A one-button start signal recognition device for hydrogen fuel cell vehicles

Abstract

The present invention provides a one-key start signal recognition device for a hydrogen fuel cell vehicle, comprising: a one-key start switch, a vehicle controller VCU or a body controller BCM, a fuel cell controller FCU, and a 12V low-voltage battery; the one-key start switch is electrically connected to the vehicle controller VCU or the body controller BCM, and the 12V low-voltage battery at low voltage; the vehicle controller VCU or the body controller BCM is electrically connected to the fuel cell controller FCU by hard wire or CAN communication respectively; the 12V low-voltage battery is electrically connected to the vehicle controller VCU or the body controller BCM, and the fuel cell controller FCU at low voltage. The one-key start switch circuit of the present invention is simple, and the key position processing logic is integrated in the processing program. The processing program can be changed according to functional requirements without changing the hardware circuit, and the modification cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen energy vehicles, and in particular to a one-button start signal recognition device for a hydrogen fuel cell vehicle. Background Art

[0002] Although the one-button start function has been widely used in traditional fuel vehicles and pure electric new energy vehicles, its application in hydrogen fuel cell vehicles is a new step, and its control logic is more complex and complete.

[0003] Since hydrogen fuel cell vehicles have complex and expensive fuel cell systems, their shutdown time may be as long as several minutes. Directly cutting off the low-voltage power supply during the shutdown process may cause irreversible damage. Summary of the invention

[0004] In view of this, this patent proposes a one-button start signal recognition method and device that uses control logic to process and output vehicle key gear position signals and performs low-voltage relay control. A one-button start signal recognition device for a hydrogen fuel cell vehicle of the present invention includes the following:

[0005] One-button start switch, vehicle controller VCU or body controller BCM, fuel cell controller FCU, 12V low-voltage battery; the one-button start switch is electrically connected to the vehicle controller VCU or body controller BCM, and the 12V low-voltage battery at low voltage; the vehicle controller VCU or body controller BCM and the fuel cell controller FCU are electrically connected by hard wire or CAN communication respectively; the 12V low-voltage battery is electrically connected to the vehicle controller VCU or body controller BCM, and the fuel cell controller FCU at low voltage.

[0006] Furthermore, the one-button start switch has two self-reset switches, namely SW1 and SW2;

[0007] One side PIN7 and PIN8 of the self-reset switches SW1 and SW2 are electrically connected to the 12V low-voltage battery respectively, and the other side PIN1 and PIN2 are electrically connected to the signal input pins PIN98 and PIN100 of the vehicle controller VCU or the body controller BCM respectively;

[0008] When the one-button start switch is pressed, SW1 and SW2 are closed and turned on; when the one-button start switch is not pressed or released, the self-reset switch automatically disconnects the circuit.

[0009] Furthermore, the one-button start switch has three indicator LED lights, one of which is a background light LED1, and the other two are one-button start indicator lights controlled by the vehicle controller VCU or the body controller BCM, namely LED2 and LED3.

[0010] Furthermore, one end of the background light LED1 is connected to the small light power supply through the PIN9 port, and the other end is grounded through a resistor;

[0011] One end of the one-button start indicator light LED2 is electrically connected to the PIN62 port of the vehicle controller VCU or the body controller BCM through the PIN3 port, and the other end is grounded through a resistor;

[0012] One end of the one-button start indicator light LED3 is electrically connected to the PIN61 port of the vehicle controller VCU or the body controller BCM through the PIN4 port, and the other end is grounded through a resistor.

[0013] Furthermore, the vehicle controller VCU or the body controller BCM detects the high and low level signals of the self-reset switches SW1 and SW2 pins as inputs for the internal logic judgment of the processing program;

[0014] The vehicle controller VCU or the body controller BCM controls the lighting of the working indicator light in the one-button start switch through hard-line output;

[0015] The vehicle controller VCU or the body controller BCM receives the brake signal through CAN communication or hard wire as the input of the internal logic judgment of the processing program;

[0016] The vehicle controller VCU or the body controller BCM receives the high voltage power-down permission signal sent by the fuel cell controller FCU through CAN communication or hard wire as an input for the internal logic judgment of the processing program;

