Fuel cell engine control system for marine applications

Abstract

The application provides a fuel cell engine control system for ships, which comprises an input signal module, an output signal module, a power module and a communication module, wherein the input signal module comprises analog input, digital input and frequency input; the output signal module comprises high-low edge driving output, low edge PWM signal output and H bridge power output; the communication module comprises CAN communication and SENT communication; the control method comprises a start-up and shutdown module, a system control module and a fault diagnosis module; the system control module mainly realizes the control of key components in each subsystem of the fuel cell through calibration lookup table and PID control; the fault diagnosis module is divided into communication fault, equipment fault and operation fault according to fault categories, each fault has a corresponding fault code, the fault of each component can be reflected in the fault code, and the corresponding fault diagnosis control strategy is executed to ensure the reliability and safety of the fuel cell system.

Description

Technical Field

[0001] This invention belongs to the field of marine fuel cell control technology, specifically relating to a fuel cell engine control system for marine applications. Background Technology

[0002] As a primary mode of global cargo transportation, shipping plays a vital role in world economic development. With increasing environmental awareness worldwide, environmental pollution caused by the shipping industry is becoming a growing focus of international attention. Ship operations generate significant amounts of greenhouse gases and air pollutants. To address global climate change and reduce dependence on fossil fuels, many countries have proposed the concept of "carbon neutrality," and China has also set a "dual-carbon" target. Against this backdrop, developing clean, efficient, and sustainable green ships, and promoting the development and utilization of new energy sources in the shipping industry, is of great significance.

[0003] Hydrogen energy, as a widely available, clean, carbon-free, flexible, efficient, and sustainable secondary energy source, is considered the most promising clean energy source of the 21st century. It is the most likely ideal energy source to replace fossil fuels and the best choice for large-scale, deep decarbonization in transportation and other sectors, and is expected to become an important component of the "carbon neutrality" strategy. Hydrogen fuel cell systems are one of the ideal solutions for hydrogen energy application in ships, offering advantages such as high energy conversion efficiency, zero emissions, low vibration and noise, simple construction, flexible layout, ease of maintenance, and alignment with energy strategies. Currently, most existing hydrogen fuel cell ships are powered by proton exchange membrane fuel cells due to their zero emissions, relatively high power density, and rapid start-up, making them suitable for low-power vessels such as small yachts or passenger ships. Summary of the Invention

[0004] In view of the actual needs of existing technologies, the purpose of this invention is to provide a fuel cell engine control system for marine applications, which can achieve effective control of marine fuel cell systems.

[0005] The main design of the scheme includes the hardware structure and control methods of the marine fuel cell engine control system. The hardware structure includes an input signal module, an output signal module, a power supply module, and a communication module. The input signal module includes analog input, digital input, and frequency input; the output signal module includes high-side and low-side drive output, low-side PWM signal output, and H-bridge power output; the communication module includes CAN communication and SENT communication. The control methods include a start-up, operation, and shutdown module, a system control module, and a fault diagnosis module. The start-up, operation, and shutdown module includes control strategies and flows for power-on, start-up, operation, load loading, standby, shutdown, and fault shutdown. The system control module mainly uses calibration lookup tables and PID control to control key components in each subsystem of the fuel cell. The fault diagnosis module classifies faults into communication faults, equipment faults, and operational faults. Each fault has a corresponding fault code, and the fault of each component can be reflected in the fault code, executing corresponding fault diagnosis control strategies to ensure the reliability and safety of the fuel cell system.

[0006] The specific technical solution adopted by this invention to solve its technical problem is as follows:

[0007] A fuel cell engine control system for marine applications, characterized in that:

[0008] It includes an input signal module, an output signal module, a power supply module, and a communication module;

[0009] The input signal module includes an analog input section, a digital input section, and a frequency input section. The analog inputs include multiple voltage-type analog inputs and multiple resistance-type analog inputs for acquiring sensor signals. The digital inputs include multiple active-high and multiple active-low inputs for acquiring switch signals. The frequency inputs include multiple voltage-type frequency signal input channels.

