 0; then, the tail valve opening K is set to the maximum, i.e., K = 100; the time for the tail valve opening value K to change from 0 to 100 is set as t, and the maximum opening rate of the tail valve is expressed as:

[0032] Furthermore, in the protection working mode, the control strategy for the tail exhaust valve is specifically: controlling the tail exhaust valve to only execute the command of increasing the valve opening, and not executing the command of decreasing the valve opening.

[0033] Furthermore, in the normal working mode, the tail exhaust valve is opened and closed normally, and the anti-surge control strategy is not implemented on the tail exhaust valve.

[0034] A hydrogen fuel cell air system adopts any of the above-mentioned anti-surge methods for hydrogen fuel cell air compressors, and comprises at least an air compressor, a fuel cell stack, a tail exhaust valve and a controller; the controller is electrically connected to the air compressor, the fuel cell stack and the tail exhaust valve respectively.

[0035] The beneficial effects of the present invention are:

[0036] 1. The present invention collects and forms the GS value and P of the air compressor in advance 前损 Value and P 后损 The data set A with one-to-one correspondence between the values ​​is convenient for the corresponding P under different air compressor intake flow values ​​GS. 前损 Value and P 后损 The value can be quickly calculated, thereby ensuring the rapid judgment of the subsequent compression ratio, so that the air compressor can adjust the working mode in time under any working conditions, so as to adopt the most suitable anti-surge control strategy to control the tail valve.

[0037] 2. The present invention sets a protection working mode. When the working compression ratio is close to the corresponding surge limit, the tail valve is controlled by an "open only but not closed" prevention and control strategy in advance to improve the fault tolerance of the anti-surge control strategy and prevent the air compressor from shutting down due to failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a schematic structural diagram of a hydrogen fuel cell air system mentioned in one embodiment of the present invention; DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods, but the present invention is not limited to the following embodiments.

[0040] Embodiment 1:

[0041] See attached Figure 1 One aspect of the present invention discloses a method for preventing surge of a hydrogen fuel cell air compressor, comprising the following steps:

[0042] Platform construction steps: Build a hydrogen fuel cell working platform, preset the sampling period T, and set the compression ratio protection value CR of the air compressor in the hydrogen fuel cell at different speeds R 保 ;

[0043] Data set construction steps: According to the working conditions of the hydrogen fuel cell at different working powers, the corresponding air compressor front end pressure loss value P under different air compressor intake flow values ​​GS is obtained. 前损 And the pressure loss value P at the rear end of the air compressor 后损 , and then form n groups of GS values, P 前损 Value and P 后损 A data set A with one-to-one correspondence between values;

[0044] Collection steps: Whenever a new sampling cycle is entered, the current compressor speed R and compressor intake flow value GS of the current hydrogen fuel cell are recollected. 当前 , environmental pressure value P 环 And the stack pressure value P of the built-in stack of the hydrogen fuel cell 堆 ;

[0045] Calculation steps:

[0046] J1: According to the current air compressor intake flow value GS 当前 And data set A, construct the front loss function f(x) and rear loss function f'(x) corresponding to the current air compressor intake flow, and calculate the current air compressor intake flow value GS 当前 The corresponding air compressor front end pressure loss value P 前损 And the pressure loss value P at the rear end of the air compressor 后损 ;

[0047] J2: According to the preset working compression ratio CR 工 The actual working compression ratio CR of the air compressor in the current sampling period is calculated by the formula 工 ; Among them, CR 工 The specific formula is expressed as:

[0048]

[0049] Control steps: Set the CR corresponding to the current sampling period 工 CR corresponding to the current air compressor speed R 保 The values ​​are compared; then, the working mode that the air compressor should enter is selected according to the comparison results; and then, the corresponding anti-surge control strategy is adopted for the tail exhaust valve provided for the hydrogen fuel cell according to different working modes.

