Fuel cell system, control method and device thereof, vehicle and storage medium

Abstract

The invention relates to a fuel cell system, a control method and device thereof, a vehicle and a storage medium, and relates to the technical field of fuel cells. The fuel cell system comprises switching valves arranged between a first injection reflux inlet and a hydrogen-water separator and between a second injection reflux inlet and the hydrogen-water separator, and the switching valves are used for controlling opening and closing of the first injection reflux inlet and the second injection reflux inlet; a controller configured to: obtain an input current actual value of the fuel cell system; and controlling the state of the switching valve according to the actual value of the input current of the fuel cell system. Therefore, the stability of the fuel cell system can be improved, and large pressure fluctuation of the fuel cell system is avoided.

Description

Technical Field

[0001] The present application relates to the field of communication technology, in particular to the field of fuel cell technology, and specifically to a fuel cell system and a control method, device, vehicle and storage medium thereof. Background Art

[0002] Fuel cells have long driving range and high output power. The hydrogen energy they use is also an important direction for environmental protection and emission reduction, and is often used in high-power fields such as vehicles. However, the pressure on the hydrogen side of the current fuel cell system fluctuates. For example, the pressure on the hydrogen side rises rapidly, which interferes with the electrochemical reaction in the reactor inside the battery fuel, thereby directly affecting the external output power of the fuel cell system, making it difficult for the vehicle to operate stably.

[0003] Although CN113067013B adopts a dual ejector design to cover the full power range, the switching of the dual ejectors easily causes pressure fluctuations. CN115207401B aims to control the hydrogen flow direction of a single ejector by adjusting the opening of a three-way valve, but the use of a single ejector still has the problem of pressure instability. Therefore, how to improve the pressure stability of the fuel cell system has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present application provides a fuel cell system and a control method, device, vehicle and storage medium thereof, so as to at least solve the technical problem of large pressure fluctuations in the fuel cell system in the related art. The technical solution of the present application is as follows:

[0005] According to a first aspect of the present application, a fuel cell system is provided, which includes: a hydrogen supply device for providing hydrogen to a fuel cell stack; an oxygen supply device for providing oxygen to a fuel cell stack; a fuel cell stack for generating electrical energy by chemically reacting the hydrogen provided by the hydrogen supply device with the oxygen provided by the oxygen supply device; a hydrogen-water separator connected to the hydrogen outlet of the fuel cell stack and used to separate nitrogen, liquid water and hydrogen in a mixed medium output from the hydrogen outlet of the fuel cell stack; a first ejector, wherein a first ejector reflux port of the first ejector is connected to the hydrogen-water separator; and a second ejector, wherein a second ejector reflux port of the second ejector is connected to the hydrogen-water separator, and the power of the fuel cell system suitable for the first ejector is smaller than that suitable for the second ejector. The power of the fuel cell system used; a switching valve is arranged between the first injection reflux port and the hydrogen-water separator, and between the second injection reflux port and the hydrogen-water separator, and the switching valve is used to control the conduction and closing of the first injection reflux port and the second injection reflux port; the injection reflux port is in a closed state, so that the hydrogen separated by the hydrogen-water separator is re-delivered to the fuel cell stack through the first injector; when the switching valve is in a second state, the first injection reflux port is in a closed state, and the second injection reflux port is in a conducting state, so that the hydrogen separated by the hydrogen-water separator is re-delivered to the fuel cell stack through the second injector; the controller is configured to: obtain an actual value of the input current of the fuel cell system; and control the state of the switching valve according to the actual value of the input current of the fuel cell system.

[0006] According to the above-mentioned technical means, the present application provides a fuel cell system, in which the actual value of the input current of the fuel cell system can reflect the current power of the fuel cell system. The state of the switching valve is adjusted by the actual value of the input current of the fuel cell system to select an ejector that matches the current power of the fuel cell system to deliver hydrogen to the fuel cell stack. This can not only meet the hydrogen demand of the fuel cell stack under different powers of the fuel cell system, but also effectively adjust the hydrogen flow rate of the hydrogen separated by the hydrogen-water separator and re-delivered to the fuel cell stack, so as to ensure the pressure stability at the hydrogen inlet of the fuel cell stack, that is, to ensure the pressure stability of the fuel cell system, thereby avoiding unstable performance of the fuel cell system due to pressure fluctuations.

[0007] In one possible embodiment, the controller is configured to control the state of the switching valve according to the actual value of the input current of the fuel cell system, including: when the actual value of the input current of the fuel cell system is less than a first threshold value, controlling the switching valve to be in a first state; when the actual value of the input current of the fuel cell system is greater than a second threshold value, controlling the switching valve to be in a second state; the second threshold value is greater than the first threshold value.

[0008] According to the above technical means, when the input current value of the fuel cell system is less than the first threshold value, that is, when the current power of the fuel cell system is relatively small, the first ejector is selected for use. When the input current value of the fuel cell system is greater than the second threshold value, that is, when the current power of the fuel cell system is relatively large, the second ejector is selected for use. In this way. By selecting an ejector that matches the current power, the waste of resources can be reduced. In addition, the ejector that matches the current power can more effectively regulate the hydrogen flow rate of the hydrogen separated by the hydrogen-water separator and re-delivered to the fuel cell stack, thereby maintaining a stable pressure at the hydrogen inlet of the fuel cell stack and avoiding unstable performance of the fuel cell system due to pressure fluctuations.

[0009] In another possible embodiment, the fuel cell system further includes: a nitrogen exhaust valve connected to the hydrogen-water separator, for exhausting the nitrogen separated by the hydrogen-water separator; a water drain valve connected to the hydrogen-water separator, for exhausting the liquid water separated by the hydrogen-water separator; the controller is further configured to: obtain the states of the nitrogen exhaust valve and the water drain valve; when the actual value of the input current of the fuel cell system is less than the first threshold value, and the nitrogen exhaust valve and the water drain valve are both in a closed state, control the switching valve to be in a first state; when the actual value of the input current of the fuel cell system is greater than the second threshold value, and the nitrogen exhaust valve and the water drain valve are both in a closed state, control the switching valve to be in a second state.

[0010] According to the above technical means, before adjusting the state of the switching valve, it is necessary to confirm that the nitrogen exhaust valve and the water drain valve are both in the closed state to avoid the state of the switching valve changing when the nitrogen exhaust valve and the water drain valve are in the open state. In this way, it can be prevented that the state of the switching valve changes when the nitrogen exhaust valve and the water drain valve are in the open state, causing the pressure at the hydrogen inlet of the fuel cell stack to drop rapidly, thereby affecting the performance of the fuel cell stack.

[0011] In another possible embodiment, the first injection inlet of the first ejector is connected to the hydrogen supply device, and the first injection outlet of the first ejector is connected to the hydrogen inlet of the fuel cell stack; the second injection inlet of the second ejector is connected to the hydrogen supply device, and the second injection outlet of the second ejector is connected to the hydrogen inlet of the fuel cell stack; the hydrogen provided by the hydrogen supply device is transported to the fuel cell stack through the first ejector and / or the second ejector; the fuel cell system also includes: a first proportional valve, arranged between the hydrogen supply device and the first injection inlet, for adjusting the hydrogen flow rate of the hydrogen provided by the hydrogen supply device through the first ejector; a second proportional valve, arranged between the hydrogen supply device and the second injection inlet, for adjusting the hydrogen flow rate of the hydrogen provided by the hydrogen supply device through the second ejector.

[0012] According to the above technical means, a corresponding proportional valve is provided for each ejector, so that the hydrogen flow rate of the hydrogen provided by the hydrogen supply device through the ejector can be more accurately adjusted, which helps to improve the stability of the fuel cell system.