[0010] The output signal module includes high-side and low-side drive outputs, low-side PWM signal outputs, H-bridge power outputs, and Peak-Hold drive outputs. The high-side and low-side drive outputs include multiple high-side drives and multiple low-side drives for load control, including external relays and proportional valves. The low-side PWM signal outputs are multi-channel. The H-bridge power output is used to realize the forward and reverse directions of the output signal and supports current sampling.

[0011] The communication module includes multi-channel CAN communication and multi-channel SENT communication. SENT communication is used for communication between ship instruments and steering gear.

[0012] Furthermore, the marine propulsion system includes a fuel cell stack, and an air supply system, a hydrogen supply system, and a thermal management system respectively connected to the fuel cell stack. The thermal management system adopts a seawater-based heat dissipation system. The control scheme includes control strategies for start-up and shutdown modules, system control modules, and fault diagnosis modules to achieve coordinated control of the fuel cell system.

[0013] Furthermore, the start-up, operation, and shutdown modules include controls for power-on, start-up, operation, load loading, standby, shutdown, and fault shutdown.

[0014] The specific process of the power-on control strategy is as follows: Low-pressure power-on wake-up, enabling the self-test function of fuel cell system components; detecting hydrogen inlet pressure, if the hydrogen inlet pressure is too low, entering the hydrogen replenishment process; if the hydrogen replenishment process fails, entering the fault state, if the hydrogen replenishment process ends normally, entering the fuel cell system state initialization process; receiving the start signal and high-voltage power-on signal, entering the start state; if the low-pressure power-on wake-up signal is pulled low, entering the fuel cell system state initialization process, and low-pressure power-off;

[0015] The specific process for starting the control strategy is as follows: High voltage power-on; if the high voltage value is normal, enter the hydrogen replenishment process; otherwise, enter the fault state; receive the fuel cell system start signal and detect that the fuel cell power is greater than the set value, enter the running state; receive the fuel cell system shutdown signal and enter the high voltage power-off process.

[0016] The specific process of the operation control strategy is as follows: If the fuel cell system start signal is received again, the start-up purging process is entered; otherwise, the high-pressure process is entered and the hydrogen replenishment process is returned. The voltage of the stack cells is detected. If the voltage value is normal, the stack output process is entered; otherwise, the fault state is entered. If the fuel cell system start signal is received and the fuel cell power is detected to be greater than the set value, the load state is entered; otherwise, the standby state is entered.

[0017] The specific process of the standby control strategy is as follows: enter the standby shutdown purging process; standby high pressure reduction; enter the hydrogen replenishment process. If the high-voltage power supply signal continues to fail, then enter the power-on control strategy process. If the start signal of the fuel cell system is received and the power demand is greater than the set value, then enter the operation control strategy process.

[0018] The specific process of the load control strategy is as follows: determine whether the system enters the loading mode or the unloading mode based on the current power and the requested power; if a shutdown signal of the fuel cell system is received, enter the shutdown state; if the power of the fuel cell system is less than the set value, enter the standby state.

[0019] The specific process of the shutdown control strategy is as follows: enter the normal temperature shutdown purging process; discharge process; shutdown and high voltage reduction;

[0020] The specific process of the fault shutdown control strategy is as follows: Based on the received fault level signal, determine whether to enter the corresponding fault shutdown process and emergency stop process. The fault shutdown process includes the fault purging process and the fault shutdown high-pressure process. The emergency stop process is the process of executing the emergency stop high-pressure process.

[0021] Furthermore, the fault diagnosis module is used to diagnose communication faults, equipment faults, and operational faults. By analyzing and judging sensor information and information on stack voltage and individual cell voltage, it diagnoses the location and severity of faults in the fuel cell system. Faults in each component are reflected in status codes, and corresponding actions are taken based on the fault codes output by the fault diagnosis module. In order to ensure that the hydrogen supply circulation device meets the requirements of both low-power and high-power operating conditions of the marine fuel cell system, the hydrogen circulation pump and ejector need to work alternately under complex operating conditions, which is prone to CAN communication faults. If no communication message is received within the set transmission cycle, it is identified as a CAN communication fault, and a fault shutdown procedure is initiated. Under complex operating conditions, the required hydrogen flow rate is constantly changing. Faults will occur if the hydrogen inlet pressure is higher or lower than the corresponding threshold. If it is higher than the set value, it indicates that the inlet pressure is too high and the pressure reducing valve is malfunctioning; if it is lower than the set value, it indicates that the hydrogen supply is insufficient.

