An integrated fuel cell system

Abstract

This invention discloses an integrated fuel cell system, including a fuel cell stack, and further comprising: an anode hydrogen supply system, an anode exhaust and hydrogen recirculation system, a cathode low-pressure gas supply system, a cathode exhaust humidification system, a fuel cell cell voltage monitoring system (CVM), and a fuel cell controller. By introducing hydrogen and air into the fuel cell system of this application, chemical energy can be converted into continuously output electrical energy under the control of the fuel cell controller. This device can be applied to new energy fuel cell vehicles, combined heat and power (CHP) systems, and residential power plants, serving as a device for providing direct current (DC) or alternating current (AC).

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, and specifically relates to an integrated fuel cell system. Background Technology

[0002] A hydrogen fuel cell is an energy conversion device that converts the chemical energy of hydrogen into electrical energy. Hydrogen and oxygen continuously output electrical energy through an electrochemical reaction, offering advantages such as high energy conversion efficiency and zero pollution. A standalone fuel cell cannot generate electricity; it must be integrated with a fuel supply and circulation system, an oxidant supply system, a hydrothermal management system, and a control system to form a fuel cell system that can output power.

[0003] Currently, fuel cell technology is developing towards higher integration, lighter materials, lower complexity, and miniaturization, thereby improving the specific power and safety of fuel cell systems. Fuel cell integration technologies vary, and the selection of materials, components, and functions significantly impacts the system's integration level and operating efficiency. In particular, fuel cell systems adapted to low-pressure fuel cells and organic liquid hydrogen storage technologies are virtually nonexistent. Breakthroughs in technologies to reduce hydrogen storage pressure and adapt to low-pressure hydrogen fuel cell systems can improve the safety of fuel cell vehicles. Summary of the Invention

[0004] The purpose of this invention is to provide an integrated fuel cell system for hydrogen fuel cells.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an integrated fuel cell system, including a fuel cell stack, and further comprising:

[0006] The anode hydrogen supply system is used to reduce the pressure of the incoming hydrogen based on the hydrogen source pressure, and to regulate the pressure, temperature and humidity of the hydrogen using the unreacted exhaust gas from the fuel cell.

[0007] The anode exhaust and hydrogen recirculation system is used to detect and separate the exhaust gas emitted from the fuel cell anode. The separated hydrogen is humidified and recycled through the anode hydrogen supply system.

[0008] The cathode low-pressure air supply system is used to absorb outside air, cool and humidify it before sending it to the fuel cell, and regulate the temperature, humidity and pressure of the air entering the fuel cell stack by regulating the air at the cathode outlet of the fuel cell stack.

[0009] The cathode tail exhaust humidification system is used to divert the gas from the cathode outlet of the fuel cell as humidifying gas to the cathode low-pressure gas supply system for humidifying and drying gas, and to control the flow rate of humidifying gas by detecting the voltage and current between the positive and negative electrodes of the fuel cell stack.

[0010] The fuel cell cell voltage monitoring system (CVM) is used to detect the voltage of fuel cell cells.

[0011] The fuel cell controller is used to receive signals from sensors within the hydrogen fuel cell system and to monitor and modify various parameters of the fuel cell system in real time.

[0012] Furthermore, the anode hydrogen supply system includes: a pressure reducing unit, an intake regulating unit, a three-way valve, a monitoring unit, and a circulating humidification unit;

[0013] The pressure reduction unit is used to reduce the pressure of the incoming hydrogen gas;

[0014] The intake regulating unit is used to regulate the intake volume and pressure of hydrogen.

[0015] The monitoring unit is used to monitor the pressure, temperature, and humidity of the hydrogen entering the anode of the fuel cell stack in real time;

[0016] The circulating humidification unit is used to regulate the pressure, temperature, and humidity of the hydrogen entering the anode of the fuel cell using the exhaust gas generated by the fuel cell; the circulating humidification unit is also used to regulate the pressure, temperature, and humidity of the hydrogen exiting the intake regulating unit using the unreacted exhaust gas from the fuel cell.

[0017] The fuel cell controller sets the parameter values ​​for the hydrogen entering the fuel cell and collects the hydrogen parameter values ​​in real time. It compares the real-time hydrogen parameter values ​​with the set values ​​and adjusts the opening degree of the pressure reducing unit, the air intake regulating unit, the valve opening degree in the circulating humidification unit, and the pump speed.

[0018] Hydrogen from an external hydrogen source enters the stack anode after passing through a pressure reducing unit, an intake regulating unit, the first and second ports of a three-way valve, and a monitoring unit under the control of the fuel cell controller. Exhaust gas generated by the fuel cell is returned to the stack anode after passing through a circulating humidification unit connected to the third port of the three-way valve and then through the monitoring unit.

[0019] Furthermore, it also includes a hydrogen leak detection subsystem, which is installed outside the system to detect the concentration of leaking hydrogen and transmit the signal to the fuel cell controller, which then takes a safety response.

[0020] Furthermore, the anode tail exhaust and hydrogen circulation system includes: a tail gas detection module, a vapor-water separator, a humidity-adjustable circulation branch, an anode tail exhaust branch, and a drain valve;

[0021] The exhaust gas detection module is connected at one end to the anode outlet of the fuel cell stack and at the other end to the air inlet of the steam-water separator; the first pipeline interface of the steam-water separator is connected to the inlet of the humidity-adjustable circulation branch, the second pipeline interface is connected to the anode tail discharge branch, and the third pipeline interface is connected to the drain valve.

[0022] The exhaust gas emitted by the fuel cell is monitored by an exhaust gas detection module to detect its temperature, pressure, and humidity. Then, it enters a gas-water separator to separate hydrogen and water. Part of the hydrogen is transferred to the fuel cell's hydrogen supply system through a humidity-adjustable circulation branch for humidification and hydrogen circulation. Excess hydrogen is discharged through the anode exhaust branch, and water is discharged through a drain valve.

[0023] The fuel cell controller is used to connect the exhaust gas detection module, the gas-water separation device, the humidity adjustable circulation branch, the anode exhaust branch, and the drain valve. It collects the detection results and controls the opening and closing of the above devices based on the detection results, thereby controlling the circulation or emission of the separated hydrogen.

[0024] Furthermore, the cathode low-pressure gas supply system includes:

[0025] An air cooling and humidification system is used to absorb outside air, cool and humidify it, and then send it to the cathode inlet of the fuel cell stack.

[0026] The air monitoring module is used to collect the temperature, humidity, and pressure of the air entering the cathode of the fuel cell stack in real time.

[0027] The back pressure subsystem is used to regulate the back pressure at the cathode outlet of the fuel cell stack.

[0028] The fuel cell controller connects to and controls the air cooling and humidification system, the air monitoring module, and the back pressure subsystem. By adjusting the air cooling and humidification system and the back pressure subsystem, the temperature, humidity, and pressure of the air entering the cathode are brought to a preset range.

[0029] Furthermore, the air cooling and humidification system includes an air absorption subsystem, an air cooling subsystem, and an air humidification subsystem arranged sequentially; the air absorption subsystem is used to absorb outside air, the air cooling subsystem is used to cool the absorbed air, and the air humidification subsystem is used to humidify the absorbed air.

[0030] Furthermore, the back pressure subsystem includes an electric control valve and an exhaust gas pipeline. The exhaust gas pipeline is connected to an air cooling and humidification system, and the gas discharged from the electric control valve is used as the air source for the humidification system to humidify the air.

