A control method for a hydrogen fuel cell system

Abstract

The present invention discloses a control method for a hydrogen fuel cell system, including determining whether the hydrogen fuel cell stack corresponding to a fuel cell control unit is in the "shutdown complete" state. If all hydrogen fuel cell stacks corresponding to the fuel cell control units are in the "shutdown complete" state and the operating state currently transmitted by any fuel cell control unit is not "standby," the load is disconnected. Due to the adoption of the above technical solution, compared with the prior art, the present invention provides a control method applicable to multi-stack hydrogen fuel cell systems. This method determines whether all hydrogen fuel cell stacks have completed shutdown based on the operating state identified by each FCCU, and then controls the disconnection of loads to ensure the safe operation of the multi-stack hydrogen fuel cell system.

Description

Technical Field

[0001] The present invention relates to the field of fuel cells, and in particular to a control method for a hydrogen fuel cell system. Background Art

[0002] The existing hydrogen fuel cell system generally consists of a hydrogen fuel cell stack and a fuel cell control unit (FCCU), wherein the FCCU is used to control the operation of the hydrogen fuel cell stack and identify the current operating status of the hydrogen fuel cell stack. The operating status flow chart of the existing hydrogen fuel cell system is as follows: Figure 1 As shown, the operating states include initialization, self-test, standby, starting, idling, normal operation, normal shutdown, fault shutdown, emergency shutdown, and shutdown completed. To ensure the safety of the hydrogen fuel cell stack, the hydrogen fuel cell system is generally required to be connected to the load before startup to prevent the energy generated by the hydrogen fuel cell stack from having nowhere to be released, and the hydrogen fuel cell system is required to be disconnected from the load after shutdown. This is easy to achieve in a single FCCU hydrogen fuel cell system. For example, when the operating state is detected as "shutdown completed", the hydrogen fuel cell stack is controlled to be disconnected from the load. When the operating state is detected as "standby" and a startup command is received, the load is controlled to be connected.

[0003] Since the discharge power of a single hydrogen fuel cell system is relatively small, a multi-stack hydrogen fuel cell system consisting of multiple hydrogen fuel cell systems connected in parallel is currently used. Its structure is as follows: Figure 2 This multi-stack hydrogen fuel cell system has the advantages of high discharge power, easy assembly, and easy expansion. However, since it is difficult for the operating status recognized by each FCCU in the multi-stack hydrogen fuel cell system to be completely consistent at the same time (the "shutdown complete" state lasts for a short time and automatically enters the standby state after a period of time), it is impossible to control the disconnection of the load based on the current operating status recognized by a single FCCU. Summary of the Invention

[0004] The present application provides a hydrogen fuel cell system to solve the problem that the existing control method of a single FCCU is not applicable to a multi-stack hydrogen fuel cell system and cannot control load disconnection according to the current operating status identified by a single FCCU.

[0005] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions.

[0006] A control method for a hydrogen fuel cell system is provided, for controlling the hydrogen fuel cell system; the hydrogen fuel cell system includes multiple hydrogen fuel cell stacks, multiple fuel cell control units, and a central control unit, each hydrogen fuel cell stack is electrically connected to each fuel cell control unit in a one-to-one correspondence, and multiple fuel cell control units are all electrically connected to the central control unit; the fuel cell control unit is used to obtain the operating status of the corresponding hydrogen fuel cell stack and send the operating status to the central control unit; the control method includes:

[0007] Determine whether the hydrogen fuel cell stack corresponding to a fuel cell control unit is in the "shutdown complete" state:

[0008] S11, determine whether the fuel cell control unit has sent a "starting" status after powering on; if so, jump to S12; if not, jump to S14;

[0009] S12, determine whether the fuel cell control unit has sent a "standby" state after being powered on; if so, jump to S14; if not, jump to S13;

[0010] S13, determining whether the current operating status sent by the fuel cell control unit is "shutdown completed"; if so, jump to S14;

[0011] S14, determining that the hydrogen fuel cell stack corresponding to the fuel cell control unit is in a "shutdown complete" state;

[0012] Determine whether all hydrogen fuel cell stacks have completed shutdown:

[0013] If the hydrogen fuel cell stacks corresponding to all fuel cell control units are in the "shutdown completed" state, and the operating state currently sent by any fuel cell control unit is not "standby", the load is cut off.

