High voltage electric heater for fuel cell system, control method, apparatus and medium

Abstract

The application provides a high-voltage electric heater for a fuel cell system, a control method, equipment and a medium. The high-voltage electric heater adopts a pure resistance mode, adopts a series connection mode of a first resistance heating unit and a second resistance heating unit, and controls the first resistance heating unit and / or the second resistance heating unit to be connected to an output end of a DCDC power module of the fuel cell system based on different states of the fuel cell system by a control unit, so that different output powers can be realized. The difficulty of control implementation is low, mature and reliable in hardware. The high-voltage electric heater can be applied to commercial vehicles and passenger vehicles, can realize high and low voltage platform compatibility, is conducive to mass production, is low in cost, simple and reliable in circuit, easy to implement, has great application value for protection and life extension of the fuel cell system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fuel cell, in particular to a high-voltage electric heater for fuel cell system and a control method, device and medium thereof. BACKGROUND

[0002] At present, the high-voltage electric heater in the hydrogen fuel cell system of the hydrogen fuel cell vehicle is mainly used for cold start auxiliary heating of the hydrogen fuel cell system when the ambient temperature is below 0℃ in winter. The requirements of the high-voltage electric heater are: 1. water-cooled heat dissipation, 2. fast start speed, 3. stable heating power, and 4. small volume.

[0003] At present, the hydrogen fuel cell system developed mainly uses a water heating PTC (Positive Temperature Coefficient) electric heater for the heating of new energy vehicles. The PTC electric heater is safe and has accurate temperature control, but it is not suitable for the cold start working condition of the hydrogen fuel cell system, because:

[0004] 1. The resistance of the PTC electric heater is a positive temperature coefficient, the matching controller starts slowly, the power increases at a rate of about 100W / s, the power reaches 6kW or more, and the time consumption is about 1min, which seriously affects the cold start time of the hydrogen fuel cell system.

[0005] 2. In order to meet the condition of fast start speed, the PTC electric heater can cancel its matching controller, but this will bring a new problem, that is, the starting impact current is 3 times or more than the rated current. In the cold start state, the discharge capacity of the battery is poor and cannot support large current impact, which will damage the power battery.

[0006] 3. The PTC electric heater is large in size and high in cost. In the cold start of the hydrogen fuel cell system, the PTC electric heater is only an auxiliary part and is used only at subzero temperature. It is unnecessary to use the PTC electric heater which is large in size and high in cost.

[0007] 4. The DC 540V voltage platform of commercial vehicles and the DC 350V voltage platform of passenger vehicles cannot be universal. SUMMARY

[0008] The present application provides a high-voltage electric heater for fuel cell system and a control method, device and medium thereof, which are used to solve the technical problem that the existing heater cannot be applied to different power requirements.

[0009] In a first aspect, the present application provides a high-voltage electric heater for fuel cell system, comprising a first resistance heating unit, a second resistance heating unit and a control unit.

[0010] The first and second resistance heating units are respectively connected to the output terminals of a DCDC power module of a fuel cell system via the control unit, and the first resistance heating unit is also connected to the second resistance heating unit;

[0011] The control unit is configured to control the first and second resistance heating units to be respectively connected to the output terminals of the DCDC power module when the fuel cell system is in an emergency shutdown state, control the second resistance heating unit to be connected to the output terminals of the DCDC power module when the fuel cell system is in an idle speed state, and control the first and second resistance heating units to be connected in series to the output terminals of the DCDC power module when the fuel cell system is in a low-temperature cold start state.

[0012] In some embodiments of the present application, based on the foregoing scheme, the control unit comprises a first high-voltage contactor, a second high-voltage contactor, and a third high-voltage contactor.

[0013] The first end of the first resistance heating unit is connected to the positive output terminal of the DCDC power module of the fuel cell system via the first high-voltage contactor, connected to the negative output terminal of the DCDC power module via the second high-voltage contactor, and the second end of the first resistance heating unit is connected to the positive output terminal via the third high-voltage contactor.

