Hydrogen supply control system and method of hydrogen fuel cell, cell and vehicle

Abstract

The invention provides a hydrogen supply control system and method of a hydrogen fuel cell, the cell and a vehicle. The control system comprises a backstepping method controller; the backstepping method controller is connected with the hydrogen circulating pump, the pressure difference of hydrogen in the hydrogen supply pipeline serves as input, hydrogen partial pressure of an anode channel of the electric pile serves as feedback input, backstepping method control over the hydrogen excess ratio is achieved, and the pressure difference of the hydrogen supply pipeline is obtained through the hydrogen excess ratio. By means of the technical scheme, high-precision tracking control over the hydrogen excess ratio can be achieved, and therefore the control precision and the response speed of the hydrogen excess ratio under the dynamic working condition are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and particularly to a hydrogen supply control system, method, battery and vehicle of a hydrogen fuel cell. Background Art

[0002] A proton exchange membrane fuel cell system (PEMFC, Proton Exchange Membrane Fuel Cell System) is an efficient and clean energy conversion system that directly converts hydrogen and oxygen or air into electrical energy through an electrochemical reaction. The core of PEMFC is a proton exchange membrane fuel cell, which directly converts the chemical energy in hydrogen fuel into electrical energy through an electrochemical reaction. It is an efficient power generation device with the characteristics of high energy conversion efficiency, no pollution, and low operating temperature. Currently, it has been applied and developed in the fields of transportation, power systems, aerospace, etc.

[0003] A hydrogen fuel cell system is the core of a fuel cell power system, mainly composed of a stack and system auxiliary components. Among them, the hydrogen supply system is responsible for obtaining pure hydrogen from a high-pressure hydrogen cylinder, and after pressure regulation and circulation, delivering the hydrogen to the anode of the stack, which is the key to ensuring the stable operation of the stack. However, in actual operation, the PEMFC system often faces problems such as unstable hydrogen supply and low utilization rate. Among them, the hydrogen excess ratio of the fuel cell hydrogen supply system, as one of the core parameters of the fuel cell, has a very important impact on the output performance of the stack. A good control strategy can ensure that the hydrogen concentration in the anode flow field of the stack is appropriate, thereby increasing the rate of the electrochemical reaction and enabling the output of the stack to meet the expectations.

[0004] However, the control of the hydrogen excess ratio in the existing hydrogen supply control system of hydrogen fuel cells has the following problems:

[0005] Slow dynamic response: The linear characteristics of traditional PID control do not match the non-linearity of the fuel cell system. PID control relies on fixed parameters. When the load changes suddenly, such as when the vehicle accelerates / brakes, the adjustment time is long, resulting in a large fluctuation amplitude of the hydrogen excess ratio λ H2 and causing hydrogen waste or local hydrogen starvation;

[0006] High experience dependence: Existing methods require manual parameter adjustment, which needs to be repeatedly adjusted under different working conditions, with a long debugging period and insufficient robustness. Summary of the Invention

[0007] Embodiments of the present invention provide a hydrogen supply control system, method, battery and vehicle of a hydrogen fuel cell to achieve high-precision tracking control of the hydrogen excess ratio based on the backstepping control method.

[0008] To achieve the above object, on the one hand, a hydrogen supply control system for a hydrogen fuel cell is provided, which is applied to the hydrogen supply system of the hydrogen fuel cell. The hydrogen supply system includes: a hydrogen cylinder, a hydrogen supply pipeline, a hydrogen return pipeline, and a hydrogen circulation pump. The hydrogen cylinder supplies hydrogen to the stack of the hydrogen fuel cell through the hydrogen supply pipeline. The unused hydrogen of the stack is input into the hydrogen circulation pump through the hydrogen return pipeline and supplied to the stack through the hydrogen circulation pump. Among them, the control system includes:

[0009] A backstepping controller, connected to the hydrogen circulation pump, to achieve backstepping control of the hydrogen excess ratio with the pressure difference of hydrogen in the hydrogen supply pipeline as the input and the hydrogen partial pressure in the anode channel of the stack as the feedback input. The pressure difference of the hydrogen supply pipeline is obtained through the hydrogen excess ratio, where:

[0010]

[0011] is the hydrogen flow rate flowing into the anode of the stack, is the hydrogen flow rate flowing out of the anode of the stack, is the pressure difference of hydrogen in the hydrogen supply pipeline, is the hydrogen excess ratio, k sm,out is the flow coefficient at the outlet of the hydrogen supply pipeline, P an is the total anode pressure of the stack, P sm is the total pressure of the hydrogen supply pipeline, I st is the current of the stack, N cell is the number of stacks included in the hydrogen fuel cell, F is the Faraday constant, is the hydrogen mass fraction in the hydrogen fuel cell, m s is the hydrogen mass fraction in the hydrogen supply pipeline.