[0022] The system control module includes controls for the air system, hydrogen system, and thermal management system.

[0023] Furthermore, the control of the air supply system includes: air compressor and throttle control. The air compressor is controlled by calibration lookup table. According to the power requirements of marine operating conditions, the target air flow is matched to obtain the target speed of the air compressor. The electronic throttle is controlled by PI. By inputting the cathode outlet pressure and the target pressure, the throttle opening is output.

[0024] Furthermore, the control of the hydrogen supply system includes: controlling the pressure reducing valve, shut-off valve, proportional valve, hydrogen circulation pump, ejector, and drain valve. Using the load current as input, the target anode pressure, hydrogen circulation pump speed, ejector flow rate, and drain valve characteristic curve are used to obtain the target anode pressure, hydrogen circulation pump speed, ejector flow rate, drain valve opening cycle, and opening duration, respectively. The pressure reducing valve, shut-off valve, proportional valve, hydrogen circulation pump, ejector, and drain valve are then subjected to corresponding lookup table and PI control.

[0025] The ejector and hydrogen circulation pump are connected in parallel: when the fuel cell is running at high power, the hydrogen circulation pump is turned off and hydrogen is circulated only through the ejector; when the fuel cell is running at low power, the hydrogen circulation pump is turned on to circulate hydrogen, so as to ensure that the hydrogen supply circulation device can meet the requirements of the marine fuel cell system under both low-power and high-power conditions.

[0026] Furthermore, the control of the thermal management system includes: controlling the water pump, heat exchanger, coolant circulation pump, PTC heater, and thermostat; providing auxiliary heating to the PTC heater when the coolant outlet temperature is too low; using the coolant outlet temperature as a judgment signal to determine whether the cooling circuit is opened; and using a PI control strategy to collect the coolant inlet and outlet temperatures and the target temperature difference, outputting the coolant circulation pump speed.

[0027] Compared with the prior art, the main innovations of this invention and its preferred embodiments are reflected in at least the following aspects:

[0028] 1. A SENT communication interface has been added to the communication module for communication between ship instruments and steering gear and the controller.

[0029] 2. A control method for marine fuel cell engines was designed, which is divided into a start-up, operation and shutdown module, a system control module and a fault diagnosis module, realizing the control functions of each component of the marine fuel cell system.

[0030] 3. The hydrogen system control strategy adopts a parallel configuration of the ejector and the hydrogen circulation pump. When the fuel cell is running at high power, the hydrogen circulation pump is turned off, and hydrogen circulation is carried out only through the ejector. When the fuel cell is running at low power, the hydrogen circulation pump is turned on to circulate hydrogen, ensuring that the hydrogen supply circulation device meets the requirements of the marine fuel cell system under both low-power and high-power conditions. Attached Figure Description

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0032] Figure 1 This is a hardware architecture diagram of the control system according to an embodiment of the present invention.

[0033] Figure 2 This is a block diagram of the control strategy according to an embodiment of the present invention.

[0034] Figure 3 This is a structural diagram of a marine fuel cell system according to an embodiment of the present invention.

[0035] Figure 4 This is a flowchart of the power-on control strategy according to an embodiment of the present invention.

[0036] Figure 5 This is a flowchart of the startup control strategy according to an embodiment of the present invention.

[0037] Figure 6 This is a flowchart illustrating the operation control strategy of an embodiment of the present invention.

[0038] Figure 7 This is a flowchart of the standby control strategy according to an embodiment of the present invention.

[0039] Figure 8 This is a flowchart of the load control strategy according to an embodiment of the present invention.

[0040] Figure 9 This is a flowchart illustrating the shutdown and fault stop control strategy according to an embodiment of the present invention.

