Hydrogen fuel cell system abnormal de-energization protection circuit and automobile

Abstract

The application provides a hydrogen fuel cell system abnormal power-off protection circuit and a car. The hydrogen fuel cell system abnormal power-off protection circuit comprises a storage battery, a mechanical switch, a key switch, a VCU, a mode switch, a diode D1, a diode D2, a relay R1, a relay R2, a power battery device and a fuel cell system. By setting the diode D1, the diode D2, the relay R1 and the relay R2, the relay R1 and the relay R2 are connected in parallel, the delay power-off signal of the VCU is effectively isolated through the diode D1 and the diode D2, the vehicle cannot be powered off caused by directly disconnecting the key switch when the mode switch is not disconnected, and thus the abnormal power-off can be prevented from causing damage to the fuel cell system, the fuel cell system and vehicle parts are protected, and the service life of the fuel cell system and the vehicle is prolonged.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of new energy, and particularly relates to an abnormal power-off protection circuit of a hydrogen fuel cell system and an automobile. BACKGROUND

[0002] After the fuel cell system is shut down, a blowing work is performed to remove excess water in the stack and improve the service life of the fuel cell system. During the blowing process, the high and low voltage power supply of the whole vehicle cannot be disconnected, so the whole vehicle needs to be delayed to ensure the blowing work of the fuel cell system. In the prior art, abnormal power-off of the whole vehicle may be caused by the misoperation of the driver or the imperfect design of the delay power-off circuit during the power-off process of the whole vehicle, which affects the service life of the whole vehicle and the fuel cell system, and even causes high pressure hazards in serious cases. SUMMARY

[0003] In view of the problems in the prior art, the application provides an abnormal power-off protection circuit of a hydrogen fuel cell system and an automobile, which at least partially solves the problem that abnormal power-off causes damage to the fuel cell system.

[0004] In a first aspect, the application provides an abnormal power-off protection circuit of a hydrogen fuel cell system, which comprises a storage battery, a mechanical switch, a key switch, a VCU, a mode switch, a diode D1, a diode D2, a relay R1, a relay R2, a power battery device and a fuel cell system.

[0005] The positive electrode of the storage battery is connected in series with the fuel cell mode switch signal pin of the VCU through the mechanical switch, the key switch and the mode switch.

[0006] The node between the mechanical switch and the key switch is electrically connected to the constant power supply pin of the VCU.

[0007] The node between the key switch and the mode switch is connected in series with the first end of the coil of the relay R1 through the diode D1, and the cathode of the diode D1 is electrically connected to the first end of the coil of the relay R1.

[0008] The first end of the coil of the relay R1 is electrically connected to the first end of the coil of the relay R2.

[0009] The second end of the coil of the relay R1 and the second end of the coil of the relay R2 are both electrically connected to the negative electrode of the storage battery.

[0010] One end of the fuel cell system is electrically connected to the negative electrode of the storage battery.

[0011] The fuel cell system delay power-off control signal pin of the VCU is connected in series with the first end of the coil of the relay R1 through the diode D2, and the anode of the diode D2 is electrically connected to the fuel cell system delay power-off control signal pin of the VCU.

[0012] The node between the mechanical switch and the key switch is electrically connected with one switch contact of the relay R1;

[0013] The node between the mechanical switch and the key switch is electrically connected with one switch contact of the relay R2;

[0014] The other switch contact of the relay R1 is electrically connected with the other end of the fuel cell system;

[0015] The other switch contact of the relay R2 is electrically connected with the working enable signal pin of the VCU;

[0016] The power battery device is electrically connected with the VCU.

[0017] Optionally, the power battery device comprises a power battery and a DC / DC converter, the power battery is electrically connected with the DC / DC converter, the low-voltage power supply pin of the DC / DC converter is electrically connected with the working enable signal pin of the VCU, the output pin of the DC / DC converter is electrically connected with the node between the mechanical switch and the key switch, and the ground pin of the DC / DC converter is electrically connected with the negative pole of the storage battery.

[0018] Optionally, the DC / DC converter is a 24V DC / DC converter.

[0019] Optionally, further comprising an instrument, one input end of the instrument is electrically connected with the other switch contact of the relay R2, the other input end of the instrument is electrically connected with the working enable signal pin of the VCU, and the output end of the instrument is electrically connected with the negative pole of the storage battery.

[0020] Optionally, further comprising a load, the load is electrically connected with the working enable signal pin of the VCU.

