Fuel cell system, vehicle, and control method

Abstract

The application relates to a fuel cell system, a vehicle and a control method, which comprises the following steps: the positive and negative electrodes of a first electric pile are connected with the positive and negative input ends of a first conversion assembly respectively, the positive and negative output ends of the first conversion assembly are connected with the first and second input ends of a first switch assembly respectively, the first and second output ends of the first switch assembly are connected with the first and second input ends of a second switch assembly respectively, the output end of the second switch assembly is connected with a high-voltage bus of the vehicle, the positive and negative electrodes of a second electric pile are connected with the positive and negative input ends of a second conversion assembly respectively, the positive output end of the second electric pile is connected with a first connecting node, the negative output end of the second electric pile is connected with a second connecting node, and an auxiliary machine assembly is connected with the third and fourth connecting nodes between the first and second switch assemblies. Therefore, the problems that a high-power liquid hydrogen fuel cell cannot realize zero-power output and the heat of liquid hydrogen gasification is insufficient are solved.

Description

Technical Field

[0001] This application relates to the field of fuel cell technology, and in particular to a fuel cell system, vehicle, and control method. Background Technology

[0002] Zero-power output mode is a key function of fuel cell systems in vehicle applications. In China's road traffic environment, congestion is severe, average vehicle speeds are low, and the proportion of vehicles idling is relatively high. For fuel cell vehicles, when idling, when the battery's state of charge (SOC) is high, or in other states where charging is not permitted, the vehicle's power demand is zero, requiring the fuel cell system to enter zero-power output mode.

[0003] In related technologies, the method to achieve zero power output is usually to keep the fuel cell stack in a low power output state, using the Balance of Plant (BOP) to consume the power output of the stack, so that the overall system output power is zero. For fuel cell systems using liquid hydrogen, the liquid hydrogen needs to be vaporized before it can be supplied to the stack. Traditional liquid hydrogen vaporizers generally use waste heat from the fuel cell for water bath heating or air bath heating.

[0004] However, in related technologies, for high-power fuel cell systems, due to the large number of stack segments, the minimum sustainable output power is often high to avoid performance degradation caused by excessively high stack voltage. This means that in zero-power mode, the Balance of Power (BOP) cannot fully utilize the stack power, and the stack output is usually stopped while maintaining low-power operation of the BOP. In this state, the system as a whole is in a negative power mode, consuming the power of the entire vehicle, and cannot achieve true zero power. Prolonged operation in this mode leads to poor vehicle economy. Furthermore, in low ambient temperatures and during cold starts of the fuel cell system, the stack cooling water temperature is too low to provide sufficient waste heat, while the system has a high demand for gaseous hydrogen. The liquid hydrogen vaporization rate cannot meet the hydrogen demand, limiting the system power output. When a high-power fuel cell system using liquid hydrogen has zero power demand, the stack stops working, resulting in the inability to provide heat for liquid hydrogen vaporization. In zero power mode, hydrogen purging still needs to be maintained to consume a small amount of hydrogen. As the zero power operation time increases, the gaseous hydrogen stored in the liquid hydrogen vaporizer and pipeline is gradually consumed. When the fuel cell needs to be restarted, there is not enough pressure and flow of gaseous hydrogen to supply, causing the system to fail to start normally, which urgently needs to be solved. Summary of the Invention

[0005] This application provides a fuel cell system, vehicle, and control method to solve problems such as the inability of high-power liquid hydrogen fuel cells to achieve zero power output and insufficient heat for liquid hydrogen vaporization.

[0006] The first aspect of this application provides a fuel cell system, including: The system comprises a first fuel cell stack, a second fuel cell stack, a first conversion assembly, a second conversion assembly, a first switching assembly, a second switching assembly, and an auxiliary assembly, wherein... The positive output terminal of the first fuel cell stack is electrically connected to the positive input terminal of the first conversion component, and the negative output terminal of the first fuel cell stack is electrically connected to the negative input terminal of the first conversion component. The positive output terminal of the first conversion component is electrically connected to the first input terminal of the first switching component, and the negative output terminal of the first conversion component is electrically connected to the second input terminal of the first switching component. The first output terminal of the first switch assembly is electrically connected to the first input terminal of the second switch assembly, and the second output terminal of the first switch assembly is electrically connected to the second input terminal of the second switch assembly. The output terminal of the second switch assembly is electrically connected to the high-voltage busbar of the vehicle. The positive output terminal of the second fuel cell stack is electrically connected to the positive input terminal of the second conversion component, and the negative output terminal of the second fuel cell stack is electrically connected to the negative input terminal of the second conversion component. The positive output terminal of the second battery stack is electrically connected to the first connection node between the first switching assembly and the second switching assembly, and the negative output terminal of the second battery stack is electrically connected to the second connection node between the first switching assembly and the second switching assembly. The first input terminal of the auxiliary component is electrically connected to the third connection node between the first switch component and the second switch component, and the second input terminal of the auxiliary component is electrically connected to the fourth connection node between the first switch component and the second switch component.

[0007] Optionally, the auxiliary component includes: The oxygen supply unit includes a multi-way valve and a throttle assembly, wherein... The input terminal of the multi-way valve is connected to the input terminal of the oxygen supply unit, the first output terminal of the multi-way valve is connected to the oxygen input terminal of the first fuel cell stack, the second output terminal of the multi-way valve is connected to the oxygen input terminal of the second fuel cell stack, the first input terminal of the throttle assembly is connected to the gas output terminal of the first fuel cell stack, the second input terminal of the throttle assembly is connected to the gas output terminal of the second fuel cell stack, and the output terminal of the throttle assembly is connected to the output terminal of the oxygen supply unit.

[0008] The throttle valve assembly includes: The first throttle valve has its input terminal connected to the gas output terminal of the first fuel cell stack, and its output terminal connected to the output terminal of the oxygen supply unit. The second throttle valve has its input terminal connected to the gas output terminal of the second fuel cell stack, and the output terminal of the first throttle valve is connected to the output terminal of the oxygen supply unit.