[0041] Figure 10 The results are the fault diagnosis results of a specific embodiment of the present invention. Detailed Implementation

[0042] To make the features and advantages of this patent more apparent and understandable, specific embodiments are provided below for detailed explanation:

[0043] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0044] This invention provides a fuel cell engine control system for marine applications, specifically including the hardware structure and control method of the marine fuel cell engine control system.

[0045] The hardware structure mainly includes an input signal module, an output signal module, a power supply module, and a communication module; the control methods include control strategies for the start-up and shutdown module, the system control module, and the fault diagnosis module, in order to achieve coordinated control of the entire fuel cell system.

[0046] Figure 1 This is a hardware architecture diagram of the fuel cell engine control system for marine applications provided in this embodiment. The controller microcontroller in the hardware structure uses a STMicroelectronics SPC series microcontroller with a 32-bit PowerPC architecture processor. Functionally, it mainly includes an input signal module, an output signal module, a power supply module, and a communication module.

[0047] like Figure 1 The input signal module shown includes an analog input section, a digital input section, and a frequency input section. The analog inputs include 10 voltage-type analog inputs and 6 resistance-type analog inputs for acquiring sensor signals. The digital inputs include 3 active-high and 3 active-low inputs for acquiring switch signals. The frequency inputs include 6 voltage-type frequency signal input channels.

[0048] like Figure 1The output signal module shown includes high-side and low-side drive outputs, low-side PWM signal outputs, H-bridge power outputs, and Peak-Hold drive outputs. The high-side and low-side drive outputs include 4 high-side drive channels and 8 low-side drive channels, used for external relay, proportional valve, and other load control. There are 3 low-side PWM signal outputs. The H-bridge power outputs have 3 channels that can reverse the output signal and support current sampling. The power signal module includes 3 positive power supply channels, 4 negative power supply channels (9-32V), 7 5V sensor power supply channels, and 3 12V sensor power supply channels. The communication module includes 4 CAN communication channels and 2 SENT communication channels. SENT communication is used for communication between ship instruments and steering gear.

[0049] Figure 2 This is a block diagram of the control strategy for a marine fuel cell engine control system provided in this embodiment. It should be noted that, to better understand the control and management strategy for the marine fuel cell system provided in this embodiment, the marine fuel cell system is first described. Figure 3 As shown, it includes a fuel cell stack, and an air supply system, a hydrogen supply system, and a thermal management system respectively connected to the fuel cell stack, wherein the thermal management system adopts a seawater-based heat dissipation system.

[0050] like Figure 2 As shown, the startup, operation, and shutdown modules include power-on, startup, operation, load, standby, shutdown, and fault shutdown.

[0051] like Figure 4 As shown, the specific process of the power-on control strategy is as follows: low-voltage power-on wake-up, enabling the self-test function of fuel cell system components; detecting hydrogen inlet pressure, if the hydrogen inlet pressure is too low, entering the hydrogen replenishment process; if the hydrogen replenishment process fails, entering the fault state, if the hydrogen replenishment process ends normally, entering the fuel cell system state initialization process; receiving the start signal and high-voltage power-on signal, entering the start state; if the low-voltage power-on wake-up signal is pulled low, entering the fuel cell system state initialization process, and low-voltage power-off.

[0052] like Figure 5 As shown, the specific process of starting the control strategy is as follows: High voltage is applied. If the high voltage value is normal, the hydrogen replenishment process is entered; otherwise, the fault state is entered. The fuel cell system start signal is received and the fuel cell power is detected to be greater than the set value, and the running state is entered. The fuel cell system shutdown signal is received and the high voltage power-off process is entered.

[0053] like Figure 6As shown, the specific process of the operation control strategy is as follows: If the fuel cell system start signal is received again, the start-up purging process is entered; otherwise, the high-pressure process is entered and the hydrogen replenishment process is returned. The voltage of the stack cells is detected. If the voltage value is normal, the stack output process is entered; otherwise, the fault state is entered. If the fuel cell system start signal is received and the fuel cell power is detected to be greater than the set value, the load state is entered; otherwise, the standby state is entered.

