A test method for hydrogen inlet pressure of vehicle-mounted fuel cell system being too high

Abstract

The present application relates to the field of vehicle-mounted fuel cell system, and particularly relates to a test method for hydrogen inlet pressure being too high in a vehicle-mounted fuel cell system. The test method provides multiple analog output channels through a HIL test platform, simulates any value of hydrogen inlet pressure, and modifies the analog output quantity during the test process. The hydrogen inlet pressure model in the HIL is simulated to keep the test conditions consistent with the working conditions on the real fuel cell system, and the design of the fault test case for the hydrogen inlet pressure being too high ensures the effectiveness and timeliness of the software function and solves the danger brought by the actual fuel cell system test.

Description

Technical Field

[0001] This invention relates to the field of vehicle-mounted fuel cell systems, and more particularly to a test method for excessive hydrogen inlet pressure in a vehicle-mounted fuel cell system. Background Technology

[0002] As the core component for the protection and management of a fuel cell system, the FCU (Fuel Cell Controller) must not only fully utilize the fuel cell's output capacity but also ensure its safe and reliable operation. To guarantee the stability of the output power, the FCU needs to control the hydrogen inlet pressure in real time and provide effective protection measures when the hydrogen inlet pressure becomes abnormal. Currently, when testing for excessive hydrogen inlet pressure in a fuel cell system, a command can be sent from the host computer to the FCU to forcibly control the output of the proportional valve and the speed of the hydrogen circulation pump to trigger the excessive hydrogen inlet pressure fault. When the FCU detects excessive hydrogen inlet pressure, it reports the fault level and fault code via the CAN bus and simultaneously controls the fuel cell system to enter the shutdown phase, closing various valves.

[0003] Firstly, the aforementioned testing method is extremely complex to operate. When forcibly controlling the hydrogen inlet pressure, we do not know what control values ​​the proportional valve and hydrogen pump need to provide when the hydrogen inlet pressure becomes too high. We need to continuously modify the control values ​​during testing, which is very time-consuming. At the same time, hydrogen is a very reactive gas with certain dangers. The higher the hydrogen inlet pressure, the higher the flow rate of hydrogen entering the fuel cell system needs to be controlled. In this project, there is a possibility of dangerous situations caused by hydrogen leakage. Summary of the Invention

[0004] To address the problems existing in the background technology, a test method for excessive hydrogen inlet pressure in vehicle fuel cell systems is proposed. The method uses the hydrogen inlet pressure model in HIL to simulate the test conditions to keep them consistent with the actual operating conditions of fuel cell systems. At the same time, the design of the fault test case for excessive hydrogen inlet pressure ensures the effectiveness and timeliness of this function in the software, while also solving the dangers that may arise during actual fuel cell system testing.

[0005] This invention proposes a test method for excessive hydrogen inlet pressure in a vehicle-mounted fuel cell system. The method provides multiple simulated output channels through the HIL test platform to simulate arbitrary values ​​of hydrogen inlet pressure, and the test is conducted by modifying the simulated output quantities.

[0006] Preferably, the specific steps are as follows:

[0007] S1. Configure the analog output channels on the HIL test bench, and configure one of the channels as the hydrogen infeed pressure output channel; connect this channel to the FCU hydrogen infeed pressure acquisition channel;

[0008] S2. Establish the hydrogen inlet pressure model: The model mainly consists of two parts. The first part is to establish the anode model of the fuel cell stack and calculate the hydrogen inlet pressure value. The second part is the hydrogen inlet pressure output model. The voltage value of the hydrogen inlet pressure is obtained by looking up the inlet pressure value output by the first part.

[0009] S3. Configure the CAN communication-related settings in the HIL test system;

[0010] S4. The FCU is put into working state by giving instructions through the HIL test bench. The infeed pressure value is modified through the HIL test equipment. When the pressure value reaches the high pressure threshold, the FCU enters the shutdown state, controls all related valves to close, and reports the level 3 fault and corresponding fault code through CAN communication.

[0011] Preferably, the anode model of the fuel cell stack is based on the mass-energy conservation formula of ideal gas equilibrium:

[0012] PMan=(mMan*RMan*TMan) / VMan;

[0013] PMan is the pressure value of the manifold, which is the hydrogen inlet pressure value calculated in this paper; RMan is the specific gas constant in the manifold; TMan is the temperature value of the manifold; VMan is the volume of the manifold.

[0014] Preferably, the configuration in S3 includes connecting the CAN communication channel of the HIL test platform to the corresponding CAN communication channel of the FCU, and importing the CAN communication matrix into the HIL test system.

[0015] Preferably, the instructions given by the HIL test bench in S4 include constant power, wake-up signal, and CAN communication.

[0016] Compared with existing technologies, this invention has the following beneficial technical effects: It provides multiple simulation output channels through the HIL test platform to simulate arbitrary values ​​of hydrogen infeed pressure, and the test is conducted by modifying the simulation output during the testing process. By utilizing the hydrogen infeed pressure model in HIL, the test conditions are kept consistent with the operating conditions of a real fuel cell system. Furthermore, the design of the fault test case for excessively high hydrogen infeed pressure ensures both the effectiveness and timeliness of this software function, while also mitigating the hazards associated with actual fuel cell system testing. Attached Figure Description

[0017] Figure 1 This is an electrical connection diagram for the test method of excessive hydrogen inlet pressure in the vehicle-mounted fuel cell system of the present invention.