[0021] Optionally, when the whole vehicle is powered on,

[0022] The mechanical switch is closed to start power supply, and the first end of the coil of the relay R1 and the relay R2 is powered on;

[0023] The key switch is closed to control the coil of the relay R1 and the relay R2, the contact of the relay R1 and the relay R2 is closed, and the electrical equipment is powered on and woken up, at this time, the fuel cell system is in a sleep mode;

[0024] When the whole vehicle is powered on with high voltage, the VCU controls the DC / DC converter of the power battery device to output 24V power supply;

[0025] When the mode switch is closed, the fuel cell mode is opened, and the fuel cell mode switch signal pin of the VCU receives the positive controllable signal of the mode switch, the fuel cell system delay power-off control signal pin of the VCU continuously outputs 24V positive signal, so as to ensure the low-voltage power supply of the system, and the VCU controls the fuel cell system to start.

[0026] Optionally, when the whole vehicle normally powers off:

[0027] When the mode switch is closed, the fuel cell mode is opened, and the fuel cell system executes the power-off purging work;

[0028] When the key switch is turned off, the high-voltage circuit of the whole vehicle is disconnected first, and then the low-voltage circuit of the whole vehicle is disconnected;

[0029] If the fuel cell system power-off purging work is not completed when the key switch is turned off, the fuel cell system sends the purging state information, and when the VCU receives the purging state information, the VCU controls the relay R1 and the relay R2 to continue to be closed, the VCU controls the DC / DC converter of the power battery device to work, until the fuel cell system purging is completed and the standby state is sent, and after the VCU receives the standby state signal, the VCU controls the DC / DC converter to stop outputting, then powers off the high voltage, then disconnects the low-voltage circuit, and finally stops the fuel cell system delay power-off control signal pin of the VCU from outputting;

[0030] When the power-off is completed, the mechanical switch is turned off.

[0031] Optionally, when the abnormal power-off is caused by misoperation:

[0032] When the mode switch is not turned off and the key switch is directly turned off, the fuel cell mode switch signal pin of the VCU does not receive the instruction of the fuel cell mode, the VCU determines that the fuel cell mode is turned off, the fuel cell system executes the power-off purging work, and the fuel cell system delay power-off control signal pin of the VCU continuously outputs when the VCU receives the standby state feedback of the fuel cell system, the VCU controls the whole vehicle to first power off the high voltage, then disconnects the low voltage, and finally stops the fuel cell system delay power-off control signal pin of the VCU from outputting, so as to complete the power-off of the whole vehicle.

[0033] Optionally, when the abnormal power-off is caused by misoperation:

[0034] When the key is turned off and the whole vehicle purging delay power-off is not completed, the mechanical switch is directly turned off, the VCU controls the DC / DC converter to continuously output 24V voltage, when the VCU receives the delay power-off completion signal, the VCU controls the DC / DC converter to stop outputting, at this time, the power supply of the whole vehicle is completely disconnected, the fuel cell system delay power-off control signal pin of the VCU also stops outputting at the same time, and the VCU controls the contacts of the relay R1 and the relay R2 to be disconnected.

[0035] In a second aspect, the present disclosure also provides a vehicle comprising the hydrogen fuel cell system abnormal power-off protection circuit according to any one of the first aspect.

[0036] The hydrogen fuel cell system abnormal power-off protection circuit and the vehicle provided by the present disclosure can prevent the vehicle from being unable to power off caused by directly disconnecting the key switch when the off mode switch is not disconnected, thereby avoiding the damage of abnormal power-off to the fuel cell system, achieving the purpose of protecting the fuel cell system and vehicle parts, and improving the service life of the fuel cell system and the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0037] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the figures, and wherein:

[0038] Figure 1 An electronic circuit diagram of the hydrogen fuel cell system abnormal power-off protection circuit according to an embodiment of the present disclosure is provided.

[0039] Figure 2 An electronic circuit diagram of another hydrogen fuel cell system abnormal power-off protection circuit according to an embodiment of the present disclosure is provided. DETAILED DESCRIPTION

[0040] The embodiments of the present disclosure will be described in detail below with reference to the drawings.

[0041] It should be apparent that the following describes only some embodiments of the present disclosure and not all embodiments of the present disclosure. The present disclosure can be implemented or applied in other different specific embodiments, and the details in the specification can be modified or changed based on different views and applications without departing from the spirit of the present disclosure. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present disclosure.