[0017] The vehicle controller VCU or the body controller BCM outputs a one-button start vehicle key position signal through hard wire or CAN communication: OFF position, ACC position, ON position, Start position;

[0018] The vehicle controller VCU or the body controller BCM outputs the low-voltage ACC gear and ON gear electric relay control instructions of the hydrogen fuel cell vehicle through hard wire or CAN communication;

[0019] The fuel cell controller FCU sends a high-voltage power-off disapproval signal through CAN communication or hard wire before the fuel cell system is shut down; after the fuel cell system is shut down, it sends a high-voltage power-off permission signal through CAN communication or hard wire;

[0020] The vehicle controller VCU performs high-voltage power-off of the vehicle after the fuel cell controller FCU feeds back high-voltage power-off permission, and outputs a low-voltage power-off permission signal through hard wire or CAN communication after the high-voltage power-off of the vehicle is completed.

[0021] Furthermore, the working steps of the device are as follows:

[0022] S1. Initialization after the vehicle controller VCU or the body controller BCM is powered on: the vehicle key gear position signal output is OFF gear, the ACC gear low-voltage relay is disconnected, the ON gear low-voltage relay is disconnected, and the one-button start indicator lights LED2 and LED3 are controlled to be off; execute step S2;

[0023] S2, judging whether the brake is not pressed and the key signal input of the vehicle's one-key start switch is at a high level, if so, executing step S3; if not, executing step S4;

[0024] S3, close the ACC gear low-voltage relay, start timing, and go to step S5;

[0025] S4, judging whether the brake is pressed and the key signal of the one-key start switch is at a high level, if so, jumping to step S9; if not, returning to step S1;

[0026] S5, judging whether the feedback of the ACC relay state within 3S is closed, if so, executing step S6; if not, jumping to the fault state S99;

[0027] S6, the vehicle key gear position signal output is ACC gear, the one-touch start indicator light is orange, that is, LED2 is green, LED3 is red, and the mixed light is orange; execute step S7;

[0028] S7, judging: the key signal of the one-key start switch is at a low level, if so, executing step S8; if not, continuing to wait until the key signal of the one-key start switch is at a low level, and then entering S8;

[0029] S8, judging: the key signal of the one-key start switch is at a high level, if so, executing step S9; if not, continuing to wait until the key signal of the one-key start switch is at a high level, and then entering S9;

[0030] S9, close the ACC low-voltage relay, close the ON low-voltage relay, and start timing; execute step S10;

[0031] S10, judging: within 3 seconds, the ACC relay state feedback is closed and the ON relay state feedback is closed. If so, execute step S11; if not, jump to the fault state S99;

[0032] S11, the one-button start indicator light LED2 lights up green; go to step S12;

[0033] S12, judging whether the brake is in the pressed state, if so, executing step S13; if not, jumping to S15 for execution;

[0034] S13, the vehicle key position signal output is Start position, and the timing starts;

[0035] S14, judging whether the vehicle key position signal output is the Start position for 3 seconds, if so, executing step S15; if not, continuing to wait until the vehicle key position signal output is the Start position;

[0036] S15, the vehicle key position signal output is ON, and S16 is executed;

[0037] S16, judging whether the key signal of the one-key start switch is at a low level, if so, executing step S17; if not, continuing to wait until the key signal of the one-key start switch is at a low level;

[0038] S17, judging whether the key signal of the one-key start switch is at a high level, if so, executing step S18; if not, continuing to wait;

[0039] S18, the vehicle key position signal output is OFF, and the one-button start indicator LED2 is off; execute step S19;

[0040] S19, judging: the key signal of the one-key start switch is at a low level, if so, executing step S20; if not, continuing to wait;

[0041] S20, the vehicle key position signal output is OFF, the one-button start indicator LED2 is green, and the timing starts; execute step S21;

[0042] S21, judge: whether the low voltage power-off permission sent by the vehicle controller VCU or the body controller BCM is received within the time T? If yes, return to step S1; if no, jump to the fault state S99; T is the preset value;

[0043] S99, the vehicle key position signal output is OFF, the ACC relay is disconnected, the ON relay is disconnected, and the one-button start indicator LED3 is red; start timing; when the timing reaches X seconds, jump to step S1; X is a preset value.