[0031] Furthermore, the cathode tail exhaust humidification system includes: a humidification subsystem and a fuel cell stack electrical performance monitoring and diagnostic system;

[0032] The humidification subsystem and the stack electrical performance monitoring and diagnostic system are controlled by the fuel cell controller.

[0033] The humidification subsystem is used to collect the gas diversion from the cathode outlet of the fuel cell stack as humidification gas and supply it to the cathode low-pressure gas supply system for humidification and drying. It also monitors the temperature and humidity values ​​of the gas to be humidified before being fed into the fuel cell and the humidity value of the gas discharged from the cathode outlet of the fuel cell stack in real time and sends them to the fuel cell controller.

[0034] The stack electrical performance monitoring and diagnostic system is used to detect the voltage and current between the positive and negative electrodes of the stack and the voltage of the individual cells in real time, and send the data to the fuel cell controller.

[0035] The fuel cell controller sets a target value, starts the fuel cell, and adjusts the flow rate of humidifying gas through the humidification subsystem to bring the humidity of the air entering the stack close to the target value based on the received real-time detection values. It also performs a diagnostic response when the humidity deviates significantly from the target value.

[0036] Furthermore, the single-unit voltage monitoring system (CVM) includes: one or more detection units, wherein the detection unit includes: a voltage measurement module, a control module, a communication module, and an isolated power supply module;

[0037] The voltage measurement module includes two individual voltage chips, each chip is configured with n measurement channels, n≥1, and each measurement channel is used to measure the voltage of one fuel cell cell.

[0038] The control module is used to control the cell voltage chip to measure the cell voltage of the fuel cell and send the obtained voltage value to external devices through the communication module;

[0039] The isolated power supply module is used to provide power to the entire detection unit and to provide electrical isolation to the voltage measurement module, communication module and control module;

[0040] When there are two or more detection units, the detection units operate independently, and all individual cell voltage chips are connected in series when detecting the voltage of a single battery cell.

[0041] Furthermore, the fuel cell controller includes:

[0042] The signal acquisition module is used to receive signals from sensors within the hydrogen fuel cell system.

[0043] The signal output module is used to connect to the actuator of the hydrogen fuel cell system and output adjustment signals.

[0044] The communication module is used to connect the CAN and Modbus devices of the hydrogen fuel cell system.

[0045] The debugging module is used to connect to the processor on the controller board of the hydrogen fuel cell system;

[0046] The processor is used to connect the signal acquisition module, signal output module, communication module, debugging module and power management module in the controller to monitor and modify various parameters of the fuel cell system in real time.

[0047] The power management module is used to supply power to the various modules within the controller.

[0048] An integrated fuel cell system comprises all the aforementioned systems within a single enclosed space, functioning as a whole. By introducing hydrogen and air into this system, chemical energy can be converted into continuously output electrical energy under the control of the fuel cell controller. This device can be applied in scenarios such as new energy fuel cell vehicles, combined heat and power (CHP), and residential power plants, serving as a provider of direct current (DC) or alternating current (AC).

[0049] The present invention has the following beneficial effects: (1) Wide applicability of hydrogen source pressure range: It is compatible with high-pressure hydrogen sources and low-pressure hydrogen sources. Only the parameters of the first-stage pressure reducing valve and the second-stage pressure reducing valve need to be adjusted to obtain a wide range of pressure reduction capabilities. Then, the target pressure and flow rate can be adjusted by the proportional valve, with pressure as low as 10 kPa. It is particularly suitable for organic liquid hydrogen storage technology and application scenarios with low hydrogen source pressure. Due to parameter matching, it can be fully applied (low-pressure hydrogen system), and is also suitable for methanol and other hydrocarbon reforming hydrogen fuel cells. (2) The present invention does not require additional water replenishment: The system does not require additional water replenishment. The water source of the humidifier is entirely generated by the fuel cell reaction. Attached Figure Description

[0050] Figure 1 A schematic diagram of the anode hydrogen supply system in the example.

[0051] Figure 2 This is a schematic diagram of the structure of the anode tailpipe and hydrogen circulation system in the embodiment.

[0052] Figure 3 This is a schematic diagram of the cathode low-pressure gas supply system in the embodiment.

[0053] Figure 4 This is a schematic diagram of the structure of the cathode tail exhaust humidification system in the embodiment.

[0054] Figure 5 This is a block diagram of the detection system of the fuel cell cell voltage monitoring system (CVM) in the embodiment.

[0055] Figure 6 This is a schematic diagram of the CVM detection system for a fuel cell cell voltage monitoring system, as shown in the embodiment.

[0056] Figure 7 This is a schematic diagram of the structural principle of the fuel cell controller in this embodiment.

[0057] Figure 8This is a schematic diagram of the output of the DA output unit of the fuel cell controller in an embodiment.

[0058] Figure 9 This is a schematic diagram of the output of the PWM adjustable signal output unit of the fuel cell controller in an embodiment.

[0059] Figure 10 This is a schematic diagram of the output of the intelligent high-side switch drive unit of the fuel cell controller in an embodiment.

[0060] Figure 11 This is a schematic diagram of the output of the DC motor drive unit of the fuel cell controller in an embodiment.

[0061] Figure 12 This is a schematic diagram of the voltage acquisition signal of the fuel cell controller in an embodiment.

[0062] Figure 13 This is a schematic diagram of the current acquisition signal of the fuel cell controller in an embodiment.

[0063] Figure 14 This is a schematic diagram of the power safety module structure of the fuel cell controller in an embodiment. Detailed Implementation

[0064] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0065] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification and claims of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0066] An integrated fuel cell system includes a fuel cell stack, and further includes: an anode hydrogen supply system for depressurizing incoming hydrogen based on hydrogen source pressure and regulating the pressure, temperature, and humidity of the hydrogen using unreacted exhaust gas from the fuel cell; an anode exhaust and hydrogen recirculation system for detecting and separating exhaust gas from the fuel cell anode, with the separated hydrogen partially humidified and recycled through the anode hydrogen supply system; a cathode low-pressure gas supply system for absorbing external air, cooling and humidifying it before supplying it to the fuel cell, and regulating the temperature, humidity, and pressure of the air entering the stack by regulating the air outlet at the fuel cell stack cathode; a cathode exhaust humidification system for diverting gas from the fuel cell cathode outlet as humidifying gas to the cathode low-pressure gas supply system for humidifying and drying gas, and controlling the humidifying gas flow rate by detecting the voltage and current between the positive and negative electrodes of the fuel cell stack; a fuel cell cell voltage monitoring system (CVM) for detecting the voltage of individual fuel cells; and a fuel cell controller for receiving signals from sensors within the hydrogen fuel cell system and monitoring and modifying various parameters of the fuel cell system in real time.

[0067] Anode hydrogen supply system

[0068] like Figure 1 The fuel cell anode hydrogen supply system shown is adapted to hydrogen sources with different pressures and includes: a pressure reducing unit 101, an air intake regulating unit 102, a three-way valve 103, a monitoring unit 104, and a circulating humidification unit 105.

[0069] The pressure reducing unit is used to reduce the pressure of the incoming hydrogen gas, and includes a primary pressure reducing valve 108 and a secondary pressure reducing valve 109 connected in sequence from the gas supply input port 107.