[0012] Preferably, in the hydrogen supply control system of the hydrogen fuel cell, the backstepping controller uses the pressure difference of hydrogen in the hydrogen supply pipeline as the input and the hydrogen partial pressure in the anode channel of the stack as the feedback input to achieve backstepping control of the hydrogen excess ratio, including:

[0013] Taking the first derivative of the pressure difference of hydrogen in the supply pipeline :

[0014]

[0015] Taking the second derivative of the pressure difference Z of hydrogen in the supply pipeline H2 :

[0016]

[0017] Preferably, for the hydrogen supply control system of the hydrogen fuel cell, the backstepping controller uses the pressure difference of hydrogen in the hydrogen supply pipeline as the input and the hydrogen partial pressure in the anode channel of the stack as the feedback input to implement backstepping control of the hydrogen excess ratio, and further includes:

[0018] For the pressure difference of hydrogen in the supply pipeline Define the first error;

[0019] Construct the first Lyapunov function according to the first error, and obtain the derivative of the first Lyapunov function;

[0020] Introduce a first virtual control quantity according to the first error, and the first virtual control quantity is used to control the convergence of the first Lyapunov function;

[0021] Define a second error according to the first virtual control quantity;

[0022] Construct the second Lyapunov function according to the second error, and obtain the derivative of the second Lyapunov function;

[0023] Introduce a second virtual control quantity according to the second error;

[0024] Substitute the first virtual control quantity and the second virtual control quantity into the derivative of the first Lyapunov function and the derivative of the second Lyapunov function respectively. When the derivatives of the first Lyapunov function and the second Lyapunov function are both less than zero, the backstepping controller globally converges.

[0025] Preferably, for the hydrogen supply control system of the hydrogen fuel cell, the hydrogen partial pressure in the anode channel of the stack is the estimated value of the hydrogen partial pressure in the anode channel obtained by a hydrogen partial pressure observer. The hydrogen partial pressure observer uses the output voltage of the hydrogen fuel cell as the feedback, where:

[0026]

[0027] b0 = 4.308*10 -5 T st

[0028]

[0029] is the estimated value of the hydrogen partial pressure in the anode channel, is the estimated value of the fuel cell output voltage, is the oxygen partial pressure in the cathode channel, v ohm is the ohmic voltage loss, v act is the activation voltage loss, vcon is the concentration difference voltage loss, T0 is the temperature under standard conditions, and P0 is the air pressure under standard conditions;

[0030]

[0031] Among them, is the hydrogen inflow calculated based on the estimated hydrogen partial pressure, is the hydrogen outflow calculated based on the estimated hydrogen partial pressure, f6 is the hydrogen consumption in the stack reaction, is the estimated hydrogen partial pressure, is the change in the estimated hydrogen partial pressure, V st is the actual value of the fuel cell output voltage, is the estimated value of the fuel cell output voltage, is the error between the actual value of the fuel cell output voltage and the observed value of the fuel cell output voltage, K4 is the observation gain, T st is the stack temperature, I st is the stack current, k sm.out is the supply pipeline outlet flow coefficient, k an.out is the anode channel outlet flow coefficient, m a is the hydrogen mass fraction in the anode channel, is the predetermined non-linear correction term.