[0013] In another possible embodiment, the controller is further configured to: after controlling the state of the switching valve, control the target proportional valve corresponding to the target ejector whose ejector reflux port is in the conducting state to open, and control the opening of the second target proportional valve corresponding to the second target ejector in the closed state to remain unchanged, so that the hydrogen flow rate of hydrogen provided by the hydrogen supply device through the second target ejector remains unchanged until the actual value of the input current of the fuel cell system meets the ejector switching condition for a duration exceeding the preset time; wherein the first target ejector is the first ejector, the first target proportional valve is the first proportional valve, the second target ejector is the second ejector, and the second target proportional valve is the second proportional valve; or, the first target ejector is the second ejector, the first target proportional valve is the second proportional valve, the second target ejector is the first ejector, and the second target proportional valve is the first proportional valve.

[0014] According to the above-mentioned technical means, after controlling the state of the switching valve, by delaying the closing of the second target proportional valve corresponding to the second target ejector, the fuel cell system can be given sufficient time to adapt to the pressure changes caused by the change in the state of the switching valve, thereby reducing the pressure fluctuations caused by the sudden closing of the target proportional valve.

[0015] In another possible embodiment, the controller is further configured to: obtain a hydrogen pressure request value and an actual hydrogen pressure value at the hydrogen inlet of the fuel cell stack; determine, based on the hydrogen pressure request value and the actual hydrogen pressure value, a corrected opening of a first target proportional valve corresponding to a first target ejector whose ejection reflux port is in a conducting state; wherein the first target ejector is a first ejector, and the first target proportional valve is a first proportional valve; or, the first target ejector is a second ejector, and the first target proportional valve is a second proportional valve; determine, based on a correspondence between an input current value and a feedforward opening of the proportional valve, a feedforward opening of the first target proportional valve corresponding to the actual input current value; determine a target opening of the first target proportional valve based on the feedforward opening of the target proportional valve and the corrected opening of the first target proportional valve; and adjust the opening of the first target proportional valve to the target opening to adjust the hydrogen flow rate of the hydrogen provided by the hydrogen supply device through the first target ejector.

[0016] According to the above technical means, based on the corresponding relationship between the input current value and the feedforward opening of the proportional valve, the feedforward opening of the first target proportional valve corresponding to the actual value of the input current can be preliminarily predicted to quickly respond to the current needs of the fuel cell system and improve the stability of the fuel cell system. In addition, according to the hydrogen pressure request value and the actual value of the hydrogen pressure, the correction opening of the first target proportional valve corresponding to the first target ejector in the conductive state of the ejector reflux port is determined to ensure a more accurate response. Then, through the feedforward opening of the target proportional valve and the correction opening of the target proportional valve, the prediction and the actual situation are effectively balanced, so that the opening adjustment of the first target proportional valve is more accurate.

[0017] In another possible embodiment, the controller is further configured as follows: in the process of the hydrogen separated by the hydrogen-water separator re-entering the fuel cell stack through the first target ejector whose ejection reflux port is in a conducting state, if the state of the nitrogen exhaust valve and / or the water drain valve is in an open state, then according to the correspondence between the input current value and the proportional valve opening compensation value, the opening compensation value of the first target proportional valve corresponding to the actual value of the input current is determined; wherein the first target ejector is the first ejector, and the first target proportional valve is the first proportional valve; or, the first target ejector is the second ejector, and the first target proportional valve is the second proportional valve; according to the opening compensation value of the first target proportional valve, the opening of the first target proportional valve is compensated to increase the hydrogen flow rate of the hydrogen provided by the hydrogen supply device through the first target ejector.

[0018] According to the above technical means, by compensating the opening of the target proportional valve to increase the hydrogen flow rate of the hydrogen provided by the hydrogen supply device through the target ejector, the hydrogen pressure fluctuation in the fuel cell stack caused by the escape of hydrogen or gas can be offset, thereby maintaining the stability of the hydrogen pressure in the fuel cell stack.

[0019] According to a second aspect provided by the present application, a control method for a fuel cell system is provided, the method comprising: obtaining an actual value of an input current of the fuel cell system; and controlling a state of a switching valve according to the actual value of the input current of the fuel cell system.

[0020] In one possible implementation, the state of the switching valve is controlled according to the actual value of the input current of the fuel cell system, including: when the actual value of the input current of the fuel cell system is less than a first threshold value, the switching valve is controlled to be in a first state; when the actual value of the input current of the fuel cell system is greater than a second threshold value, the switching valve is controlled to be in a second state; the second threshold value is greater than the first threshold value.

[0021] According to the third aspect provided by the present application, a control device for a fuel cell system is provided, which includes an acquisition unit and a control unit; the acquisition unit is used to acquire an actual value of an input current of the fuel cell system; the control unit is used to control the state of a switching valve according to the actual value of the input current of the fuel cell system.

[0022] According to the fourth aspect provided by the present application, a vehicle is provided, comprising: a processor; a memory for storing processor executable instructions; wherein the processor is configured to execute instructions to implement the method of the above-mentioned second aspect and any possible implementation manner thereof.

[0023] According to the fifth aspect provided by the present application, a computer-readable storage medium is provided. When the instructions in the computer-readable storage medium are executed by the processor of the vehicle, the vehicle is enabled to execute the method in the above-mentioned second aspect and any possible implementation method thereof.

[0024] According to the sixth aspect provided by the present application, a computer program product is provided, the computer program product comprising computer instructions, and when the computer instructions are executed on a vehicle, the vehicle executes the method of the above-mentioned second aspect and any possible implementation manner thereof.

[0025] Therefore, the above technical features of the present application have the following beneficial effects:

[0026] (1) The actual value of the input current of the fuel cell system can reflect the current power of the fuel cell system. The state of the switching valve is adjusted according to the actual value of the input current of the fuel cell system to select an ejector that matches the current power of the fuel cell system to transport hydrogen to the fuel cell stack. This can not only meet the hydrogen demand of the fuel cell stack under different powers of the fuel cell system, but also effectively adjust the hydrogen flow rate of the hydrogen separated by the hydrogen-water separator and re-transmitted to the fuel cell stack to ensure the pressure at the hydrogen inlet of the fuel cell stack is stable, that is, to ensure the pressure of the fuel cell system is stable, thereby avoiding unstable performance of the fuel cell system due to pressure fluctuations.

[0027] (2) When the input current value of the fuel cell system is less than the first threshold value, that is, when the current power of the fuel cell system is relatively small, the first ejector is selected for use. When the input current value of the fuel cell system is greater than the second threshold value, that is, when the current power of the fuel cell system is relatively large, the second ejector is selected for use. In this way. By selecting an ejector that matches the current power, the waste of resources can be reduced. In addition, the ejector that matches the current power can more effectively regulate the hydrogen flow rate of the hydrogen separated by the hydrogen-water separator and re-delivered to the fuel cell stack, thereby maintaining a stable pressure at the hydrogen inlet of the fuel cell stack and avoiding unstable performance of the fuel cell system due to pressure fluctuations.

[0028] (3) Before adjusting the state of the switching valve, it is necessary to confirm that both the nitrogen exhaust valve and the water drain valve are in the closed state to avoid the state of the switching valve changing when the nitrogen exhaust valve and the water drain valve are in the open state. In this way, it can be prevented that the state of the switching valve changes when the nitrogen exhaust valve and the water drain valve are in the open state, causing the pressure at the hydrogen inlet of the fuel cell stack to drop rapidly, thereby affecting the performance of the fuel cell stack.

[0029] (4) A corresponding proportional valve is provided for each ejector, so that the hydrogen flow rate of the hydrogen provided by the hydrogen supply device through the ejector can be more accurately adjusted, which helps to improve the stability of the fuel cell system.

[0030] (5) After controlling the state of the switching valve, by delaying the closing of the second target proportional valve corresponding to the second target ejector, the fuel cell system can be given sufficient time to adapt to the pressure change caused by the change in the state of the switching valve, thereby reducing the pressure fluctuation caused by the sudden closing of the target proportional valve.