[0009] Optionally, the oxygen supply unit further includes: The system includes an air compressor unit, an intercooler unit, a third throttle valve, an air-water separator unit, an expansion unit, and a muffler unit. The input terminal of the air compressor unit is used to input air, and the output terminal of the air compressor unit is connected to the input terminal of the intercooler unit. The output terminal of the intercooler unit is connected to the input terminal of the multi-way valve and the input terminal of the third throttle valve, respectively. The output end of the third throttle valve is connected to the input end of the gas-water separation unit; The input terminal of the gas-water separation unit is connected to the output terminal of the first throttle valve and the output terminal of the second throttle valve, respectively. The first output terminal of the gas-water separation unit is connected to the input terminal of the expansion unit, and the second output terminal of the gas-water separation unit is connected to the input terminal of the muffler unit. The output terminal of the expansion unit is connected to the input terminal of the silencing unit; The output of the noise reduction unit is connected to the atmosphere.

[0010] Optionally, the auxiliary equipment component further includes: First cooling unit and second cooling unit, wherein... The second cooling unit includes a liquid hydrogen water bath vaporizer and a water pump, wherein, The input end of the liquid hydrogen water bath vaporizer is connected to the coolant output end of the second fuel cell stack, and the output end of the liquid hydrogen water bath vaporizer is connected to the input end of the water pump. The output end of the water pump is connected to the coolant input end of the second fuel cell stack.

[0011] Optionally, the first switching assembly includes: a first contactor and a second contactor, wherein, One end of the first contactor is electrically connected to the positive output terminal of the first fuel cell stack, and the other end of the first contactor is electrically connected to the first input terminal of the second switching assembly. One end of the second contactor is electrically connected to the negative output terminal of the first fuel cell stack, and the other end of the second contactor is electrically connected to the second input terminal of the second switching assembly. The second switching assembly includes a third contactor and a fourth contactor, wherein, One end of the third contactor is electrically connected to the other end of the first contactor, and the other end of the third contactor is electrically connected to the positive terminal of the high-voltage busbar of the vehicle. One end of the fourth contactor is electrically connected to the other end of the second contactor, and the other end of the fourth contactor is electrically connected to the negative terminal of the vehicle's high-voltage busbar.

[0012] A second aspect of this application provides a vehicle employing a fuel cell system as described in any of the preceding claims.

[0013] A third aspect of this application provides a control method for a fuel cell system, employing a fuel cell system as shown in any of the above embodiments, comprising the following steps: Obtain the vehicle's total power requirements; The target power mode of the fuel cell system is determined based on the power range in which the vehicle's power demand is located. The first stack, second stack, first switching assembly, second switching assembly, and auxiliary equipment of the fuel cell system are controlled according to the control strategy corresponding to the target power mode.

[0014] Optionally, the target power mode is a zero power mode, and the control of the first stack, second stack, first switching assembly, second switching assembly, and auxiliary equipment of the fuel cell system according to the control strategy corresponding to the target power mode includes: The first fuel cell stack is controlled to be in a shutdown state, and the second fuel cell stack is controlled to be in an operating state; The first switch assembly is controlled to be in the open state, and the second switch assembly is controlled to be in the closed state; The first hydrogen supply unit of the auxiliary equipment assembly is controlled to supply hydrogen to the first fuel cell stack based on the first hydrogen supply pressure, and the second hydrogen supply unit of the auxiliary equipment assembly is controlled to supply hydrogen to the second fuel cell stack based on the second hydrogen supply pressure; The first output terminal of the multi-way valve of the oxygen supply unit of the auxiliary machine component is closed, and the second output terminal of the multi-way valve is opened, while the output terminal of the first throttle valve is closed. The water pump of the cooling unit corresponding to the first fuel cell stack is controlled to be at the first target power, and the cooling circuit of the cooling unit corresponding to the second fuel cell stack is controlled to be connected to the liquid hydrogen water bath vaporizer. The output power of the second fuel cell stack is controlled to be equal to the power consumed by the auxiliary components.

[0015] Optionally, the target power mode is a first power mode, and the control of the first stack, second stack, first switching assembly, second switching assembly, and auxiliary assembly of the fuel cell system according to the control strategy corresponding to the target power mode includes: The first fuel cell stack is controlled to be in a shutdown state, and the second fuel cell stack is controlled to be in an operating state; The first switch assembly is controlled to be in the open state, and the second switch assembly is controlled to be in the closed state; The first hydrogen supply unit of the auxiliary equipment component is controlled to supply hydrogen to the first fuel cell stack based on a third hydrogen supply pressure, and the second hydrogen supply unit of the auxiliary equipment component is controlled to supply hydrogen to the second fuel cell stack based on a fourth hydrogen supply pressure, wherein the fourth hydrogen supply pressure is greater than the third hydrogen supply pressure; The first output terminal of the multi-way valve of the oxygen supply unit of the auxiliary machine component is closed, and the second output terminal of the multi-way valve is opened, while the output terminal of the first throttle valve is closed. The water pump of the cooling unit corresponding to the first fuel cell stack is controlled to be at the first target power, and the cooling circuit of the cooling unit corresponding to the second fuel cell stack is controlled to be connected to the liquid hydrogen water bath vaporizer. The output power of the second fuel cell stack is controlled to be equal to the power consumed by the auxiliary components and the power required by the vehicle.

[0016] Optionally, the target power mode is a second power mode, where the output power of the second power mode is greater than the output power of the first power mode. The step of controlling the first fuel cell stack, second fuel cell stack, first switching assembly, second switching assembly, and auxiliary equipment assembly of the fuel cell system according to the control strategy corresponding to the target power mode includes: Control the first fuel cell stack and the second fuel cell stack to be in working condition; Both the first switch assembly and the second switch assembly are controlled to be in a closed state; The first hydrogen supply unit of the auxiliary equipment assembly supplies hydrogen to the first fuel cell stack based on the fifth hydrogen supply pressure, and controls the second hydrogen supply unit of the auxiliary equipment assembly to supply hydrogen to the second fuel cell stack based on the sixth hydrogen supply pressure; The first output terminal of the multi-way valve of the oxygen supply unit of the auxiliary machine component is controlled to be at a first opening degree, and the second output terminal of the multi-way valve is controlled to be at a second opening degree; The water pump of the cooling unit corresponding to the first fuel cell stack is controlled to be at the second target power, and the cooling circuit of the cooling unit corresponding to the second fuel cell stack is controlled to be connected to the liquid hydrogen water bath vaporizer. The total output power of the first fuel cell stack and the second fuel cell stack is controlled to be equal to the power consumed by the auxiliary components and the power required by the vehicle.