[0032] On the other hand, a hydrogen supply control method for a hydrogen fuel cell is provided, which is applied to the hydrogen supply control system of the hydrogen fuel cell described in any one of the above, and includes:

[0033] Obtain the hydrogen excess ratio of the hydrogen fuel cell;

[0034] According to the obtained hydrogen excess ratio, obtain the pressure difference of hydrogen in the hydrogen supply pipeline;

[0035] Using the pressure difference of hydrogen in the hydrogen supply pipeline as the input and the hydrogen partial pressure in the anode channel of the stack as the feedback input, use the backstepping controller to perform backstepping control on the hydrogen excess ratio, where:

[0036]

[0037] is the hydrogen flow rate flowing into the anode of the stack, is the hydrogen flow rate flowing out of the anode of the stack, is the pressure difference of hydrogen in the hydrogen supply pipeline, is the hydrogen excess ratio, k sm,out is the supply pipeline outlet flow coefficient, P an is the total anode pressure of the stack, P smis the total pressure of the hydrogen supply pipeline, I st is the current of the stack, N cell is the number of stacks included in the hydrogen fuel cell, F is the Faraday constant, is the hydrogen mass fraction in the fuel cell, m s is the hydrogen mass fraction in the hydrogen supply pipeline.

[0038] Preferably, in the hydrogen supply control method of the hydrogen fuel cell, the backstepping control of the hydrogen excess ratio using a backstepping controller includes:

[0039] Taking the first derivative of the pressure difference of the hydrogen in the supply pipeline :

[0040]

[0041] Taking the first derivative of the pressure difference of the hydrogen in the supply pipeline :

[0042]

[0043] Preferably, in the hydrogen supply control method of the hydrogen fuel cell, the backstepping control of the hydrogen excess ratio by using the backstepping controller with the pressure difference of the hydrogen in the hydrogen supply pipeline as the input and the hydrogen partial pressure in the anode channel of the stack as the feedback input further includes:

[0044] Defining a first error for the pressure difference of the hydrogen in the supply pipeline ;

[0045] Constructing a first Lyapunov function according to the first error and obtaining the derivative of the first Lyapunov function;

[0046] Introducing a first virtual control quantity according to the first error, and the first virtual control quantity is used to control the convergence of the first Lyapunov function;

[0047] Defining a second error according to the first virtual control quantity;

[0048] Constructing a second Lyapunov function according to the second error and obtaining the derivative of the second Lyapunov function;

[0049] Introducing a second virtual control quantity according to the second error;

[0050] Substitute the first virtual control quantity and the second virtual control quantity into the derivatives of the first Lyapunov function and the second Lyapunov function respectively. When the derivatives of the first Lyapunov function and the second Lyapunov function are both less than zero, the backstepping controller converges globally.

[0051] Preferably, in the hydrogen supply control method of the hydrogen fuel cell, the hydrogen partial pressure in the anode channel of the stack is the estimated value of the hydrogen partial pressure in the anode channel obtained by a hydrogen partial pressure observer. The hydrogen partial pressure observer uses the output voltage of the hydrogen fuel cell as feedback, where:

[0052]

[0053] b0 = 4.308 * 10 -5 T st

[0054]

[0055] is the estimated value of the hydrogen partial pressure in the anode channel, is the estimated value of the fuel cell output voltage, is the oxygen partial pressure in the cathode channel, v ohm is the ohmic voltage loss, v act is the activation voltage loss, v con is the concentration difference voltage loss, T0 is the temperature under standard conditions, and P0 is the atmospheric pressure under standard conditions;

[0056]

[0057] where, is the hydrogen inflow calculated according to the estimated value of the hydrogen partial pressure, is the hydrogen outflow calculated according to the estimated value of the hydrogen partial pressure, f6 is the hydrogen consumption in the stack reaction, is the estimated value of the hydrogen partial pressure, is the change in the estimated value of the hydrogen partial pressure, V st is the actual value of the fuel cell output voltage, is the estimated value of the fuel cell output voltage, is the error between the actual value of the fuel cell output voltage and the observed value of the fuel cell output voltage, K4 is the observation gain, T st is the stack temperature, I st is the stack current, k sm.out is the outlet flow coefficient of the supply pipeline, k an.out is the outlet flow coefficient of the anode channel, m a is the hydrogen mass fraction in the anode channel, is a predetermined non-linear correction term.

[0058] In another aspect, a hydrogen fuel cell is provided, which uses the hydrogen supply control system of the hydrogen fuel cell described above to control the hydrogen supply.