[0042] It is important to note that the various aspects described hereinafter pertain to embodiments within the scope of the appended claims. It should be apparent that the aspects described herein can be embodied in a wide variety of forms and that any specific structure and / or function described herein is merely illustrative. Based on the teachings herein one skilled in the art should appreciate that an aspect described herein can be implemented independently of any other aspects and that an aspect described herein can be implemented both as any claim and as an aspect of a claim. For example, an apparatus can be implemented using any number of the aspects described herein. In addition, an apparatus can be implemented using other structure and / or functionality not expressly described herein. Similarly, a method can be implemented using any number of the aspects described herein. In addition, a method can be implemented using other structure and / or functionality not expressly described herein.

[0043] It is also important to note that the diagram in the following embodiments only illustrates the basic idea of the present disclosure, and only shows the components related to the present disclosure in the diagram, but not drawn according to the number, shape and size of the components in actual implementation, the shape, number and proportion of each component in actual implementation can be a kind of arbitrary change, and the component layout pattern can be more complex.

[0044] In addition, in the following description, specific details are provided in order to facilitate a thorough understanding of the examples. However, one skilled in the art will understand that the aspects described can be practiced without these specific details.

[0045] 24V battery: low-voltage power supply for vehicle electrical components;

[0046] Mechanical switch: total gate between 24V battery and electrical equipment, used to disconnect the low-voltage power supply of the vehicle;

[0047] GND: vehicle ground, connected to the negative pole of the 24V battery.

[0048] Key switch: manual control switch when starting and stopping the vehicle, divided into ACC / ON / START three gears, the key switch in this embodiment refers to the ON gear switch;

[0049] Mode switch: switch for switching between fuel cell vehicle pure electric mode and fuel cell operation mode, the switch is closed to start the fuel cell mode;

[0050] 24VDC / DC: device for converting high voltage of 400-750V of vehicle power battery to 24V, used for charging 24V battery and supplying power to the vehicle;

[0051] Power battery: power source for electric vehicles, used to supply power to high-voltage components of the vehicle;

[0052] VCU: vehicle controller;

[0053] Instruments: Devices that reflect the operating status of a vehicle and its systems;

[0054] Fuel cell system: A device that generates electricity from hydrogen and oxygen through a chemical reaction, used in automotive power systems.

[0055] To address the issue of abnormal power-down in the vehicle, the following solutions were proposed: Figure 1 The technical solution, in Figure 1 The output pin of the DC / DC converter is directly connected to the positive terminal of the battery.

[0056] But the inventor discovered Figure 1 The technical solution has the following problems:

[0057] 1. Since the high and low voltage power supply of the whole vehicle cannot be disconnected during the delayed power-off process, if the fuel cell mode switch is controlled by a low voltage power supply with delayed control, and the key switch is directly turned off without disconnecting the mode switch, the VCU pin 4 will continue to output, the mode switch will always have voltage, and the VCU pin 3 will continuously receive the mode switch closing command, which will cause the whole vehicle to work in fuel cell mode in a cycle and cannot be powered off. Ultimately, the whole vehicle will be continuously powered on, which poses a high voltage risk and is also prone to hydrogen depletion and battery depletion.

[0058] 2. When the fuel cell system is powered down with a delay, the 24V DC / DC converter stops working. If the delay is too long or there is a need for fan power, the 24V battery may be depleted, affecting the next start of the vehicle.

[0059] 3. Most commercial vehicles are equipped with low-voltage mechanical switches. In the existing solution, the 24V DC / DC converter is connected to the positive terminal of the battery. If the driver accidentally turns off the mechanical switch after turning off the key, it will cause the 24V power to be cut off directly, and the delayed power-off operation cannot be performed.

[0060] Figure 1 and Figure 2 U is the storage battery, K1 is the mechanical switch, K2 is the key switch, and K3 is the mode switch.

[0061] Inventor Figure 1 Based on this, improvements were proposed, such as Figure 2 The diagram shows the power-off protection circuit for an abnormal hydrogen fuel cell system. (Example:) Figure 2 As shown, a power-off protection circuit for a hydrogen fuel cell system includes: a battery, a mechanical switch, a key switch, a VCU, a mode switch, diodes D1 and D2, relays R1 and R2, a power battery device, and a fuel cell system.

[0062] A mechanical switch, a key switch, and a mode switch are connected in series between the positive terminal of the battery and the fuel cell mode switch signal pin of the VCU.