[0054] like Figure 7 As shown, the specific process of the standby control strategy is as follows: enter the standby shutdown purging process; standby high pressure; enter the hydrogen replenishment process; if the high-voltage power supply signal continues to fail, then enter the power-on control strategy process; if the start signal of the fuel cell system is received and the power demand is greater than the set value, then enter the operation control strategy process.

[0055] like Figure 8 As shown, the specific process of the load control strategy is as follows: determine whether the system enters the loading mode or the unloading mode based on the current power and the requested power; if a shutdown signal of the fuel cell system is received, enter the shutdown state; if the power of the fuel cell system is less than the set value, enter the standby state.

[0056] like Figure 9 As shown, the specific process of the shutdown control strategy is as follows: enter the normal temperature shutdown purging process; discharge process; shutdown and high voltage reduction.

[0057] like Figure 9 As shown, the specific process of the fault shutdown control strategy is as follows: Based on the received fault level signal, determine whether to enter the corresponding fault shutdown process and emergency stop process. The fault shutdown process includes the fault purging process and the fault shutdown high-pressure process. The emergency stop process mainly executes the emergency stop high-pressure process.

[0058] The system control module includes control strategies for the air system, hydrogen system, and thermal management system.

[0059] refer to Figure 2 The air system control strategy mainly involves air compressor and throttle control. The air compressor is controlled by calibration lookup table. Based on the power requirements of marine operation, the target air flow is matched to obtain the target speed of the air compressor. The electronic throttle uses PI control. By inputting the cathode outlet pressure and the target pressure, the throttle opening is output.

[0060] refer to Figure 2The hydrogen system control strategy mainly controls the pressure reducing valve, shut-off valve, proportional valve, hydrogen circulation pump, ejector, and drain valve. Using the load current as input, the target pressure of the anode, the speed of the hydrogen circulation pump, the correspondence between the ejector flow rate and the load current, and the characteristic curve of the drain valve are used to obtain the target pressure of the anode, the speed of the hydrogen circulation pump, the flow rate of the ejector, the opening cycle and the opening duration of the drain valve, and the corresponding table lookup and PI control are performed on the pressure reducing valve, shut-off valve, proportional valve, hydrogen circulation pump, ejector, and drain valve.

[0061] refer to Figure 2 The thermal management system's control strategy primarily controls the water pumps, heat exchangers, coolant circulation pumps, PTC heaters, and thermostats. The PTC heaters provide auxiliary heating when the coolant outlet temperature is too low. The thermostat uses the coolant outlet temperature as a signal to determine whether the cooling circuit should be opened. The coolant circulation pumps, by collecting the coolant inlet and outlet temperatures and employing a PI control strategy, output the coolant circulation pump speed based on the input coolant inlet / outlet temperature difference and the target temperature difference.

[0062] In the preferred fault diagnosis and control strategy provided in this embodiment, faults are divided into communication faults, air system faults, hydrogen system faults, thermal management system faults, stack faults, and fuel cell system faults. All possible faults are divided into four levels, with level 1 being the highest and level 4 being the lowest. A four-byte fault code is set according to different faults, representing the faults that occurred in different systems. Each bit of the fault code has a clear fault definition. Other modules in the upper-level control algorithm will perform corresponding control based on the fault codes output by the fault diagnosis module.

[0063] refer to Figure 2 The control strategy of the fault diagnosis module mainly includes communication faults, equipment faults, and operational faults. By analyzing and judging sensor information and data such as stack voltage and individual cell voltage, the location and severity of faults in the fuel cell system are diagnosed. Faults in each component can be reflected in the status code, and other modules in the upper-level control algorithm will perform corresponding control based on the fault codes output by the fault diagnosis module. Specifically, to ensure that the hydrogen supply circulation device simultaneously meets the requirements of both low-power and high-power operating conditions of the marine fuel cell system, the hydrogen circulation pump and ejector must work alternately under complex conditions, which can easily lead to CAN communication faults. Failure to receive a communication message within a set transmission cycle is considered a CAN communication fault, fault level 2, initiating a fault shutdown procedure. Under complex operating conditions, the required hydrogen flow rate constantly changes; hydrogen inlet pressure exceeding or falling below the corresponding threshold will cause a fault. Pressure exceeding the set value indicates excessive inlet pressure and failure of the pressure reducing valve; pressure falling below the set value indicates insufficient hydrogen supply, fault level 2.