[0059] In another aspect, a vehicle using the hydrogen fuel cell is provided.

[0060] The above technical solutions have the following technical effects:

[0061] The control of the hydrogen excess ratio is achieved by using a backstepping controller with non-linear control characteristics in the hydrogen supply control system of the hydrogen fuel cell. Moreover, the backstepping controller uses the pressure difference of hydrogen in the supply pipeline obtained by converting the hydrogen excess ratio through a conversion formula as the input of the backstepping controller and the hydrogen partial pressure in the anode channel to control the hydrogen excess ratio, improving the control accuracy and response speed of the hydrogen excess ratio under dynamic conditions. Among them, controlling the flow through the pressure difference makes the flow characteristics of the channel relatively stable, which overcomes the defect that controlling the flow alone cannot ensure the stability of the pressure difference. Unstable pressure difference will cause the flow characteristics of the channel to change and the flow will become relatively unstable. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 is a schematic structural diagram of the hydrogen supply system of the hydrogen fuel cell;

[0063] Figure 2 is a schematic diagram of the principle of the hydrogen supply control system of the hydrogen fuel cell according to an embodiment of the present invention;

[0064] Figure 3 is a schematic diagram of the design flow of the backstepping controller in the hydrogen supply control system according to an embodiment of the present invention;

[0065] Figure 4 is a schematic diagram of the load current in an example;

[0066] Figure 5 is a schematic diagram of the hydrogen excess ratio in an example;

[0067] Figure 6 is a schematic diagram of the change of the stack voltage output by the fuel cell over time in an example;

[0068] Figure 7 is a schematic diagram of the input voltage of the hydrogen circulation pump in an example;

[0069] Figure 8 is a schematic diagram of the hydrogen partial pressure in an example. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0070] To further illustrate each embodiment, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention, mainly used to illustrate the embodiments and can be combined with the relevant descriptions in the specification to explain the operating principle of the embodiments. With reference to these contents, those of ordinary skill in the art should be able to understand other possible implementation manners and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0071] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation manners.

[0072] Figure 1 It is a schematic structural diagram of the hydrogen supply system for a hydrogen fuel cell. As Figure 1 , the hydrogen supply system of a hydrogen fuel cell generally includes: a hydrogen cylinder, a proportional valve, a hydrogen supply pipeline, a humidifier, a hydrogen return pipeline, a water vapor separator, a check valve, a hydrogen circulation pump, an exhaust and drainage valve, etc. The hydrogen supply control system of the present invention is applied to the hydrogen supply system of a hydrogen fuel cell. To highlight the improvement points of the present invention, in the description of the control system and control method of the embodiments of the present invention, the components in the hydrogen supply system related to the backstepping controller of the present invention, such as the hydrogen cylinder, the hydrogen supply pipeline, the hydrogen return pipeline, and the hydrogen circulation pump, are mainly described, and the operations of other conventional components belonging to the hydrogen supply system are not elaborated here.

[0073] Embodiment 1:

[0074] The embodiment of the present invention provides a control system for a hydrogen supply system, which is applied to the hydrogen supply system of a hydrogen fuel cell. Among them, in the hydrogen supply system: the hydrogen cylinder supplies hydrogen to the stack of the hydrogen fuel cell through the hydrogen supply pipeline, and the hydrogen unused by the stack is input into the hydrogen circulation pump through the hydrogen return pipeline and supplied to the stack by the hydrogen circulation pump.

[0075] Figure 2 It is a schematic diagram of the principle of the control system for the hydrogen supply system according to an embodiment of the present invention. As Figure 2 , the control system for the hydrogen supply system according to the embodiment of the present invention includes:

[0076] A backstepping controller, connected to the hydrogen circulation pump, to perform backstepping control on the hydrogen excess ratio with the pressure difference of hydrogen in the hydrogen supply pipeline as the input and the hydrogen partial pressure in the anode channel of the stack as the feedback input. The pressure difference of the hydrogen supply pipeline is obtained through the hydrogen excess ratio, where:

[0077]

[0078]

[0079] is the hydrogen flow rate flowing into the anode of the stack, is the hydrogen flow rate flowing out of the anode of the stack, is the pressure difference of hydrogen in the hydrogen supply pipeline, is the hydrogen excess ratio, k sm,out is the outlet flow coefficient of the hydrogen supply pipeline, P an is the total anode pressure of the stack, P sm is the total pressure of the hydrogen supply pipeline, I st is the current of the stack, N cell is the number of stacks included in the hydrogen fuel cell, F is the Faraday constant, is the hydrogen mass fraction in the fuel cell, m s is the hydrogen mass fraction in the hydrogen supply pipeline.