[0031] (6) According to the corresponding relationship between the input current value and the feedforward opening of the proportional valve, the feedforward opening of the first target proportional valve corresponding to the actual value of the input current can be preliminarily predicted to quickly respond to the current demand of the fuel cell system and improve the stability of the fuel cell system. In addition, according to the hydrogen pressure request value and the actual value of the hydrogen pressure, the correction opening of the first target proportional valve corresponding to the first target ejector in the conductive state of the ejector reflux port can be determined to ensure a more accurate response. Then, through the feedforward opening of the target proportional valve and the correction opening of the target proportional valve, the prediction and the actual situation are effectively balanced, so that the opening adjustment of the first target proportional valve is more accurate.

[0032] (7) By compensating the opening of the target proportional valve to increase the hydrogen flow rate of the hydrogen provided by the hydrogen supply device through the target ejector, the hydrogen pressure fluctuation in the fuel cell stack caused by the escape of hydrogen or gas can be offset, thereby maintaining the stability of the hydrogen pressure in the fuel cell stack.

[0033] It should be noted that the technical effects brought about by any implementation method in the second to sixth aspects can refer to the technical effects brought about by the corresponding implementation method in the first aspect, and will not be repeated here.

[0034] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application, and do not constitute an improper limitation on the present application.

[0036] Figure 1 is a schematic diagram showing the composition of a fuel cell system according to an exemplary embodiment;

[0037] Figure 2 is a schematic diagram showing another fuel cell system composition according to an exemplary embodiment;

[0038] Figure 3 is a schematic diagram showing another fuel cell system composition according to an exemplary embodiment;

[0039] Figure 4 is a flow chart showing a method for controlling a fuel cell system according to an exemplary embodiment;

[0040] Figure 5 is a flow chart showing another method for controlling a fuel cell system according to an exemplary embodiment;

[0041] Figure 6 is a flow chart showing another method for controlling a fuel cell system according to an exemplary embodiment;

[0042] Figure 7 is a flow chart showing another method for controlling a fuel cell system according to an exemplary embodiment;

[0043] Figure 8 is a flow chart showing another method for controlling a fuel cell system according to an exemplary embodiment;

[0044] Fig. 9 is a flow chart showing another method for controlling a fuel cell system according to an exemplary embodiment;

[0045] Fig.10 is a block diagram of a control device for a fuel cell system according to an exemplary embodiment;

[0046] Fig.11 is a block diagram of a vehicle according to an exemplary embodiment. DETAILED DESCRIPTION

[0047] In order to enable ordinary persons in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0048] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0049] In order to solve the technical problem of large pressure fluctuations in fuel cell systems in related technologies, the present application proposes a control method for a fuel cell system. Since the actual value of the input current of the fuel cell system can reflect the current power of the fuel cell system, the state of the switching valve is adjusted according to the actual value of the input current of the fuel cell system to select an ejector that matches the current power of the fuel cell system to deliver hydrogen to the fuel cell stack. This can not only meet the hydrogen demand of the fuel cell stack under different powers of the fuel cell system, but also effectively adjust the hydrogen flow rate of the hydrogen separated by the hydrogen-water separator and re-delivered to the fuel cell stack, so as to ensure the pressure stability at the hydrogen inlet of the fuel cell stack, that is, to ensure the pressure stability of the fuel cell system, thereby avoiding unstable performance of the fuel cell system due to pressure fluctuations.

[0050] For ease of understanding, the control method of the fuel cell system provided in the present application is specifically introduced below with reference to the accompanying drawings.

[0051] Figure 1 FIG. 1 is a schematic diagram showing the composition of a fuel cell system according to an exemplary embodiment. Figure 1 As shown, the fuel cell system includes a hydrogen supply device 101 and an oxygen supply device 102 ( Figure 1 ), a first ejector 103, a second ejector 104, a fuel cell stack 105, a hydrogen-water separator 106, a nitrogen exhaust valve 107, a water drain valve 108, a tail exhaust pipe 109, and a controller 110 ( Figure 1 not shown).

[0052] In some embodiments, the hydrogen supply device 101 may be connected to the hydrogen inlet of the fuel cell stack 105 through the first ejector 103, or may be connected to the hydrogen inlet of the fuel cell stack 105 through the second ejector 104. Under the action of the first ejector 103 and / or the second ejector 104, the hydrogen supply device 101 may provide hydrogen to the fuel cell stack 105. For example, the hydrogen supply device 101 may be a hydrogen storage bottle.

[0053] In some embodiments, the oxygen supply device 102 is connected to the fuel cell stack 105 and can provide oxygen to the fuel cell stack 105 .

[0054] In some embodiments, the first ejector 103 is provided with a first ejection inlet, a first ejection outlet, and a first ejection reflux port. The first ejection inlet is connected to the hydrogen supply device 101, the first ejection outlet is connected to the hydrogen inlet of the fuel cell stack, and the first ejection reflux port is connected to the hydrogen-water separator 106. The first ejector 103 is used to output the hydrogen input from the first ejection inlet and the first ejection reflux port to the fuel cell stack 105 through the first ejection outlet.

[0055] In some embodiments, the second ejector 104 is provided with a second ejection inlet, a second ejection outlet and a second ejection reflux port. Wherein, the second ejection inlet is connected to the hydrogen supply device 101, the second ejection outlet is connected to the hydrogen inlet of the fuel cell stack, and the second ejection reflux port is connected to the hydrogen-water separator 106. The second ejector 104 is used to deliver hydrogen input from the second ejection inlet and the second ejection reflux port to the fuel cell stack 105 through the second ejection outlet. In some embodiments, in order to ensure that the fuel cell stack 105 can operate stably under different powers of the fuel cell system, the first ejector 103 can be set to a fuel cell system suitable for a smaller power range, and the second ejector 104 can be set to a fuel cell system suitable for a larger power range, that is, the power of the fuel cell system to which the first ejector 103 is applicable is less than the power of the fuel cell system to which the second ejector 104 is applicable. In this way, according to the power of the fuel cell system, the corresponding ejector can be flexibly selected to deliver hydrogen to the fuel cell stack 105, thereby accurately adjusting and maintaining the pressure stability at the hydrogen inlet of the fuel cell stack 105.

[0056] In some embodiments, the fuel cell stack 105 is used to generate electrical energy through a chemical reaction between hydrogen provided by the hydrogen supply device 101 and oxygen provided by the oxygen supply device 102 to power the vehicle.

[0057] In some embodiments, the hydrogen-water separator 106 is connected to the hydrogen outlet of the fuel cell stack 105 to separate nitrogen, liquid water and hydrogen in the mixed medium output from the hydrogen outlet of the fuel cell stack 105 .

[0058] In some embodiments, the nitrogen exhaust valve 107 is connected to the hydrogen-water separator 106 for exhausting the nitrogen separated by the hydrogen-water separator 106 .

[0059] In some embodiments, the drain valve 108 is connected to the hydrogen-water separator 106 for discharging the liquid water separated by the hydrogen-water separator 106 .

[0060] In some embodiments, the tail pipe 109 is used to receive the nitrogen and liquid water separated by the hydrogen-water separator 106 .

[0061] In some embodiments, the controller 110 refers to a device that can generate an operation control signal according to the instruction operation code and the timing signal to instruct the fuel cell system to execute the control instruction. Exemplarily, the controller can be a central processing unit (CPU), a general-purpose processor network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. The controller can also be other devices with processing functions, such as circuits, devices, or software modules, and the embodiments of the present application do not impose any restrictions on this.

[0062] Figure 2 FIG. 1 is a schematic diagram showing another fuel cell system composition according to an exemplary embodiment. Figure 2 As shown, the fuel cell system may include a switching valve 201 .