[0017] Therefore, the positive and negative terminals of the first fuel cell stack are respectively connected to the positive and negative input terminals of the first conversion component, and the positive and negative output terminals of the first conversion component are respectively connected to the first and second input terminals of the first switching component; the first and second output terminals of the first switching component are respectively connected to the first and second input terminals of the second switching component, and the output terminal of the second switching component is connected to the high-voltage bus of the vehicle; the positive and negative terminals of the second fuel cell stack are respectively connected to the positive and negative input terminals of the second conversion component, the positive output terminal of the second fuel cell stack is connected to the first connection node, and the negative output terminal of the second fuel cell stack is connected to the second connection node; the auxiliary equipment component and the third and fourth connection nodes between the first and second switching components are connected. This solves the problems of high-power liquid hydrogen fuel cells being unable to achieve zero power output and insufficient heat for liquid hydrogen vaporization.

[0018] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of a fuel cell system provided in accordance with this application; Figure 2 This is a schematic diagram of the high-voltage electrical architecture of a fuel cell system according to this application; Figure 3 This is a schematic diagram of the air subsystem and auxiliary stack cooling circuit subsystem of a fuel cell system according to this application; Figure 4 This is a flowchart illustrating the operation of a fuel cell system according to this application; Figure 5 This is a flowchart of a control method for a fuel cell system provided in this application. Detailed Implementation

[0020] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0021] Before introducing the fuel cell system of the embodiments of this application, let's briefly introduce the fuel cell system in related technologies.

[0022] Zero-power output mode is a key function of fuel cell systems in vehicle applications. Currently, China's road conditions are characterized by severe congestion, low average vehicle speeds, and a relatively high proportion of idling. For fuel cell vehicles, when idling, when the battery's state of charge (SOC) is high, or in other states where charging is not permitted, the vehicle's power demand is zero, necessitating the fuel cell to enter zero-power output mode. Currently, the most common method for achieving zero-power output is to keep the fuel cell stack in a low-power output state, allowing the battery plant (BOP) to consume the stack's output power, resulting in zero overall system output power. However, for high-power fuel cell systems, with a large number of stack cells, the minimum sustainable output power of the stack is often high to avoid excessive voltage and performance degradation. This means that in zero-power mode, the BOP cannot fully consume the stack's power. Therefore, for high-power fuel cell systems, zero-power mode typically involves stopping the stack's output and maintaining low-power operation of the BOP. In this state, the system is in a negative power mode, consuming the vehicle's power, and cannot achieve true zero power. Prolonged operation in this state leads to poor vehicle fuel economy.

[0023] Liquid hydrogen has a much higher volumetric energy density than high-pressure gaseous hydrogen, making it crucial for vehicles requiring long driving ranges (such as heavy trucks and long-distance buses). However, liquid hydrogen needs to be vaporized before it can be supplied to fuel cell systems. Traditional liquid hydrogen vaporizers typically use waste heat from the fuel cell for water bath heating or air bath heating. However, when the ambient temperature is low and the fuel cell system is undergoing a cold start, the low temperature of the fuel cell stack cooling water means that it cannot provide enough waste heat. Furthermore, when the fuel cell requires a large flow rate of gaseous hydrogen, the liquid hydrogen vaporization rate cannot meet the fuel cell's hydrogen demand. This results in insufficient hydrogen flow and pressure to meet the system's operational requirements, thus limiting the system's power output.

[0024] Furthermore, when a high-power fuel cell system using liquid hydrogen has zero-power requirements, the stack needs to be shut down, resulting in a lack of heat to provide for liquid hydrogen vaporization. In zero-power mode, hydrogen purging is maintained, which also consumes a small amount of hydrogen. As zero-power operation continues, the gaseous hydrogen stored in the liquid hydrogen vaporizer and pipelines is gradually depleted. When the fuel cell needs to be restarted, there is insufficient pressure and flow of gaseous hydrogen to supply, preventing the fuel cell system from starting normally.

[0025] In summary, high-power fuel cell systems cannot achieve true zero power operation; liquid hydrogen fuel cell systems have insufficient heat of vaporization during zero-power operation; and high-power fuel cell systems have a high minimum sustainable output power, which cannot meet the low-power requirements of the vehicle.

[0026] This application addresses the aforementioned problems by proposing a fuel cell system in which the positive and negative terminals of a first fuel cell stack are connected to the positive and negative input terminals of a first conversion component, respectively; the positive and negative output terminals of the first conversion component are connected to the first and second input terminals of a first switching component, respectively; the first and second output terminals of the first switching component are connected to the first and second input terminals of the second switching component, respectively; and the output terminal of the second switching component is connected to the high-voltage bus of the vehicle. The positive and negative terminals of a second fuel cell stack are connected to the positive and negative input terminals of the second conversion component, respectively; the positive output terminal of the second fuel cell stack is connected to a first connection node; and the negative output terminal of the second fuel cell stack is connected to a second connection node. The auxiliary equipment component and the third and fourth connection nodes between the first and second switching components are connected. This solves the problems of high-power liquid hydrogen fuel cells being unable to achieve zero-power output and insufficient heat for liquid hydrogen vaporization.

[0027] Specifically, Figure 1 This is a schematic diagram of a fuel cell system provided in an embodiment of this application.

[0028] like Figure 1 As shown, the fuel cell system 10 includes: a first fuel cell stack 100, a second fuel cell stack 200, a first conversion assembly 300, a second conversion assembly 400, a first switching assembly 500, a second switching assembly 600, and an auxiliary equipment assembly 700, wherein, The positive output terminal of the first fuel cell stack 100 is electrically connected to the positive input terminal of the first conversion component 300, and the negative output terminal of the first fuel cell stack 100 is electrically connected to the negative input terminal of the first conversion component 300. The positive output terminal of the first conversion component 300 is electrically connected to the first input terminal of the first switching component 500, and the negative output terminal of the first conversion component 300 is electrically connected to the second input terminal of the first switching component 500. The first output terminal of the first switch assembly 500 is electrically connected to the first input terminal of the second switch assembly 600, and the second output terminal of the first switch assembly 500 is electrically connected to the second input terminal of the second switch assembly 600. The output terminal of the second switch assembly 600 is electrically connected to the high-voltage bus of the vehicle. The positive output terminal of the second battery stack 200 is electrically connected to the positive input terminal of the second conversion component 400, and the negative output terminal of the second battery stack 200 is electrically connected to the negative input terminal of the second conversion component 400. The positive output terminal of the second battery stack 200 is electrically connected to the first connection node between the first switch assembly 500 and the second switch assembly 600, and the negative output terminal of the second battery stack 200 is electrically connected to the second connection node between the first switch assembly 500 and the second switch assembly 600. The first input terminal of the auxiliary component 700 is electrically connected to the third connection node between the first switch component 500 and the second switch component 600, and the second input terminal of the auxiliary component 700 is electrically connected to the fourth connection node between the first switch component 500 and the second switch component 600.

