Power-off purging control system and method for fuel cell tractor electric pile system
By adding a purge switch and control system to the hydrogen fuel cell vehicle, power-off purge is achieved, solving the problem of icing blockage in the fuel cell stack circuit and ensuring system safety and smooth start-up.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-10
- Publication Date
- 2026-04-14
AI Technical Summary
In hydrogen fuel cell vehicles, the stack circuit is prone to icing and blockage under low temperature conditions. Existing technologies make it difficult to effectively purge the circuit after power-off, affecting system safety and smooth start-up.
A purge switch is added to the instrument panel in the vehicle cab. The power supply relay of the power distribution box is closed by the vehicle control unit, keeping the electromagnetic main switch closed and continuously supplying power to the fuel cell control unit to achieve power-off purge, ensuring that the stack fan works and reducing the generation of moisture in the stack components.
It effectively removes unreacted fuel gases and liquid water, ensuring the safety and service life of the fuel cell stack system and guaranteeing a smooth start-up next time.
Smart Images
Figure CN121848930A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an electric purging control system and method for a fuel cell tractor stack system, belonging to the technical field of hydrogen fuel cell tractors. Background Technology
[0002] With increasing pressure on energy and the environment, core technologies for new energy vehicles have become crucial for the sustainable development of the automotive industry. Currently, new energy vehicles broadly include hybrid electric vehicles, pure electric vehicles, and fuel cell electric vehicles. Among them, hydrogen fuel cell vehicles, with their high efficiency, energy saving, and zero-emission environmental performance, have become a hot topic in the global energy and transportation sectors and have now entered the commercialization stage. However, numerous technical challenges have arisen during the commercialization of hydrogen fuel cell vehicles, particularly the issue of purging after power generation. The final product of hydrogen fuel cell power generation is liquid water. After normal operation, liquid water accumulates in the reaction zone of the hydrogen fuel cell. In low outdoor temperatures, ice can form in the stack circuit, blocking the circuit and preventing normal operation. Therefore, when the power generation system is shut down, unreacted fuel gas and liquid water in the reaction channels must be purged. Simultaneously, the temperature of the hydrogen fuel cell must be lowered to near ambient temperature to ensure the safety of the hydrogen fuel cell and system, and to facilitate a smooth restart. Summary of the Invention
[0003] The purpose of this invention is to provide a control system and method for electrically purging a fuel cell tractor stack system, which enables low-temperature purging of the entire vehicle's hydrogen fuel cell stack and can effectively purge unreacted fuel gas and liquid water in the reaction channel.
[0004] To achieve the above objectives, the present invention employs the following technical solution: An electric purging control system for a fuel cell tractor stack system includes: A vehicle control unit having six input / output pins; The fuel cell control unit is used to control the fuel cell purging system; The battery is used to power the vehicle control unit and the fuel cell control unit. The distribution box, used to distribute power, includes switch K2 and switch K5; The system includes an electromagnetic master switch, a rocker switch, and a purge switch, with one end of the purge switch connected to the electromagnetic master switch and the other end connected to the vehicle control unit. After the purge switch is closed, the vehicle control unit receives a high-side signal through pin 3. Upon receiving the high-side signal, it sends a high-side signal through pin 2 to control switch K2 to close. At the same time, the vehicle control unit sends a low-side signal through pin 5 to control switch K5 to close. The battery provides wake-up power to the fuel cell control unit through the power distribution box. The vehicle control unit also sends an enable signal to the fuel cell control unit through pins 4 and 8 so that the fuel cell control unit can still maintain its working state after the key power and rocker switch are disconnected, and complete the power-off purge task.
[0005] Preferably, the high-side signal is triggered by the driver pressing the purge switch after the parking brake is applied, and the vehicle control unit receives the high-side signal after the purge switch is closed and before the rocker switch is disconnected.
[0006] Preferably, the electromagnetic master switch remains closed during the purging process, and the vehicle control unit receives power from the battery via pin 1.