[0014] The first end of the second resistance heating unit is connected to the positive output terminal via the third high-voltage contactor, and the second end of the second resistance heating unit is connected to the negative output terminal.

[0015] The second end of the first resistance heating unit is connected to the first end of the second resistance heating unit.

[0016] When the fuel cell system is in an emergency shutdown state, the first high-voltage contactor is open, the second high-voltage contactor is closed, and the third high-voltage contactor is closed; when the fuel cell system is in an idle speed state, the first high-voltage contactor is open, the second high-voltage contactor is open, and the third high-voltage contactor is closed; and when the fuel cell system is in a low-temperature cold start state, the first high-voltage contactor is closed, the second high-voltage contactor is open, and the third high-voltage contactor is open.

[0017] In some embodiments of the present application, based on the foregoing scheme, a controller is further included, and the controller is connected to the control terminals of the first, second, and third high-voltage contactors, respectively.

[0018] The controller is configured to control the first high-voltage contactor to be open, the second high-voltage contactor to be closed, and the third high-voltage contactor to be closed when the state of the fuel cell system is emergency shutdown; control the first high-voltage contactor to be open, the second high-voltage contactor to be open, and the third high-voltage contactor to be closed when the state of the fuel cell system is shutdown idle speed; and control the first high-voltage contactor to be closed, the second high-voltage contactor to be open, and the third high-voltage contactor to be open when the state of the fuel cell system is low-temperature cold start.

[0019] In some embodiments of the present application, based on the foregoing scheme, the first resistance heating unit includes three parallel heating pipes, and the second resistance heating unit includes three parallel heating pipes, and the resistances of all the heating pipes are the same.

[0020] In some embodiments of the present application, based on the foregoing scheme, the power supply interfaces of the control coils of the first high-voltage contactor and the second high-voltage contactor adopt an interlocking design to prevent the first high-voltage contactor and the second high-voltage contactor from being closed at the same time.

[0021] In some embodiments of the present application, based on the foregoing scheme, the controller is integrated into a DCDC controller of the fuel cell system.

[0022] In some embodiments of the present application, based on the foregoing scheme, the high-voltage electric heater can be applied to commercial vehicles and passenger vehicles.

[0023] In the second aspect, the present application provides a control method of a high-voltage electric heater for a fuel cell system, applied to the high-voltage electric heater for the fuel cell system in any one of the first aspect, and comprising:

[0024] obtaining a state of the fuel cell system;

[0025] controlling the first resistance heating unit and the second resistance heating unit to be connected to the output end of the DCDC power module when the state of the fuel cell system is emergency shutdown;

[0026] controlling the second resistance heating unit to be connected to the output end of the DCDC power module when the state of the fuel cell system is shutdown idle speed;

[0027] controlling the first resistance heating unit and the second resistance heating unit to be connected to the output end of the DCDC power module in series when the state of the fuel cell system is low-temperature cold start.

[0028] In the third aspect, the present application provides an electronic device, comprising:

[0029] a processor;

[0030] a memory for storing instructions executable by the processor;

[0031] The processor is configured to perform to realize the control method of the high-voltage electric heater for the fuel cell system according to the second aspect.

[0032] In a fourth aspect, the application provides a computer-readable storage medium, when the instructions in the computer-readable storage medium are executed by the processor of an electronic device, the electronic device can execute the control method of the high-voltage electric heater for the fuel cell system according to the second aspect.