[0014] The above method determines whether all hydrogen fuel cell stacks have been shut down based on the operating status identified by each FCCU, and then controls the disconnection of the load to ensure the safe operation of the multi-stack hydrogen fuel cell system.

[0015] In order to prevent possible damage to vehicle equipment due to unknown operating status, in some embodiments, when determining whether the hydrogen fuel cell stack corresponding to a fuel cell control unit is in the "shutdown completed" state, if the fuel cell control unit sends a communication failure with the central control unit, jump to S14.

[0016] In some embodiments, the control method includes: determining whether a hydrogen fuel cell stack corresponding to a fuel cell control unit is in a "shutdown complete" state:

[0017] S21, determine whether the fuel cell control unit has sent a "starting" status after powering on; if so, jump to S12; if not, jump to S24;

[0018] S22, determine whether the fuel cell control unit has sent a "standby" state after being powered on; if so, jump to S14; if not, jump to S23;

[0019] S23, judging whether the current operating status sent by the fuel cell control unit is "fault shutdown" or "emergency shutdown"; if so, jumping to S24;

[0020] S24, determining that the hydrogen fuel cell stack corresponding to the fuel cell control unit is in an "abnormal shutdown" state;

[0021] Determine whether all hydrogen fuel cell stacks have completed shutdown:

[0022] If the hydrogen fuel cell stacks corresponding to all fuel cell control units are in the "abnormal shutdown" state, the load is cut off.

[0023] In some embodiments, when determining whether the hydrogen fuel cell stack corresponding to a fuel cell control unit is in an "abnormal shutdown" state, if a communication failure occurs between the fuel cell control unit and the central control unit, the process jumps to S24.

[0024] In some embodiments, when the load is removed, the external power source electrically connected to the hydrogen fuel cell stack is also removed.

[0025] Compared with the existing technology, the control method of the present application is applicable to multi-stack hydrogen fuel cell systems. It determines whether all hydrogen fuel cell stacks have been shut down based on the operating status identified by each FCCU, and then controls the disconnection of the load to ensure the safe operation of the multi-stack hydrogen fuel cell system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of an existing multi-stack hydrogen fuel cell system;

[0027] Figure 2 It is a flow chart of the control method of an existing single FCCU;

[0028] Figure 3 A schematic diagram of a process for determining whether a hydrogen fuel cell stack is in a "shutdown complete" state for this application;

[0029] Figure 4 This is a flow chart for determining whether a hydrogen fuel cell stack is in an "abnormal shutdown" state in this application. DETAILED DESCRIPTION

[0030] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0031] See also Figure 1-Figure 4 , a control method for a hydrogen fuel cell system, used to control a hydrogen fuel cell system; the hydrogen fuel cell system includes multiple hydrogen fuel cell stacks, multiple fuel cell control units and a central control unit, each hydrogen fuel cell stack is electrically connected to each fuel cell control unit in a one-to-one correspondence, and multiple fuel cell control units are electrically connected to the central control unit; the fuel cell control unit is used to obtain the operating status of the corresponding hydrogen fuel cell stack and send the operating status to the central control unit.

[0032] The control method includes:

[0033] Determine whether the hydrogen fuel cell stack corresponding to a fuel cell control unit is in the "shutdown complete" state:

[0034] S11, determine whether the fuel cell control unit has sent a "starting" status after powering on; if so, jump to S12; if not, jump to S14;

[0035] S12, determine whether the fuel cell control unit has sent a "standby" state after being powered on; if so, jump to S14; if not, jump to S13;

[0036] S13, determining whether the current operating status sent by the fuel cell control unit is "shutdown completed"; if so, jump to S14;

[0037] S14, determining that the hydrogen fuel cell stack corresponding to the fuel cell control unit is in a "shutdown complete" state;

[0038] Determine whether all hydrogen fuel cell stacks have completed shutdown:

[0039] If the hydrogen fuel cell stacks corresponding to all fuel cell control units are in the "shutdown completed" state, and the operating state currently sent by any fuel cell control unit is not "standby", the load and the external power supply electrically connected to the hydrogen fuel cell stack are cut off.

[0040] Furthermore, when determining whether the hydrogen fuel cell stack corresponding to a fuel cell control unit is in the "shutdown completion" state, if there is a communication failure between the fuel cell control unit and the central control unit, the process jumps to S14.

