A fuel cell hydrogen system control method and system

Abstract

The present application relates to the technical field of vehicle control, in particular to a fuel cell hydrogen system control method and system, the hydrogen system is powered on from the initial state in turn low voltage and high voltage, enters the power-on state; the fuel cell is self-checked according to the instruction in the power-on state, and starts after the self-checking succeeds; if the fuel cell self-checking succeeds, and the hydrogen system can be normally powered on, and the hydrogen system main valve and each bottle valve are in the closed state, the hydrogen system enters the preparation state; in the preparation state, the main valve of the hydrogen system is opened, and each bottle valve maintains the closed state; if the fuel cell controller sends an enable signal to the hydrogen system, the hydrogen system enters the working state, and the hydrogen system controls the opening of the corresponding bottle valve under the condition that the main valve maintains the opening according to the received enable signal, supplies the hydrogen required for vehicle operation to the fuel cell; when the fuel cell does not send the enable signal, the main valve and each bottle valve of the hydrogen system are closed.

Description

A control method and system for a fuel cell hydrogen system Technical Field

[0001] This invention relates to the field of vehicle control technology, specifically to a control method and system for a fuel cell hydrogen system. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Most fuel cell buses use four- or six-cylinder hydrogen systems. Each hydrogen cylinder typically has a separate valve, along with a main valve to control the flow between the refueling station and the hydrogen cylinders, allowing hydrogen to be supplied from the refueling nozzle at the refueling station to the hydrogen cylinders.

[0004] When a fuel cell bus is running, it is necessary to ensure a stable supply of hydrogen. At the same time, considering the pressure balance between the various cylinder valves, multiple hydrogen cylinders in the hydrogen system will usually open simultaneously when the hydrogen system receives a control command from the fuel cell system. However, this method can easily lead to excessively high instantaneous pressure at the moment the hydrogen cylinders are started. Summary of the Invention

[0005] To address the technical problems mentioned above, this invention provides a fuel cell hydrogen system control method and system. The method divides the hydrogen system into different operating states, and opens the main valve in the preparation state and opens the main valve and each cylinder valve in the operating state, forming a two-stage pressure regulation and control mechanism. This allows the hydrogen gas in the hydrogen cylinder to pass through the cylinder valves and the main valve before entering the fuel cell, reducing the impact of excessively high instantaneous pressure on the system when all cylinder valves are open.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of the present invention provides a control method for a fuel cell hydrogen system, comprising the following steps:

[0008] The hydrogen system transitions from an initial state to an energized state by sequentially applying low-voltage electricity and then high-voltage electricity.

[0009] When powered on, the fuel cell performs a self-test according to instructions, and starts up after a successful self-test.

[0010] If the fuel cell self-test is successful and the hydrogen system can be powered on normally, and the main valve of the hydrogen system and the valves of each cylinder are in the closed state, the hydrogen system enters the ready state; in the ready state, the main valve of the hydrogen system is opened and the valves of each cylinder remain closed.

[0011] If the fuel cell controller sends an enable signal to the hydrogen system, the hydrogen system enters the working state. Based on the received enable signal, the hydrogen system controls the corresponding cylinder valves to open while the main valve remains open, supplying the fuel cell with the hydrogen required for vehicle operation. When the fuel cell does not send an enable signal, the main valve and each cylinder valve of the hydrogen system are closed.

[0012] Furthermore, in the initial state, the hydrogen system did not receive any instructions, and the main valve and each cylinder valve were in the closed state.

[0013] Furthermore, the ready state specifically refers to the following: after the hydrogen system is powered on and there are no faults, the main cylinder valve of the hydrogen system is in the open state, and the valves of each cylinder are in the closed state.

[0014] Furthermore, the operating status is as follows: the fuel cell controller sends an enable signal to the hydrogen controller, controlling the main valve and each cylinder valve to be in the open state.

[0015] Furthermore, during operation, when the fuel cell controller no longer sends an enable signal to the hydrogen controller, the main control valve and each cylinder valve are in the closed state.

[0016] Furthermore, when hydrogen is added to the hydrogen system, the system controls the corresponding cylinder valves to open while the main valve remains open, based on the received enable signal. This allows the high-pressure hydrogen from the hydrogen refueling gun to pass through the main valve and each cylinder valve to the corresponding hydrogen cylinder.

[0017] Furthermore, the hydrogen system also has a fault state. When the communication fault flag of the hydrogen system is 0, and the fault level of the hydrogen system is less than the set level or there is no hydrogen leakage, the hydrogen system changes from the fault state to the ready state.

[0018] Furthermore, if a hydrogen leak emergency stop signal or communication failure occurs during operation, the hydrogen system will switch from an operational state to a fault state.