[0070] The intake regulating unit is used to regulate the intake volume and pressure of hydrogen, and includes a hydrogen flow meter 110, a first pressure sensor 111, an intake valve 112, a second pressure sensor 113 and a proportional regulating valve 114 connected in sequence from the pressure reducing unit.

[0071] The monitoring unit is used to monitor the pressure, temperature and humidity of hydrogen entering the anode 115 of the fuel cell stack in real time, including a third pressure sensor 116, a temperature sensor 117 and a humidity sensor 118 connected in sequence from the second port of the three-way valve.

[0072] The circulating humidification unit is used to regulate the pressure, temperature and humidity of hydrogen gas from the outlet of the intake regulating unit using the unreacted exhaust gas of the fuel cell. It includes a circulating input interface 119, a hydrogen circulation pump 120 and a shut-off valve 121 connected in sequence from the anode outlet of the fuel cell stack to the third interface of the three-way valve.

[0073] The fuel cell controller 6 sets the parameter values ​​for the hydrogen entering the fuel cell and collects the hydrogen parameter values ​​in real time. It compares the real-time hydrogen parameter values ​​with the set values ​​and adjusts the opening degree of the pressure reducing unit, the air intake regulating unit, the valve opening degree in the circulating humidification unit, and the pump speed. The control unit adopts an integrated fuel cell controller.

[0074] The system also includes a hydrogen leak detection subsystem 122, which is set up outside the system to detect the concentration of leaking hydrogen and transmit the signal to the control unit, so that the fuel cell controller can make a safety response.

[0075] Hydrogen from an external hydrogen source enters the fuel cell anode after passing through a pressure reducing unit, an intake regulating unit, the first and second ports of a three-way valve, and a monitoring unit under the control of the control unit. Exhaust gas generated by the fuel cell is returned to the fuel cell anode after passing through a circulating humidification unit connected to the third port of the three-way valve and then through the monitoring unit.

[0076] The control and diagnostic methods for hydrogen supply systems include the following steps:

[0077] 1) Check if the gas supply system is in the off state. If it is in the off state, proceed to step 2.

[0078] 2) Obtain the current actual feed pressure (third pressure sensor), actual feed temperature, actual feed humidity, and actual feed flow rate.

[0079] 3) Set the target infeed pressure, target infeed temperature, target infeed humidity, and target infeed flow rate through the fuel cell controller.

[0080] 4) Adjust the first-stage pressure reducing valve to bring the outlet pressure range to normal and diagnose the pressure.

[0081] 5) Adjust the secondary pressure reducing valve to bring the outlet pressure range to normal and diagnose the pressure.

[0082] 6) Obtain the pressure value of the first pressure sensor, diagnose the pressure, and if the pressure is within the normal range, proceed to step 7.

[0083] 7) Open the intake valve through the fuel cell controller, obtain the pressure value of the second pressure sensor, diagnose the pressure, and if the pressure is within the normal range, proceed to step 8.

[0084] 8) Adjust the opening of the hydrogen regulating valve through the fuel cell controller to make the actual infeed pressure close to the target infeed pressure, diagnose the absolute values ​​of the actual infeed pressure and the target pressure, and feed them back to the fuel cell control unit (FCU) for closed-loop automatic control.

[0085] 9) Obtain the pressure value from the third pressure sensor and diagnose the pressure.

[0086] 10) Check if the fuel cell battery system has output voltage and current, diagnose the output voltage and current values, and if there is normal output, proceed to step 11.

[0087] 11) Open the shut-off valve.

[0088] 12) Turn on the hydrogen circulation pump.

[0089] 13) Obtain the flow rate value from the flow meter and adjust the opening of the hydrogen regulating valve according to the actual output power of the fuel cell stack.

[0090] 14) Obtain the values ​​of the temperature sensor and humidity sensor, diagnose the absolute values ​​of the actual feed temperature and the target temperature, diagnose the absolute values ​​of the actual feed humidity and the target humidity, adjust the shut-off valve and the speed of the circulating pump, and perform closed-loop regulation.

[0091] 15) The fuel cell controller periodically acquires hydrogen concentration signals from the hydrogen monitoring module sensor and the hydrogen monitoring module controller for diagnostic purposes.

[0092] When any abnormality is diagnosed in steps 1-15, the shutdown procedure is as follows:

[0093] 1) Close the intake valve.

[0094] 2) Close the hydrogen regulating valve.

[0095] 3) Turn off the hydrogen circulation pump.

[0096] 4) Close the shut-off valve.

[0097] 5) Wait a few seconds.

[0098] 6) Open the hydrogen regulating valve to a small opening.

[0099] 7) When all pressure sensor gauges show a reading of 0, close the hydrogen regulating valve.

[0100] Anode tail exhaust and hydrogen recirculation system

[0101] like Figure 2 The fuel cell anode tailpipe and hydrogen circulation system shown includes: a tail gas detection module 201, a gas-water separator 202, a humidity adjustable circulation branch 203, an anode tailpipe branch 204, and a drain valve 205.

[0102] One end of the exhaust gas detection module is connected to the anode outlet of the fuel cell stack, and the other end is connected to the air inlet of the steam-water separator. The first pipeline interface of the steam-water separator is connected to the inlet of the humidity-adjustable circulation branch, the second pipeline interface is connected to the anode tail discharge branch, and the third pipeline interface is connected to the drain valve.

[0103] The exhaust gas detection module includes a pressure sensor 207, a temperature sensor 208, and a dew point sensor 209 (or a relative humidity sensor). The vapor-liquid separator is equipped with high-level and low-level sensors. The humidity-adjustable circulation branch includes a hydrogen circulation pump 210 and a shut-off valve 211, which is an explosion-proof solenoid valve. The anode exhaust branch includes an exhaust valve 212 and an exhaust port 213, which is also an explosion-proof solenoid valve.

[0104] The exhaust gas emitted by the fuel cell is monitored by an exhaust gas detection module to detect its temperature, pressure, and humidity. Then, it enters a gas-water separator to separate hydrogen and water. Some of the hydrogen is transferred to the fuel cell's hydrogen supply system or other systems through a humidity-adjustable circulation branch for humidification and hydrogen circulation. Excess hydrogen is discharged through the anode tailpipe branch, and water is discharged through a drain valve.

[0105] Unreacted hydrogen from the fuel cell anode outlet enters the anode tailpipe system. Temperature, pressure, and dew point sensors detect the temperature, pressure, dew point, and relative humidity of the unreacted hydrogen, transmitting this information to the fuel cell controller 6 for processing, control, and diagnostics. Hydrogen containing significant moisture in the anode tailpipe is separated by a specially designed vapor-water separator. After reducing the moisture content, a portion of the hydrogen can be humidified and recycled by a hydrogen circulation pump, conserving hydrogen. Another line connected to the bottom of the vapor-water separator discharges the separated moisture through a drain outlet controlled by an explosion-proof solenoid valve. The need for drainage is detected by upper and lower liquid level sensors on the vapor-water separator, which are then monitored by the fuel cell controller 6 to implement appropriate drainage strategies. Another line connected to the top of the vapor-water separator allows excess dried hydrogen to be discharged through the explosion-proof tailpipe valve when not in circulation. Tailpipe operation can also be performed simultaneously when circulation is required.