[0080] In the hydrogen control system of the embodiment of the present invention, the backstepping controller does not directly control the hydrogen excess ratio itself, but uses the pressure difference of hydrogen on the supply pipeline obtained by the above conversion formula from the hydrogen excess ratio as the input to implement backstepping control. As Figure 2 , the hydrogen excess ratio obtained from the hydrogen fuel cell and the reference quantity of the hydrogen excess ratio as the control target obtain the corresponding pressure difference of the hydrogen supply pipeline through the above conversion formula and the reference quantity of the pressure difference of the hydrogen supply pipeline and input the difference into the backstepping controller. As Figure 2 , in this embodiment, the partial pressure of hydrogen in the cathode channel is used as the feedback input of the backstepping controller. Among them, the partial pressure of hydrogen in the anode channel is obtained through a hydrogen partial pressure observer; the hydrogen partial pressure observer uses the output voltage of the hydrogen fuel cell as the feedback. The current actual hydrogen excess ratio of the hydrogen fuel cell and the current actual output voltage V st are obtained through corresponding sensors and corresponding calculation formulas. The control system of the embodiment of the present invention uses the circulating pump voltage output by the backstepping controller to control the hydrogen circulating pump, and further controls the hydrogen flow rate input to the stack of the hydrogen fuel cell, so as to achieve precise control of the hydrogen excess ratio.

[0081] Figure 3 is a schematic diagram of the design process of the backstepping controller in an embodiment of the present invention. As Figure 3 , the design of the backstepping controller in the control system of the embodiment of the present invention includes the following process:

[0082] ① Establish a dynamic equation for controlling the hydrogen excess ratio with the circulating pump voltage of the hydrogen:

[0083] Express the hydrogen excess ratio as the following equation:

[0084]

[0085] The pressure difference of hydrogen in the supply pipeline can be obtained through the excess ratio:

[0086]

[0087] Taking the first derivative of this pressure difference gives:

[0088]

[0089] Taking the second derivative of this pressure difference gives:

[0090]

[0091] The meanings of the variables are as described in the above records and will not be repeated here;

[0092] Finally, rewrite the system expression according to the common nonlinear system expression form of the backstepping method as where f(x) and g(x) are expressions obtained from the expansion of the second derivative of the pressure difference, x has no specific meaning, and u is the voltage of the hydrogen circulation pump;

[0093] ② Define the error: The goal of the backstepping method is to make the error e1 converge to zero, that is Approaching the desired trajectory step by step

[0094] ③ Construct the Lyapunov function: Taking the derivative of the Lyapunov function gives

[0095] ④ Introduce the virtual control quantity: α = -K1e1 to control the convergence of V1, so that where K1 is a constant representing the gain;

[0096] ⑤ Define the error again: So that

[0097] ⑥ Construct the Lyapunov function again: Taking the derivative of the Lyapunov function gives

[0098] ⑦ Introduce the virtual control quantity again:

[0099] ⑧ System stability analysis: Substitute the control quantities u and α into the Lyapunov function respectively and It can be obtained that and are both less than zero, and the derivative of the Lyapunov function of the entire closed-loop system is negative, ensuring global convergence.

[0100] (3) Design of hydrogen partial pressure observer

[0101] Regarding the detection of the gas partial pressure in the anode channel, the measuring instrument is expensive, and the detection method itself interferes with the gas flow in the pipeline and lacks real-time performance, so it cannot be industrialized. Therefore, in the embodiments of the present invention, a gas partial pressure observer with the output voltage of the fuel cell as the feedback is designed to achieve the effect of quickly and accurately estimating the hydrogen partial pressure. Among them, the calculation of the output voltage V of the fuel cell st The classical formula is:[[]]

[0102]

[0103] b0 = 4.308 * 10 -5 T st

[0104] E0 = 1.229 - 0.85 * 10 -3 (T st - T0)

[0105] is the hydrogen partial pressure in the anode channel, is the oxygen partial pressure in the cathode channel, v ohm is the ohmic voltage loss, v act is the activation voltage loss, v con is the concentration difference voltage loss, T0 is the temperature under standard conditions, P0 is the atmospheric pressure under standard conditions, T st is the stack temperature.