[0019] Furthermore, in a fault state, if the enable signals of the main valve and each cylinder valve of the hydrogen system sent by the fuel cell are reset to 1, the hydrogen system will switch from a fault state to a working state.

[0020] A second aspect of the present invention provides a control system for a fuel cell hydrogen system, comprising:

[0021] The fuel cell controller receives instructions from the vehicle controller and the status information of the hydrogen system. It matches the corresponding power point according to the fuel cell status, controls the fuel, air and combustion products required during the operation of the fuel cell, and sends control enable commands to the hydrogen controller according to the status of the fuel cell.

[0022] The vehicle controller obtains the status information of the fuel cell and hydrogen system based on the fuel cell controller and hydrogen controller, and issues corresponding power control commands to the fuel cell controller according to the actual operating conditions.

[0023] The hydrogen controller, based on instructions from the vehicle controller and enable signals from the fuel cell controller, controls the opening or closing of the main valve and individual cylinder valves in the hydrogen system.

[0024] Compared with existing technologies, one or more of the above technical solutions have the following beneficial effects:

[0025] The hydrogen system is divided into different operating states, and the opening states of the main valve and cylinder valves are controlled according to the different operating states of the hydrogen system. In the preparation state of the hydrogen system, only the main valve is opened and the cylinder valves are not opened. In the operating state, the main valve and the cylinder valves are opened, forming a two-stage pressure regulation and control method. The hydrogen in the hydrogen cylinder passes through the cylinder valves and the main valve in sequence before entering the fuel cell. The two-stage control valves generate resistance to the instantaneous high pressure hydrogen at each stage, reducing the impact of excessive instantaneous pressure on the system when all cylinder valves are open. Attached Figure Description

[0026] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0027] Figure 1 is a schematic diagram of the control process of a fuel cell hydrogen system provided by one or more embodiments of the present invention;

[0028] Figure 2 is a schematic diagram of a fuel cell hydrogen system control system provided by one or more embodiments of the present invention;

[0029] Figure 3 is a schematic diagram of a fuel cell hydrogen system provided by one or more embodiments of the present invention. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] As described in the background technology, when a fuel cell bus is running, it is necessary to ensure a stable supply of hydrogen. At the same time, considering the pressure balance between the various cylinder valves, multiple hydrogen cylinders of the hydrogen system will usually open simultaneously when the hydrogen system receives the control command from the fuel cell system. However, this method can easily lead to excessively high instantaneous pressure at the moment the hydrogen cylinders are started.

[0034] Therefore, the following embodiments provide a control method and system for a fuel cell hydrogen system. The system divides the hydrogen system into different operating states and controls the opening states of the main valve and cylinder valves according to these states. In the preparation state, only the main valve is opened, while the cylinder valves are not. In the operating state, both the main valve and the cylinder valves are opened, forming a two-stage pressure regulation control method. This allows the hydrogen gas in the cylinders to pass sequentially through the cylinder valves and the main valve before entering the fuel cell. The two-stage control valves progressively generate resistance to the instantaneous high-pressure hydrogen, reducing the impact of excessively high instantaneous pressure on the system when all cylinder valves are open.

[0035] Example 1:

[0036] As shown in Figure 1, a control method for a fuel cell hydrogen system includes the following steps:

[0037] Initially, the hydrogen system does not receive any commands, and the main valve and cylinder valves of the hydrogen system are closed. The vehicle sequentially connects to the low-voltage and high-voltage power supplies, entering the power-up state.

[0038] When powered on, the fuel cell FC-EV switch starts, the fuel cell performs a self-test, and starts up after a successful self-test.

[0039] The hydrogen system determines whether to start based on the status of the fuel system. If the fuel cell self-test is successful and the hydrogen system can be powered normally, and the main valve and all cylinder valves of the hydrogen system are closed, the hydrogen system enters the standby state. In the standby state, the main valve of the hydrogen system is open, and all cylinder valves remain closed. If the fuel cell is in an error state, the hydrogen system fails to start normally and the operation ends.

[0040] The system determines whether the fuel cell controller sends an enable signal to the hydrogen system. If it has, the hydrogen system enters the working state and controls the main valve and each cylinder valve to open according to the received enable signal, supplying the fuel cell with the hydrogen required for vehicle operation. When the fuel cell does not send an enable signal, the main valve and each cylinder valve of the hydrogen system are closed.

[0041] When hydrogen is added to the hydrogen system, the system receives an enable signal again, and the high-pressure hydrogen from the hydrogen refueling gun passes through the main valve and the individual cylinder valves to the individual hydrogen cylinders.

[0042] In this embodiment, the FC-EV switch refers to a key component that controls the start-up, operation, and shutdown of the fuel cell electric vehicle power system. These switches typically include a main power switch, a fuel cell system switch, and other mode selection switches that may exist.