[0063] The node between the mechanical switch and the key switch is electrically connected to the constant power supply pin of the VCU;

[0064] A diode D1 is connected in series between the node between the key switch and the mode switch and the first terminal of the coil of relay R1, and the cathode of diode D1 is electrically connected to the first terminal of the coil of relay R1.

[0065] The first terminal of the coil of relay R1 is electrically connected to the first terminal of the coil of relay R2;

[0066] The second terminal of the coil of relay R1 and the second terminal of the coil of relay R2 are both electrically connected to the negative terminal of the battery.

[0067] One end of the fuel cell system is electrically connected to the negative terminal of the battery;

[0068] A diode D2 is connected in series between the fuel cell system delayed power-down control signal pin of the VCU and the first terminal of the coil of relay R1. The anode of diode D2 is electrically connected to the fuel cell system delayed power-down control signal pin of the VCU.

[0069] The node between the mechanical switch and the key switch is electrically connected to one of the switch contacts of relay R1;

[0070] The node between the mechanical switch and the key switch is electrically connected to one of the switch contacts of relay R2;

[0071] The other switch contact of relay R1 is electrically connected to the other end of the fuel cell system;

[0072] The other switch contact of relay R2 is electrically connected to the VCU's enable signal pin;

[0073] The power battery unit is electrically connected to the VCU.

[0074] Figure 2 In the VCU, there are 5 I / O ports: pin 1 is the constant power supply pin, pin 2 is the work wake-up (enable) signal pin, pin 3 is the fuel cell mode switch signal pin, pin 4 is the fuel cell system delayed power-down control signal pin, and pin 5 is the ground pin; relays R1 and R2 are normally open relays; for the 24VDC / DC relay, pin 1 is the low-voltage power supply pin, pin 2 is the output pin, and pin 3 is the ground pin; for the instrument, pin 1 is the constant power supply pin, pin 2 is the instrument wake-up (enable) signal pin, and pin 3 is the ground pin; for the fuel cell system, pin 1 is the power supply pin, and pin 2 is the ground pin.

[0075] The power supply pin of the fuel cell system is electrically connected with the contact of the relay R1, and the ground pin of the fuel cell system is grounded. The power supply pin of the instrument, the instrument wake-up (enable) signal pin and the normally-on power supply pin of the instrument are electrically connected with the contact of the relay R2, and the ground pin of the instrument is grounded.

[0076] Optionally, the power battery device comprises a power battery and a DC / DC converter, the power battery is electrically connected with the DC / DC converter, the low-voltage power supply pin of the DC / DC converter is electrically connected with the working enable signal pin of the VCU, the output pin of the DC / DC converter is electrically connected with the node between the mechanical switch and the key switch, and the ground pin of the DC / DC converter is electrically connected with the negative pole of the storage battery.

[0077] Optionally, the DC / DC converter is a 24V DC / DC converter.

[0078] Optionally, the instrument is further included, one input end of the instrument is electrically connected with the other switch contact of the relay R2, the other input end of the instrument is electrically connected with the working enable signal pin of the VCU, and the output end of the instrument is electrically connected with the negative pole of the storage battery.

[0079] Optionally, the load is further included, and the load is electrically connected with the working enable signal pin of the VCU.

[0080] Optionally, when the whole vehicle is powered on,

[0081] The mechanical switch is closed to start power supply, and the first end of the coil of the relay R1 and the relay R2 is powered on;

[0082] The key switch is closed to control the coil of the relay R1 and the relay R2, the contact of the relay R1 and the relay R2 is closed, and the electrical equipment is powered on and woken up, at this time, the fuel cell system is in a sleep mode;

[0083] When the whole vehicle is powered on with high voltage, the VCU controls the DC / DC converter of the power battery device to output 24V power supply;

[0084] The mode switch is closed to start the fuel cell mode, after the fuel cell mode switch signal pin of the VCU receives the positive controllable signal of the mode switch, the fuel cell system delay power-off control signal pin of the VCU continuously outputs 24V positive signal, so as to ensure the low-voltage power supply of the system, and the VCU controls the fuel cell system to start.