[0044] Furthermore, the one-button start indicator light is used to indicate the power-on gear status: the OFF gear is off; the ACC gear is orange; the ON gear and the Start gear are green; if an abnormality occurs during the power-on or power-off process, the indicator light is red.

[0045] In step S21, T is the longest time required for the hydrogen fuel cell system to be powered off normally.

[0046] The beneficial effects brought by the technical solution provided by the present invention are:

[0047] The control logic is used to process and output the vehicle key position signal and perform low-voltage relay control. The beneficial effects are mainly three points:

[0048] 1. The one-button start switch circuit is simple, and the key position processing logic is all done in the processing program. The processing program code can be changed according to functional requirements without changing the hardware circuit, and the modification cost is low.

[0049] 2. The processing logic of this handler is concise and effective. It can be embedded in both the VCU handler and the BCM handler, and has good compatibility and portability.

[0050] 3. Solve the timing problem between the shutdown waiting time of the hydrogen fuel cell system and the low-voltage power supply. (Hydrogen fuel cell vehicles have complex and expensive fuel cell systems, and their shutdown time may be as long as several minutes. Directly cutting off the low-voltage power supply during the shutdown process may cause irreversible damage). BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a structural diagram of a one-button start signal recognition device for a hydrogen fuel cell vehicle of the present invention;

[0052] Figure 2 This is a schematic diagram of the internal circuit of the one-button start switch of the present invention;

[0053] Figure 3 This is a flow chart of a one-button start signal recognition device for a hydrogen fuel cell vehicle of the present invention; DETAILED DESCRIPTION

[0054] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0055] Please refer to Figure 1 The present invention provides Figure 1 The present invention is a one-key start signal recognition device for a hydrogen fuel cell vehicle, comprising:

[0056] One-button start switch, vehicle controller VCU or body controller BCM, fuel cell controller FCU, 12V low-voltage battery; the one-button start switch is electrically connected to the vehicle controller VCU or body controller BCM, and the 12V low-voltage battery at low voltage; the vehicle controller VCU or body controller BCM and the fuel cell controller FCU are electrically connected by hard wire or CAN communication respectively; the 12V low-voltage battery is electrically connected to the vehicle controller VCU or body controller BCM, and the fuel cell controller FCU at low voltage.

[0057] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the internal circuit of a one-button start switch; the one-button start switch has two self-reset switches, namely SW1 and SW2;

[0058] One side PIN7 and PIN8 of the self-reset switches SW1 and SW2 are electrically connected to the 12V low-voltage battery respectively, and the other side PIN1 and PIN2 are electrically connected to the signal input pins PIN98 and PIN100 of the vehicle controller VCU or the body controller BCM respectively;

[0059] When the one-button start switch is pressed, SW1 and SW2 are closed and turned on; when the one-button start switch is not pressed or released, the self-reset switch automatically disconnects the circuit.

[0060] The one-button start switch also has three indicator LED lights, one of which is a background light LED1, and the other two are one-button start indicator lights controlled by the vehicle controller VCU or the body controller BCM, namely LED2 and LED3.

[0061] One end of the background light LED1 is connected to the low light gear power supply through the PIN9 port, and the other end is grounded through a resistor; one end of the one-button start indicator LED2 is electrically connected to the PIN62 port of the vehicle controller VCU or the body controller BCM through the PIN3 port, and the other end is grounded through a resistor; one end of the one-button start indicator LED3 is electrically connected to the PIN61 port of the vehicle controller VCU or the body controller BCM through the PIN4 port, and the other end is grounded through a resistor.