[0063] In some embodiments, the switching valve 201 is disposed between the first ejector 103 and the hydrogen-water separator 106, and between the second ejector 104 and the hydrogen-water separator 106. The switching valve 201 is used to control the conduction and closing of the first ejector reflux port and the second ejector reflux port. When the switching valve 201 is in the first state, the first ejector reflux port is in the conducting state, and the second ejector reflux port is in the closed state, so that the hydrogen separated by the hydrogen-water separator 106 is re-delivered to the fuel cell stack 105 through the first ejector 103; when the switching valve 201 is in the second state, the first ejector reflux port is in the closed state, and the second ejector reflux port is in the conducting state, so that the hydrogen separated by the hydrogen-water separator 106 is re-delivered to the fuel cell stack 105 through the second ejector 104.

[0064] Figure 3 FIG. 1 is a schematic diagram showing another fuel cell system composition according to an exemplary embodiment. Figure 3 As shown, the fuel cell system may include a first proportional valve 301 and a second proportional valve 302 .

[0065] In some embodiments, the first proportional valve 301 is disposed between the hydrogen supply device 101 and the first ejector 103 to adjust the hydrogen flow rate of the hydrogen provided by the hydrogen supply device 101 passing through the first ejector 103 .

[0066] In some embodiments, the second proportional valve 301 is disposed between the hydrogen supply device 101 and the second ejector 104 to adjust the hydrogen flow rate of the hydrogen provided by the hydrogen supply device 101 passing through the second ejector 104 .

[0067] In some embodiments, the fuel cell system may further include one or more of the following: a current sensor, a pressure sensor.

[0068] In some embodiments, a current sensor is used to detect an actual value of an input current of the fuel cell system.

[0069] In some embodiments, a pressure sensor is disposed at the hydrogen inlet of the fuel cell stack 105 to detect an actual value of the hydrogen pressure at the hydrogen inlet of the fuel cell stack 105 .

[0070] It should be noted that the system architecture and application scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Ordinary technicians in this field can know that with the evolution of the system architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0071] Figure 4 is a flow chart showing a control method of a fuel cell system according to an exemplary embodiment. Figure 4 As shown, the control method of the fuel cell system includes the following steps:

[0072] S101. Obtain an actual value of an input current of a fuel cell system.

[0073] As a possible implementation manner, the actual value of the input current of the fuel cell system may be obtained by a current sensor disposed at a current input end of the fuel cell system.

[0074] S102 . Control the state of the switching valve according to the actual value of the input current of the fuel cell system.

[0075] It can be understood that the actual value of the input current of the fuel cell system can reflect the operating power of the fuel cell system. By adjusting the state of the switching valve according to the actual value of the input current of the battery system and selecting an ejector that matches the operating power of the fuel cell system, it can be ensured that the fuel cell system can maintain stable output under different operating powers, thereby not only meeting the diverse operating conditions, but also improving the stability of the fuel cell system.

[0076] In some embodiments, the state of the switching valve includes a first state and a second state. When the switching valve is in the first state, the first ejector reflux port is in a conducting state, and the second ejector reflux port is in a closed state, so that the hydrogen separated by the hydrogen-water separator is re-delivered to the fuel cell stack through the first ejector; when the switching valve is in the second state, the first ejector reflux port is in a closed state, and the second ejector reflux port is in a conducting state, so that the hydrogen separated by the hydrogen-water separator is re-delivered to the fuel cell stack through the second ejector.

[0077] In some embodiments, since the fuel cell system usually operates in a relatively large power range, and the second ejector is applicable to a relatively large power fuel cell system, the initial state of the switching valve can be set to the second state, so that the hydrogen separated by the hydrogen-water separator is re-transported to the fuel cell stack through the second ejector. In this way, the frequent switching of the switching valve is reduced, thereby reducing the overall energy consumption.

[0078] In some embodiments, after controlling the state of the switching valve, the target proportional valve corresponding to the first target ejector whose ejection reflux port is in a conducting state is controlled to be opened, and the second target proportional valve corresponding to the second target ejector which is in a closed state is controlled to be closed, so that the hydrogen provided by the hydrogen supply device can only be delivered to the fuel cell stack through the first target ejector.

[0079] In other embodiments, after controlling the state of the switching valve, the target proportional valve corresponding to the first target ejector whose ejection reflux port is in the conducting state is controlled to open, and the opening of the second target proportional valve corresponding to the second target ejector in the closed state is controlled to remain unchanged, so that the hydrogen flow rate of the hydrogen provided by the hydrogen supply device through the second target ejector remains unchanged, until the actual value of the input current of the fuel cell system meets the ejector switching condition for a duration longer than the preset duration. Wherein, the first target ejector is the first ejector, the first target proportional valve is the first proportional valve, the second target ejector is the second ejector, and the second target proportional valve is the second proportional valve; or, the first target ejector is the second ejector, the first target proportional valve is the second proportional valve, the second target ejector is the first ejector, and the second target proportional valve is the first proportional valve.

[0080] It can be understood that after controlling the state of the switching valve, by delaying the closing of the second target proportional valve corresponding to the second target ejector, the fuel cell system can be given sufficient time to adapt to the pressure changes caused by the change in the state of the switching valve, thereby reducing the pressure fluctuations caused by the sudden closing of the target proportional valve.

[0081] based on Figure 4In the embodiment shown, the present application proposes a control method for a fuel cell system. Since the actual value of the input current of the fuel cell system can reflect the current power of the fuel cell system, the state of the switching valve is adjusted by the actual value of the input current of the fuel cell system to select an ejector that matches the current power of the fuel cell system to deliver hydrogen to the fuel cell stack. This can not only meet the hydrogen demand of the fuel cell stack under different powers of the fuel cell system, but also effectively adjust the hydrogen flow rate of the hydrogen separated by the hydrogen-water separator and re-delivered to the fuel cell stack, so as to ensure the pressure stability at the hydrogen inlet of the fuel cell stack, that is, to ensure the pressure stability of the fuel cell system, thereby avoiding unstable performance of the fuel cell system due to pressure fluctuations.

[0082] In some embodiments, Figure 5 As shown, in order to improve the stability of the fuel cell system, the above step S102 can be specifically implemented as the following steps S201-S203:

[0083] S201. When the actual value of the input current of the fuel cell system is less than a first threshold value, control the switching valve to be in a first state.

[0084] It is understandable that if the input current value of the fuel cell system is less than the first threshold value, it means that the current power of the fuel cell system is small and it is suitable to use the first ejector. Therefore, in this case, the switching valve can be controlled to be in the first state so that the hydrogen separated by the hydrogen-water separator is re-delivered to the fuel cell stack through the first ejector. In this way. By selecting an ejector that matches the current power, the waste of resources can be reduced. In addition, the ejector that matches the current power can more effectively regulate the hydrogen flow rate of the hydrogen separated by the hydrogen-water separator to be re-delivered to the fuel cell stack, thereby maintaining a stable pressure at the hydrogen inlet of the fuel cell stack, and avoiding unstable performance of the fuel cell system due to pressure fluctuations.

[0085] Exemplarily, when the actual value of the input current of the fuel cell system decreases from being greater than the second threshold value to being less than the first threshold value, the switching valve is controlled to switch from being in the second state to being in the first state.

[0086] In other embodiments, when the actual value of the input current of the fuel cell system decreases from greater than the second threshold to less than the third threshold and greater than the first threshold, the first proportional valve is controlled to open, wherein the third threshold is greater than the first threshold.

[0087] It can be understood that if the actual value of the input current is less than the third threshold value and greater than the first threshold value, it means that the actual value of the input current is close to the first threshold value. When the actual value of the input current is close to the first threshold value but has not reached the first threshold value, opening the first proportional valve in advance can ensure that the hydrogen delivered to the fuel cell pair is more stable and reduce the instantaneous pressure fluctuation when the switching valve is actuated.

[0088] Exemplarily, the second threshold is 10 A, the third threshold is 15 A, and the first threshold is 5 A. When the input current of the fuel cell system decreases from 18 A (greater than the second threshold) to 8 A (less than the third threshold and greater than the first threshold), the first proportional valve is controlled to open.

[0089] S202: When the actual value of the input current of the fuel cell system is not less than the first threshold value and when the actual value of the input current of the fuel cell system is greater than the second threshold value, control the switching valve to be in the second state.