[0029] Specifically, high-power fuel cell systems are generally dual-stack parallel configurations. This application adds an auxiliary small-power stack to the dual-stack configuration of a high-power fuel cell system, resulting in a system architecture of main stack (first stack 100) + auxiliary stack (second stack 200). Figure 2 As shown, Figure 2 This is a schematic diagram of the high-voltage electrical architecture of a fuel cell system according to this application. The auxiliary stack is matched with the main DC-DC system and the auxiliary small DC-DC system, respectively. The main DC-DC has a larger power output, matching the system power, while the auxiliary DC-DC has a smaller power output. However, the voltage platforms at the high-voltage output terminals of the main and auxiliary DC-DC should be the same. The positive and negative output terminals of the main and auxiliary DC-DC are connected to the high-voltage bus via relays, achieving a parallel connection in the electrical architecture. The main and auxiliary DC-DC can be controlled to connect to the high-voltage bus separately or simultaneously via relays. By connecting the auxiliary unit 700 to the same node, the second stack 200 can independently power the BOP, thus maintaining the operation of the auxiliary system even when the main stack is shut down. This provides the hardware foundation for achieving a true zero-power output mode and solves the problems of high-power stacks being unable to operate at low loads for extended periods and insufficient heat of vaporization in liquid hydrogen zero-power mode.

[0030] Optionally, in some embodiments, the auxiliary component 700 includes: an oxygen supply unit 800, which includes a multi-way valve 301 and a throttle assembly 302. The input terminal of the multi-way valve 301 is connected to the input terminal of the oxygen supply unit 800, the first output terminal of the multi-way valve 301 is connected to the oxygen input terminal of the first fuel cell stack 100, and the second output terminal of the multi-way valve 301 is connected to the oxygen input terminal of the second fuel cell stack 200. The first input terminal of the throttle assembly 302 is connected to the gas output terminal of the first fuel cell stack 100, and the second input terminal of the throttle assembly 302 is connected to the gas output terminal of the second fuel cell stack 200. The gas output terminal of the first fuel cell stack 200 is connected, and the output terminal of the throttle assembly 302 is connected to the output terminal of the oxygen supply unit 800; wherein, the throttle assembly 302 includes: a first throttle valve 3021, the input terminal of the first throttle valve 3021 is connected to the gas output terminal of the first fuel cell stack 100, and the output terminal of the first throttle valve 3021 is connected to the output terminal of the oxygen supply unit 800; a second throttle valve 3022, the input terminal of the second throttle valve 3022 is connected to the gas output terminal of the second fuel cell stack 200, and the output terminal of the first throttle valve 3021 is connected to the output terminal of the oxygen supply unit 800.

[0031] It is understandable that, such as Figure 3As shown, Figure 3 This is a PID diagram of the air subsystem and auxiliary stack cooling circuit subsystem of a fuel cell system according to this application. The high-voltage power supply of the BOP (Boiler Plant) of the fuel cell system, including the air compressor unit 303, water pump 502, air circulation pump, and PTC, is directly connected to the high-voltage output bus of the auxiliary DC-DC converter. The auxiliary stack and the main stack share an air supply system. The outlet of the air compressor unit 303 is connected to the main stack and the auxiliary stack via an electrically controlled three-way valve. The air volume distribution between the main stack and the auxiliary stack is controlled by adjusting the opening of the inlet three-way valve. The electrically controlled three-way valve can also be used to cut off the air inlet of the main stack. The multi-way valve 301 flexibly distributes the air intake of the two stacks according to the system operating mode (such as zero power, low power, or high power mode), and can independently cut off or open the air supply to either stack.

[0032] Furthermore, the throttle valve assembly 302 independently adjusts the outlet back pressure of each of the two fuel cell stacks, ensuring the stability of their respective internal reaction pressures and broadening the system's power output range to achieve full operating condition coverage from zero power to rated power. The main and auxiliary fuel cell stacks are each equipped with an outlet throttle valve to control the air path pressure, enabling independent and precise adjustment and control of the exhaust pressure of the two fuel cell stacks. This allows for dynamic adjustments based on the air demand and back pressure requirements of each fuel cell stack in different parallel operation modes, effectively ensuring the stability and balance of the internal reaction pressure of each fuel cell stack.

[0033] Optionally, in some embodiments, the oxygen supply unit 800 further includes: an air compressor unit 303, an intercooler unit 304, a third throttle valve 305, an air-water separator unit 306, an expansion unit 307, and a muffler unit 308. The input terminal of the air compressor unit 303 is used to input air, and the output terminal of the air compressor unit 303 is connected to the input terminal of the intercooler unit 304. The output terminal of the intercooler unit 304 is connected to both the input terminal of the multi-way valve 301 and the input terminal of the third throttle valve 305. The third throttle valve 305... The output terminal of the gas-water separation unit 306 is connected to the input terminal of the gas-water separation unit 306; the input terminal of the gas-water separation unit 306 is connected to the output terminal of the first throttle valve 3021 and the output terminal of the second throttle valve 3022 respectively; the first output terminal of the gas-water separation unit 306 is connected to the input terminal of the expansion unit 307; the second output terminal of the gas-water separation unit 306 is connected to the input terminal of the muffler unit 308; the output terminal of the expansion unit 307 is connected to the input terminal of the muffler unit 308; the output terminal of the muffler unit 308 is connected to the atmosphere.

[0034] Understandably, the oxygen supply unit 800 draws in air through the air compressor unit 303 and cools it through the intercooler unit 304. Then, the air is distributed to the first fuel cell stack 100 and the second fuel cell stack 200 as needed by the multi-way valve 301. At the same time, the flow rate can be regulated by the third throttle valve 305. After the exhaust gas from the fuel cell stack reaction is discharged through the first throttle valve 3021 and the second throttle valve 3022, it is mixed with the bypass air in the gas-water separation unit 306 to remove moisture. After the exhaust gas from the outlet throttle valves of the main fuel cell stack and the auxiliary fuel cell stack merges with the exhaust gas from the third throttle valve 305, it enters the expansion unit 307 through the water vapor separator to achieve energy recovery. After the exhaust gas from the expansion unit 307 is connected to the silencer unit 308, it is discharged into the atmosphere. This achieves independent and precise air supply and pressure regulation for the two fuel cell stacks and improves the overall energy efficiency of the system.