[0062] The vehicle controller VCU or the body controller BCM detects the high and low level signals of the self-reset switches SW1 and SW2 pins as inputs for the internal logic judgment of the processing program;

[0063] The vehicle controller VCU or the body controller BCM controls the lighting of the working indicator light in the one-button start switch through hard-wire output; the vehicle controller VCU or the body controller BCM receives the brake signal through CAN communication or hard-wire as the input of the internal logic judgment of the processing program; the vehicle controller VCU or the body controller BCM receives the high-voltage power-down permission signal sent by the fuel cell controller FCU through CAN communication or hard-wire as the input of the internal logic judgment of the processing program;

[0064] The vehicle controller VCU or the body controller BCM outputs a one-button start vehicle key position signal through hard wire or CAN communication: OFF position, ACC position, ON position, Start position;

[0065] The vehicle controller VCU or the body controller BCM outputs the low-voltage ACC gear and ON gear electric relay control instructions of the hydrogen fuel cell vehicle through hard wire or CAN communication;

[0066] The fuel cell controller FCU sends a high-voltage power-off disapproval signal through CAN communication or hard wire before the fuel cell system is shut down; after the fuel cell system is shut down, it sends a high-voltage power-off permission signal through CAN communication or hard wire;

[0067] The vehicle controller VCU performs high-voltage power-off of the vehicle after the fuel cell controller FCU feeds back high-voltage power-off permission, and outputs a low-voltage power-off permission signal through hard wire or CAN communication after the high-voltage power-off of the vehicle is completed.

[0068] Please refer to Figure 3 , Figure 3 It is the working flow chart of the device; the specific steps are as follows:

[0069] S1. Initialization after the vehicle controller VCU or the body controller BCM is powered on: the vehicle key gear position signal output is OFF gear, the ACC gear low-voltage relay is disconnected, the ON gear low-voltage relay is disconnected, and the one-button start indicator lights LED2 and LED3 are controlled to be off; execute step S2;

[0070] S2, judging whether the brake is not pressed and the key signal input of the vehicle's one-key start switch is at a high level, if so, executing step S3; if not, executing step S4;

[0071] S3, close the ACC gear low-voltage relay, start timing, and go to step S5;

[0072] S4, judging whether the brake is pressed and the key signal of the one-key start switch is at a high level, if so, jumping to step S9; if not, returning to step S1;

[0073] S5, judging whether the feedback of the ACC relay state within 3S is closed, if so, executing step S6; if not, jumping to the fault state S99;

[0074] S6, the vehicle key gear position signal output is ACC gear, the one-touch start indicator light is orange, that is, LED2 is green, LED3 is red, and the mixed light is orange; execute step S7;

[0075] S7, judging: the key signal of the one-key start switch is at a low level, if so, executing step S8; if not, continuing to wait until the key signal of the one-key start switch is at a low level, and then entering S8;

[0076] S8, judging: the key signal of the one-key start switch is at a high level, if so, executing step S9; if not, continuing to wait until the key signal of the one-key start switch is at a high level, and then entering S9;

[0077] S9, close the ACC low-voltage relay, close the ON low-voltage relay, and start timing; execute step S10;

[0078] S10, judging: within 3 seconds, the ACC relay state feedback is closed and the ON relay state feedback is closed. If so, execute step S11; if not, jump to the fault state S99;

[0079] S11, the one-button start indicator light LED2 lights up green; go to step S12;

[0080] S12, judging whether the brake is in the pressed state, if so, executing step S13; if not, jumping to S15 for execution;

[0081] S13, the vehicle key position signal output is Start position, and the timing starts;

[0082] S14, judging whether the vehicle key position signal output is the Start position for 3 seconds, if so, executing step S15; if not, continuing to wait until the vehicle key position signal output is the Start position;

[0083] S15, the vehicle key position signal output is ON, and S16 is executed;

[0084] S16, judging whether the key signal of the one-key start switch is at a low level, if so, executing step S17; if not, continuing to wait until the key signal of the one-key start switch is at a low level;

[0085] S17, judging whether the key signal of the one-key start switch is at a high level, if so, executing step S18; if not, continuing to wait;

[0086] S18, the vehicle key position signal output is OFF, and the one-button start indicator LED2 is off; execute step S19;

[0087] S19, judging: the key signal of the one-key start switch is at a low level, if so, executing step S20; if not, continuing to wait;

[0088] S20, the vehicle key position signal output is OFF, the one-button start indicator LED2 is green, and the timing starts; execute step S21;

[0089] S21, judge: whether the low voltage power-off permission sent by the vehicle controller VCU or the body controller BCM is received within the time T? If yes, return to step S1; if no, jump to the fault state S99; T is the preset value;

[0090] S99, the vehicle key position signal output is OFF, the ACC relay is disconnected, the ON relay is disconnected, and the one-button start indicator LED3 is red; start timing; when the timing reaches X seconds, jump to step S1; X is a preset value.