[0085] Optionally, when the whole vehicle is normally powered off:

[0086] The mode switch is closed, the fuel cell mode is closed, and the fuel cell system performs power-off purging work;

[0087] Turn off the key switch, the whole vehicle power down, first disconnect the high voltage circuit, then disconnect the low voltage circuit of the whole vehicle;

[0088] If the fuel cell system power down purge work is not completed when the key switch is turned off, the fuel cell system sends a purge state information, when the VCU receives the purge state information, the VCU controls the relay R1 and the relay R2 to continue to close, the VCU controls the DC / DC converter of the power battery device to work until the fuel cell system purge is completed and sends a standby state, after the VCU receives the standby state signal, the VCU controls the DC / DC converter to stop output, then the high voltage is turned off, and then the low voltage circuit is disconnected, finally the VCU fuel cell system delay power down control signal pin output is stopped;

[0089] After the power down is completed, the mechanical switch is turned off.

[0090] Optionally, when the abnormal power down is caused by misoperation:

[0091] When the mode switch is not turned off and the key switch is directly turned off, the VCU fuel cell mode switch signal pin does not receive the fuel cell mode instruction, the VCU determines that the fuel cell mode is turned off, the fuel cell system performs the power down purge work, at this time the VCU fuel cell system delay power down control signal pin continues to output, when the VCU receives the standby state feedback from the fuel cell system, the VCU controls the whole vehicle to first turn off the high voltage, then turn off the low voltage, and finally stop the VCU fuel cell system delay power down control signal pin output, to complete the whole vehicle power down.

[0092] Optionally, when the abnormal power down is caused by misoperation:

[0093] When the key is turned off and the whole vehicle purge delay power down is not completed, the mechanical switch is directly turned off, the VCU controls the DC / DC converter to continue to output 24V voltage, when the VCU receives the delay power down completion signal, the VCU controls the DC / DC converter to stop output, at this time the whole vehicle power supply is completely disconnected, the VCU fuel cell system delay power down control signal pin is also stopped output, and the VCU controls the relay R1 and the relay R2 to be disconnected.

[0094] In a specific scenario, the 24V storage battery negative electrode is grounded, the mechanical switch is placed between the 24V storage battery positive electrode and the electrical equipment, and the mechanical switch is connected to the 24V storage battery positive electrode;

[0095] The key switch, the VCU, the instrument, the relay R1 and the relay R2 are connected to the storage battery positive electrode through the mechanical switch, and take the normal power supply;

[0096] The relay R1, the relay R2, the VCU, the 24V DC / DC converter, the instrument and the fuel cell system are grounded;

[0097] Mode switch and key switch in series, mode switch and VCU 3-pin electrical connection, used to control the vehicle pure electric mode and fuel cell mode switch;

[0098] Diode D1 anode and key switch, diode D1 cathode relay R1 and relay R2 first end;

[0099] Diode D2 anode pin and VCU 4-pin electrical connection, diode D2 cathode relay R1 and relay R2;

[0100] Relay R1 and 2-pin to the instrument, VCU 2-pin, 24VDC / DC converter 1-pin and other electronic components connected to the parts of the low-voltage control circuit for supply or wake up;

[0101] Relay R2 and fuel cell system 1-pin connection, for fuel cell system low voltage power supply and wake up;

[0102] 24VDC / DC converter high voltage input to the vehicle power battery, 24VDC / DC converter output pin for 3-pin, output 24V low voltage, 24VDC / DC converter 3-pin to the mechanical switch, for the whole vehicle 24V low voltage power supply and battery charging;

[0103] Fuel cell system, VCU, 24VDC / DC converter, instrument and other electronic components of the communication through the CAN communication.

[0104] The hydrogen fuel vehicle abnormal power protection circuit of the embodiment, its protection logic is as follows:

[0105] 1, the vehicle power on:

[0106] a) close the mechanical switch, the vehicle to provide power to the device (such as instruments, etc.), the relay R1 and relay R2 coil power supply;

[0107] b) close the key switch, control the relay R1 and relay R2 coil, close the relay R1 and relay R2 contact, to the instrument, VCU, 24VDC / DC converter and fuel cell system for power supply and wake up, at this time the fuel cell system in sleep mode;

[0108] c) vehicle start (key switch START gear or start button), the vehicle high voltage, VCU through the CAN signal control 24VDC / DC converter 2-pin to start output 24V power supply, replace the battery for the vehicle to provide 24V power supply, while charging 24V battery;

[0109] d) Close the mode switch, open the fuel cell mode, the 3-pin of VCU receives the positive control signal of the mode switch, the 4-pin continuously outputs 24V positive signal to ensure the low-voltage power supply of the system, and the fuel cell system is started through CAN signal control;

[0110] e) The vehicle runs in fuel cell mode.