[0033] The high-voltage electric heater provided by the technical solution of the application adopts a pure resistance mode, adopts a series connection mode of the first resistance heating unit and the second resistance heating unit, and controls the first resistance heating unit and / or the second resistance heating unit to be connected to the output end of the DCDC power module of the fuel cell system based on different states of the fuel cell system by the control unit, so that different output powers can be realized. The difficulty of control implementation is low, mature, and the hardware is reliable. It can be applied to commercial vehicles and passenger cars, can realize high and low voltage platform compatibility, is conducive to mass production, has low cost, simple and reliable circuit, and is easy to implement. It has great application value for the protection and life extension of the fuel cell system. BRIEF DESCRIPTION OF DRAWINGS

[0034] The drawings incorporated into the specification and forming a part thereof, show embodiments consistent with the application, and together with the specification serve to explain the principles of the application. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained from these drawings without creative labor for those skilled in the art. In the drawings:

[0035] Figure 1 It is a structural block diagram of the high-voltage electric heater for the fuel cell system of the application;

[0036] Figure 2 It is a circuit schematic diagram of the high-voltage electric heater for the fuel cell system of the application;

[0037] Figure 3 It is a physical structure diagram of the high-voltage electric heater for the fuel cell system of an embodiment of the application;

[0038] Figure 4 It is a structural schematic diagram of the electronic device of the application. DETAILED DESCRIPTION

[0039] In order to make the purposes, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0040] Some embodiments of the present application will be described in detail below with reference to the drawings. The following embodiments and features in the embodiments can be combined with each other without conflict.

[0041] In order to facilitate understanding of the technical solutions of the present application, a fuel cell system is first described, which can use hydrogen fuel and generally includes a fuel DCDC (Direct current-Direct current converter) 1 and a fuel FCCU (Fuel cell control unit) 2. The fuel DCDC 1 includes a DCDC controller 101 and a DCDC power module 103, and the output end of the DCDC power module 103 includes an output positive electrode DC+ and an output negative electrode DC-.

[0042] As shown in Figure 1 The present application provides a high-voltage electric heater 2 for a fuel cell system, which includes a first resistance heating unit 21, a second resistance heating unit 22 and a control unit 102.

[0043] The first resistance heating unit 21 and the second resistance heating unit 22 are respectively connected to the output end of the DCDC power module 103 of the fuel cell system through the control unit 102, and the first resistance heating unit 21 is also connected to the second resistance heating unit 22.

[0044] The control unit 102 is used to control the first resistance heating unit 21 and the second resistance heating unit 22 to be respectively connected to the output end of the DCDC power module 103 when the state of the fuel cell system is emergency shutdown, control the second resistance heating unit 22 to be connected to the output end of the DCDC power module 103 when the state of the fuel cell system is shutdown idle speed, and control the first resistance heating unit 21 and the second resistance heating unit 22 to be connected to the output end of the DCDC power module 103 in series when the state of the fuel cell system is low-temperature cold start.

[0045] In some embodiments, as shown in Figure 2 The control unit 102 includes a first high-voltage contactor K1, a second high-voltage contactor K2 and a third high-voltage contactor K3.

[0046] The first end of the first resistance heating unit 21 is connected to the output positive pole DC+ of the DCDC power module 103 of the fuel cell system through the first high-voltage contactor K1, and the output negative pole DC- of the DCDC power module 103 through the second high-voltage contactor K2, and the second end of the first resistance heating unit 21 is connected to the output positive pole DC+ through the third high-voltage contactor K3.

[0047] The first end of the second resistance heating unit 22 is connected to the output positive pole DC+ through the third high-voltage contactor K3, and the second end of the second resistance heating unit 22 is connected to the output negative pole DC-.

[0048] The second end of the first resistance heating unit 21 is connected to the first end of the second resistance heating unit 22.

[0049] When the state of the fuel cell system is emergency shutdown, the first high-voltage contactor K1 is opened, the second high-voltage contactor K2 is closed, and the third high-voltage contactor K3 is closed; when the state of the fuel cell system is shutdown idle speed, the first high-voltage contactor K1 is opened, the second high-voltage contactor K2 is opened, and the third high-voltage contactor K3 is closed; when the state of the fuel cell system is low-temperature cold start, the first high-voltage contactor K1 is closed, the second high-voltage contactor K2 is opened, and the third high-voltage contactor K3 is opened.