[0007] Preferably, the electromagnetic main switch, switch K2, and switch K5 are electromagnetic relays.
[0008] A method for controlling the electrical purging of a fuel cell tractor stack system includes the following steps: After the driver applies the parking brake, press the purge switch and then disconnect the ignition key and rocker switch. After receiving the high-side signal through pin 3, the vehicle control unit sends a high-side signal through pin 2 to close switch K2; The vehicle control unit sends a low-side signal via pin 5 to control switch K5 to close. The battery provides wake-up power to the fuel cell control unit via the power distribution box; The vehicle control unit sends an enable signal to the fuel cell control unit via pins 4 and 8, so that the fuel cell control unit remains operational even after the key switch and rocker switch are turned off. The fuel cell control unit controls the fuel cell purging system to complete the power-off purging task; After the purging task is completed, the vehicle control unit stops sending signals and enters a sleep state, and the electromagnetic master switch, switch K2, and switch K5 are disconnected.
[0009] Preferably, the duration of the electric purging task is 10 minutes.
[0010] Preferably, the vehicle control unit enters a sleep state after the purging task is completed.
[0011] Preferably, the purge switch, rocker switch, and key switch are all located on the dashboard in the driver's cab.
[0012] Preferably, the vehicle controller and the power supply relay of the power distribution box are connected by a hard wire; The fuel cell controller and the vehicle controller communicate via a CAN bus. The fuel cell controller and the stack fan are connected via a CAN bus.
[0013] The advantages of this invention are as follows: A purge switch is added to the instrument panel in the vehicle cab. Before the driver disconnects the ignition, the purge switch is pressed. After receiving the purge switch signal, the vehicle controller controls the power supply relay of the distribution box to close, so that the electromagnetic master switch remains closed after the driver disconnects the ignition and rocker switch. The VCU is still in working state and can continuously supply power to the FCU. The FCU sends an enable signal to the fuel cell stack fan to realize power-off purge. After 10 minutes, the VCU cuts off the power supply relay of the distribution box to a low level through the control logic. In this way, the electromagnetic switch relay is automatically disconnected, and the vehicle is powered off. This method can effectively reduce the moisture generated by the fuel cell stack components during the discharge process, ensuring the working safety and service life of the fuel cell stack system. Attached Figure Description
[0014] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.
[0015] Figure 1 This is a schematic diagram of the circuit structure of the present invention.
[0016] Figure 2 This is a schematic diagram of the method flow of the present invention.
[0017] In the diagram, K1 is the main electromagnetic switch, K2 is switch K2, K3 is the rocker switch, K4 is the purge switch, K5 is switch K5, A is the battery, B is the power distribution box, C is the key switch, VCU is the vehicle control unit, and FCU is the fuel cell control unit. Detailed Implementation
[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0019] Example 1 like Figure 1As shown, a power-off purging control system and method for a fuel cell tractor stack system is disclosed. A purging switch K4 is added to the instrument panel in the driver's cab. Before the driver disconnects the ignition switch C, the driver presses the purging switch K4. After receiving the signal from the purging switch K4, the vehicle controller controls the power supply relay of the distribution box B to close. This ensures that the electromagnetic master switch K1 remains closed even after the driver disconnects the ignition switch C and the rocker switch K3. The VCU remains operational and continuously supplies power to the FCU. The FCU sends an enable signal to the stack fan to achieve power-off purging. After 10 minutes, the VCU cuts off the power supply relay of the distribution box B to a low level through control logic. This automatically disconnects the electromagnetic switch relay, and the vehicle is powered off.
[0020] The pins 1, 2, 3, 4, and 5 of the Vehicle Control Unit (VCU) represent different pin positions of the VCU's electrical interface. The pin definitions may differ for different VCU product wiring harnesses. These pin definitions are only functional and vary depending on the hardware. Pins 6 and 7 represent different pin definitions of the Fuel Cell Control Unit (FCU)'s electrical interface. Again, these pin definitions are only functional and vary depending on the hardware.