[0090] The second threshold is greater than the first threshold.

[0091] It is understandable that if the input current value of the fuel cell system is greater than the second threshold value, it means that the current power of the fuel cell system is small and it is suitable to use the second ejector. Therefore, in this case, the switching valve can be controlled to be in the second state so that the hydrogen separated by the hydrogen-water separator is re-delivered to the fuel cell stack through the second ejector. In this way. By selecting an ejector that matches the current power, the waste of resources can be reduced. In addition, the ejector that matches the current power can more effectively regulate the hydrogen separated by the hydrogen-water separator to re-deliver the hydrogen flow rate to the fuel cell stack, thereby maintaining a stable pressure at the hydrogen inlet of the fuel cell stack, and avoiding unstable performance of the fuel cell system due to pressure fluctuations.

[0092] Exemplarily, when the actual value of the input current of the fuel cell system increases from less than a first threshold value to greater than a second threshold value, the switching valve is controlled to switch from the first state to the second state.

[0093] In other embodiments, when the actual value of the input current of the fuel cell system increases from less than the first threshold to greater than a fourth threshold and less than the second threshold, the second proportional valve is controlled to open, wherein the fourth threshold is less than the second threshold.

[0094] It can be understood that if the actual value of the input current is greater than the fourth threshold value and less than the second threshold value, it means that the actual value of the input current is close to the second threshold value. When the actual value of the input current is close to the second threshold value but has not reached the second threshold value, opening the second proportional valve in advance can ensure that the hydrogen delivered to the fuel cell pair is more stable and reduce the instantaneous pressure fluctuation when the switching valve is actuated.

[0095] Exemplarily, the first threshold is 5 A, the second threshold is 10 A, and the fourth threshold is 7 A. When the actual value of the input current of the fuel cell system increases from 4 A (less than the first threshold) to 8 A (greater than the fourth threshold and less than the second threshold), the second proportional valve is controlled to open.

[0096] S203: When the input current value of the fuel cell system is less than or equal to the second threshold value and greater than or equal to the first threshold value, control the switching valve to maintain the current state unchanged.

[0097] Exemplarily, if the switching valve is currently in the first state, and the input current value of the fuel cell system is less than or equal to the second threshold value and greater than or equal to the first threshold value, the switching valve continues to be controlled to be in the first state.

[0098] based on Figure 5 In the embodiment shown, the present application proposes another control method for a fuel cell system, in which the first ejector is selected for use when the input current value of the fuel cell system is less than the first threshold value, that is, when the current power of the fuel cell system is relatively small. When the input current value of the fuel cell system is greater than the second threshold value, that is, when the current power of the fuel cell system is relatively large, the second ejector is selected for use. In this way. By selecting an ejector that matches the current power, the waste of resources can be reduced. In addition, the ejector that matches the current power can more effectively regulate the hydrogen flow rate of the hydrogen separated by the hydrogen-water separator and re-delivered to the fuel cell stack, thereby maintaining a stable pressure at the hydrogen inlet of the fuel cell stack and avoiding unstable performance of the fuel cell system due to pressure fluctuations.

[0099] In other embodiments, in order to further improve the stability of the fuel cell system, the above step S102 may also be specifically implemented as the following steps S301-S303:

[0100] S301, obtaining the status of the nitrogen exhaust valve and the water exhaust valve.

[0101] As a possible implementation, during the operation of the fuel cell system, a Hall sensor disposed near the nitrogen exhaust valve can be used to monitor the magnetic field changes near the nitrogen exhaust valve and output a corresponding signal. When the exhaust valve is in an open or closed state, the Hall sensor detects different magnetic field strengths, thereby generating different signals. By analyzing these signals, the state of the nitrogen exhaust valve can be determined. Similarly, the specific determination process of the state of the drain valve can refer to the specific determination process of the state of the nitrogen exhaust valve described above, and this application will not be repeated here.

[0102] S302: When the actual value of the input current of the fuel cell system is less than the first threshold value and the nitrogen exhaust valve and the water exhaust valve are both in a closed state, control the switching valve to be in a first state.

[0103] It is understandable that when the nitrogen exhaust valve or the water drain valve is in the open state, if the state of the switching valve changes, the pressure at the hydrogen inlet of the fuel cell stack may drop rapidly, thereby affecting the performance of the fuel cell stack. Therefore, before adjusting the state of the switching valve, it is necessary to confirm that both the nitrogen exhaust valve and the water drain valve are in the closed state. Only when both are closed can the state of the switching valve be adjusted safely.

[0104] In addition, regarding the specific process of controlling the switching valve to be in the first state, reference may be made to the specific description of step S201 above, and this application will not elaborate on it here.

[0105] S303: When the actual value of the input current of the fuel cell system is greater than the second threshold value and the nitrogen exhaust valve and the water exhaust valve are both in the closed state, control the switching valve to be in the second state.

[0106] In addition, regarding the specific process of controlling the switching valve to be in the second state, reference may be made to the specific description of step S202 above, and this application will not elaborate on it here.

[0107] Based on the above steps S301-S302, the present application proposes another control method for a fuel cell system. Before adjusting the state of the switching valve, it is necessary to confirm that the nitrogen exhaust valve and the water drain valve are both in a closed state to avoid the state of the switching valve changing when the nitrogen exhaust valve and the water drain valve are in an open state. In this way, it is possible to prevent the state of the switching valve from changing when the nitrogen exhaust valve and the water drain valve are in an open state, thereby preventing the pressure at the hydrogen inlet of the fuel cell stack from dropping rapidly, thereby affecting the performance of the fuel cell stack.

[0108] In some embodiments, in order to control the pressure at the ejector outlet of the ejector and thus control the hydrogen pressure at the hydrogen inlet of the fuel cell stack, the control method of the fuel cell system provided in the embodiment of the present application further includes the following steps:

[0109] S401 . Obtain a requested value of hydrogen pressure and an actual value of hydrogen pressure at a hydrogen inlet of a fuel cell stack.

[0110] The hydrogen pressure request value is the hydrogen pressure at the hydrogen inlet of the fuel cell stack that is expected to be achieved.

[0111] As a possible implementation manner, the actual value of the hydrogen pressure at the hydrogen inlet of the fuel cell stack may be obtained by a hydrogen pressure sensor disposed at the inlet of the fuel cell stack.

[0112] S402: Determine, according to the hydrogen pressure request value and the hydrogen pressure actual value, a corrected opening of a first target proportional valve corresponding to a first target ejector whose ejector reflux port is in a conducting state.

[0113] Wherein, the first target ejector is a first ejector, and the first target proportional valve is a first proportional valve; or, the first target ejector is a second ejector, and the first target proportional valve is a second proportional valve.

[0114] As a possible implementation, the difference between the hydrogen pressure request value and the actual hydrogen pressure value can be input into the first target PID controller corresponding to the first target proportional valve, and then the target PID controller determines the corrected opening of the first target proportional valve through proportional integral derivative (PID) operation. Wherein, the first target proportional valve is the first proportional valve, and the first target PID controller is the first PID controller; or, the first target proportional valve is the second proportional valve, and the first target PID controller is the second PID controller.

[0115] As another possible implementation, the correspondence between the hydrogen pressure request value, the actual hydrogen pressure value and the corrected opening of the proportional valve may be determined in advance through experiments or simulations. Then, based on the correspondence between the hydrogen pressure request value, the actual hydrogen pressure value and the corrected opening of the proportional valve, the corrected opening of the first target proportional valve corresponding to the hydrogen pressure request value and the actual hydrogen pressure value may be determined.

[0116] S403 . Determine a first target proportional valve feedforward opening corresponding to the actual value of the input current according to a corresponding relationship between the input current value and the proportional valve feedforward opening.

[0117] As a possible implementation manner, the correspondence between the input current value and the proportional valve feedforward opening includes the correspondence between the input current value and the first proportional valve feedforward opening and the correspondence between the input current value and the second proportional valve feedforward opening.