[0050] Specifically, the high-voltage electric heater 2 for the fuel cell system further comprises a controller, the controller being connected to the control ends of the first high-voltage contactor K1, the second high-voltage contactor K2, and the third high-voltage contactor K3, respectively.

[0051] The controller is used to control the first high-voltage contactor K1 to be opened, the second high-voltage contactor K2 to be closed, and the third high-voltage contactor K3 to be closed when the state of the fuel cell system is emergency shutdown; control the first high-voltage contactor K1 to be opened, the second high-voltage contactor K2 to be opened, and the third high-voltage contactor K3 to be closed when the state of the fuel cell system is shutdown idle speed; and control the first high-voltage contactor K1 to be closed, the second high-voltage contactor K2 to be opened, and the third high-voltage contactor K3 to be opened when the state of the fuel cell system is low-temperature cold start.

[0052] Specifically, the first resistance heating unit 21 comprises three parallel heating pipes, the second resistance heating unit 22 comprises three parallel heating pipes, and the resistances of all the heating pipes are the same.

[0053] Specifically, in order to prevent short circuit, the power supply interfaces of the control coils of the first high-voltage contactor K1 and the second high-voltage contactor K2 adopt an interlocking design to prevent the first high-voltage contactor K1 and the second high-voltage contactor K2 from being closed at the same time.

[0054] Specifically, the controller is integrated in the DCDC controller 101 of the fuel cell system, so that the control strategy is mature through the fuel FCCU control.

[0055] Specifically, the high-voltage electric heater can be applied to commercial vehicles (DC 540V) and passenger vehicles (DC 350V).

[0056] In a specific embodiment, the control unit 102 further comprises a protection fuse F1, thereby playing a role of a protection circuit. Figure 3 The high-voltage electric heater 2 comprises six "U"-shaped heating pipes 204, an insulating magnetic column 200, an electrically sealed insulating pad 201, a stainless steel plate 202, and a water sealing pad 203. Three of the "U"-shaped heating pipes 204 are connected in parallel, and the other three "U"-shaped heating pipes 204 are connected in parallel and then connected in series by a copper bar, forming a first high-voltage electrical interface 106, a second high-voltage electrical interface 107, and a third high-voltage electrical interface 108.

[0057] The first end of the first resistance heating unit 21 is connected to the first high-voltage electrical interface 106, and the second end is connected to the second high-voltage electrical interface 107. The first end of the second resistance heating unit 22 is connected to the second high-voltage electrical interface 107, and the second end is connected to the third high-voltage electrical interface 108.

[0058] The output positive pole DC+ of the DCDC power module 103 is connected to the first end of the protection fuse F1. The second end of the protection fuse F1 is connected to one end of the first high-voltage contactor K1 and the third high-voltage contactor K3. The other end of the first high-voltage contactor K1 is connected to the first high-voltage electrical interface 106, and the other end of the third high-voltage contactor K3 is connected to the second high-voltage electrical interface 107. One end of the second high-voltage contactor K2 is connected to the first high-voltage electrical interface 106, and the other end is connected to the third high-voltage electrical interface 108. The output negative pole DC- of the DCDC power module 103 is connected to the third high-voltage electrical interface 108.

[0059] It should be noted that, assuming that the resistance of the first resistance heating unit 21 is R1, the resistance of the second resistance heating unit 22 is R2, and the output voltage of the DCDC power module 103 is U, when the first high-voltage contactor K1 is open, the second high-voltage contactor K2 is closed, and the third high-voltage contactor K3 is closed, the output power of the high-voltage electric heater 2 is recorded as W1 (power mode 1), W1 = U 2 / R1+U 2 / R2; when the first high-voltage contactor K1 is open, the second high-voltage contactor K2 is open, and the third high-voltage contactor K3 is closed, the output power of the high-voltage electric heater 2 is recorded as W2 (power mode 2), W2 = U2 / R2; when the first high-voltage contactor K1 is closed, the second high-voltage contactor K2 is opened, and the third high-voltage contactor K3 is opened, the output power of the high-voltage electric heater 2 is recorded as W3 (power mode 3), W3 = U 2 / (R1+R2);