[0021] Specifically, including: The vehicle control unit (VCU) has six input / output pins. The fuel cell control unit (FCU) is used to control the fuel cell purging system. Battery A is used to power the vehicle control unit (VCU) and the fuel cell control unit (FCU); Distribution box B, used for distributing power, includes switch K2 and switch K5; The electromagnetic master switch K1, rocker switch K3, and purge switch K4 are provided. One end of the purge switch K4 is connected to the electromagnetic master switch K1, and the other end is connected to the vehicle control unit (VCU). After the purge switch K4 is closed, the vehicle control unit (VCU) receives a high-side signal through pin 3. Upon receiving the high-side signal, it sends a high-side signal through pin 2 to control switch K2 to close. At the same time, the VCU sends a low-side signal through pin 5 to control switch K5 to close. Battery A provides wake-up power to the fuel cell control unit (FCU) through the power distribution box B. The VCU also sends an enable signal to the FCU through pins 4 and 8, so that the FCU can maintain its working state after the key power C and rocker switch K3 are disconnected, and complete the power-off purge task.
[0022] As a refinement of the above embodiment, the high-side signal is triggered by the driver pressing the purge switch K4 after the parking brake is applied, and the vehicle control unit (VCU) receives the high-side signal after the purge switch K4 is closed and before the rocker switch K3 is disconnected.
[0023] As a refinement of the above embodiment, the electromagnetic master switch K1 remains closed during the purging process, and the vehicle control unit VCU receives power from the battery A through pin 1.
[0024] As a refinement of the above embodiments, the electromagnetic main switch K1, switch K2 and switch K5 are electromagnetic relays.
[0025] It should be noted that with this solution, the vehicle can still supply power to the FCU after the driver presses the rocker switch K3 or the key C, thereby enabling the vehicle's hydrogen fuel cell stack to be powered off and purged at low temperature. This effectively purges unreacted fuel gases and liquid water in the reaction channel. At the same time, the temperature of the hydrogen fuel cell needs to be reduced to near the ambient temperature to ensure the safety of the hydrogen fuel cell and system and the smooth start-up of the system next time.
[0026] Example 2 A method for controlling the electrical purging of a fuel cell tractor stack system includes the following steps: S1: After the driver applies the parking brake, press the blow switch K4, and then disconnect the key power supply C and the rocker switch K3; S2: After receiving the high-side signal through pin 3, the vehicle control unit (VCU) sends a high-side signal through pin 2 to close switch K2. S3: The vehicle control unit (VCU) sends a low-side signal through pin 5 to control switch K5 to close. S4: Battery A provides wake-up power to the fuel cell control unit (FCU) via distribution box B; S5: The vehicle control unit (VCU) sends an enable signal to the fuel cell control unit (FCU) via pins 4 and 8, so that the fuel cell control unit (FCU) remains operational even after the key switch (C) and rocker switch (K3) are disconnected. S6: The fuel cell control unit (FCU) controls the fuel cell purging system to complete the power-off purging task; S7: After the purging task is completed, the vehicle control unit (VCU) stops sending signals and enters a sleep state. The electromagnetic master switch K1, switch K2, and switch K5 are disconnected.
[0027] As a refinement of the above embodiment, the duration of the power-down purging task is 10 minutes.
[0028] As a refinement of the above embodiments, the vehicle control unit (VCU) enters a sleep state after the purging task is completed.
[0029] As a refinement of the above embodiments, the purge switch K4, rocker switch K3 and key switch are all arranged on the dashboard of the cab.
[0030] As a refinement of the above embodiment, the vehicle controller is connected to the power supply relay of the power distribution box B via a hard wire; The fuel cell controller and the vehicle controller communicate via a CAN bus. The fuel cell controller and the stack fan are connected via a CAN bus.