[0041] The control method further includes:

[0042] Determine whether the hydrogen fuel cell stack corresponding to a fuel cell control unit is in the "shutdown complete" state:

[0043] S21, determine whether the fuel cell control unit has sent a "starting" status after powering on; if so, jump to S12; if not, jump to S24;

[0044] S22, determine whether the fuel cell control unit has sent a "standby" state after being powered on; if so, jump to S14; if not, jump to S23;

[0045] S23, judging whether the current operating status sent by the fuel cell control unit is "fault shutdown" or "emergency shutdown"; if so, jumping to S24;

[0046] S24, determining that the hydrogen fuel cell stack corresponding to the fuel cell control unit is in an "abnormal shutdown" state;

[0047] Determine whether all hydrogen fuel cell stacks have completed shutdown:

[0048] If the hydrogen fuel cell stacks corresponding to all fuel cell control units are in the "abnormal shutdown" state, the load and the external power supply electrically connected to the hydrogen fuel cell stack are cut off.

[0049] Furthermore, when determining whether the hydrogen fuel cell stack corresponding to a fuel cell control unit is in an "abnormal shutdown" state, if there is a communication failure between the fuel cell control unit and the central control unit, the process jumps to S24.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for controlling a hydrogen fuel cell system, for controlling a hydrogen fuel cell system; the hydrogen fuel cell system comprises a plurality of hydrogen fuel cell stacks, a plurality of fuel cell control units, and a central control unit, wherein each hydrogen fuel cell stack is electrically connected to each fuel cell control unit in a one-to-one correspondence, and each of the plurality of fuel cell control units is electrically connected to the central control unit; the fuel cell control unit is used to obtain the operating status of the corresponding hydrogen fuel cell stack and send the operating status to the central control unit; characterized in that: The control method includes: Determine whether the hydrogen fuel cell stack corresponding to a fuel cell control unit is in the "shutdown complete" state: S11, determine whether the fuel cell control unit has sent a "starting" status after power-on; if so, jump to S12; if not, jump to S14; S12, determining whether the fuel cell control unit has sent a "standby" state after being powered on; if so, jump to S14; if not, jump to S13; S13, determining whether the current operating status sent by the fuel cell control unit is "shutdown completed"; if so, jump to S14; S14, determining that the hydrogen fuel cell stack corresponding to the fuel cell control unit is in a "shutdown complete" state; Determine whether all hydrogen fuel cell stacks have completed shutdown: If the hydrogen fuel cell stacks corresponding to all fuel cell control units are in the "shutdown completed" state, and the operating state currently sent by any fuel cell control unit is not "standby", the load is cut off.

2. The control method of the hydrogen fuel cell system according to claim 1, characterized in that: When determining whether the hydrogen fuel cell stack corresponding to a fuel cell control unit is in the "shutdown completed" state, if there is a communication failure between the fuel cell control unit and the central control unit, jump to S14.

3. The control method of the hydrogen fuel cell system according to claim 1, characterized in that: The control method includes: determining whether a hydrogen fuel cell stack corresponding to a fuel cell control unit is in a "shutdown completed" state; S21, determine whether the fuel cell control unit has sent a "starting" status after power-on; if so, jump to S12; if not, jump to S24; S22, determine whether the fuel cell control unit has sent a "standby" state after power on; if so, jump to S14; if not, jump to S23; S23, determining whether the current operating status sent by the fuel cell control unit is "fault shutdown" or "emergency shutdown"; if so, jump to S24; S24, determining that the hydrogen fuel cell stack corresponding to the fuel cell control unit is in an "abnormal shutdown" state; Determine whether all hydrogen fuel cell stacks have completed shutdown: If the hydrogen fuel cell stacks corresponding to all fuel cell control units are in the "abnormal shutdown" state, the load is cut off.

4. The control method of the hydrogen fuel cell system according to claim 3, characterized in that: When determining whether the hydrogen fuel cell stack corresponding to a fuel cell control unit is in the "abnormal shutdown" state, if there is a communication failure between the fuel cell control unit and the central control unit, jump to S24.

5. The method for controlling a hydrogen fuel cell system according to any one of claims 1 to 4, wherein: When the load is cut off, the external power supply electrically connected to the hydrogen fuel cell stack is also cut off.

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