[0060] Please refer to Figure 2 , the electric energy output by the fuel cell stack (not shown in the figure) is transmitted to the DCDC power module 103 through the input positive electrode IN+ and the input negative electrode IN- (i.e. Figure 2 the input interface 104, 105 in the figure), and the DCDC power module 103 outputs electric energy (i.e. Figure 2 through the output positive electrode DC+ and the output negative electrode DC- in the figure) to the high-voltage electric heater 2, and mainly outputs electric energy to the power battery (not shown in the figure). When the fuel cell system is in emergency shutdown, since the power battery of the whole vehicle is disconnected at this time, the main energy transmission channel of the fuel cell stack is disconnected, which will form a counter electromotive force, causing the bus voltage to surge, which may break the high-voltage components. At this time, the high-voltage electric heater 2 outputs the maximum power W1 to discharge for 3-5s, that is, the energy can be quickly discharged to realize emergency stop protection. When the fuel cell system is in idle speed shutdown, in order to meet the minimum power requirement of the fuel cell stack, the high-voltage electric heater 2 outputs power W2 at this time, and the heat generated by the high-voltage electric heater 2 is taken to the radiator by the cooling system for heat dissipation, without the risk of overheating, which is safer than the air compressor power consumption and has low noise. When the fuel cell system is cold started at low temperature, the high-voltage electric heater 2 outputs power W3, that is, the cooling liquid of the fuel cell is heated at normal power to ensure that the fuel cell can work normally under low temperature conditions (such as below 0℃).

[0061] Assuming that the resistance of all heating pipes 204 is R, and the voltage of each heating pipe 204 is U, the power is W = U 2 / R, then the resistance R1 of the first resistance heating unit 21 is R / 3, the resistance R2 of the second resistance heating unit 22 is R / 3, and the three power modes of the high-voltage electric heater 2 are as follows:

[0062] Mode 1 K1 open, K2 closed, K3 closed [W1 = U 2 / R1 + U 2 / R2 = 6W Mode 2 K1 open, K2 open, K3 closed [W2 = U 2 / R2 = 3W Mode 3 K1 closed, K2 open, K3 open [W3 = U 2 (R1 + R2) = 1.5W

[0063] The high-voltage electric heater for a fuel cell system provided by the application adopts a pure resistance mode, adopts a series connection mode of a first resistance heating unit and a second resistance heating unit, and controls the first resistance heating unit and / or the second resistance heating unit to be connected to the output end of a DCDC power module of the fuel cell system based on different states of the fuel cell system by a control unit, so that different output powers can be achieved. The high-voltage contactor is used to control the on-off, the heating can be started quickly and the power is constant. The control implementation is low in difficulty, mature and reliable in hardware. The high-voltage electric heater can be applied to commercial vehicles and passenger vehicles, can realize high and low voltage platform compatibility, is conducive to mass production, is low in cost, simple and reliable in circuit and easy to implement, and has great application value for the protection of the fuel cell system and the extension of the service life of the fuel cell system.

[0064] Based on the same inventive concept, the application further provides a control method of a high-voltage electric heater for a fuel cell system, which is applied to the high-voltage electric heater for a fuel cell system provided in the foregoing embodiments and includes the following steps.

[0065] Obtaining the state of the fuel cell system;

[0066] When the state of the fuel cell system is emergency shutdown, controlling the first resistance heating unit 21 and the second resistance heating unit 22 to be connected to the output end of the DCDC power module 103, respectively;

[0067] When the state of the fuel cell system is shutdown idle speed, controlling the second resistance heating unit 22 to be connected to the output end of the DCDC power module 103;

[0068] When the state of the fuel cell system is low-temperature cold start, controlling the first resistance heating unit 21 and the second resistance heating unit 22 to be connected to the output end of the DCDC power module 103 in series.