[0035] Optionally, in some embodiments, the auxiliary assembly 700 further includes: a first cooling unit 900 and a second cooling unit 910, wherein the second cooling unit 910 includes a liquid hydrogen water bath vaporizer 501 and a water pump 502, wherein the input end of the liquid hydrogen water bath vaporizer 501 is connected to the coolant output end of the second fuel cell stack 200, and the output end of the liquid hydrogen water bath vaporizer 501 is connected to the input end of the water pump 502; the output end of the water pump 502 is connected to the coolant input end of the second fuel cell stack 200.

[0036] Understandably, the main fuel cell stack and the auxiliary fuel cell stack each employ independent cooling systems (first cooling circuit and second cooling circuit). The main fuel cell stack is cooled by the vehicle's fan, while the auxiliary fuel cell stack's cooling circuit is separately connected to a liquid hydrogen water bath vaporizer, relying entirely on the cold energy of the liquid hydrogen for heat dissipation. Similarly, the heat required for liquid hydrogen vaporization is entirely provided by the waste heat from the auxiliary fuel cell stack. The liquid hydrogen water bath vaporizer 501 and water pump 502, connected in series in the second cooling circuit, utilize the waste heat generated by the auxiliary fuel cell stack's operation to heat and vaporize the liquid hydrogen. Thus, when the auxiliary fuel cell stack operates independently in zero-power or low-power mode, it solves the heat dissipation problem of the auxiliary fuel cell stack and provides a continuous supply of gaseous hydrogen to the system, avoiding the problem of insufficient heat for liquid hydrogen vaporization and depletion of hydrogen reserves due to a shutdown of the main fuel cell stack, preventing the system from restarting.

[0037] Optionally, in some embodiments, the first switching assembly 500 includes: a first contactor 5001 and a second contactor 5002, wherein one end of the first contactor 5001 is electrically connected to the positive output terminal of the first fuel cell stack 100, and the other end of the first contactor 5001 is electrically connected to the first input terminal of the second switching assembly; one end of the second contactor 5002 is electrically connected to the negative output terminal of the first fuel cell stack 100, and the other end of the second contactor 5002 is electrically connected to the second input terminal of the second switching assembly; wherein the second switching assembly 600 includes a third contactor 5003 and a fourth contactor 5004, wherein one end of the third contactor 5003 is electrically connected to the other end of the first contactor 5001, and the other end of the third contactor 5003 is electrically connected to the positive terminal of the vehicle's high-voltage busbar; one end of the fourth contactor 5004 is electrically connected to the other end of the second contactor 5002, and the other end of the fourth contactor 5004 is electrically connected to the negative terminal of the vehicle's high-voltage busbar.

[0038] It is understandable that, such as Figure 2 As shown, S1 and S2 are the positive and negative contactors for the main DC-DC output to the high-voltage bus, respectively, and S3 and S4 are the positive and negative contactors for the system output to the vehicle's high-voltage bus, respectively. Through the coordinated control of the first switching assembly 500 (first and second contactors 5002) and the second switching assembly 600 (third and fourth contactors 5004), flexible electrical connection and isolation between the dual fuel cell stacks and the vehicle's high-voltage bus are achieved. The first switching assembly 500 controls the connection and disconnection between the main fuel cell stack and its internal connection nodes, while the second switching assembly 600 controls the connection and disconnection between the system as a whole and the vehicle's high-voltage bus. By selectively controlling the opening or closing of the first contactor 5001 and the second contactor 5002, the main battery stack can be connected to or disconnected from the high-voltage bus independently. By controlling the closing of the third contactor 5003 and the fourth contactor 5004, it is ensured that in zero-power or low-power mode, the auxiliary battery stack supplies power to the auxiliary equipment assembly 700 and the whole vehicle through the second conversion component 400. At the same time, in high-power mode, the output power of the main battery stack and the auxiliary battery stack is combined into the high-voltage bus.

[0039] It should be noted that the embodiments of this application also include a filter 309 and a flow meter 310. The output end of the filter 309 is connected to the input end of the flow meter 310. The flow meter 310 is installed on the pipeline between the air compressor unit 303 and the filter 309 and is used to detect the air flow. The filter 309 is used to purify the external air entering the air compressor or fuel cell stack, filtering out dust, particulate matter and other impurities to prevent contaminants from adhering to the surface of the fuel cell stack catalyst or wearing the air compressor impeller, thereby ensuring the cleanliness of the internal reaction interface of the fuel cell stack and the long-term operational reliability of the air compressor. The flow meter 310 is used to monitor the air flow entering the air subsystem in real time and feed the detection signal back to the system controller so as to accurately adjust parameters such as the air compressor speed and the opening of the three-way valve according to the power requirements of the vehicle, ensuring that the first fuel cell stack 100 and the second fuel cell stack 200 obtain an accurately matched oxygen supply, while preventing energy waste due to excessive flow or oxygen deficiency in the fuel cell stack due to insufficient flow.

[0040] To facilitate those skilled in the art to further understand the fuel cell system of the embodiments of this application, the following is combined with... Figure 4 The embodiments shown will be described in detail.

[0041] Specifically, such as Figure 4 As shown, Figure 4 This is a flowchart illustrating the operation of a fuel cell system according to this application. The high-power fuel cell system provided in this application includes a main stack and an auxiliary stack, and defines three operating modes.

[0042] Mode 1: Zero-power mode (only auxiliary stack operates, P0 (power required by the vehicle) = 0, P2 (output power of the auxiliary stack) = PBOP (power consumed by the fuel cell system during BOP operation)) In the fuel cell field, "zero-power mode" refers to a fuel cell system that does not output power (i.e., net output power is 0kW or <0kW), but the entire system is not completely shut down. Instead, it maintains a minimum operating state, ready to respond to power demands at any time. In zero-power mode, the fuel cell does not completely stop working or lose power; rather, it refers to a specific low-power standby mode. Simply put, "zero-power" in fuel cells is an intelligent standby strategy that sacrifices a small amount of fuel consumption for rapid response, system reliability, and long lifespan. Balancing the two key requirements of "instant availability" and "durability," it is one of the technologies that enables the practical application and automotive-grade use of fuel cell systems. Zero-power mode effectively prevents overcharging of the vehicle's battery and reduces the frequency of fuel cell system startup and shutdown in conventional modes. Furthermore, from exiting zero-power mode to system startup, shutdown, and power output, it can quickly respond to vehicle requests.