[0118] In the case where the first target proportional valve is the first proportional valve, the feedforward opening of the first proportional valve corresponding to the actual value of the input current can be determined according to the corresponding relationship between the input current value and the feedforward opening of the first proportional valve. In the case where the first target proportional valve is the second proportional valve, the feedforward opening of the second proportional valve corresponding to the actual value of the input current can be determined according to the corresponding relationship between the input current value and the feedforward opening of the second proportional valve.

[0119] Exemplarily, the correspondence between the actual value of the input current and the feedforward opening of the proportional valve can be recorded in a feedforward opening mapping table, and then the feedforward opening of the first target proportional valve corresponding to the actual value of the input current can be found from the feedforward opening mapping table by table lookup.

[0120] S404 . Determine a first target opening of the first target proportional valve according to the feedforward opening of the first target proportional valve and the corrected opening of the first target proportional valve.

[0121] It can be understood that the feedforward opening of the first target proportional valve is obtained by preliminary prediction based on the current demand of the fuel cell system, so as to quickly respond to the current demand of the fuel cell system and improve the stability of the fuel cell system. The corrected opening of the first target proportional valve is the opening obtained by fine-tuning the actual feedback of the fuel cell system to ensure a more accurate response. The feedforward opening of the first target proportional valve and the corrected opening of the first target proportional valve effectively balance the prediction and the actual situation, making the control more intelligent and reliable.

[0122] As a possible implementation manner, the sum of the feedforward opening of the first target proportional valve and the corrected opening of the first target proportional valve may be determined as the first target opening of the first target proportional valve.

[0123] S405. Adjust the opening of the first target proportional valve to the target opening to adjust the hydrogen flow rate of the hydrogen provided by the hydrogen supply device through the first target ejector.

[0124] In some embodiments, before adjusting the opening of the first target proportional valve to the first target opening, it may be detected whether the fuel cell system meets a preset condition. When the fuel cell system meets the preset condition, the opening of the first target proportional valve is adjusted to the target opening. The preset condition may include: the fuel cell system is in a normal working state; the switching valve is in a second state. The fuel cell system is in a normal working state means that there is no fault in the fuel cell system that causes the fuel cell system to fail to operate normally.

[0125] The specific process of adjusting the opening of the first proportional valve is exemplarily described below. Figure 6 As shown, first, the hydrogen pressure request value and the actual hydrogen pressure value are input into the first PID controller to obtain the corrected opening of the first proportional valve output by the first PID controller. At the same time, according to the corresponding relationship between the input current value and the feedforward opening of the first proportional valve, the feedforward opening of the first proportional valve corresponding to the actual value of the input current is determined. Then, when the fuel cell system is in a normal working state and the switching valve is in the second state, the target opening of the first proportional valve is obtained according to the corrected opening of the first proportional valve output by the first PID controller and the feedforward opening of the first proportional valve.

[0126] The specific process of adjusting the opening of the second proportional valve is described below by way of example. Figure 7As shown, first, the hydrogen pressure request value and the actual hydrogen pressure value are input into the second PID controller to obtain the corrected opening of the second proportional valve output by the second PID controller. At the same time, according to the corresponding relationship between the input current value and the feedforward opening of the second proportional valve, the feedforward opening of the second proportional valve corresponding to the actual value of the input current is determined. Then, when the fuel cell system is in a normal working state and the switching valve is in the second state, the target opening of the second proportional valve is obtained according to the corrected opening of the second proportional valve output by the second PID controller and the feedforward opening of the second proportional valve.

[0127] Based on the above steps S401-S405, the present application proposes another control method for a fuel cell system. According to the corresponding relationship between the input current value and the feedforward opening of the proportional valve, the feedforward opening of the first target proportional valve corresponding to the actual value of the input current can be preliminarily predicted to quickly respond to the current needs of the fuel cell system and improve the stability of the fuel cell system. In addition, according to the hydrogen pressure request value and the actual value of the hydrogen pressure, the correction opening of the first target proportional valve corresponding to the first target ejector in the conductive state of the ejector reflux port is determined to ensure a more accurate response. Then, through the feedforward opening of the first target proportional valve and the correction opening of the first target proportional valve, the prediction and the actual situation are effectively balanced, so that the opening adjustment of the first target proportional valve is more accurate.

[0128] In some embodiments, in order to control the pressure at the hydrogen outlet of the fuel cell stack when the nitrogen exhaust valve or the water exhaust valve is in an open state, the control method of the fuel cell system provided in the embodiment of the present application further includes the following steps:

[0129] S501. In the process of the hydrogen separated by the hydrogen-water separator re-entering the fuel cell stack through the first target ejector whose ejector reflux port is in a conducting state, if the nitrogen exhaust valve or the water drain valve is in an open state, the opening compensation value of the first target proportional valve corresponding to the actual value of the input current is determined according to the corresponding relationship between the input current value and the proportional valve opening compensation value.

[0130] Wherein, the first target ejector is a first ejector, and the first target proportional valve is a first proportional valve; or, the first target ejector is a second ejector, and the first target proportional valve is a second proportional valve.

[0131] It is understandable that in the process of delivering hydrogen to the fuel cell stack through the first target ejector, when the nitrogen exhaust valve changes from a closed state to an open state, the hydrogen that has not been completely reacted in the fuel cell stack will be discharged through the nitrogen exhaust valve, causing the hydrogen pressure in the fuel cell stack to drop, causing pressure fluctuations, thereby affecting the performance of the fuel cell stack. In addition, when the drain valve changes from a closed state to an open state, the liquid water in the fuel cell stack will be discharged through the drain valve, and it may also take away part of the hydrogen and other gases in the fuel cell stack, thereby causing the hydrogen pressure in the fuel cell stack to drop, causing pressure fluctuations, thereby affecting the performance of the fuel cell stack. Therefore, by compensating the opening of the first target proportional valve to increase the hydrogen flow rate of the hydrogen provided by the hydrogen supply device through the first target ejector, the hydrogen pressure fluctuation in the fuel cell stack caused by the escape of hydrogen or gas can be offset, thereby maintaining the stability of the hydrogen pressure in the fuel cell stack.

[0132] As a possible implementation, the correspondence between the input current value and the proportional valve opening compensation value includes: a first correspondence between the input current value and the proportional valve opening compensation value and a second correspondence between the input current value and the proportional valve opening compensation value. When the nitrogen exhaust valve is in an open state, the first target proportional valve opening compensation value corresponding to the actual value of the input current is determined according to the first correspondence between the input current value and the proportional valve opening compensation value. When the drain valve is in an open state, the first target proportional valve opening compensation value corresponding to the actual value of the input current is determined according to the second correspondence between the input current value and the proportional valve opening compensation value.

[0133] Exemplarily, the correspondence between the actual value of the input current and the proportional valve opening compensation value may be stored in a mapping table, and then the first target proportional valve opening compensation value corresponding to the actual value of the input current may be obtained by a table lookup method.

[0134] S502. Compensate the opening of the first target proportional valve according to the opening compensation value of the first target proportional valve to increase the hydrogen flow rate of the hydrogen provided by the hydrogen supply device through the first target ejector.

[0135] It can be understood that by compensating the opening of the first target proportional valve to increase the hydrogen flow rate of hydrogen provided by the hydrogen supply device through the first target ejector, the hydrogen pressure fluctuations in the fuel cell stack caused by hydrogen or gas escape can be offset, thereby maintaining the stability of the hydrogen pressure in the fuel cell stack.

[0136] As a possible implementation method, when compensating the opening of the first target proportional valve, the opening change rate of the first target proportional valve can be limited by a speed limiter so that the opening change rate of the first target proportional valve matches the opening rate of the nitrogen exhaust valve or the water drain valve, thereby preventing the problem of abnormal increase in pressure at the hydrogen inlet of the fuel cell stack due to excessive compensation, thereby ensuring the stability and safety of the system operation.