[0043] This embodiment sends different control commands to the hydrogen system based on the different operating states of the fuel cell. The hydrogen system has four operating states: Powerup, Standby, Work, and Error. The hydrogen system will only switch to the corresponding operating state after receiving the command. The state changes of the hydrogen system mainly include the state of the main valve and the individual cylinder valves. The hydrogen controller controls the normal operation of each valve. By opening the main valve in the standby state and opening the main valve and the individual cylinder valves in the working state, a two-stage pressure regulation and control method is formed. This allows the hydrogen in the hydrogen cylinder to enter the fuel cell through the cylinder valves and the main valve, reducing the impact of excessively high instantaneous pressure on the system when multiple cylinder valves are all open, ensuring the order and safety of hydrogen supply, and achieving effective control of the hydrogen system.

[0044] Example 2:

[0045] As shown in Figure 2, a control system for a fuel cell hydrogen system includes:

[0046] The fuel cell controller receives information from the vehicle controller and the hydrogen system. Under the control of the fuel cell controller, the fuel cell system matches an appropriate power point according to the fuel cell status. When the fuel cell is operating, it sends control enable commands to the hydrogen controller to control the opening and closing of the main valve and cylinder valve of the hydrogen tank. The fuel cell controller can control the relevant components of the hydrogen, air, and water circuits of the fuel cell system, keeping the fuel cell system and hydrogen system operating in a controllable state.

[0047] The vehicle controller receives information from the fuel cell system and hydrogen system, presents the vehicle status via CAN communication, and displays information such as fuel cell status, power, hydrogen system hydrogen reserve, main valve, cylinder valve, pressure, temperature, and leakage on the instrument panel. Simultaneously, the controller can adjust the fuel cell power according to actual operating conditions, thereby regulating the hydrogen system. Therefore, the controller is the control center for receiving and sending commands.

[0048] The hydrogen controller receives CAN communication information from the vehicle controller and fuel cell controller. Upon receiving commands, the hydrogen controller executes corresponding control instructions. The hydrogen controller adjusts according to the hydrogen system's status, which changes in accordance with the vehicle's operational requirements.

[0049] Furthermore, the initial state of the hydrogen system is that the hydrogen system has not received any instructions, and at this time the main valve of the hydrogen system and the valves of each cylinder are in the closed state.

[0050] Furthermore, the preparation state of the hydrogen system is when the hydrogen system is powered on without faults. In this case, the hydrogen system enters the preparation stage, and the main cylinder valve is in the open state and all cylinder valves are in the closed state.

[0051] Furthermore, the hydrogen system operates by the fuel cell controller sending an enable signal to the hydrogen controller, which opens the main valve and all cylinder valves. When the fuel cell controller stops sending enable signals, the main valve and cylinder valves close. When hydrogen is refilled into the system, the main valve and cylinder valves receive the enable signal again, and the valves reopen.

[0052] Furthermore, the hydrogen system is in a fault state when the communication fault flag is 0, the hydrogen system fault level is less than 4, or there is no hydrogen leakage in the hydrogen system, at which point the hydrogen system enters the ready state from the fault state; if a hydrogen leakage emergency stop signal or communication fault occurs while the hydrogen system is in the working state, the hydrogen system enters the fault state from the working state; if the hydrogen system is in a fault state, the enable signals of the main valve and each cylinder valve sent by the fuel cell are reset to 1, then the hydrogen system enters the working state from the fault state.

[0053] Furthermore, the hydrogen system also includes a manual adjustment mode. When the CAN control mode fails, the main valve of the hydrogen system and the valves of each cylinder can be manually opened. When no manual signal is sent, the hydrogen system maintains its original working state.

[0054] In the fuel cell hydrogen system control system, the vehicle controller, fuel cell controller, and hydrogen controller communicate with each other via CAN communication, and achieve mutual control between the controllers by sending and receiving messages.

[0055] The fuel cell controller receives instructions from the vehicle controller to control the on / off status and power of the vehicle's fuel cell system. Similarly, the hydrogen controller receives instructions from the vehicle controller to control the on / off status of the main valve and cylinder valve of the fuel cell hydrogen system.

[0056] Meanwhile, the fuel cell controller and hydrogen controller send the status information of the fuel cell system and hydrogen system to the vehicle controller. The vehicle controller uses the feedback instructions from the fuel cell controller to control the power of the fuel cell system, and uses the feedback instructions from the hydrogen controller to control the status of the main valve and cylinder valve of the hydrogen system.

[0057] The hydrogen system operates in four states: Powerup, Standby, Work, and Error. There are transition conditions between these states, and the transition can be achieved when the transition conditions are met.