[0043] When the vehicle has zero power demand, the system enters zero-power operation mode. During zero-power operation, to avoid excessively high main stack voltage leading to reduced system lifespan, the main stack needs to be shut down, maintaining zero current and zero output power, with the stack voltage remaining below the protection threshold. At this time, the main DC-DC converter stops drawing current, contactors S1 and S2 open, and contactors S3 and S4 close, cutting off the air supply to the main stack and closing the air path, but the air compressor unit should continue operating. The hydrogen supply should be maintained at a low pressure to prepare for a rapid response when the system switches to the operating mode. To maintain system temperature balance, the main stack cooling circuit should remain operational, and the water pump should operate at a low power.

[0044] By controlling the inlet three-way valve, the air supply to the main fuel cell stack is shut off, and air completely enters the auxiliary fuel cell stack. At this time, the main fuel cell stack shuts down, maintaining the power output of the auxiliary fuel cell stack. The operating power of the auxiliary fuel cell stack is controlled to be equal to the BOP power of the system's air compressor unit, water pumps, etc., achieving zero overall system output power. The cooling of the auxiliary fuel cell stack is entirely achieved by the liquid hydrogen water bath vaporizer through heat exchange with liquid hydrogen. This provides a small amount of gaseous hydrogen for consumption during zero-power operation and maintains sufficient hydrogen storage in the vaporizer to ensure a sufficient hydrogen supply when the main fuel cell stack starts up, in preparation for the system exiting zero-power mode.

[0045] Mode 2: Normal operation mode - low power operation (auxiliary stack only, P0=P2-PBOP) Mode 2 operates similarly to Mode 1. When the system makes a low-power request, the vehicle's requested power P0 is lower than the main battery's minimum sustainable output power P. If the main battery is activated at this time, it can only output the minimum output power P, causing the overall system output power to exceed the vehicle's requested power P0. This could lead to risks such as overcharging of the vehicle's battery. Therefore, in Mode 2, the main battery remains powered off, contactors S1 and S2 are open, and contactors S3 and S4 are closed. The system relies entirely on the auxiliary battery for power output, and the output power P2 equals the vehicle's requested power P0 plus the power consumed by PBOP.

[0046] Mode 3: Normal operation mode - high power operation (auxiliary fuel cell stack and main fuel cell stack work simultaneously, P0 = P1 (main fuel cell stack output power) + P2 - PBOP) When the vehicle requests high power, the requested power P0 must be greater than or equal to the minimum output power P of the main fuel cell stack. At this time, the main fuel cell stack can be started, operating in a mode where both the main and auxiliary fuel cell stacks work simultaneously. Pressurized air from the air compressor unit is supplied to both the main and auxiliary fuel cell stacks simultaneously through the inlet three-way valve. The outlet throttle valves of the main and auxiliary fuel cell stacks control the air pressure within their respective stacks. Contactors S1, S2, S3, and S4 are all closed, allowing both the main and auxiliary fuel cell stacks to output power simultaneously. The system output power equals the sum of the auxiliary fuel cell stack output power P2 and the main fuel cell stack output power P1 minus PBOP, and is equal to the vehicle's requested power P0.

[0047] Therefore, this application proposes a solution to the problem that high-power fuel cell systems cannot achieve true zero power by adding an auxiliary fuel cell stack, and achieves a net system output power of zero. The auxiliary fuel cell stack provides heat for liquid hydrogen vaporization, solving the problem of insufficient hydrogen vaporization and storage during long-term zero-power operation. This application broadens the power output range of high-power fuel cell systems, breaking through the limitation of high idling power (minimum sustainable output power) and achieving a full-power output mode from zero power to rated power, while also improving the system's rated power and system efficiency.

[0048] According to the fuel cell system proposed in this application, the positive and negative terminals of the first fuel cell stack are respectively connected to the positive and negative input terminals of the first conversion component, and the positive and negative output terminals of the first conversion component are respectively connected to the first and second input terminals of the first switching component; the first and second output terminals of the first switching component are respectively connected to the first and second input terminals of the second switching component, and the output terminal of the second switching component is connected to the high-voltage bus of the vehicle; the positive and negative terminals of the second fuel cell stack are respectively connected to the positive and negative input terminals of the second conversion component, the positive output terminal of the second fuel cell stack is connected to the first connection node, and the negative output terminal of the second fuel cell stack is connected to the second connection node; the auxiliary equipment component and the third and fourth connection nodes between the first and second switching components are connected. This solves the problems of high-power liquid hydrogen fuel cells being unable to achieve zero power output and insufficient heat for liquid hydrogen vaporization.

[0049] This application also provides a vehicle that employs the fuel cell system as described above.

[0050] Next, referring to the accompanying drawings, a control method for a fuel cell system proposed according to an embodiment of this application is described, using the fuel cell system as shown above.

[0051] Figure 5 This is a flowchart of a control method for a fuel cell system according to an embodiment of this application.

[0052] In step S5011, the vehicle's total power requirement is obtained. In step S5012, the target power mode of the fuel cell system is determined based on the power range in which the vehicle's power demand is located.

[0053] In step S5013, the first stack, second stack, first switching assembly, second switching assembly, and auxiliary assembly of the fuel cell system are controlled according to the control strategy corresponding to the target power mode.

[0054] Optionally, in some embodiments, the target power mode is a zero power mode, and the first stack, second stack, first switching assembly, second switching assembly, and auxiliary components of the fuel cell system are controlled according to the control strategy corresponding to the target power mode, including: controlling the first stack to be in a shutdown state and controlling the second stack to be in an operating state; controlling the first switching assembly to be in an open state and controlling the second switching assembly to be in a closed state; The system controls the first hydrogen supply unit of the auxiliary equipment assembly to supply hydrogen to the first fuel cell stack based on the first hydrogen supply pressure, and controls the second hydrogen supply unit of the auxiliary equipment assembly to supply hydrogen to the second fuel cell stack based on the second hydrogen supply pressure; the system controls the first output terminal of the multi-way valve of the oxygen supply unit of the auxiliary equipment assembly to be closed, and controls the second output terminal of the multi-way valve to be open, while closing the output terminal of the first throttle valve; the system controls the water pump of the cooling unit corresponding to the first fuel cell stack to be at the first target power, and controls the cooling circuit of the cooling unit corresponding to the second fuel cell stack to be connected to the liquid hydrogen water bath vaporizer; the system controls the output power of the second fuel cell stack to be equal to the power consumed by the auxiliary equipment assembly.