[0050] The present invention collects various parameters of the air compressor under different working powers in advance to obtain a data set A related to the front-end pressure loss and rear-end pressure loss of the compressor under different flow rates, and then calculates the actual corresponding working compression ratio in the cycle according to the current intake flow value corresponding to the air compressor in each sampling period, the data set A and the preset working compression ratio formula, and then quickly and accurately judges the real-time operation of the air compressor under different working conditions by comparing the working compression ratio and the corresponding compression ratio protection value, and selects the corresponding air compressor working mode to implement different anti-surge control strategies. Among them, the surge protection curve of the air compressor is provided by the air compressor manufacturer, and those skilled in the art can obtain the maximum allowable compression ratio under different air compressor speeds according to the surge protection curve, and use it as the compression ratio protection value CR corresponding to the speed. 保 In addition, the present invention dynamically adjusts the anti-surge control strategy by re-comparing the working compression ratio with the corresponding compression ratio protection value in different acquisition cycles, and makes timely and accurate responses to different working conditions, so that the anti-surge strategy is well adapted to the air compressor and can achieve an ideal anti-surge effect.

[0051] Embodiment 2:

[0052] See attached Figure 1 Based on the first embodiment, the data set construction steps are specifically as follows:

[0053] S1: Make the hydrogen fuel cell operate at a preset initial power P 工 Normal start; the initial working power value P 工 Set to the maximum output power P of the hydrogen fuel cell max 5%, that is, P 工 =5%×P max ;

[0054] S2: Make the hydrogen fuel cell work stably for a preset time at the current working power; then, obtain and record the ambient pressure value P at the current working power. 环 , air compressor intake flow value GS, air compressor speed value R, air compressor intake pressure value P 进 , the pressure value of the air compressor outlet p 出 , the stack pressure value P of the built-in stack of the hydrogen fuel cell 堆 ; Then calculate the pressure loss value P at the front end of the air compressor 前损 And the pressure loss value P at the rear end of the air compressor 后损 ;

[0055] S3: Determine whether the current working power is the maximum output power P max If not reached, let P 工 =P 工 +5%×Pmax , then return to step S2; if the current working power is the maximum output power P max , then proceed to step S4;

[0056] S4: Compare the obtained air intake flow value GS of each air compressor with its corresponding air compressor front end pressure loss value P 前损 And the pressure loss value P at the rear end of the air compressor 后损 to form n groups including GS value, P 前损 Value and P 后损 The data set A contains three data sets with one-to-one correspondence. The data set of the nth group is represented by A n , when calling the data of group n, call A at the same time n The data in can be expressed as [GS n , P 前损n , P 后损n ].

[0057] Among them, for step S2, calculate the intake pressure loss value P at the front end of the air compressor 前损 The specific formula is P 前损 =P 进 -P 环 , calculate the intake pressure loss value P at the rear end of the air compressor 后损 The specific formula is P 后损 =P 出 -P 堆 .

[0058] When the air compressor in the hydrogen fuel cell is working, its working power is positively correlated with the intake air flow rate. Therefore, the present invention obtains the actual operating conditions of the air compressor under different working powers by gradually increasing the working power and collecting relevant data, thereby reducing the error in the subsequent calculation of the working compression ratio, ensuring accurate judgment of the actual working conditions of the air compressor, and ultimately making the adopted anti-surge strategy adapt to the current operating status of the air compressor.

[0059] In the calculation steps, the J1 step specifically includes:

[0060] Data calling steps: Call the two sets of data sets A that are closest to the current air compressor intake flow value GS 当前 Data A x and A x+1 , and in A x Medium, G.S. x <GS 当前 , while in A x+1 Medium, G.S. x+1 >GS 当前 ;

[0061] The steps of constructing the compression function are as follows: x and Ax+1 Construct the air compressor intake flow value GS about the air compressor front end pressure loss value P 前损 The changing front loss function f(x) and the air compressor inlet flow value GS are related to the air compressor rear pressure loss value P 后损 The variable loss function f'(x), where f(x) and f'(x) are both linear functions;

[0062] Pressure loss calculation steps: The current air compressor intake flow value GS is calculated by constructing the front loss function f(x) and the rear loss function f'(x). 当前 The corresponding air compressor front end pressure loss value P 前损 And the pressure loss value P at the rear end of the air compressor 后损 .