[0106] The method for controlling fuel cell exhaust emissions using the above-mentioned fuel cell anode exhaust system includes the following steps:

[0107] (1) Real-time acquisition of temperature, pressure and humidity of exhaust gas from fuel cell (humidity is dew point temperature or relative humidity), and real-time detection of air humidity at fuel cell anode inlet;

[0108] (2) Determine whether the fuel cell system meets the exhaust gas recirculation conditions. If the conditions are met (the conditions for exhaust gas recirculation are that the humidity of the air at the fuel cell anode inlet is lower than the fuel cell set value, and the flow rate of the exhaust gas discharged from the fuel cell is higher than the set value), set the hydrogen circulation volume and the target humidity value at the anode inlet. By controlling the opening and closing of the drain valve and the liquid level in the gas-water separator, the gas-water separator forms a liquid seal. Open and adjust the humidity adjustable circulation branch so that the circulation volume and humidity value reach the target value. At the same time, control the anode exhaust branch to periodically discharge.

[0109] (3) If any abnormality occurs in the above steps, a shutdown operation shall be performed.

[0110] The shutdown procedure involves first closing the humidity-adjustable circulation branch, then opening the anode tailpipe branch to perform venting.

[0111] Cathode low-pressure gas supply system

[0112] like Figure 3 The diagram shows a low-pressure gas supply system for the fuel cell cathode, comprising, in sequence, an air absorption subsystem 301, an air cooling subsystem 302, an air humidification subsystem 303, an air monitoring module 304, and a gas supply output interface 305, which is connected to the fuel cell stack cathode inlet 306. It also includes a back pressure subsystem 307, one end of which is connected to the fuel cell stack cathode outlet 308, and the other end has an interface for docking with any cathode tailpipe system.

[0113] The air absorption subsystem, air cooling subsystem, air humidification subsystem, air monitoring module, and back pressure subsystem are controlled by the fuel cell controller 6.

[0114] The air absorption subsystem includes an air filter 310, an air compressor 311, and an air compressor controller 312. The fuel cell controller controls the operation of the air compressor through the air compressor controller.

[0115] The air cooling subsystem includes a first temperature sensor 313, an intercooler 314, a water pump 315, and a radiator 316. Air absorbed from the air absorption subsystem is cooled by the first temperature sensor before entering the intercooler and then being sent to the air humidification subsystem. The intercooler is a water-cooled intercooler; water is pumped into the intercooler to cool the air, then enters the radiator for further cooling before returning to the water pump for recirculation.

[0116] The air humidification subsystem includes a second temperature sensor 317, an air flow meter 318, and a humidifier 19 connected in sequence.

[0117] The air monitoring module includes a pressure sensor 320, a third temperature sensor 321, and a humidity sensor 322.

[0118] The humidity sensor is either a dew point sensor or a relative humidity sensor.

[0119] The back pressure subsystem includes an electric control valve 323 and an exhaust gas pipeline 324. The exhaust gas pipeline is connected to an air cooling and humidification system, and uses the gas discharged from the electric control valve as the air source for the humidification system to humidify the air.

[0120] A gas supply control method for a low-pressure gas supply system at the cathode of a fuel cell includes the following steps:

[0121] 1) Check if the gas supply system is in the off state. If it is in the off state, proceed to step 2.

[0122] 2) Real-time acquisition of the current values ​​collected by the first temperature sensor (air compressor outlet temperature), the second temperature sensor (intercooler outlet temperature), the air flow meter, the third temperature sensor (air inlet temperature), the pressure sensor (air inlet pressure), and the humidity sensor (air compressor inlet humidity).

[0123] 3) Set the target stack pressure, target stack temperature, target stack humidity, and target stack flow rate through the fuel cell battery controller, and enable the diagnostic function.

[0124] 4) Set the target speed according to the air compressor curve, and approximate the target feed flow rate and target feed pressure with an initial value.

[0125] 5) Check whether the value collected by the first temperature sensor (air compressor outlet temperature) is within the appropriate temperature range. If not, perform a diagnostic response.

[0126] 6) Check if the value collected by the second temperature sensor (intercooler outlet temperature) is within the appropriate temperature range. If not, perform a diagnostic response.

[0127] 7) Turn on the water pump and radiator to cool the air temperature, and diagnose in real time whether the value collected by the second temperature sensor (intercooler outlet temperature) is within the appropriate temperature range.

[0128] 8) After the air is humidified by the humidifier, the actual humidity of the feed air is diagnosed in real time. The feed air temperature and pressure are obtained in real time through the air detection module.

[0129] 9) Dynamically adjust the back pressure valve opening and air compressor speed to make the actual feed pressure and feed flow rate close to the target feed pressure and target feed flow rate.

[0130] 10) Dynamically adjust the pump speed and radiator speed to make the actual infeed temperature close to the target infeed temperature.

[0131] When an abnormality is diagnosed in any of the steps 1-10 above, the shutdown procedure is as follows:

[0132] 1) If the temperature sensor reading (air compressor outlet temperature) is irreversibly over-temperature or under-temperature, shut down the machine.

[0133] 2) If the temperature reading from the second temperature sensor (intercooler outlet temperature) is irreversibly over-temperature or under-temperature, shut down the machine.

[0134] 3) If the temperature reading from the third temperature sensor (air inlet temperature) is found to be irreversibly over-temperature or under-temperature, a shutdown operation should be performed.

[0135] 4) If the pressure sensor reading (air inlet temperature) indicates irreversible overpressure or underpressure, perform a shutdown operation.

[0136] 5) If the humidity sensor readings (air humidity entering the stack) show irreversible overpressure or underpressure, shut down the machine.

[0137] The shutdown procedure is as follows:

[0138] 1) Open the back pressure valve to 100%.

[0139] 2) Turn off the air compressor.

[0140] 3) Turn off the water pump and heat sink.

[0141] 4) Turn off the humidifier.

[0142] 5) Turn on the air compressor to purge.

[0143] 6) Turn off the air compressor.

[0144] The system draws in ambient air through an air compressor. This air is then filtered to remove harmful gases and particulate matter that could cause poisoning in the fuel cell. The appropriate air compressor outlet pressure is obtained by adjusting the air compressor speed and the pressure sensor at the fuel cell stack cathode inlet. As the air compressor speed increases, the outlet temperature also rises. When the outlet temperature is too high, the fuel cell controller performs a high-temperature diagnostic. It then controls the water-cooled intercooler, radiator, and water pump to regulate the temperature, ensuring the intercooler outlet reaches the ideal humidifier inlet temperature. The system also controls the air compressor outlet pressure by adjusting the speed and, through the electric control valve at the fuel cell stack cathode outlet, alters the back pressure of the fuel cell stack, fine-tuning the pressure in the cathode air to meet the air compressor outlet pressure requirements of the fuel cell stack cathode inlet. Information is collected by an air mass flow meter; if the flow rate is insufficient, diagnostics and feedback adjustments can be made. The air then continues to be humidified by the humidifier, whose output humidity can be controlled to meet the fuel cell stack's requirements. After being inspected and fed back by pressure, temperature, and humidity sensors before entering the fuel cell stack, the air is supplied to the fuel cell stack with air whose pressure, temperature, humidity, and flow rate are satisfied through closed-loop control of air compressor speed, water pump speed, and back pressure of electric control valve.

[0145] Cathode exhaust humidification system

[0146] like Figure 4 The cathode exhaust humidification system shown includes a humidification subsystem and a fuel cell stack electrical performance monitoring and diagnostic system. Both the humidification subsystem and the fuel cell stack electrical performance monitoring and diagnostic system are controlled by the fuel cell controller 6.