[0137] In some embodiments, during the process of hydrogen separated by the hydrogen-water separator re-entering the fuel cell stack through the first target ejector whose ejection reflux port is in a conducting state, if the drain valve is in an open state, the current opening cycle and continuous opening time of the drain valve can be detected. When the current opening cycle of the drain valve reaches a preset cycle and / or the continuous opening time reaches a preset time, the drain valve is controlled to change from an open state to a closed state to avoid the complete discharge of liquid water in the hydrogen-water separator. It can also prevent part of the hydrogen and other gases in the fuel cell stack from escaping when the drain valve is opened, resulting in too low a pressure at the hydrogen inlet of the fuel cell stack. Even if the opening of the first target proportional valve is compensated, the hydrogen pressure fluctuation in the fuel cell stack caused by the escape of hydrogen or gas cannot be offset.

[0138] Similarly, in the process of the hydrogen separated by the hydrogen-water separator re-entering the fuel cell stack through the first target ejector whose ejection reflux port is in a conducting state, if the nitrogen exhaust valve is in an open state, the current opening cycle and continuous opening time of the nitrogen exhaust valve can be detected. When the current opening cycle of the nitrogen exhaust valve reaches the preset cycle and / or the continuous opening time reaches the preset time, the nitrogen exhaust valve is controlled to change from an open state to a closed state.

[0139] In combination with the above step S501 and step S502, the specific process of adjusting the opening of the first target proportional valve when the nitrogen exhaust valve is in the open state is exemplarily described below. Figure 8 As shown, first, the hydrogen pressure request value and the actual value of the hydrogen pressure are input into the target PID controller to obtain the corrected opening of the first target proportional valve output by the target PID controller. At the same time, according to the corresponding relationship between the input current value and the proportional valve feedforward opening, the feedforward opening of the first target proportional valve corresponding to the actual value of the input current is determined. At the same time, when the nitrogen exhaust valve is in an open state, the opening compensation value of the first target proportional valve corresponding to the actual value of the input current is also determined according to the first corresponding relationship between the input current value and the proportional valve opening compensation value. Then, when the fuel cell system is in a normal working state and the switching valve is in a second state, the target opening of the first target proportional valve is obtained according to the corrected opening of the first target proportional valve output by the second PID controller, the feedforward opening of the first target proportional valve, and the opening compensation value of the first target proportional valve.

[0140] In combination with the above step S501 and step S502, the specific process of adjusting the opening of the first target proportional valve when the drain valve is in the open state is exemplified below. Fig. 9 As shown, first, the hydrogen pressure request value and the actual value of the hydrogen pressure are input into the target PID controller to obtain the corrected opening of the first target proportional valve output by the target PID controller. At the same time, according to the corresponding relationship between the input current value and the proportional valve feedforward opening, the feedforward opening of the first target proportional valve corresponding to the actual value of the input current is determined. At the same time, when the drain valve is in the open state, the opening compensation value of the first target proportional valve corresponding to the actual value of the input current is also determined according to the second corresponding relationship between the input current value and the proportional valve opening compensation value. Then, when the fuel cell system is in a normal working state and the switching valve is in the second state, the target opening of the first target proportional valve is obtained according to the corrected opening of the first target proportional valve output by the second PID controller, the feedforward opening of the first target proportional valve, and the opening compensation value of the first target proportional valve.

[0141] Based on the above steps S501 and S502, the present application proposes another control method for a fuel cell system, which compensates for the opening of the first target proportional valve to increase the hydrogen flow rate of the hydrogen provided by the hydrogen supply device through the first target ejector, thereby offsetting the hydrogen pressure fluctuations in the fuel cell stack caused by hydrogen or gas escape, thereby maintaining the stability of the hydrogen pressure in the fuel cell stack.

[0142] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of the method. In order to achieve the above functions, the control device or vehicle of the fuel cell system includes a hardware structure and / or software module corresponding to the execution of each function. It should be easily appreciated by those skilled in the art that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0143] The embodiment of the present application can divide the control device or vehicle of the fuel cell system into functional modules according to the above method. For example, the control device or vehicle of the fuel cell system may include various functional modules corresponding to the various functional divisions, or two or more functions may be integrated into one processing module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. There may be other division methods in actual implementation.

[0144] Fig.10 FIG. 1 is a block diagram of a control device for a fuel cell system according to an exemplary embodiment. Fig.10 The control device 1000 of the fuel cell system includes: an acquisition unit 1001 and a control unit 1002.

[0145] Wherein, the acquisition unit 1001 is used to acquire the actual value of the input current of the fuel cell system;

[0146] The control unit 1002 is used to control the state of the switching valve according to the actual value of the input current of the fuel cell system.

[0147] According to the above-mentioned technical means, since the actual value of the input current of the fuel cell system can reflect the current power of the fuel cell system, the state of the switching valve is adjusted by the actual value of the input current of the fuel cell system to select an ejector that matches the current power of the fuel cell system to deliver hydrogen to the fuel cell stack. This can not only meet the hydrogen demand of the fuel cell stack under different powers of the fuel cell system, but also effectively adjust the hydrogen flow rate of the hydrogen separated by the hydrogen-water separator and re-delivered to the fuel cell stack, so as to ensure the pressure stability at the hydrogen inlet of the fuel cell stack, that is, to ensure the pressure stability of the fuel cell system, thereby avoiding unstable performance of the fuel cell system due to pressure fluctuations.

[0148] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0149] Fig.11 FIG. 1 is a block diagram of a vehicle according to an exemplary embodiment. Fig.11 As shown, vehicle 1100 includes, but is not limited to, a processor 1101 and a memory 1102 .

[0150] The memory 1102 is used to store executable instructions of the processor 1101. It can be understood that the processor 1101 is configured to execute instructions to implement the control method of the fuel cell system in the above embodiment.

[0151] It should be noted that those skilled in the art can understand that Fig.11 The vehicle structure shown in the figure does not constitute a limitation on the vehicle, and the vehicle may include Fig.11 More or fewer components may be shown, or certain components may be combined, or the components may be arranged differently.

[0152] The processor 1101 is the control center of the vehicle, which uses various interfaces and lines to connect various parts of the entire vehicle, and executes various functions of the vehicle and processes data by running or executing software programs and / or modules stored in the memory 1102, and calling data stored in the memory 1102, so as to monitor the vehicle as a whole. The processor 1101 may include one or more processing units. Optionally, the processor 1101 may integrate an application processor and a modem processor, wherein the application processor mainly processes the operating system, user interface, and application programs, etc., and the modem processor mainly processes wireless communications. It is understandable that the above-mentioned modem processor may not be integrated into the processor 1101.

[0153] The memory 1102 may be used to store software programs and various data. The memory 1102 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application program required by at least one functional module (such as a determination unit, a processing unit, etc.), etc. In addition, the memory 1102 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0154] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided, such as a memory 1102 including instructions, and the above instructions can be executed by the processor 1101 of the vehicle 1100 to implement the control method of the fuel cell system in the above embodiment.

[0155] In actual implementation, Fig.10 The functions of the acquisition unit 1001 and the control unit 1002 in Fig.11 The processor 1101 in the embodiment calls the computer program stored in the memory 1102 to implement. The specific execution process can refer to the description of the method part in the above embodiment, which will not be repeated here.

[0156] Optionally, the computer-readable storage medium may be a non-temporary computer-readable storage medium, for example, the non-temporary computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0157] In an exemplary embodiment, the present application also provides a computer program product including one or more instructions, which can be executed by the processor 1101 of the vehicle to implement the control method of the fuel cell system in the above embodiment.

[0158] It should be noted that when the instructions in the above-mentioned computer-readable storage medium or one or more instructions in the computer program product are executed by the vehicle's processor, the various processes of the above-mentioned method embodiment are implemented and the same technical effect as the above-mentioned method can be achieved. To avoid repetition, they will not be repeated here.