[0063] In each collection cycle T, the current air compressor intake flow value GS is obtained 当前 Find the two closest sets of parameters A in data set A x and A x+1 , and reconstruct the related front loss function f(x) and rear loss function f'(x) and calculate them. Since the set A is set in advance, this method can not only reduce the repeated collection of various types of data by the air compressor during operation, but also simplify the calculation process, reduce the calculation error, and simply, quickly and accurately reflect the actual front-end pressure loss and rear-end pressure loss of the air compressor in each collection cycle T. In addition, the interval of each collection cycle T is very short, so even in the face of rapid changes in the operating conditions of the air compressor, it can respond in time to ensure that the subsequent anti-surge strategy can be adjusted in real time to adapt to different air compressor operating conditions. Specifically, the interval range of each collection cycle T can be set to 0.1 milliseconds-0.1 seconds.

[0064] In the control step, the specific steps for selecting the working mode of the hydrogen fuel cell are:

[0065] When CR 工 ≥CR 保 When the hydrogen fuel cell is judged to have surge risk, the air compressor is put into anti-surge working mode;

[0066] When 0.9×CR 保 <CR 工 <CR 保 When the hydrogen fuel cell is detected, it is judged that there is a possibility of surge risk, and the air compressor enters the protection working mode;

[0067] When CR 工 ≤0.9×CR 保 When the hydrogen fuel cell is judged to be operating normally, the air compressor enters the normal working mode.

[0068] The present invention adapts to the anti-surge requirements of different working conditions by reselecting the working mode adapted to the current air compressor working condition in each acquisition cycle T. And this method can be set as a control method with a higher priority than any other control strategy according to the use requirements to ensure the anti-surge effect.

[0069] In the anti-surge working mode, the control strategy for the tail exhaust valve is specifically: controlling the tail exhaust valve to open at a preset maximum opening rate v max Increase valve opening.

[0070] In the anti-surge working mode, the maximum opening rate v of the tail exhaust valve is max The setting steps are as follows:

[0071] The hydrogen fuel cell is started normally with the tail valve closed, i.e., the tail valve opening K = 0; then, the tail valve opening K is set to the maximum, i.e., K = 100; the time for the tail valve opening value K to change from 0 to 100 is set as t, and the maximum opening rate of the tail valve is expressed as:

[0072] In the protection working mode, the control strategy for the tail exhaust valve is specifically: the tail exhaust valve is controlled to only execute the command of increasing the valve opening, and not to execute the command of decreasing the valve opening.

[0073] In the normal working mode, the tail exhaust valve opens and closes normally, and the anti-surge control strategy is not implemented on the tail exhaust valve.

[0074] In the anti-surge working mode, the present invention releases the pressure of the built-in stack in the hydrogen fuel cell by quickly opening the tail valve, thereby preventing the air compressor from reaching the protection line value of the anti-surge pressure, thereby achieving the anti-surge effect. The protection working mode is set so that when the working compression ratio is close to the corresponding surge limit, the present invention adopts the "open only but not close" prevention and control strategy for the tail valve in advance, so as to improve the fault tolerance of the anti-surge control strategy and prevent the air compressor from shutting down due to failure.

[0075] Embodiment three:

[0076] See attached Figure 1 . On the basis of the second embodiment, the present invention further discloses a hydrogen fuel cell air system, which adopts the anti-surge method of the hydrogen fuel cell air compressor as described in any one of the second embodiments, and at least includes an air compressor, a fuel cell stack, a tail exhaust valve and a controller; the controller is electrically connected to the air compressor, the fuel cell stack and the tail exhaust valve, respectively. It can be seen from the above structure that the controller adjusts the operating condition by adjusting the speed of the air compressor, and adjusts the tail exhaust valve opening in real time by executing the anti-surge method of the hydrogen fuel cell air compressor, so as to dynamically adjust the anti-surge strategy of the air compressor to adapt to the current operating condition of the air compressor. In addition, the controller is preset with the compression ratio protection value CR corresponding to different speeds R. 保By obtaining the speed value R of the air compressor at each sampling period T, the corresponding compression ratio protection value CR at the current speed can be retrieved. 保 In addition, the present invention does not make additional modifications to the hydrogen fuel cell air system, does not add new control bypasses or redundant components, reduces structural complexity and control difficulty, and enables the hydrogen fuel cell air system to still ensure normal output under the intervention of the anti-surge strategy, thereby ensuring reliability of use.

[0077] Preferably, the specific structure of the hydrogen fuel cell air system may include a controller and a filter, an air compressor, an intercooler, an electric membrane humidifier, an air intake valve, a fuel cell stack, and a tail valve connected in sequence. A flow temperature sensor is also provided between the air compressor and the filter to detect the air intake pressure P of the air compressor. 进 and intake air flow GS; a pressure sensor is also provided between the air compressor and the intercooler to detect the air compressor outlet pressure p 出 The front end of the fuel cell stack intake valve is equipped with a stack intake temperature and pressure sensor, which can detect the stack pressure value P 堆 .

[0078] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preventing surge of a hydrogen fuel cell air compressor, characterized in that: The following steps are involved: Platform construction steps: Build a hydrogen fuel cell working platform, preset the sampling period T, and set the compression ratio protection value CR of the air compressor in the hydrogen fuel cell at different speeds R 保 ; Data set construction steps: According to the working conditions of the hydrogen fuel cell at different working powers, the corresponding air compressor front end pressure loss value P under different air compressor intake flow values ​​GS is obtained. 前损 And the pressure loss value P at the rear end of the air compressor 后损 , and then form n groups of GS values, P 前损 Value and P 后损 A data set A with one-to-one correspondence between values; Collection steps: Whenever a new sampling cycle is entered, the current compressor speed R and compressor intake flow value GS of the current hydrogen fuel cell are recollected. 当前 , environmental pressure value P 环 And the stack pressure value P of the built-in stack of the hydrogen fuel cell 堆 ; Calculation steps: J1: According to the current air compressor intake flow value GS 当前 And data set A, construct the front loss function f(x) and rear loss function f'(x) corresponding to the current air compressor intake flow, and calculate the current air compressor intake flow value GS 当前 The corresponding air compressor front end pressure loss value P 前损 And the pressure loss value P at the rear end of the air compressor 后损 ; J2: According to the preset working compression ratio CR 工 The actual working compression ratio CR of the air compressor in the current sampling period is calculated by the formula 工 ; Among them, CR 工 The specific formula is expressed as: Control steps: The CR obtained in the current sampling period T 工 CR corresponding to the current air compressor speed R 保 The values ​​are compared; then, the working mode that the air compressor should enter is selected according to the comparison results; and then, the corresponding anti-surge control strategy is adopted for the tail exhaust valve provided for the hydrogen fuel cell according to different working modes.

2. The anti-surge method for a hydrogen fuel cell air compressor according to claim 1, characterized in that: The steps of constructing the data set are specifically as follows: S1: Make the hydrogen fuel cell operate at a preset initial power P 工 Normal start; the initial working power value P 工 Set to the maximum output power P of the hydrogen fuel cell max 5%, that is, P 工 =5%×P max ; S2: Make the hydrogen fuel cell work stably for a preset time at the current working power; then, obtain and record the ambient pressure value P at the current working power. 环 , air compressor intake flow value GS, air compressor speed value R, air compressor intake pressure value P 进 , the pressure value p at the air compressor outlet 出 , the stack pressure value P of the built-in stack of the hydrogen fuel cell 堆 ; Then calculate the pressure loss value P at the front end of the air compressor 前损 And the pressure loss value P at the rear end of the air compressor 后损 ; S3: Determine whether the current working power is the maximum output power P max If not reached, let P 工 =P 工 +5%×P max , then return to step S2; if the current working power is the maximum output power P max , then proceed to step S4; S4: Compare the obtained air intake flow value GS of each air compressor with its corresponding air compressor front end pressure loss value P 前损 And the pressure loss value P at the rear end of the air compressor 后损 to form n groups including GS value, P 前损 Value and P 后损 A data set A with three types of data in one-to-one correspondence.