[0147] The humidification subsystem collects the gas from the cathode outlet of the fuel cell stack, diverts it as humidifying gas, humidifies and dries the air before sending it into the fuel cell, and monitors in real time the temperature and humidity values ​​of the humidified gas before it enters the fuel cell and the humidity value of the gas exiting the cathode outlet of the fuel cell stack, sending the data to the fuel cell controller 6. The humidification subsystem is sequentially configured along the airflow direction as follows: a dry gas input interface 402, a humidifier 403, a temperature sensor 404, a first humidity sensor 405, a connecting pipe to the cathode inlet of the fuel cell stack (connected to the cathode inlet 406), a connecting pipe to the cathode outlet of the fuel cell stack, a second humidity sensor 407, an adjustable three-way valve 408, a three-way valve 409, and a tailpipe interface 410, with the connecting pipe connected to the cathode outlet 411.

[0148] The adjustable three-way valve and the third port of the three-way valve are both connected to the humidifier. The humidifying gas is humidified by the humidifier through the adjustable three-way valve. The humidified air that is not used by the humidifier is mixed with the humidified air at the other port of the adjustable three-way valve through the three-way valve and then discharged to the outside of the system.

[0149] The humidifier is a membrane humidifier. Both the first and second humidity sensors are relative humidity sensors or dew point sensors. The adjustable three-way valve has one inlet and two outlets, with each outlet adjustable from 0% to 100%.

[0150] The fuel cell stack electrical performance monitoring and diagnostic system is used to detect the voltage and current between the positive and negative electrodes of the fuel cell stack, as well as the voltage of each individual cell, in real time, and send the data to the fuel cell controller 6. The fuel cell stack performance monitoring and diagnostic system includes a voltage sensor 412 and a current sensor 413 connected between the positive and negative electrodes of the fuel cell stack, and a cell voltage monitoring subsystem (CVM) connected to each individual cell of the fuel cell stack.

[0151] The fuel cell controller 6 sets a target value, starts the fuel cell, and adjusts the flow rate of humidifying gas through the humidification subsystem to bring the humidity of the air entering the stack close to the target value based on the received real-time detection values. It also performs a diagnostic response when the humidity deviates significantly from the target value.

[0152] The fuel cell stack performance monitoring and diagnostic system includes voltage sensors and current sensors connected between the positive and negative terminals of the fuel cell stack, as well as a single-unit voltage monitoring subsystem (CVM) connected to each individual cell of the fuel cell stack.

[0153] The method for controlling the humidity of a fuel cell using the above-mentioned fuel cell cathode humidification system includes the following steps:

[0154] (1) Set the target stack humidity value and the target small current value of the fuel cell through the fuel cell controller 6; the number of target stack humidity values ​​is n, and the maximum power generation current of the fuel cell is divided into n intervals, and a target stack humidity value is set for each interval.

[0155] (2) Start the fuel cell system. After the fuel cell generates electricity, acquire the temperature sensor value, the first humidity sensor value (cathode inlet humidity), and the second humidity sensor value (cathode outlet humidity) in real time. These values ​​reflect the humidity in the fuel cell cathode exhaust gas. At the same time, acquire the voltage and current between the positive and negative electrodes of the stack and the voltage of the individual cells in real time.

[0156] (3) When the fuel cell power generation reaches the target low current value, the flow rate of the gas diverted from the cathode outlet of the fuel cell stack is adjusted to be used as humidifying gas, so that the humidity value of the gas at the cathode outlet of the fuel cell stack approaches the target humidity value. By adjusting the opening of the adjustable three-way valve to the humidifier, the flow rate of the humidifying gas is controlled so that the value collected by the first humidity sensor (cathode humidity) approaches the target humidity.

[0157] (4) Continue to start the fuel cell system through the fuel cell controller 6 to make the fuel cell generate a larger current. At this time, the tail gas temperature of the cathode increases and the relative humidity increases, which also increases the upper limit of the humidification capacity of the humidifier. According to the target infeed humidity value in this current range, the adjustable three-way valve is dynamically adjusted to switch between dry and wet conditions. When the humidity increases, the humidity decreases.

[0158] (5) When the humidity value of the humidified gas fed into the fuel cell deviates significantly from the target in-pile humidity value, a diagnostic response is initiated. The diagnostic response involves shutting down the humidification subsystem via the fuel cell controller 6, and then stopping the fuel cell.

[0159] In a fuel cell system, dry air in the pipeline passes through a membrane humidifier. When the system is in standby mode, the humidifier is not active, and the humidification capacity is provided by the moisture in the dry air. In the open-circuit state of the fuel cell (which can be collected by a voltage sensor and transmitted to the fuel cell controller), the fuel cell produces very little water. The fuel cell needs to quickly switch from the open-circuit state to the power generation state. When the fuel cell controller controls the stack to generate a certain current, the stack output current collected by the current sensor can be transmitted to the fuel cell controller. Based on the values ​​of the voltage and current sensors and the stack polarization curve, the fuel cell controller determines the amount of generated water in the cathode exhaust gas. The cathode exhaust gas is a mixture of water and air. The dew point sensor at the cathode outlet of the stack can detect the dew point value. After receiving this information, the fuel cell system controller generates a larger current based on the dew point value and other relevant fuel cell parameters. As the current increases, the moisture content in the cathode exhaust gas increases. An adjustable three-way valve allows for bidirectional switching of the valve's opening, with each direction offering an opening of 0-100%. This allows for switching between dry and wet conditions in the fuel cell reaction-based water production process. During fuel cell power generation, the moisture-adjustable air passes through a humidifier to humidify the dry air. The humidified air not utilized by the humidifier mixes with humidified air from the other port of the three-way valve and is then vented outside the system. As the fuel cell's power output increases, the flow rate of the cathode exhaust gas entering the humidifier can be adjusted by changing the opening ratio of the valves on both sides of the adjustable three-way valve, thus controlling the humidification output. The humidifier and the adjustable three-way valve work together to regulate the humidification output. Values ​​collected by the temperature and dew point sensors at the cathode inlet are transmitted to the fuel cell controller. The fuel cell controller determines the humidification control strategy based on these values: whether to increase or decrease humidity, provide full or partial humidification, or disable humidification.

[0160] Fuel Cell Voltage Monitoring System (CVM)

[0161] The CVM system comprises n (n≥1) identical circuit boards. Each circuit board mainly includes a voltage measurement circuit, a control circuit, a CAN communication circuit, and an isolated power supply circuit. The voltage measurement circuit includes two individual voltage chips, each measuring the voltage of one or more fuel cell cells and transmitting the cell voltage values ​​and other information to the control chip via an isolated SPI bus. The isolated power supply circuit provides power to the entire detection unit and provides electrical isolation between the voltage measurement circuit, the control circuit, and the CAN communication circuit. The n circuit boards are connected together via a CAN bus, forming a CAN bus network. Each circuit board transmits cell voltage values ​​and other information to other devices through this CAN bus network.

[0162] The CVM system block diagram is shown in Figure 5. Each cell voltage chip has 12 measurement channels, and each channel can measure the voltage of one cell. All cell voltage chips are connected in series when detecting the cell voltage of a battery cell. That is, the 12th channel of the previous cell voltage chip is connected to the 1st channel of the adjacent cell voltage chip, thus forming a measurement capability of 12×n (n is the number of chips) cell voltages.