[0111] 2. When the whole vehicle normally powers off:

[0112] a) Turn off the mode switch, close the fuel cell mode, and the fuel cell system performs power-off purging work;

[0113] b) Turn off the key switch, power off the whole vehicle, first disconnect the high-voltage circuit, and then disconnect the low-voltage circuit;

[0114] c) If the fuel cell system power-off purging work is not completed when the key switch is turned off, the fuel cell system sends a purging state information, and when the VCU receives this signal, the 4-pin of the VCU continuously outputs 24V signal to control the relay R1 and the relay R2 to continue to close, and control the 24VDC / DC converter to continue to work, to ensure the normal work of related parts, until the fuel cell system purging is completed and the standby state is sent, and after the VCU receives the standby state, the 24VDC / DC converter is stopped through CAN signal control, then the high-voltage is turned off, the low-voltage circuit is disconnected, and finally the 4-pin output of the VCU is stopped;

[0115] d) Power off, disconnect the mechanical switch.

[0116] When powering on and powering off, the 24VDC / DC converter continuously outputs during the fuel cell system purging process to prevent the battery from running out of power.

[0117] 3. When the driver misoperates to cause abnormal power-off:

[0118] Misoperation 1: The driver does not disconnect the mode switch and directly disconnects the key switch.

[0119] Protection circuit analysis: This protection circuit mode switch power supply is not controlled by the 4-pin of the VCU, when the key switch is turned off, even if the mode switch is not turned off, the 3-pin of the VCU will not receive the fuel cell mode instruction, the VCU determines to turn off the fuel cell mode, and the fuel cell system performs power-off purging work, at this time the 4-pin of the VCU continuously outputs, when the fuel cell system feedback standby state, the VCU controls the whole vehicle to first turn off the high-voltage, then disconnect the low-voltage, and finally stop the 4-pin output of the VCU, to complete the power-off of the whole vehicle;

[0120] The problem of the whole vehicle unable to power off is solved;

[0121] Misoperation 2: When the whole vehicle purging delay power-off is not completed after the key is turned off, the mechanical switch is directly disconnected.

[0122] The protection circuit analyzes: during the whole vehicle delay power-down process, the VCU controls the 24VDC / DC to continuously output 24V power through the CAN signal, so that even if the mechanical switch is disconnected during the delay power-down process, the 24V output by the 24VDC / DC can still meet the use of the whole vehicle delay power-down process; when the delay power-down is completed, the VCU controls the 24VDC / DC to stop outputting, at this time the whole vehicle 24V power supply is completely disconnected, the 4-pin of the VCU also stops outputting at the same time, and the relay is disconnected.

[0123] When the misoperation 2 occurs, the fuel cell system and the whole vehicle parts are protected, and the service life is improved.

[0124] Figure 2 The abnormal power-down protection circuit of the hydrogen fuel cell system shown in the embodiment solves the problem that the whole vehicle cannot be normally powered down when the driver directly powers down without closing the mode switch, and prevents battery depletion and high-voltage risk. Figure 1 The protection circuit shown in the embodiment:

[0125] 1. The problem that the whole vehicle cannot be normally powered down when the driver directly powers down without closing the mode switch is solved, and battery depletion and high-voltage risk are prevented.

[0126] 2. The problem of battery depletion caused by the non-operation of the 24VDC / DC converter during the delay power-down process, which affects the next start of the whole vehicle, is solved.

[0127] 3. The problem that the whole vehicle is directly powered off during the delay power-down process, which affects the service life of the fuel cell system and the whole vehicle, is solved.

[0128] In the embodiment, the control pins of the relay R1 and the relay R2 are connected in parallel, the control signal of the relay is connected in parallel with the ON mode signal of the key switch and the delay power-down control signal of the VCU, the ON mode wake-up during the power-on of the fuel cell system and the delay power-down during the power-down are met, the delay power-down signal is effectively isolated by adding the diode D1 and the diode D2, the problem that the whole vehicle cannot be powered down caused by the direct disconnection of the key switch when the driver does not disconnect the mode switch is prevented, the 24VDC / DC converter is controlled in the power-on and power-down sequence, the fuel cell can still work continuously during the delay power-down of the fuel cell parking purging, the completeness of the power-down process of the fuel cell system is ensured, the risk caused by the misoperation of the driver is prevented, and the service life of the fuel cell system is improved.