[0055] Optionally, in some embodiments, the target power mode is a first power mode. The first fuel cell stack, second fuel cell stack, first switching assembly, second switching assembly, and auxiliary components of the fuel cell system are controlled according to the control strategy corresponding to the target power mode. This includes: controlling the first fuel cell stack to be in a shutdown state and controlling the second fuel cell stack to be in an operating state; controlling the first switching assembly to be in an open state and controlling the second switching assembly to be in a closed state; controlling the first hydrogen supply unit of the auxiliary components to supply hydrogen to the first fuel cell stack based on a third hydrogen supply pressure, and controlling the second hydrogen supply unit of the auxiliary components to supply hydrogen to the second fuel cell stack based on a fourth hydrogen supply pressure, wherein the fourth hydrogen supply pressure is greater than the third hydrogen supply pressure; controlling the first output terminal of the multi-port valve of the oxygen supply unit of the auxiliary components to be in a closed state, and controlling the second output terminal of the multi-port valve to be in an open state, while closing the output terminal of the first throttle valve; controlling the water pump of the cooling unit corresponding to the first fuel cell stack to be at a first target power, and controlling the cooling circuit of the cooling unit corresponding to the second fuel cell stack to be connected to a liquid hydrogen water bath vaporizer; and controlling the output power of the second fuel cell stack to be equal to the power consumed by the auxiliary components and the power required by the entire vehicle.

[0056] Optionally, in some embodiments, the target power mode is a second power mode, the output power of the second power mode is greater than the output power of the first power mode, and the first stack, second stack, first switching assembly, second switching assembly, and auxiliary assembly of the fuel cell system are controlled according to the control strategy corresponding to the target power mode, including: controlling the first stack and the second stack to be in an operating state; controlling the first switching assembly and the second switching assembly to be in a closed state; controlling the first hydrogen supply unit of the auxiliary assembly to supply hydrogen to the first stack based on a fifth hydrogen supply pressure, and controlling the second hydrogen supply unit of the auxiliary assembly to supply hydrogen to the second stack based on a sixth hydrogen supply pressure; controlling the first output terminal of the multi-way valve of the oxygen supply unit of the auxiliary assembly to be at a first opening degree, and controlling the second output terminal of the multi-way valve to be at a second opening degree; controlling the water pump of the cooling unit corresponding to the first stack to be at a second target power, and controlling the cooling circuit of the cooling unit corresponding to the second stack to be connected to the liquid hydrogen water bath vaporizer; controlling the total output power of the first stack and the second stack to be equal to the power consumed by the auxiliary assembly and the power required by the vehicle.

[0057] It should be noted that the foregoing explanation of the fuel cell system embodiment also applies to the control method of the fuel cell system in this embodiment, and will not be repeated here.

[0058] According to the control method for a fuel cell system proposed in this application, the target power mode of the fuel cell system is determined based on the power range of the vehicle's overall power demand. The first fuel cell stack, second fuel cell stack, first switching assembly, second switching assembly, and auxiliary components of the fuel cell system are controlled according to the control strategy corresponding to the target power mode. This solves the problems of high-power liquid hydrogen fuel cells being unable to achieve zero power output and insufficient heat for liquid hydrogen vaporization.

[0059] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0060] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0061] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0062] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0063] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

Claims

1. A fuel cell system, characterized in that, include: The system comprises a first fuel cell stack, a second fuel cell stack, a first conversion assembly, a second conversion assembly, a first switching assembly, a second switching assembly, and an auxiliary assembly, wherein... The positive output terminal of the first fuel cell stack is electrically connected to the positive input terminal of the first conversion component, and the negative output terminal of the first fuel cell stack is electrically connected to the negative input terminal of the first conversion component. The positive output terminal of the first conversion component is electrically connected to the first input terminal of the first switching component, and the negative output terminal of the first conversion component is electrically connected to the second input terminal of the first switching component. The first output terminal of the first switch assembly is electrically connected to the first input terminal of the second switch assembly, and the second output terminal of the first switch assembly is electrically connected to the second input terminal of the second switch assembly. The output terminal of the second switch assembly is electrically connected to the high-voltage busbar of the vehicle. The positive output terminal of the second fuel cell stack is electrically connected to the positive input terminal of the second conversion component, and the negative output terminal of the second fuel cell stack is electrically connected to the negative input terminal of the second conversion component. The positive output terminal of the second battery stack is electrically connected to the first connection node between the first switching assembly and the second switching assembly, and the negative output terminal of the second battery stack is electrically connected to the second connection node between the first switching assembly and the second switching assembly. The first input terminal of the auxiliary component is electrically connected to the third connection node between the first switch component and the second switch component, and the second input terminal of the auxiliary component is electrically connected to the fourth connection node between the first switch component and the second switch component.

2. The fuel cell system according to claim 1, characterized in that, The auxiliary equipment components include: The oxygen supply unit includes a multi-way valve and a throttle assembly, wherein... The input terminal of the multi-way valve is connected to the input terminal of the oxygen supply unit, the first output terminal of the multi-way valve is connected to the oxygen input terminal of the first fuel cell stack, the second output terminal of the multi-way valve is connected to the oxygen input terminal of the second fuel cell stack, the first input terminal of the throttle assembly is connected to the gas output terminal of the first fuel cell stack, the second input terminal of the throttle assembly is connected to the gas output terminal of the second fuel cell stack, and the output terminal of the throttle assembly is connected to the output terminal of the oxygen supply unit. The throttle valve assembly includes: The first throttle valve has its input terminal connected to the gas output terminal of the first fuel cell stack, and its output terminal connected to the output terminal of the oxygen supply unit. The second throttle valve has its input terminal connected to the gas output terminal of the second fuel cell stack, and the output terminal of the first throttle valve is connected to the output terminal of the oxygen supply unit.