[0163] See schematic diagram Figure 6 It adopts an integrated chip, and a single chip can detect the voltage value of up to 12 fuel cell cells. It is small in size and requires very few external components, which facilitates the miniaturization of PCB size. It has the advantages of high voltage measurement accuracy and good stability.

[0164] The CVM system consists of 11 identical circuit boards, each of which mainly includes a voltage measurement circuit, a control circuit, a CAN communication circuit, and an isolated power supply circuit.

[0165] The voltage measurement module includes two individual cell voltage chips. Each individual cell voltage chip measures the voltage of 12 fuel cell cells and transmits the voltage values ​​of the 12 cells to the control circuit via an isolated SPI bus.

[0166] The isolated power supply module is used to provide power to the entire detection unit and to provide electrical isolation for the voltage measurement circuit, control circuit, and communication circuit.

[0167] The 11 circuit boards are connected together via a CAN communication bus to form a CAN bus network. The control circuit of each circuit board transmits information such as the individual cell voltage value to other systems through this CAN bus network, thereby realizing the measurement and information transmission of the voltage of 264 fuel cell cells.

[0168] The individual voltage chip is model LTC6804-2. The LTC6804-2 chip has two independent AD converters. Each AD converter is connected to a 6-to-1 multiplexer analog switch, meaning that each AD converter can measure the voltage of 6 individual chips, for a total of 12 individual chip voltages. By sending the corresponding commands to the LTC6804-2 chip through an isolated SPI bus, the LTC6804-2 chip can complete the AD conversion of the voltages of 12 individual chips.

[0169] fuel cell controller

[0170] like Figure 7 The fuel cell controller includes a processor, a signal output module, a signal acquisition module, a communication module, a debugging module, a power safety module, and a power management module.

[0171] The system includes: a signal acquisition module for receiving signals from sensors within the hydrogen fuel cell system; a signal output module for connecting to the actuators of the hydrogen fuel cell system and outputting adjustment signals; a communication module for connecting to the CAN and Modbus devices of the hydrogen fuel cell system; a debugging module for connecting to the processor on the controller board of the hydrogen fuel cell system; a processor for connecting to other modules within the fuel cell controller to monitor and modify various system parameters in real time; and a power management module for supplying power to other modules within the fuel cell controller.

[0172] The sensor components of a hydrogen fuel cell system include temperature sensors, pressure transmitters, flow transmitters, humidity sensors, and liquid level sensors, while the actuators include water-cooled fans, various valves, DC motors, and other equipment.

[0173] The processor uses a 32-bit ARM core, conforms to automotive-grade standards, and features the AEC-Q100 standard. It supports multiple CAN communication channels and allows for real-time monitoring and modification of system parameters via UART communication during online debugging and data monitoring. The power management chip circuitry is composed of automotive-grade high-current, low-power chips, a JTAG interface circuit, a dedicated PWM driver circuit, an AD sampling and filtering circuit, a DA output and operational amplifier circuit, and other circuit modules. The processor chip is a dedicated automotive VCU controller chip with multiple dedicated AD channels, multiple dedicated CAN channels, and multiple dedicated LSPI channels. The chip's internal clock can use an internal or external clock tree, achieving a 112MHz rate through PLL frequency multiplication. The power management chip conforms to the automotive-grade AEC-Q100 standard and features a wide operating range, high current capacity, small size, and simple peripheral circuitry. The JTAG interface circuit uses a standard 20-pin connector, directly connecting to the corresponding pins of the FS32K148 microcontroller. The PWM circuit features discrete circuitry with 24V and 5V selectable options. It can drive small-current PWM signals using transistors or large-current PWM signals using MOSFETs. It offers filtering and amplification capabilities, ensuring undistorted PWM waveforms. The frequency can be freely adjusted from 1Hz to 20kHz, providing a wide driving range. The AD sampling and filtering circuit features bypass decoupling capabilities, suitable for signal acquisition within the 0-5V range. It also allows for external 0-20mA current signal acquisition. The circuit design utilizes operational amplifiers to amplify small external signals without distortion before transmitting them to the corresponding pins of the microcontroller. This enables real-time adjustment of system parameters, ensuring interference-free signal transmission. The DA output circuit is composed of a 16-bit dedicated analog chip and a rail-to-rail dual operational amplifier chip at the back end. Its features include real-time updates, linear variation, and enhanced driving capability for small signals.

[0174] The signal output module includes a DA output unit, a PWM output unit, a high-side switch drive output unit, and a DC motor drive unit.

[0175] The DA output unit uses a dedicated 16-bit DA chip and a dedicated rail-to-rail operational amplifier combination circuit as a voltage follower amplifier. Through the processor's LSPI communication interface, it can linearly output a 0-5V analog signal. A dedicated current conversion chip is added to the subsequent stage of the circuit to convert the 0-5V voltage signal into a 0-20mA or 4-20mA standard current signal. Traditional fuel cell controllers mostly use standard 0-5V voltage signals to drive and control electrical equipment (such as ball valves), while our fuel cell controller uses standard 0-20mA or 4-20mA current signals to drive and control ball valves. The biggest advantage of using standard 0-20mA or 4-20mA current signal transmission is its strong anti-interference capability. The signal can be transmitted completely and intact to the actuator. During transmission, the signal will not be lost due to excessively long wiring or wiring interference. After receiving the signal, the electrical components accurately control the operation of the actuators, thus improving the system's safety and stability. Figure 8 As shown.

[0176] The PWM adjustable signal output unit employs a discrete component design, offering high flexibility. It can be driven by either transistors or MOSFETs, with the choice of transistor or MOSFET depending on the load current. Compared to PWM signals driven by integrated chips, it provides excellent frequency range and drive current adjustment. Furthermore, it can be configured with multiple PWM signal outputs, each with independently adjustable frequency and duty cycle to meet the driving requirements of different devices. For example, a fan may require a 200Hz drive frequency to operate, while a valve may require a 6kHz drive frequency. Such a circuit allows for independent design of the output frequency for each device. Figure 9 As shown.

[0177] The intelligent high-side switch driver unit uses a dedicated integrated chip. This chip has four high-current output channels, independent I / O port control, and features overcurrent protection and short-circuit protection for downstream loads. It has strong anti-interference capabilities and can effectively drive various solenoid valves while protecting their lifespan. Compared to traditional relay-driven high-current signal components like solenoid valves, this intelligent high-side chip circuit has load short-circuit protection and overcurrent / undercurrent detection functions. The chip's switching output can be controlled by a microcontroller's I / O port to turn the power output on and off, thereby controlling the open and closed states of the solenoid valve. Figure 10 As shown.

[0178] The DC motor drive unit uses a dedicated motor drive chip with dual-channel motor drive. It can achieve speed control by changing the duty cycle of the PWM signal, and can switch the motor between forward and reverse rotation. Motor direction can be controlled through two sets of I / O ports, A and B. It has excellent protection functions against motor overcurrent, idling, and dead running, ensuring the motor's lifespan. The motor speed is determined by the duty cycle of the PWM signal on the MCU pin; a larger duty cycle results in a faster speed, and a smaller duty cycle results in a slower speed. Figure 11 As shown.