[0018] Figure 2This is a flowchart of the test method for excessive hydrogen inlet pressure in the vehicle-mounted fuel cell system of the present invention. Detailed Implementation

[0019] This invention proposes a testing method for excessive hydrogen inlet pressure in a vehicle-mounted fuel cell system. The method utilizes a HIL testing platform to provide multiple simulated output channels, simulating arbitrary values ​​of hydrogen inlet pressure. Furthermore, the testing process involves modifying the simulated output values. The specific steps are as follows:

[0020] S1. First, the analog output channels need to be configured on the HIL test bench, and one of these channels needs to be configured as the hydrogen infeed pressure output channel. Connect this channel to the FCU hydrogen infeed pressure acquisition channel using a wiring harness. For specific electrical connections, see [link to details]. Figure 1 ;

[0021] S2. Secondly, a hydrogen inlet pressure model needs to be established. This model mainly consists of two parts. The first part is establishing the anode model of the fuel cell stack, and calculating the hydrogen inlet pressure value. The principle of the anode model is based on the input demand current, the duty cycle parameters controlled by the proportional valve, and the speed of the hydrogen circulation pump, according to the mass-energy conservation formula of ideal gas equilibrium.

[0022] PMan=(mMan*RMan*TMan) / VMan;

[0023] PMan is the pressure value of the manifold, which is the hydrogen inlet pressure value calculated in this paper; RMan is the specific gas constant in the manifold; TMan is the temperature value of the manifold; VMan is the volume of the manifold.

[0024] The second part of the model is the hydrogen infeed pressure output model. The infeed pressure value output in the first part is used to obtain the voltage value of the hydrogen infeed pressure by looking up a table (this table is a mapping table of pressure value and voltage value).

[0025] S3. Configure CAN communication-related settings in the HIL test system; the configuration includes connecting the HIL test platform's CAN communication channel to the corresponding CAN communication channel of the FCU. See [link to electrical connection details] for specific electrical connections. Figure 1 At the same time, the CAN communication matrix needs to be imported into the HIL test system;

[0026] S4. The FCU is put into working state by giving instructions (including constant power, wake-up signal, and CAN communication) through the HIL test bench. The infeed pressure value is modified through the HIL test equipment. When the pressure value reaches the high pressure threshold, the FCU enters the shutdown state, controls all related valves to close, and reports the level 3 fault and corresponding fault code through CAN communication.

[0027] Based on the above methods, a practical application of the test method for excessive hydrogen infeed pressure in an on-board fuel cell system is proposed, such as... Figure 2 As shown, the HIL test bench outputs a constant 24V power supply and a KL15 wake-up signal. It sends a CAN message to activate the FCU, modifies the HIL test equipment's infeed pressure to 310 kPa, and waits 5 seconds. When the pressure reaches the overpressure threshold, the FCU shuts down, controlling all relevant valves to close. Simultaneously, it reports the fault level (Level 3) and its corresponding fault code via CAN communication. If the reported fault is accurate, the test passes.

[0028] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A test method for excessive hydrogen infeed pressure in an on-board fuel cell system, characterized in that, The HIL test platform provides multiple analog output channels to simulate arbitrary values ​​of hydrogen infeed pressure, and the test is conducted by modifying the analog output during the test process. The specific steps are as follows: S1. Configure the analog output channels on the HIL test bench, and configure one of the channels as the hydrogen infeed pressure output channel; connect this channel to the FCU hydrogen infeed pressure acquisition channel; S2. Establish the hydrogen inlet pressure model: The model mainly consists of two parts. The first part is to establish the anode model of the fuel cell stack and calculate the hydrogen inlet pressure value. The second part is the hydrogen inlet pressure output model. The voltage value of the hydrogen inlet pressure is obtained by looking up the inlet pressure value output by the first part. S3. Configure the CAN communication-related settings in the HIL test system; S4. The FCU is put into working state by giving instructions through the HIL test bench. The infeed pressure value is modified through the HIL test equipment. When the pressure value reaches the high pressure threshold, the FCU enters the shutdown state, controls all related valves to close, and reports the level 3 fault and corresponding fault code through CAN communication. The anode model of the fuel cell stack is based on the mass-energy conservation formula of an ideal gas equilibrium: PMan=(mMan * RMan * TMan) / VMan; PMan is the pressure value of the manifold, which is the hydrogen inlet pressure value calculated in this paper; RMan is the specific gas constant in the manifold; TMan is the temperature value of the manifold; VMan is the volume of the manifold.

2. The test method for excessive hydrogen inlet pressure in an on-board fuel cell system according to claim 1, characterized in that, The configuration in S3 includes connecting the HIL test platform's CAN communication channel to the corresponding CAN communication channel of the FCU, and also requires importing the CAN communication matrix into the HIL test system.

3. The test method for excessive hydrogen inlet pressure in an on-board fuel cell system according to claim 1, characterized in that, The instructions provided by the S4 HIL test bench include constant power, wake-up signal, and CAN communication.

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