[0031] This invention adds a purge switch K4 to the vehicle's cab instrument panel. Before the driver disconnects the ignition switch C, pressing the purge switch K4 causes the vehicle controller to receive the signal and close the power supply relay of the distribution box B. This keeps the electromagnetic master switch K1 closed even after the driver disconnects the ignition switch C and the rocker switch K3, ensuring the VCU remains operational and continuously supplies power to the FCU. The FCU then sends an enable signal to the fuel cell stack fan to initiate a power-off purge. After 10 minutes, the VCU uses control logic to cut off the power supply relay of the distribution box B to a low level, automatically disconnecting the electromagnetic switch relay and powering off the vehicle. This method effectively reduces the moisture generated in the fuel cell stack components (proton exchange membrane) during discharge, ensuring the operational safety and lifespan of the fuel cell stack system.
[0032] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A fuel cell tractor stack system with an electric purging control system, characterized in that, include: A vehicle control unit having six input / output pins; The fuel cell control unit is used to control the fuel cell purging system; The battery is used to power the vehicle control unit and the fuel cell control unit. The distribution box, used to distribute power, includes switch K2 and switch K5; The system includes an electromagnetic master switch, a rocker switch, and a purge switch, with one end of the purge switch connected to the electromagnetic master switch and the other end connected to the vehicle control unit. After the purge switch is closed, the vehicle control unit receives a high-side signal through pin 3. Upon receiving the high-side signal, it sends a high-side signal through pin 2 to control switch K2 to close. At the same time, the vehicle control unit sends a low-side signal through pin 5 to control switch K5 to close. The battery provides wake-up power to the fuel cell control unit through the power distribution box. The vehicle control unit also sends an enable signal to the fuel cell control unit through pins 4 and 8 so that the fuel cell control unit can still maintain its working state after the key power and rocker switch are disconnected, and complete the power-off purge task.
2. The electric purging control system for the fuel cell tractor stack system according to claim 1, characterized in that, The high-side signal is triggered by the driver pressing the purge switch after the parking brake is applied, and the vehicle control unit receives the high-side signal after the purge switch is closed and before the rocker switch is disconnected.
3. The electric purging control system for the fuel cell tractor stack system according to claim 1, characterized in that, The electromagnetic master switch remains closed during the purging process, and the vehicle control unit receives power from the battery through pin 1.
4. The electric purging control system for the fuel cell tractor stack system according to claim 1, characterized in that, The main electromagnetic switch, switch K2, and switch K5 are electromagnetic relays.
5. A method for controlling the electric purging of a fuel cell tractor stack system using the system described in any one of claims 1-4, characterized in that, Includes the following steps: After the driver applies the parking brake, press the purge switch and then disconnect the ignition key and rocker switch. After receiving the high-side signal through pin 3, the vehicle control unit sends a high-side signal through pin 2 to close switch K2; The vehicle control unit sends a low-side signal via pin 5 to control switch K5 to close. The battery provides wake-up power to the fuel cell control unit via the power distribution box; The vehicle control unit sends an enable signal to the fuel cell control unit via pins 4 and 8, so that the fuel cell control unit remains operational even after the key switch and rocker switch are turned off. The fuel cell control unit controls the fuel cell purging system to complete the power-off purging task; After the purging task is completed, the vehicle control unit stops sending signals and enters a sleep state, and the electromagnetic master switch, switch K2, and switch K5 are disconnected.
6. The method for controlling the electric purging of a fuel cell tractor stack system according to claim 5, characterized in that, The duration of the electric purging task is 10 minutes.
7. The method for controlling the electric purging of a fuel cell tractor stack system according to claim 5, characterized in that, The vehicle control unit enters a dormant state after the purging task is completed.
8. The method for controlling the electric purging of a fuel cell tractor stack system according to claim 5, characterized in that, The purge switch, rocker switch, and key switch are all located on the dashboard in the driver's cab.
9. The method for controlling the electric purging of a fuel cell tractor stack system according to claim 5, characterized in that, The vehicle controller and the power supply relay of the power distribution box are connected by a hard wire; The fuel cell controller and the vehicle controller communicate via a CAN bus. The fuel cell controller and the stack fan are connected via a CAN bus.