[0179] The signal acquisition module comprises a digital signal acquisition unit and an analog signal acquisition unit. The digital signal acquisition unit acquires external liquid level switch signals from photoelectric sensors, which are then processed by the processor to drive relevant devices. The analog signal unit acquires external signals such as pressure, temperature, flow rate, voltage, current, and humidity using a dedicated analog chip and operational amplifier circuit. This allows for accurate and real-time signal acquisition. The processor integrates a 16-bit AD converter with two channels, each divided into 32 acquisition units, enabling simultaneous acquisition of 64 external analog signal inputs. The operational amplifier circuit amplifies external 0-20mA standard signals into voltage signals recognizable by the processor. Through these dedicated circuits, the hydrogen fuel cell controller accurately and in real-time acquires information from the entire fuel cell system, ensuring accurate control of external actuators. For example, the pressure sensor signal is a 0-5V standard voltage signal. After voltage division by a precision resistor connected to the controller circuit board with three wires, and filtering by a capacitor, the signal is transmitted to the microcontroller's AD sampling pin. The program then calculates the pressure value currently acquired by the pressure sensor. The temperature sensor compares the internal resistance of two wires and transmits the data to the microcontroller's AD pin to determine the current temperature inside the pipe. The humidity sensor, also using two wires, collects humidity data, converts it into a 0-20mA current signal, which is then amplified by a dedicated operational amplifier and converted into a 0-5V voltage signal. This signal is then sent to the microcontroller's AD pin to determine the humidity level inside the external pipe. Figure 12 The voltage acquisition signal shown is as follows: Figure 13 The current acquisition signal is shown.

[0180] The communication module includes CAN communication, CANFD communication and Modbus communication. The CAN communication has three channels, and each CAN channel has an independent 32 data buffer. The transmission rate can be set independently. It can receive extended frame and standard frame data at the same time. It has CANBUS OFF diagnostic and treatment methods and conforms to the J1939 international standard communication protocol. The processor communicates with the vehicle controller via CAN2 to obtain the vehicle's required power and feeds it back to the vehicle's fuel cell system controller. The processor also communicates with the CAN devices within the hydrogen fuel cell system via CAN0, controlling the isolated boost DC-DC power supply, air compressor, various valves, and water pumps based on the required power from the vehicle controller. Furthermore, the processor communicates with the individual cell voltage monitoring system controller within the hydrogen fuel cell system via CAN1, monitoring the individual fuel cell voltage status in real time and providing timely feedback to the system controller. During commissioning, the operator can update the program to the processor via a dedicated host computer using a BootLoader via CAN0 at power-on. This can be done without removing the controller housing, through the vehicle's CAN diagnostic interface. CANFD is a software application that packages and transmits multiple CAN data frames. Modbus communication is primarily used by programmers for online debugging and monitoring of system parameters to ensure stable operation of the hydrogen fuel cell system, acquiring data and transmitting it to the host computer platform via the CAN network.

[0181] The debugging module includes a JTAG protocol interface, which has a 20-pin standard protocol interface and is used for online debugging and program updates of processor chips. This debugging circuit has strong anti-interference capabilities, fast data transmission speed, and completes transmission with only 4 wires, making it simple and reliable.

[0182] The power safety module comprises components such as a TVS diode, an LC filter circuit, a large inductor for isolating the power and ground signals, and a large electrolytic capacitor for filtering. This input power safety management circuit features protection against short circuits, voltage spikes during power-on, and reverse connection. It meets EMC testing standards and effectively protects the voltage and current stability of the DC24V to DC12V and DC24V to DC5V conversion circuits. When the external voltage is momentarily too high, the TVS diode clamps the input voltage within a safe range, preventing the DC conversion chip from burning out due to excessive external voltage. This circuit uses few components and provides a drive current of up to 3A, sufficient to supply voltage and current to the microcontroller. Figure 14 As shown.

[0183] The power management module includes a 24V voltage conversion circuit, a 12V voltage conversion circuit, a 5V voltage conversion circuit, and a sampling reference voltage conversion circuit. The 24V conversion circuit features low-pass filtering technology, TVS diode protection, and isolation between the external ground and the system control board's internal ground, effectively removing spike interference from external input power supplies and noise on the power lines, ensuring the safe and stable operation of the system control board. The 12V voltage conversion circuit is independently implemented using a DC-DC step-down chip, featuring high drive current and stable voltage output, capable of powering all 12V power supply devices within the hydrogen fuel cell system. The 5V voltage conversion circuit is independently implemented using a two-stage filtering circuit and a dedicated DC-DC step-down chip, featuring high drive current, stable and adjustable voltage, and processor-controlled chip startup and low-power modes, providing a stable operating voltage to the system control board and ensuring the normal operation of the processor chip. The reference voltage conversion circuit is completed by a low-power reference voltage chip, which can provide a stable 5V sampling reference voltage. This provides a stable and consistent sampling reference voltage to the AD module inside the processor, ensuring the consistency of the external analog signals acquired by the processor chip. This ensures that the hydrogen fuel cell system controller can accurately and effectively acquire the real data from various sensors, allowing the system to operate in its optimal state.

[0184] The hydrogen fuel cell controller is encapsulated in a custom aluminum casing, which serves as electromagnetic shielding. The signal output module, signal acquisition module, communication module, debugging module, and power management module are connected to the processor through low-pass filter circuits. The use of low-pass filter circuits can improve the electromagnetic compatibility of the controller.

[0185] The hydrogen fuel cell controller connects to external devices via an IP67-rated connector. Gaps in the custom aluminum housing and between the controller board and the connector are sealed with adhesive to provide waterproofing and dustproofing. The controller for the entire hydrogen fuel cell system features protection against power-on shock, short circuits, over-temperature, over-current, over-voltage, and reverse connection. It meets the requirements of multi-sensor sampling, high-precision sampling, compatibility with different types of sensor signals, and high control precision for fuel cell systems. It also possesses excellent electromagnetic compatibility, meeting the requirements of vehicles in complex electromagnetic environments. With an IP67 protection rating, it meets the requirements of harsh onboard environments. Furthermore, it features CAN and Modbus communication interfaces and supports bootloader program updates.

[0186] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An integrated fuel cell system comprising a stack, characterized in that Also comprising: an anode hydrogen supply system for reducing the pressure of the incoming hydrogen gas according to the hydrogen source pressure and adjusting the pressure, temperature and humidity of the hydrogen gas with the tail gas of the fuel cell without reaction; an anode tail exhaust and hydrogen circulation system for detecting and separating the tail gas exhausted from the anode of the fuel cell, and recycling the separated hydrogen gas through the anode hydrogen supply system for humidification and hydrogen circulation; a cathode low pressure gas supply system for absorbing external air, reducing the temperature and humidifying the air, and then sending the air to the fuel cell, and adjusting the temperature, humidity and pressure of the air at the cathode outlet of the fuel cell stack to adjust the temperature, humidity and pressure of the air into the stack; a cathode tail exhaust humidification system for providing the gas at the cathode outlet of the fuel cell as humidification gas to the cathode low pressure gas supply system to humidify the dry gas, and controlling the flow of the humidification gas by detecting the voltage and current between the positive and negative electrodes of the stack; a fuel cell single voltage inspection system CVM for detecting the voltage of the fuel cell single; a fuel cell controller for receiving signals of sensors in the hydrogen fuel cell system, and real-time monitoring and modifying parameters of the fuel cell system; The fuel cell controller comprises: a signal acquisition module for receiving signals of sensors in the hydrogen fuel cell system; a signal output module for connecting execution devices of the hydrogen fuel cell system and outputting adjustment signals; a communication module for connecting CAN devices and Modbus devices of the hydrogen fuel cell system; a debugging module for connecting processors on the controller board of the hydrogen fuel cell system; a processor for connecting the signal acquisition module, the signal output module, the communication module, the debugging module and the power management module in the controller, and real-time monitoring and modifying parameters of the fuel cell system; a power management module for supplying power to each module in the controller; The signal output module comprises a DA output unit, a PWM output unit, a high-side switch driving output unit and a direct current motor driving unit; The DA output unit adopts a combination circuit of a special 16-bit DA chip and a special rail-to-rail operational amplifier, and a special current conversion chip is added at the rear stage of the circuit, which can convert 0-5V voltage signals into 0-20mA or 4-20mA standard current signals; The PWM output unit is driven by a triode or a MOSFET tube; The high-side switch driving output unit adopts a special integrated chip, which has four large-current output channels and independent I / O port control; The direct current motor driving unit adopts a special motor driving chip, which has double-channel motor driving, can change the duty cycle through PWM to achieve the function of speed regulation, can change the functions of motor forward and reverse rotation, and can realize motor steering operation through A and B two groups of I / O ports.