[0129] The embodiment also discloses an automobile comprising the abnormal power-down protection circuit of the hydrogen fuel cell system.

[0130] The above describes the basic principles of the present disclosure in combination with specific embodiments, but it needs to be pointed out that the advantages, benefits, effects and the like mentioned in the present disclosure are only examples and are not limiting, and these advantages, benefits, effects and the like cannot be considered as necessary for each embodiment of the present disclosure. In addition, the specific details of the above disclosure are only for the purpose of example and for the purpose of understanding, and are not limiting, and the above details do not limit the present disclosure to be necessarily implemented with the above specific details.

[0131] In the present disclosure, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. The block diagrams of the devices, apparatuses, equipment, systems involved in the present disclosure are only illustrative examples and are not intended to require or imply the connection, arrangement, configuration as shown in the block diagram. As those skilled in the art will recognize, these devices, apparatuses, equipment, systems can be connected, arranged, configured in any manner. Words such as "include", "contain", "have" and the like are open-ended words, which mean "including but not limited to", and can be used interchangeably. The words "or" and "and" used herein mean the word "and / or", and can be used interchangeably unless the context clearly indicates otherwise. The word "such as" used herein means the phrase "such as but not limited to", and can be used interchangeably.

[0132] In addition, as used herein, "or" used in the list of items preceded by "at least one of" means a disjunctive list, such that, for example, a list of "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the phrase "example of" does not mean an example of the preferred or better embodiment.

[0133] It also needs to be pointed out that in the system and method of the present disclosure, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions of the present disclosure.

[0134] Various changes, substitutions and alterations can be made to the technology described herein without departing from the teachings of the technology defined by the appended claims. In addition, the scope of the claims of the present disclosure is not limited to the specific aspects of the process, machine, manufacture, composition of matter, means, method and acts of the above described. Processes, machines, manufacture, composition of matter, means, methods or acts currently existing or later developed that perform substantially the same function or achieve substantially the same result as the corresponding aspects described herein can be utilized. Accordingly, the appended claims include within their scope such processes, machines, manufacture, composition of matter, means, methods or acts.

[0135] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other aspects without departing from the scope of the disclosure. Thus, the present disclosure is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0136] The above description has been presented to enable any person skilled in the art to make or use the disclosure. Furthermore, the purpose of the above description is not intended to limit the embodiments of the present disclosure to the form disclosed herein. Although various example aspects and embodiments have been discussed above, those of ordinary skill in the art will appreciate a variety of modifications, alternatives, permutations, additions, and sub-combinations, which fall within the scope of the disclosed aspects.

Claims

1. A hydrogen fuel cell system abnormal de-energization protection circuit, characterized by, The application relates to a power supply system of a fuel cell vehicle, which comprises a storage battery, a mechanical switch, a key switch, a VCU, a mode switch, a diode D1, a diode D2, a relay R1, a relay R2, a power battery device and a fuel cell system. The positive pole of the storage battery is connected in series with the fuel cell mode switch signal pin of the VCU through the mechanical switch, the key switch and the mode switch. The node between the mechanical switch and the key switch is electrically connected with the constant power supply pin of the VCU. The node between the key switch and the mode switch is connected in series with the first end of the coil of the relay R1 through the diode D1, and the cathode of the diode D1 is electrically connected with the first end of the coil of the relay R1. The first end of the coil of the relay R1 is electrically connected with the first end of the coil of the relay R2. The second end of the coil of the relay R1 and the second end of the coil of the relay R2 are both electrically connected with the negative pole of the storage battery. One end of the fuel cell system is electrically connected with the negative pole of the storage battery. The fuel cell system delay power-off control signal pin of the VCU is connected in series with the first end of the coil of the relay R1 through the diode D2, and the anode of the diode D2 is electrically connected with the fuel cell system delay power-off control signal pin of the VCU. The node between the mechanical switch and the key switch is electrically connected with one switch contact of the relay R1. The node between the mechanical switch and the key switch is electrically connected with one switch contact of the relay R2. The other switch contact of the relay R1 is electrically connected with the other end of the fuel cell system. The other switch contact of the relay R2 is electrically connected with the working enable signal pin of the VCU. The power battery device is electrically connected with the VCU. The power battery device comprises a power battery and a DC / DC converter, the power battery is electrically connected with the DC / DC converter, the low-voltage power supply pin of the DC / DC converter is electrically connected with the working enable signal pin of the VCU, the output pin of the DC / DC converter is electrically connected with the node between the mechanical switch and the key switch, and the grounding pin of the DC / DC converter is electrically connected with the negative pole of the storage battery.