[0091] Furthermore, the one-button start indicator light is used to indicate the power-on gear status: the OFF gear is off; the ACC gear is orange; the ON gear and the Start gear are green; if an abnormality occurs during the power-on or power-off process, the indicator light is red.

[0092] In step S21, T is the longest time required for the hydrogen fuel cell system to be powered off normally.

[0093] The beneficial effects of the present invention are: using control logic to process and output the vehicle key gear position signal and perform low-voltage relay control, and the beneficial effects are mainly three points:

[0094] 1. The one-button start switch circuit is simple, and the key position processing logic is all done in the processing program. The processing program code can be changed according to functional requirements without changing the hardware circuit, and the modification cost is low.

[0095] 2. The processing logic of this processor is concise and effective. It can be embedded in both the VCU processor and the BCM processor, and has good compatibility and portability.

[0096] 3. Solve the timing problem between the shutdown waiting time of the hydrogen fuel cell system and the low-voltage power supply. (Hydrogen fuel cell vehicles have complex and expensive fuel cell systems, and their shutdown time may be as long as several minutes. Directly cutting off the low-voltage power supply during the shutdown process may cause irreversible damage)

[0097] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A one-button start signal recognition device for a hydrogen fuel cell vehicle, characterized in that: include: One-button start switch, vehicle controller VCU or body controller BCM, fuel cell controller FCU, 12V low-voltage battery; the one-button start switch is electrically connected to the vehicle controller VCU or body controller BCM, and the 12V low-voltage battery at low voltage; the vehicle controller VCU or body controller BCM is electrically connected to the fuel cell controller FCU by hard wire or CAN communication respectively; the 12V low-voltage battery is electrically connected to the vehicle controller VCU or body controller BCM, and the fuel cell controller FCU at low voltage; The one-button start switch has two self-reset switches, namely SW1 and SW2; One side PIN7 and PIN8 of the self-reset switches SW1 and SW2 are electrically connected to the 12V low-voltage battery respectively, and the other side PIN1 and PIN2 are electrically connected to the signal input pins PIN98 and PIN100 of the vehicle controller VCU or the body controller BCM respectively; When the one-button start switch is pressed, SW1 and SW2 are both closed and turned on; when the one-button start switch is not pressed or released, the self-reset switch automatically disconnects the circuit; The vehicle controller VCU or the body controller BCM detects the high and low level signals of the self-reset switches SW1 and SW2 pins as inputs for the internal logic judgment of the processing program; The vehicle controller VCU or the body controller BCM controls the lighting of the working indicator light in the one-button start switch through hard-line output; The vehicle controller VCU or the body controller BCM receives the brake signal through CAN communication or hard wire as the input of the internal logic judgment of the processing program; The vehicle controller VCU or the body controller BCM receives the high voltage power-down permission signal sent by the fuel cell controller FCU through CAN communication or hard wire as an input for the internal logic judgment of the processing program; The vehicle controller VCU or the body controller BCM outputs a one-button start vehicle key position signal through hard wire or CAN communication: OFF position, ACC position, ON position, Start position; The vehicle controller VCU or the body controller BCM outputs the low-voltage ACC gear and ON gear electric relay control instructions of the hydrogen fuel cell vehicle through hard wire or CAN communication; The fuel cell controller FCU sends a high-voltage power-off disapproval signal through CAN communication or hard wire before the fuel cell system is shut down; after the fuel cell system is shut down, it sends a high-voltage power-off permission signal through CAN communication or hard wire; The vehicle controller VCU performs high-voltage power-off of the vehicle after the fuel cell controller FCU feeds back high-voltage power-off permission, and outputs a low-voltage power-off permission signal through hard wire or CAN communication after the high-voltage power-off of the vehicle is completed; The working steps of the device are as follows: S1. Initialization after the vehicle controller VCU or the body controller BCM is powered on: the vehicle key gear position signal output is OFF gear, the ACC gear low-voltage relay is disconnected, the ON gear low-voltage relay is disconnected, and the one-button start indicator lights LED2 and LED3 are controlled to be off; execute step S2; S2, judging whether the brake is not pressed and the key signal input of the vehicle's one-key start switch is at a high level, if so, executing step S3; if not, executing step S4; S3, close the ACC gear low-voltage relay, start timing, and go to step S5; S4, judging whether the brake is pressed and the key signal of the one-key start switch is at a high level, if so, jumping to step S9; if not, returning to step S1; S5, judging whether the feedback of the ACC relay state within 3S is closed, if so, executing step S6; if not, jumping to the fault state S99; S6, the vehicle key gear position signal output is ACC gear, the one-touch start indicator light is orange, that is, LED2 is green, LED3 is red, and the mixed light is orange; execute step S7; S7, judging: the key signal of the one-key start switch is at a low level, if so, executing step S8; if not, continuing to wait until the key signal of the one-key start switch is at a low level, and then entering S8; S8, judging: the key signal of the one-key start switch is at a high level, if so, executing step S9; if not, continuing to wait until the key signal of the one-key start switch is at a high level, and then entering S9; S9, close the ACC low-voltage relay, close the ON low-voltage relay, and start timing; execute step S10; S10, judging: within 3 seconds, the ACC relay state feedback is closed and the ON relay state feedback is closed, if so, executing step S11; If not, jump to fault state S99; S11, the one-button start indicator light LED2 lights up green; go to step S12; S12, judging whether the brake is in the pressed state, if so, executing step S13; if not, jumping to S15 for execution; S13, the vehicle key position signal output is Start position, and the timing starts; S14, judging whether the vehicle key position signal output is the Start position for 3 seconds, if so, executing step S15; if not, continuing to wait until the vehicle key position signal output is the Start position; S15, the vehicle key position signal output is ON, and S16 is executed; S16, judging whether the key signal of the one-key start switch is at a low level, if so, executing step S17; if not, continuing to wait until the key signal of the one-key start switch is at a low level; S17, judging whether the key signal of the one-key start switch is at a high level, if so, executing step S18; if not, continuing to wait; S18, the vehicle key position signal output is OFF, and the one-button start indicator LED2 is off; execute step S19; S19, judging: the key signal of the one-key start switch is at a low level, if so, executing step S20; if not, continuing to wait; S20, the vehicle key position signal output is OFF, the one-button start indicator LED2 is green, and the timing starts; execute step S21; S21, judge: whether the low voltage power-off permission sent by the vehicle controller VCU or the body controller BCM is received within the time T? If yes, return to step S1; if no, jump to the fault state S99; T is the preset value; S99, the vehicle key position signal output is OFF, the ACC relay is disconnected, the ON relay is disconnected, and the one-button start indicator LED3 is red; start timing; when the timing reaches X seconds, jump to step S1; X is a preset value.