[0106] Define the estimated value of the hydrogen partial pressure in the anode channel as Then the estimated value of the fuel cell voltage can be obtained from expressed as:[[]]

[0107]

[0108] Design the change amount of the estimated value of the anode hydrogen partial pressure expressed as follows:[[]]

[0109]

[0110]

[0111] is the error between the actual voltage value and the observed voltage value, is the hydrogen inflow calculated based on the estimated value of the hydrogen partial pressure, is the hydrogen outflow calculated based on the estimated hydrogen partial pressure, f6 is the hydrogen consumption in the stack reaction, K4 is the observation gain, R is the gas constant, T st is the stack temperature, V st is the actual value of the output voltage of the fuel cell, i.e., the stack voltage, I st is the stack current, N cell is the number of stacks, F is the Faraday constant, k sm.out is the outlet flow coefficient of the supply pipeline, k an.out is the outlet flow coefficient of the anode pipeline, m s is the hydrogen mass fraction in the hydrogen supply pipeline, i.e., the supply manifold, m a is the hydrogen mass fraction in the anode flow channel, i.e., the anode channel, m s and m a are both functions of the estimated anode hydrogen partial pressure, and the estimator constraint term is the nonlinear correction term calculated according to the projection algorithm, and the expression is as follows:

[0112]

[0113] x 4,l (t) = x 4,min + ε

[0114] x 4,h (t) = x 4,max - ε

[0115] ε is a constant value satisfying ε ≤ |x 1,min - x 1,max |, x 1,min is the minimum value of the anode hydrogen partial pressure, x 1,max is the maximum value of the hydrogen partial pressure.

[0116] Example 2:

[0117] During the operation of the fuel cell, when the load current has a transient step change, if the gas supply system cannot respond well to the demand change of the stack, it may lead to an adverse situation of "hydrogen starvation" that reduces the output performance of the stack, and even shortens the service life of the fuel cell stack. Here, a large-amplitude load step change signal is added to verify the effectiveness of the control system and control method of the embodiment of the present invention.

[0118] Among them, Figure 4 is the schematic diagram of the load current; Figure 5 is the schematic diagram of the hydrogen excess ratio during the control process; Figure 6 is the schematic diagram of the stack voltage output by the fuel cell changing with time during the control process; Figure 7 is the schematic diagram of the input voltage of the hydrogen circulation pump during the control process;Figure 8 Schematic diagram of hydrogen partial pressure in the control process. Figure 5 and Figure 8 In, the blue represents the time value and the red represents the observed value. It can be seen from Figure 5 that by using the hydrogen supply control system and method of the present invention, high-precision tracking control of the hydrogen excess ratio can be achieved, and "hydrogen starvation" can be avoided.

[0119] Embodiment 3:

[0120] The present invention also provides a hydrogen fuel cell, which uses the hydrogen supply control system of the hydrogen fuel cell described above to control hydrogen supply.

[0121] Embodiment 4:

[0122] The present invention also provides a vehicle using the hydrogen fuel cell described above.

[0123] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, those skilled in the art should understand that various changes can be made to the present invention in terms of form and details without departing from the spirit and scope of the present invention defined by the appended claims, and all of them fall within the protection scope of the present invention.