2. The hydrogen fuel cell system abnormal de-energization protection circuit according to claim 1, characterized by, The DC / DC converter is a 24V DC / DC converter.

3. The hydrogen fuel cell system abnormal de-energization protection circuit according to claim 2, characterized by, The application further comprises an instrument, one input end of the instrument is electrically connected with the other switch contact of the relay R2, the other input end of the instrument is electrically connected with the working enable signal pin of the VCU, and the output end of the instrument is electrically connected with the negative pole of the storage battery.

4. The hydrogen fuel cell system abnormal de-energization protection circuit according to claim 1, characterized by, The application further comprises a load, which is electrically connected with the working enable signal pin of the VCU.

5. The hydrogen fuel cell system abnormal de-energization protection circuit according to claim 1, characterized by, When the whole vehicle is powered on, 6. The abnormal de-energization protection circuit for a hydrogen fuel cell system according to any one of claims 1 to 5, characterized in that, The mechanical switch is closed to start power supply, and the first ends of the coils of the relays R1 and R2 are powered on; The key switch is closed to control the coils of the relays R1 and R2, the contacts of the relays R1 and R2 are closed, and the electric equipment is powered on and woken up, at this time, the fuel cell system is in a dormant mode; When the whole vehicle is powered on with high voltage, the VCU controls the DC / DC converter of the power battery device to output 24V power supply. ​ When the mode switch is closed, the fuel cell mode is opened, and the fuel cell system delay power-off control signal pin of the VCU continuously outputs a 24V positive signal to ensure low-voltage power supply of the system, while the VCU controls the fuel cell system to start.

7. The abnormal de-energization protection circuit for a hydrogen fuel cell system according to any one of claims 1 to 5, characterized by When the vehicle normally powers off: When the mode switch is opened, the fuel cell mode is closed, and the fuel cell system performs power-off purging work; When the key switch is opened, the vehicle powers off, and the high-voltage circuit of the vehicle is disconnected first, and then the low-voltage circuit of the vehicle is disconnected; If the fuel cell system power-off purging work is not completed when the key switch is opened, the fuel cell system sends a purging state information, and when the VCU receives the purging state information, the VCU controls the relay R1 and the relay R2 to continue to be closed, the VCU controls the DC / DC converter of the power battery device to work, until the fuel cell system purging is completed and a standby state is sent, and after the VCU receives the standby state signal, the VCU controls the DC / DC converter to stop outputting, then powers off the high voltage, then disconnects the low-voltage circuit, and finally stops the output of the fuel cell system delay power-off control signal pin of the VCU; When the mechanical switch is opened, the power-off is completed.

8. The abnormal de-energization protection circuit for a hydrogen fuel cell system according to any one of claims 1 to 5, characterized by, When the mode switch is not opened and the key switch is directly opened, the fuel cell mode switch signal pin of the VCU does not receive the fuel cell mode instruction, the VCU determines that the fuel cell mode is opened, the fuel cell system performs power-off purging work, and the fuel cell system delay power-off control signal pin of the VCU continuously outputs when the VCU receives the standby state feedback of the fuel cell system, the VCU controls the vehicle to power off the high voltage first, then disconnects the low voltage, and finally stops the output of the fuel cell system delay power-off control signal pin of the VCU, and the power-off of the vehicle is completed. When the key is opened and the vehicle purging delay power-off is not completed, the mechanical switch is directly opened, the VCU controls the DC / DC converter to continuously output 24V voltage, when the VCU receives the delay power-off completion signal, the VCU controls the DC / DC converter to stop outputting, at this time, the power supply of the vehicle is completely disconnected, the fuel cell system delay power-off control signal pin of the VCU also stops outputting, and the VCU controls the contacts of the relay R1 and the relay R2 to be opened.

9. The abnormal de-energization protection circuit for a hydrogen fuel cell system according to any one of claims 1 to 5, characterized by, The hydrogen fuel cell system abnormal power-off protection circuit according to any one of claims 1 to 9. The hydrogen fuel cell system abnormal power-off protection circuit according to any one of claims 1 to 9.

10. An automobile characterized by comprising: ​

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