[0064] like Figure 10As shown in the fault diagnosis results of a specific embodiment of the present invention, during the high-voltage power-on process, the voltage value fed back by the power supply is abnormal, reaching 95V, exceeding the set fault threshold of 90V. At this time, the system enters the startup fault state, outputs the corresponding system status code, and enters the system power-on fault state. Based on the system status code, the system enters the state machine of the fault diagnosis module and executes the corresponding startup fault diagnosis state diagram flow. From the fault diagnosis results of this specific embodiment of the present invention, the fault code at this time is 197, the fault level is 1, and the fault shutdown enable is 1. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention in other ways. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

[0065] This patent is not limited to the above-described preferred embodiments. Anyone can derive other forms of fuel cell engine control systems for marine applications based on the guidance of this patent. All equivalent changes and modifications made within the scope of this patent application shall fall within the scope of this patent.

Claims

1. A fuel cell engine control system for marine applications, characterized in that: It includes an input signal module, an output signal module, a power supply module, and a communication module; The input signal module includes an analog input section, a digital input section, and a frequency input section. The analog inputs include multiple voltage-type analog inputs and multiple resistance-type analog inputs for acquiring sensor signals. The digital inputs include multiple active-high and multiple active-low inputs for acquiring switch signals. The frequency inputs include multiple voltage-type frequency signal input channels. The output signal module includes high-side and low-side drive outputs, low-side PWM signal outputs, H-bridge power outputs, and Peak-Hold drive outputs. The high-side and low-side drive outputs include multiple high-side drives and multiple low-side drives for load control, including external relays and proportional valves. The low-side PWM signal outputs are multi-channel. The H-bridge power output is used to realize the forward and reverse directions of the output signal and supports current sampling. The communication module includes multiple CAN communication channels and multiple SENT communication channels. The SENT communication channel is used for communication between ship instruments and steering gear. The marine propulsion system includes a fuel cell stack, and an air supply system, a hydrogen supply system, and a thermal management system connected to the fuel cell stack, respectively. The thermal management system adopts a seawater-based heat dissipation system. The control scheme includes control strategies for start-up, operation, and shutdown modules, system control modules, and fault diagnosis modules to achieve coordinated control of the fuel cell system. The fault diagnosis module is used to diagnose communication faults, equipment faults, and operational faults. By analyzing and judging sensor information and information on stack voltage and individual cell voltage, it diagnoses the location and severity of faults in the fuel cell system. Faults in each component are reflected in status codes, and corresponding actions are taken based on the fault codes output by the fault diagnosis module. In particular, to ensure that the hydrogen supply circulation device meets the requirements of both low-power and high-power operating conditions of the marine fuel cell system, the hydrogen circulation pump and ejector need to work alternately under complex operating conditions, which is prone to CAN communication faults. If no communication message is received within the set transmission cycle, it is identified as a CAN communication fault, and a fault shutdown procedure is initiated. Under complex operating conditions, the required hydrogen flow rate is constantly changing. If the hydrogen inlet pressure is higher or lower than the corresponding threshold, a fault will occur. If it is higher than the set value, it indicates that the inlet pressure is too high and the pressure reducing valve is malfunctioning; if it is lower than the set value, it indicates that the hydrogen supply is insufficient. The control of the hydrogen supply system includes: controlling the pressure reducing valve, shut-off valve, proportional valve, hydrogen circulation pump, ejector, and drain valve. Using the load current as input, the target pressure of the anode, the speed of the hydrogen circulation pump, the correspondence between the ejector flow rate and the load current, and the characteristic curve of the drain valve are used to obtain the target pressure of the anode, the speed of the hydrogen circulation pump, the flow rate of the ejector, the opening cycle and the opening duration of the drain valve, and the corresponding lookup table and PI control are performed on the pressure reducing valve, shut-off valve, proportional valve, hydrogen circulation pump, ejector, and drain valve. The ejector and hydrogen circulation pump are connected in parallel: when the fuel cell is running at high power, the hydrogen circulation pump is turned off and hydrogen is circulated only through the ejector; when the fuel cell is running at low power, the hydrogen circulation pump is turned on to circulate hydrogen, so as to ensure that the hydrogen supply circulation device can meet the requirements of the marine fuel cell system under both low-power and high-power conditions.