3. The anti-surge method for a hydrogen fuel cell air compressor according to claim 2, characterized in that: In the step S2, the air intake pressure loss value P at the front end of the air compressor is calculated. 前损 The specific formula is P 前损 =P 进 -P 环 , calculate the intake pressure loss value P at the rear end of the air compressor 后损 The specific formula is P 后损 =P 出 -P 堆 .

4. The anti-surge method for a hydrogen fuel cell air compressor according to claim 1, characterized in that: The J1 step specifically includes: Data calling steps: Call the two sets of data sets A that are closest to the current air compressor intake flow value GS 当前 Data A x and A x+1 , and in A x Medium, G.S. x <GS 当前 , while in A x+1 Medium, G.S. x+1 >GS 当前 ; The steps of constructing the compression function are as follows: x and A x+1 Construct the air compressor intake flow value GS about the air compressor front end pressure loss value P 前损 The changing front loss function f(x) and the air compressor inlet flow value GS are related to the air compressor rear pressure loss value P 后损 The variable loss function f'(x), where f(x) and f'(x) are both linear functions; Pressure loss calculation steps: The current air compressor intake flow value GS is calculated by constructing the front loss function f(x) and the rear loss function f'(x). 当前 The corresponding air compressor front end pressure loss value P 前损 And the pressure loss value P at the rear end of the air compressor 后损 .

5. The anti-surge method for a hydrogen fuel cell air compressor according to claim 1, characterized in that: In the control step, the specific steps for selecting the working mode of the hydrogen fuel cell are: When CR 工 ≥CR 保 When the hydrogen fuel cell is judged to have surge risk, the air compressor is put into anti-surge working mode; When 0.9×CR 保 <CR 工 <CR 保 When the hydrogen fuel cell is detected, it is judged that there is a possibility of surge risk, and the air compressor enters the protection working mode; When CR 工 ≤0.9×CR 保 When the hydrogen fuel cell is judged to be operating normally, the air compressor enters the normal working mode.

6. The anti-surge method for a hydrogen fuel cell air compressor according to claim 5, characterized in that: In the anti-surge working mode, the control strategy for the tail exhaust valve is specifically: controlling the tail exhaust valve to open at a preset maximum opening rate v max Increase valve opening.

7. The anti-surge method for a hydrogen fuel cell air compressor according to claim 6, characterized in that: In the anti-surge working mode, the maximum opening rate v of the tail exhaust valve is max The setting steps are as follows: The hydrogen fuel cell is started normally with the tail valve closed, i.e., the tail valve opening K = 0; then, the tail valve opening K is set to the maximum, i.e., K = 100; the time for the tail valve opening value K to change from 0 to 100 is set as t, and the maximum opening rate of the tail valve is expressed as:

8. The anti-surge method for a hydrogen fuel cell air compressor according to claim 5, characterized in that: In the protection working mode, the control strategy for the tail exhaust valve is specifically: the tail exhaust valve is controlled to only execute the command of increasing the valve opening, and not to execute the command of decreasing the valve opening.

9. The anti-surge method for a hydrogen fuel cell air compressor according to claim 5, characterized in that: In the normal working mode, the tail exhaust valve opens and closes normally, and the anti-surge control strategy is not implemented on the tail exhaust valve.

10. A hydrogen fuel cell air system, using the anti-surge method of a hydrogen fuel cell air compressor according to any one of claims 1 to 9, characterized in that: It at least includes an air compressor, a fuel cell stack, a tail exhaust valve and a controller; the controller is electrically connected to the air compressor, the fuel cell stack and the tail exhaust valve respectively.

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