[0058] Taking the fuel cell hydrogen system shown in Figure 3 as an example, the process of its control is introduced:

[0059] Open the main valve of the hydrogen system (taking the manual shut-off valve in Figure 3 as an example). The main valve is located on the main line of the hydrogen system, and each hydrogen cylinder is located on a branch line of the hydrogen system. Open the cylinder valve. The cylinder valve acts as a first-level pressure reducing valve. It uses a sensor to detect whether the actual pressure value P1 at the outlet of the hydrogen cylinder is greater than the specified value P, where P = 35 MPa. When the detected pressure value P1 > P, the hydrogen cylinder needs to release hydrogen. Then, the safety valve is opened to release the hydrogen.

[0060] If the hydrogen pressure discharged from each cylinder valve is still at a high level, a safety valve is installed between the hydrogen cylinder and the cylinder valve to release the hydrogen from the cylinder. The current pressure P2 is detected by a sensor, and the pressure value is brought within a reasonable range by a manual shut-off valve, so as to meet the pressure requirements of the hydrogen circuit end of the fuel cell. In this embodiment, the pressure at the inlet end of the fuel cell is 9.5 MPa.

[0061] 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. A control method for a fuel cell hydrogen system, characterized in that, Includes the following steps: The hydrogen system is initially powered on by low voltage and then high voltage in sequence to enter the power-on state. In the power-on state, the fuel cell performs a self-test according to the instructions, and starts up after the self-test is successful. If the fuel cell self-test is successful and the hydrogen system can be powered on normally, and the main valve and all cylinder valves of the hydrogen system are closed, the hydrogen system enters the preparation state. In the preparation state, the main valve of the hydrogen system opens, and all cylinder valves remain closed. If the fuel cell controller sends an enable signal to the hydrogen system, the hydrogen system enters the working state. According to the received enable signal, the hydrogen system controls the corresponding cylinder valves to open while the main valve remains open, supplying the fuel cell with the hydrogen required for vehicle operation. When the fuel cell does not send an enable signal, the main valve and all cylinder valves of the hydrogen system are closed. When adding hydrogen to the hydrogen system, the hydrogen system controls the corresponding cylinder valves to open while the main valve remains open, according to the received enable signal, so that the high-pressure hydrogen from the hydrogen refueling nozzle passes through the main valve and all cylinder valves to the corresponding hydrogen cylinders.

2. The fuel cell hydrogen system control method as described in claim 1, characterized in that, Initially, the hydrogen system did not receive any commands, and the main valve and all cylinder valves were closed.

3. The fuel cell hydrogen system control method as described in claim 1, characterized in that, The ready state is as follows: after the hydrogen system is powered on and there are no faults, the main cylinder valve of the hydrogen system is in the open state, and the valves of each cylinder are in the closed state.

4. The fuel cell hydrogen system control method as described in claim 1, characterized in that, The working state is as follows: the fuel cell controller sends an enable signal to the hydrogen controller, controlling the main valve and each cylinder valve to be in the open state.

5. The fuel cell hydrogen system control method as described in claim 1, characterized in that, When the fuel cell controller stops sending an enable signal to the hydrogen controller during operation, the main control valve and all cylinder valves are closed.

6. The fuel cell hydrogen system control method as described in claim 1, characterized in that, The hydrogen system also has a fault state. When the communication fault flag of the hydrogen system is 0, and the fault level of the hydrogen system is less than the set level or there is no hydrogen leakage, the hydrogen system changes from the fault state to the ready state.

7. The fuel cell hydrogen system control method as described in claim 6, characterized in that, If a hydrogen leak emergency stop signal or communication failure occurs during operation, the hydrogen system will switch from an operational state to a fault state.

8. The fuel cell hydrogen system control method as described in claim 6, characterized in that, In a fault state, if the enable signals of the main valve and each cylinder valve of the hydrogen system sent by the fuel cell are reset to 1, the hydrogen system will switch from a fault state to a working state.

9. A system required to implement the fuel cell hydrogen system control method according to any one of claims 1-8, characterized in that, include: The fuel cell controller receives instructions from the vehicle controller and status information of the hydrogen system. It matches the appropriate power point according to the fuel cell status, controls the fuel, air, and combustion products required during fuel cell operation, and sends control enable commands to the hydrogen controller according to the fuel cell status. The vehicle controller obtains the status information of the fuel cell and hydrogen system from the fuel cell controller and the hydrogen controller, and issues corresponding power control commands to the fuel cell controller according to the actual operating conditions. The hydrogen controller controls the opening or closing of the main valve and each cylinder valve in the hydrogen system according to the instructions from the vehicle controller and the enable signal from the fuel cell controller.

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