[0159] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0160] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0161] The units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0162] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0163] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or the full classification part or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium, including a number of instructions to enable a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to execute the full classification part or part of the steps of each embodiment method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, ROM, RAM, disk or CD and other media that can store program code.

[0164] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A fuel cell system, characterized in that: The fuel cell system comprises: A hydrogen supply device, used for providing hydrogen to the fuel cell stack; An oxygen supply device, used to provide oxygen to the fuel cell stack; A fuel cell stack, used to generate electrical energy through a chemical reaction between the hydrogen provided by the hydrogen supply device and the oxygen provided by the oxygen supply device; a hydrogen-water separator connected to the hydrogen outlet of the fuel cell stack and used to separate nitrogen, liquid water and hydrogen in the mixed medium output from the hydrogen outlet of the fuel cell stack; A first ejector, wherein a first ejector reflux port of the first ejector is connected to the hydrogen-water separator; A second ejector, wherein a second ejector reflux port of the second ejector is connected to the hydrogen-water separator, and the power of the fuel cell system to which the first ejector is applicable is smaller than the power of the fuel cell system to which the second ejector is applicable; a switching valve, arranged between the first ejection reflux port and the hydrogen-water separator, and between the second ejection reflux port and the hydrogen-water separator, the switching valve being used to control the conduction and closure of the first ejection reflux port and the second ejection reflux port; when the switching valve is in a first state, the first ejection reflux port is in an on state, and the second ejection reflux port is in a closed state, so that the hydrogen separated by the hydrogen-water separator is re-delivered to the fuel cell stack through the first ejector; when the switching valve is in a second state, the first ejection reflux port is in a closed state, and the second ejection reflux port is in an on state, so that the hydrogen separated by the hydrogen-water separator is re-delivered to the fuel cell stack through the second ejector; The controller is configured as: Acquiring an actual value of an input current of the fuel cell system; The state of the switching valve is controlled according to the actual value of the input current of the fuel cell system.

2. The fuel cell system according to claim 1, characterized in that: The controller is configured to control the state of the switching valve according to the actual value of the input current of the fuel cell system, including: When the actual value of the input current of the fuel cell system is less than a first threshold value, controlling the switching valve to be in the first state; When the actual value of the input current of the fuel cell system is greater than a second threshold, the switching valve is controlled to be in the second state; the second threshold is greater than the first threshold.

3. The fuel cell system according to claim 2, characterized in that: The fuel cell system further comprises: a nitrogen exhaust valve, connected to the hydrogen-water separator, for exhausting the nitrogen separated by the hydrogen-water separator; a drain valve connected to the hydrogen-water separator and used to discharge the liquid water separated by the hydrogen-water separator; The controller is also configured to: Acquiring the states of the nitrogen exhaust valve and the water exhaust valve; When the actual value of the input current of the fuel cell system is less than a first threshold value and the nitrogen exhaust valve and the water drain valve are both in a closed state, controlling the switching valve to be in the first state; When the actual value of the input current of the fuel cell system is greater than a second threshold value and the nitrogen exhaust valve and the water exhaust valve are both in a closed state, the switching valve is controlled to be in the second state.

4. The system according to claim 1, characterized in that The first ejector inlet is connected to the hydrogen supply device, and the first ejector outlet is connected to the hydrogen inlet of the fuel cell stack; the second ejector inlet is connected to the hydrogen supply device, and the second ejector outlet is connected to the hydrogen inlet of the fuel cell stack; The hydrogen provided by the hydrogen supply device is transported to the fuel cell stack through the first ejector and / or the second ejector; The fuel cell system further comprises: a first proportional valve, disposed between the hydrogen supply device and the first ejector inlet, for adjusting a hydrogen flow rate of the hydrogen provided by the hydrogen supply device passing through the first ejector; The second proportional valve is arranged between the hydrogen supply device and the second ejector inlet, and is used to adjust the hydrogen flow rate of the hydrogen provided by the hydrogen supply device passing through the second ejector.

5. The system according to claim 4, characterized in that The controller is also configured to: After controlling the state of the switching valve, the first target proportional valve corresponding to the first target ejector whose ejection reflux port is in the conducting state is controlled to open, and the opening degree of the second target proportional valve corresponding to the second target ejector in the closed state is controlled to remain unchanged, so that the hydrogen flow rate of the hydrogen provided by the hydrogen supply device through the second target ejector remains unchanged, until the duration of the actual value of the input current of the fuel cell system meeting the ejector switching condition reaches a preset duration or longer; Among them, the first target ejector is the first ejector, the first target proportional valve is the first proportional valve, the second target ejector is the second ejector, and the second target proportional valve is the second proportional valve; or, the first target ejector is the second ejector, the first target proportional valve is the second proportional valve, the second target ejector is the first ejector, and the second target proportional valve is the first proportional valve.

6. The system according to claim 4, characterized in that The controller is also configured to: Acquiring a hydrogen pressure request value and an actual hydrogen pressure value at a hydrogen inlet of the fuel cell stack; Determine, according to the hydrogen pressure request value and the hydrogen pressure actual value, a corrected opening of a first target proportional valve corresponding to a first target ejector whose ejection reflux port is in the conducting state; wherein the first target ejector is the first ejector, and the first target proportional valve is the first proportional valve; or, the first target ejector is the second ejector, and the first target proportional valve is the second proportional valve; Determining the feedforward opening of the first target proportional valve corresponding to the actual value of the input current according to the corresponding relationship between the input current value and the feedforward opening of the proportional valve; determining a target opening of the first target proportional valve according to the feedforward opening of the target proportional valve and the corrected opening of the first target proportional valve; The opening of the first target proportional valve is adjusted to the target opening to adjust the hydrogen flow rate of the hydrogen provided by the hydrogen supply device passing through the first target ejector.

7. The system according to claim 3, characterized in that The controller is also configured to: In the process that the hydrogen separated by the hydrogen-water separator re-enters the fuel cell stack through the first target ejector whose ejection reflux port is in the conductive state, if the state of the nitrogen exhaust valve or the water drain valve is in the open state, the opening compensation value of the first target proportional valve corresponding to the actual value of the input current is determined according to the corresponding relationship between the input current value and the proportional valve opening compensation value; wherein the first target ejector is the first ejector, and the first target proportional valve is the first proportional valve; or, the first target ejector is the second ejector, and the first target proportional valve is the second proportional valve; The opening of the first target proportional valve is compensated according to the opening compensation value of the first target proportional valve to increase the hydrogen flow rate of the hydrogen provided by the hydrogen supply device passing through the first target ejector.

8. A control method for a fuel cell system, characterized in that: The method comprises: Acquiring an actual value of an input current of the fuel cell system; The state of the switching valve is controlled according to the actual value of the input current of the fuel cell system.

9. The method according to claim 8, characterized in that The step of controlling the state of the switching valve according to the actual value of the input current of the fuel cell system comprises: When the actual value of the input current of the fuel cell system is less than a first threshold value, controlling the switching valve to be in a first state; When the actual value of the input current of the fuel cell system is greater than a second threshold, the switching valve is controlled to be in a second state; the second threshold is greater than the first threshold.

10. A control device for a fuel cell system, characterized in that: It includes an acquisition unit and a control unit; The acquisition unit is used to acquire the actual value of the input current of the fuel cell system; The control unit is used to control the state of the switching valve according to the actual value of the input current of the fuel cell system.

11. A vehicle, characterized in that: include: processor; a memory for storing instructions executable by the processor; The processor is configured to execute the instructions to implement the method according to claim 8 or 9.

12. A computer-readable storage medium, characterized in that: When the computer-executable instructions stored in the computer-readable storage medium are executed by a processor of a vehicle, the vehicle is capable of performing the method of claim 8 or 9.

13. A computer program product, characterized in that The computer program product comprises computer instructions which, when executed on a vehicle, cause the vehicle to perform the method according to claim 8 or 9 .

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