Claims

1. A hydrogen supply control system for a hydrogen fuel cell, applied to a hydrogen supply system for a hydrogen fuel cell, the hydrogen supply system comprising: A hydrogen bottle, a hydrogen supply pipeline, a hydrogen return pipeline and a hydrogen circulation pump, wherein the hydrogen bottle supplies hydrogen to the stack of the hydrogen fuel cell through the hydrogen supply pipeline, and the unused hydrogen of the stack is input into the hydrogen circulation pump through the hydrogen return pipeline and supplied to the stack through the hydrogen circulation pump, characterized in that the control system includes: A backstepping controller is connected to the hydrogen circulation pump, and uses the pressure difference of hydrogen in the hydrogen supply pipeline as input and the hydrogen partial pressure of the anode channel of the stack as feedback input to realize backstepping control of the hydrogen excess ratio, wherein the pressure difference of the hydrogen supply pipeline is obtained by the hydrogen excess ratio, wherein: is the hydrogen flow rate flowing into the anode of the stack, is the hydrogen flow rate flowing out of the anode of the stack, is the pressure difference of hydrogen in the hydrogen supply pipeline, is the excess ratio of hydrogen, k sm,out is the hydrogen supply pipeline outlet flow coefficient, P an is the total anode pressure of the stack, P sm is the total pressure of the hydrogen supply pipeline, I st is the current of the battery stack, N cell is the number of fuel cells contained in the hydrogen fuel cell, F is the Faraday constant, is the mass fraction of hydrogen in the hydrogen fuel cell, m s is the mass fraction of hydrogen in the hydrogen supply pipeline.

2. The hydrogen supply control system of the hydrogen fuel cell according to claim 1, characterized in that: The backstepping controller uses the pressure difference of hydrogen in the hydrogen supply pipeline as input and the hydrogen partial pressure in the anode channel of the stack as feedback input to implement backstepping control of the hydrogen excess ratio, including: The pressure difference of the hydrogen in the supply pipeline Take a derivative: The pressure difference of the hydrogen in the supply pipeline Take the second derivative:

3. The hydrogen supply control system of the hydrogen fuel cell according to claim 2, characterized in that: The backstepping controller uses the pressure difference of hydrogen in the hydrogen supply pipeline as input and the hydrogen partial pressure in the anode channel of the stack as feedback input to realize backstepping control of the hydrogen excess ratio, and further includes: The pressure difference of the hydrogen in the supply pipeline Define the first error; constructing a first Lyapunov function according to the first error, and obtaining a derivative of the first Lyapunov function; Introducing a first virtual control variable according to the first error, wherein the first virtual control variable is used to control the convergence of the first Lyapunov function; defining a second error according to the first virtual control amount; constructing a second Lyapunov function according to the second error, and obtaining a derivative of the second Lyapunov function; introducing a second virtual control variable according to the second error; The first virtual control quantity and the second virtual control quantity are respectively substituted into the derivative of the first Lyapunov function and the derivative of the second Lyapunov function. When the derivative of the first Lyapunov function and the derivative of the second Lyapunov function are both less than zero, the backstepping controller converges globally.

4. The hydrogen supply control system of the hydrogen fuel cell according to claim 1, characterized in that: The hydrogen partial pressure in the anode channel of the stack is an estimated value of the hydrogen partial pressure in the anode channel obtained by a hydrogen partial pressure observer, and the hydrogen partial pressure observer uses the output voltage of the hydrogen fuel cell as feedback, wherein: b0=4.308*10 -5 T st is the estimated hydrogen partial pressure in the anode channel, is the estimated value of the fuel cell output voltage, is the oxygen partial pressure in the cathode channel, v ohm is the ohmic voltage loss, v act is the activation voltage loss, v con is the concentration voltage loss, T0 is the temperature under standard conditions, and P0 is the gas pressure under standard conditions; in, is the hydrogen inflow calculated based on the estimated hydrogen partial pressure, is the hydrogen outflow calculated based on the estimated hydrogen partial pressure, f6 is the hydrogen consumption of the reaction in the fuel cell, is the estimated value of the hydrogen partial pressure, is the change in the estimated value of the hydrogen partial pressure, V st is the actual value of the fuel cell output voltage, is the estimated value of the fuel cell output voltage, is the error between the actual value of the fuel cell output voltage and the observed value of the fuel cell output voltage, K4 is the observation gain, T st is the stack temperature, I st is the stack current, k sm.out is the outlet flow coefficient of the supply pipe, k an.out is the anode channel outlet flow coefficient, m a is the mass fraction of hydrogen in the anode channel, is the predetermined nonlinear correction term.