2. A one-button start signal recognition device for a hydrogen fuel cell vehicle as claimed in claim 1, characterized in that: The one-button start switch also has three indicator LED lights, one of which is a background light LED1, and the other two are one-button start indicator lights controlled by the vehicle controller VCU or the body controller BCM, namely LED2 and LED3.

3. A one-button start signal recognition device for a hydrogen fuel cell vehicle as claimed in claim 2, characterized in that: One end of the background light LED1 is connected to the small light power supply through PIN9 port, and the other end is grounded through a resistor; One end of the one-button start indicator light LED2 is electrically connected to the PIN62 port of the vehicle controller VCU or the body controller BCM through the PIN3 port, and the other end is grounded through a resistor; One end of the one-button start indicator light LED3 is electrically connected to the PIN61 port of the vehicle controller VCU or the body controller BCM through the PIN4 port, and the other end is grounded through a resistor.

4. A one-button start signal recognition device for a hydrogen fuel cell vehicle as claimed in claim 1, characterized in that: The one-button start indicator light is used to indicate the power-on gear status: the OFF gear is off; the ACC gear is orange; the ON gear and the Start gear are green; if an abnormality occurs during the power-on or power-off process, the indicator light is red.

5. A one-button start signal recognition device for a hydrogen fuel cell vehicle as claimed in claim 1, characterized in that: In step S21, T is the longest time required for the hydrogen fuel cell system to be powered off normally.

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