3. The fuel cell system according to claim 2, characterized in that, The oxygen supply unit also includes: The system includes an air compressor unit, an intercooler unit, a third throttle valve, an air-water separator unit, an expansion unit, and a muffler unit. The input terminal of the air compressor unit is used to input air, and the output terminal of the air compressor unit is connected to the input terminal of the intercooler unit. The output terminal of the intercooler unit is connected to the input terminal of the multi-way valve and the input terminal of the third throttle valve, respectively. The output end of the third throttle valve is connected to the input end of the gas-water separation unit; The input terminal of the gas-water separation unit is connected to the output terminal of the first throttle valve and the output terminal of the second throttle valve, respectively. The first output terminal of the gas-water separation unit is connected to the input terminal of the expansion unit, and the second output terminal of the gas-water separation unit is connected to the input terminal of the muffler unit. The output terminal of the expansion unit is connected to the input terminal of the silencing unit; The output of the noise reduction unit is connected to the atmosphere.

4. The fuel cell system according to any one of claims 1-3, characterized in that, The auxiliary equipment assembly further includes: a first cooling unit and a second cooling unit, wherein... The second cooling unit includes a liquid hydrogen water bath vaporizer and a water pump, wherein, The input end of the liquid hydrogen water bath vaporizer is connected to the coolant output end of the second fuel cell stack, and the output end of the liquid hydrogen water bath vaporizer is connected to the input end of the water pump. The output end of the water pump is connected to the coolant input end of the second fuel cell stack.

5. The fuel cell system according to claim 1, characterized in that, The first switching assembly includes: a first contactor and a second contactor, wherein, One end of the first contactor is electrically connected to the positive output terminal of the first fuel cell stack, and the other end of the first contactor is electrically connected to the first input terminal of the second switching assembly. One end of the second contactor is electrically connected to the negative output terminal of the first fuel cell stack, and the other end of the second contactor is electrically connected to the second input terminal of the second switching assembly. The second switching assembly includes a third contactor and a fourth contactor, wherein, One end of the third contactor is electrically connected to the other end of the first contactor, and the other end of the third contactor is electrically connected to the positive terminal of the high-voltage busbar of the vehicle. One end of the fourth contactor is electrically connected to the other end of the second contactor, and the other end of the fourth contactor is electrically connected to the negative terminal of the vehicle's high-voltage busbar.

6. A vehicle, characterized in that, include: The fuel cell system as described in any one of claims 1-5.

7. A control method for a fuel cell system, characterized in that, The method is applied to the fuel cell system as described in any one of claims 1-5, wherein the method includes the following steps: Obtain the vehicle's total power requirements; The target power mode of the fuel cell system is determined based on the power range in which the vehicle's power demand is located. The first stack, second stack, first switching assembly, second switching assembly, and auxiliary equipment of the fuel cell system are controlled according to the control strategy corresponding to the target power mode.

8. The method according to claim 7, characterized in that, The target power mode is a zero power mode. The control of the first fuel cell stack, second fuel cell stack, first switching assembly, second switching assembly, and auxiliary equipment assembly of the fuel cell system according to the control strategy corresponding to the target power mode includes: The first fuel cell stack is controlled to be in a shutdown state, and the second fuel cell stack is controlled to be in an operating state; The first switch assembly is controlled to be in the open state, and the second switch assembly is controlled to be in the closed state; The first hydrogen supply unit of the auxiliary equipment assembly is controlled to supply hydrogen to the first fuel cell stack based on the first hydrogen supply pressure, and the second hydrogen supply unit of the auxiliary equipment assembly is controlled to supply hydrogen to the second fuel cell stack based on the second hydrogen supply pressure; The first output terminal of the multi-way valve of the oxygen supply unit of the auxiliary machine component is closed, and the second output terminal of the multi-way valve is opened, while the output terminal of the first throttle valve is closed. The water pump of the cooling unit corresponding to the first fuel cell stack is controlled to be at the first target power, and the cooling circuit of the cooling unit corresponding to the second fuel cell stack is controlled to be connected to the liquid hydrogen water bath vaporizer. The output power of the second fuel cell stack is controlled to be equal to the power consumed by the auxiliary components.

9. The method according to claim 7, characterized in that, The target power mode is a first power mode. The control of the first fuel cell stack, second fuel cell stack, first switching assembly, second switching assembly, and auxiliary equipment assembly of the fuel cell system according to the control strategy corresponding to the target power mode includes: The first fuel cell stack is controlled to be in a shutdown state, and the second fuel cell stack is controlled to be in an operating state; The first switch assembly is controlled to be in the open state, and the second switch assembly is controlled to be in the closed state; The first hydrogen supply unit of the auxiliary equipment component supplies hydrogen to the first fuel cell stack based on a third hydrogen supply pressure, and the second hydrogen supply unit of the auxiliary equipment component supplies hydrogen to the second fuel cell stack based on a fourth hydrogen supply pressure, wherein the fourth hydrogen supply pressure is greater than the third hydrogen supply pressure; The first output terminal of the multi-way valve of the oxygen supply unit of the auxiliary machine component is closed, and the second output terminal of the multi-way valve is opened, while the output terminal of the first throttle valve is closed. The water pump of the cooling unit corresponding to the first fuel cell stack is controlled to be at the first target power, and the cooling circuit of the cooling unit corresponding to the second fuel cell stack is controlled to be connected to the liquid hydrogen water bath vaporizer. The output power of the second fuel cell stack is controlled to be equal to the power consumed by the auxiliary components and the power required by the vehicle.

10. The method according to claim 7, characterized in that, The target power mode is a second power mode, and the output power of the second power mode is greater than the output power of the first power mode. The control of the first fuel cell stack, second fuel cell stack, first switching assembly, second switching assembly, and auxiliary equipment assembly of the fuel cell system according to the control strategy corresponding to the target power mode includes: Control the first fuel cell stack and the second fuel cell stack to be in working condition; Both the first switch assembly and the second switch assembly are controlled to be in a closed state; The first hydrogen supply unit of the auxiliary equipment assembly supplies hydrogen to the first fuel cell stack based on the fifth hydrogen supply pressure, and controls the second hydrogen supply unit of the auxiliary equipment assembly to supply hydrogen to the second fuel cell stack based on the sixth hydrogen supply pressure; The first output terminal of the multi-way valve of the oxygen supply unit of the auxiliary machine component is controlled to be at a first opening degree, and the second output terminal of the multi-way valve is controlled to be at a second opening degree. The water pump of the cooling unit corresponding to the first fuel cell stack is controlled to be at the second target power, and the cooling circuit of the cooling unit corresponding to the second fuel cell stack is controlled to be connected to the liquid hydrogen water bath vaporizer. The total output power of the first fuel cell stack and the second fuel cell stack is controlled to be equal to the power consumed by the auxiliary components and the power required by the vehicle.

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