2. The integrated fuel cell system of claim 1, wherein: The anode hydrogen supply system comprises a pressure reduction unit, an inlet gas adjustment unit, a three-way valve, a monitoring unit and a circulating humidification unit; The pressure reduction unit is used for reducing the pressure of the incoming hydrogen gas; The inlet gas adjustment unit is used for adjusting the inlet amount and pressure of the hydrogen gas; The monitoring unit is used for real-time monitoring the pressure, temperature and humidity of the hydrogen gas entering the anode of the fuel cell stack; The circulating humidification unit is used to adjust the pressure, temperature and humidity of the hydrogen gas entering the anode of the fuel cell stack by using the tail gas generated by the fuel cell; The circulating humidification unit is used to adjust the pressure, temperature and humidity of the hydrogen gas from the outlet of the gas conditioning unit by using the tail gas which is not reacted by the fuel cell; The fuel cell controller sets the parameter value of the hydrogen gas entering the fuel cell, and collects the hydrogen gas parameter value in real time, compares the real-time hydrogen gas parameter value with the set value, and adjusts the opening of the pressure reduction unit, the gas conditioning unit, the valve opening in the circulating humidification unit and the rotating speed of the pump; The hydrogen gas from the external hydrogen source enters the anode of the fuel cell stack in sequence through the pressure reduction unit, the gas conditioning unit, the first and second interfaces of the three-way valve and the monitoring unit under the control of the fuel cell controller, and the tail gas generated by the fuel cell enters the anode of the fuel cell stack through the third interface of the three-way valve connected with the circulating humidification unit and then returns to the anode of the fuel cell stack through the monitoring unit.

3. The integrated fuel cell system of claim 1, wherein: It also comprises a hydrogen leak detection subsystem which is used to detect the concentration of the leaked hydrogen outside the system and transmit signals to the fuel cell controller, and the fuel cell controller makes a safety response.

4. The integrated fuel cell system of claim 1, wherein: The anode tail exhaust and hydrogen circulation system comprises a tail gas detection module, a water separation device, a humidity adjustable circulating branch, an anode tail exhaust branch and a drain valve; The tail gas detection module is connected with the outlet of the anode of the fuel cell stack at one end and connected with the gas inlet of the water separation device at the other end; the first pipeline interface of the water separation device is connected with the inlet of the humidity adjustable circulating branch, the second pipeline interface is connected with the anode tail exhaust branch, and the third pipeline interface is connected with the drain valve; The tail gas discharged from the fuel cell is detected by the tail gas detection module for temperature, pressure and humidity, and then enters the water separation device to separate hydrogen and water, part of the hydrogen is transmitted to the hydrogen supply system of the fuel cell through the humidity adjustable circulating branch for humidification and utilization and hydrogen circulation; part of the excess hydrogen is discharged through the anode tail exhaust branch, and the water is discharged through the drain valve; The fuel cell controller is used to connect the tail gas detection module, the water separation device, the humidity adjustable circulating branch, the anode tail exhaust branch and the drain valve, collect the detection results and control the opening and closing of the above-mentioned devices according to the detection results, so as to control the circulation or discharge of the separated hydrogen.

5. The integrated fuel cell system of claim 1, wherein: The cathode low-pressure gas supply system comprises: An air cooling and humidification system for absorbing external air and cooling and humidifying the air and then sending the air to the cathode inlet of the fuel cell stack; An air monitoring module for collecting the temperature, humidity and pressure of the air entering the cathode of the fuel cell stack in real time; A back pressure subsystem for adjusting the back pressure of the cathode outlet of the fuel cell stack; The fuel cell controller connects and controls the air cooling and humidification system, the air monitoring module and the back pressure subsystem, and adjusts the air cooling and humidification system and the back pressure subsystem to make the temperature, humidity and pressure of the cathode inlet air reach the preset range.

6. The integrated fuel cell system of claim 5, wherein: The air cooling and humidification system comprises an air absorption subsystem, an air cooling subsystem and an air humidification subsystem arranged in sequence; the air absorption subsystem is used to absorb external air, the air cooling subsystem is used to cool the absorbed air, and the air humidification subsystem is used to humidify the absorbed air.

7. The integrated fuel cell system of claim 5, wherein: The back pressure subsystem comprises an electric control valve and a tail gas pipeline, the tail gas pipeline is communicated with an air cooling and humidifying system, and the electric control valve discharges gas as a gas source of the humidifying system to air humidification.

8. The integrated fuel cell system of claim 1, wherein: The cathode tail exhaust humidifying system comprises a humidifying subsystem and a stack electrical performance monitoring and diagnosis system. The humidifying subsystem and the stack electrical performance monitoring and diagnosis system are controlled by a fuel cell controller. The humidifying subsystem is used to collect gas shunted from a cathode outlet of a fuel cell stack as humidifying gas, provide the humidifying gas to a cathode low pressure air supply system to humidify dry gas, and detect in real time temperature and humidity values of the humidifying gas before being sent into the fuel cell and humidity values of gas discharged from the cathode outlet of the fuel cell stack, and send the values to the fuel cell controller. The stack electrical performance monitoring and diagnosis system is used to detect in real time voltage and current between positive and negative electrodes of the stack and voltage of a cell, and send the values to the fuel cell controller. The fuel cell controller sets a target value, starts the fuel cell, and adjusts a flow of the humidifying gas to make humidity of air into the stack approach the target value according to the real-time detection values, and performs diagnosis response when the target value is obviously deviated.

9. The integrated fuel cell system of claim 1, wherein: The cell voltage inspection system CVM comprises a plurality of detection units, and each detection unit comprises a voltage measurement module, a control module, a communication module and an isolated power supply module. The voltage measurement module comprises two cell voltage chips, each chip is configured with n measurement channels, n≥1, and each measurement channel is used to measure voltage of a piece of fuel cell. The control module is used to control the cell voltage chip to measure the voltage of the fuel cell, and send the obtained voltage value to an external device through the communication module. The isolated power supply module is used to provide power supply for the entire detection unit, and provide electrical isolation for the voltage measurement module, the communication module and the control module. When there are two or more detection units, the detection units are independently operated, and all cell voltage chips are connected in series when detecting the voltage of the cell.

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