5. A hydrogen supply control method for a hydrogen fuel cell, applied to the hydrogen supply control system of the hydrogen fuel cell according to any one of claims 1 to 4, comprising: obtaining a hydrogen excess ratio of a hydrogen fuel cell; Obtaining the pressure difference of hydrogen in the hydrogen supply pipeline according to the obtained hydrogen excess ratio; The backstepping controller is used to perform backstepping control on the hydrogen excess ratio, with the pressure difference of hydrogen in the hydrogen supply pipeline as input and the hydrogen partial pressure in the anode channel of the stack as feedback input, where: is the hydrogen flow rate flowing into the anode of the stack, is the hydrogen flow rate flowing out of the anode of the stack, is the pressure difference of hydrogen in the hydrogen supply pipeline, is the excess ratio of hydrogen, k sm,out is the hydrogen supply pipeline outlet flow coefficient, P an is the total anode pressure of the stack, P sm is the total pressure of the hydrogen supply pipeline, I st is the current of the battery stack, N cell is the number of fuel cells contained in the hydrogen fuel cell, F is the Faraday constant, is the mass fraction of hydrogen in the fuel cell, m s is the mass fraction of hydrogen in the hydrogen supply pipeline.

6. The hydrogen supply control method for a hydrogen fuel cell according to claim 5, characterized in that: Backstepping control of the hydrogen excess ratio using a backstepping controller includes: The pressure difference of the hydrogen in the supply pipeline Take a derivative: The pressure difference of the hydrogen in the supply pipeline Take the second derivative:

7. The hydrogen supply control method for a hydrogen fuel cell according to claim 5, characterized in that: The backstepping controller uses the pressure difference of hydrogen in the hydrogen supply pipeline as input and the hydrogen partial pressure in the anode channel of the stack as feedback input to realize backstepping control of the hydrogen excess ratio, and further includes: The pressure difference of the hydrogen in the supply pipeline Define the first error; constructing a first Lyapunov function according to the first error, and obtaining a derivative of the first Lyapunov function; Introducing a first virtual control variable according to the first error, wherein the first virtual control variable is used to control the convergence of the first Lyapunov function; defining a second error according to the first virtual control amount; constructing a second Lyapunov function according to the second error, and obtaining a derivative of the second Lyapunov function; introducing a second virtual control variable according to the second error; The first virtual control quantity and the second virtual control quantity are respectively substituted into the derivative of the first Lyapunov function and the derivative of the second Lyapunov function. When the derivative of the first Lyapunov function and the derivative of the second Lyapunov function are both less than zero, the backstepping controller converges globally.

8. The hydrogen supply control method for a hydrogen fuel cell according to claim 5, characterized in that: The hydrogen partial pressure in the anode channel of the stack is an estimated value of the hydrogen partial pressure in the anode channel obtained by a hydrogen partial pressure observer, and the hydrogen partial pressure observer uses the output voltage of the hydrogen fuel cell as feedback, wherein: b0=4.308*10 -5 T st is the estimated hydrogen partial pressure in the anode channel, is the estimated value of the fuel cell output voltage, is the oxygen partial pressure in the cathode channel, v ohm is the ohmic voltage loss, v act is the activation voltage loss, v con is the concentration voltage loss, T0 is the temperature under standard conditions, and P0 is the gas pressure under standard conditions; in, is the hydrogen inflow calculated based on the estimated hydrogen partial pressure, is the hydrogen outflow calculated based on the estimated hydrogen partial pressure, f6 is the hydrogen consumption of the reaction in the fuel cell, is the estimated value of the hydrogen partial pressure, is the change in the estimated value of the hydrogen partial pressure, V st is the actual value of the fuel cell output voltage, is the estimated value of the fuel cell output voltage, is the error between the actual value of the fuel cell output voltage and the observed value of the fuel cell output voltage, K4 is the observation gain, T st is the stack temperature, I st is the stack current, k sm.out is the outlet flow coefficient of the supply pipe, k an.out is the anode channel outlet flow coefficient, m a is the mass fraction of hydrogen in the anode channel, is the predetermined nonlinear correction term.

9. A hydrogen fuel cell, characterized in that: The hydrogen supply control system for a hydrogen fuel cell according to any one of claims 1 to 4 is used to control the hydrogen supply.

10. A vehicle using the hydrogen fuel cell according to claim 9.

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