2. The fuel cell engine control system for marine applications according to claim 1, characterized in that: The start-up, operation, and shutdown module includes controls for power-on, start-up, operation, load loading, standby, shutdown, and fault shutdown. The specific process of the power-on control strategy is as follows: Low-pressure power-on wake-up, enabling the self-test function of fuel cell system components; detecting hydrogen inlet pressure, if the hydrogen inlet pressure is too low, entering the hydrogen replenishment process; if the hydrogen replenishment process fails, entering the fault state, if the hydrogen replenishment process ends normally, entering the fuel cell system state initialization process; receiving the start signal and high-voltage power-on signal, entering the start state; if the low-pressure power-on wake-up signal is pulled low, entering the fuel cell system state initialization process, and low-pressure power-off; The specific process for starting the control strategy is as follows: High voltage power-on; if the high voltage value is normal, enter the hydrogen replenishment process; otherwise, enter the fault state; receive the fuel cell system start signal and detect that the fuel cell power is greater than the set value, enter the running state; receive the fuel cell system shutdown signal and enter the high voltage power-off process. The specific process of the operation control strategy is as follows: If the fuel cell system start signal is received again, the start-up purging process is entered; otherwise, the high-pressure process is entered and the hydrogen replenishment process is returned. The voltage of the stack cells is detected. If the voltage value is normal, the stack output process is entered; otherwise, the fault state is entered. If the fuel cell system start signal is received and the fuel cell power is detected to be greater than the set value, the load state is entered; otherwise, the standby state is entered. The specific process of the standby control strategy is as follows: enter the standby shutdown purging process; standby high pressure reduction; enter the hydrogen replenishment process. If the high-voltage power supply signal continues to fail, then enter the power-on control strategy process. If the start signal of the fuel cell system is received and the power demand is greater than the set value, then enter the operation control strategy process. The specific process of the load control strategy is as follows: determine whether the system enters the loading mode or the unloading mode based on the current power and the requested power; if a shutdown signal of the fuel cell system is received, enter the shutdown state; if the power of the fuel cell system is less than the set value, enter the standby state. The specific process of the shutdown control strategy is as follows: enter the normal temperature shutdown purging process; discharge process; shutdown and high voltage reduction; The specific process of the fault shutdown control strategy is as follows: Based on the received fault level signal, determine whether to enter the corresponding fault shutdown process and emergency stop process. The fault shutdown process includes the fault purging process and the fault shutdown high-pressure process. The emergency stop process is the process of executing the emergency stop high-pressure process.

3. The fuel cell engine control system for marine applications according to claim 1, characterized in that: The system control module includes control of the air system, hydrogen system, and thermal management system; The control of the air supply system includes: air compressor and throttle control. The air compressor is controlled by calibration lookup table. According to the power requirements of marine operating conditions, the target air flow is matched to obtain the target speed of the air compressor. The electronic throttle valve uses PI control, which outputs the throttle opening by inputting the cathode outlet pressure and the target pressure.

4. The fuel cell engine control system for marine applications according to claim 1, characterized in that: The control of the thermal management system includes: controlling the water pump, heat exchanger, coolant circulation pump, PTC heater, and thermostat; the PTC heater provides auxiliary heating when the coolant outlet temperature is too low; the thermostat uses the coolant outlet temperature as a judgment signal to determine whether the cooling circuit is opened; the coolant circulation pump collects the coolant inlet and outlet temperatures and adopts a PI control strategy, outputting the coolant circulation pump speed by inputting the coolant inlet and outlet temperature difference and the target temperature difference.

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