[0069] It should be noted that the control method of the high-voltage electric heater for a fuel cell system provided in the embodiments of the application is applied to the high-voltage electric heater for a fuel cell system provided in the foregoing embodiments of the application, and the related technical features refer to the high-voltage electric heater for a fuel cell system provided in the foregoing embodiments of the application, which will not be described herein again.

[0070] Based on the same inventive concept, the embodiments of the application provide an electronic device as shown in Figure 4 The electronic device includes:

[0071] a processor 51;

[0072] a memory 52 for storing executable instructions of the processor 51;

[0073] The processor 51 is configured to execute to implement the control method of the high-voltage electric heater for a fuel cell system provided in the foregoing embodiments.

[0074] Based on the same inventive concept, the embodiment provides a computer readable storage medium, when instructions in the computer readable storage medium are executed by a processor of an electronic device, the electronic device is enabled to perform the control method of the high-voltage electric heater for fuel cell system provided by the preceding embodiment.

[0075] Since the electronic device introduced in the embodiment is the electronic device used to implement the control method of the high-voltage electric heater for fuel cell system in the embodiment, based on the control method of the high-voltage electric heater for fuel cell system introduced in the embodiment, those skilled in the art can understand the specific implementation of the electronic device in the embodiment and its various forms, so the electronic device how to implement the method in the embodiment is not introduced in detail. As long as those skilled in the art implement the electronic device used to implement the control method of the high-voltage electric heater for fuel cell system in the embodiment, it belongs to the scope of the present application.

[0076] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-readable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) containing computer usable program code.

[0077] The present application is described with reference to flowcharts and / or block diagrams of the method, device (system), and computer program product according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The function specified in one or more flows and / or blocks Figure 1 The means for performing the function specified in one or more flows and / or blocks.

[0078] These computer program instructions can also be stored in a computer readable storage medium that can guide the computer or other programmable data processing apparatus to work in a specific way, so that the instructions stored in the computer readable storage medium produce a product including instruction means, which implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The function specified in one or more flows and / or blocks Figure 1 The means for performing the function specified in one or more flows and / or blocks.

[0079] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 Figure 1 The flowchart blocks or blocks in FIG. 10 represent a sequence of steps for implementing the functions specified in the flowchart block or blocks and / or in other flowcharts or block diagrams in this specification. Each representation of a flowchart block or blocks in FIG. 10 can be implemented by hardware, software, or combinations thereof, which can be provided as a computer program product, such as a computer program tangibly embodied in a information carrier, e.g., in a machine readable storage

[0080] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein. Variations and modifications of the embodiments disclosed herein can be made based on the description set forth herein, without departing from the scope and spirit of the application. Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.​

Claims

1. A high-voltage electric heater for a fuel cell system, characterized in that, It includes a first resistance heating unit, a second resistance heating unit, and a control unit; The first resistance heating unit and the second resistance heating unit are respectively connected to the output terminal of the DC-DC power module of the fuel cell system via the control unit, and the first resistance heating unit is also connected to the second resistance heating unit. The control unit is used to control the first resistance heating unit and the second resistance heating unit to be connected to the output terminal of the DC-DC power module respectively when the state of the fuel cell system is emergency shutdown; to control the second resistance heating unit to be connected to the output terminal of the DC-DC power module when the state of the fuel cell system is shutdown idling; and to control the first resistance heating unit and the second resistance heating unit to be connected in series to the output terminal of the DC-DC power module when the state of the fuel cell system is low temperature cold start. The control unit includes a first high-voltage contactor, a second high-voltage contactor, and a third high-voltage contactor; The first end of the first resistance heating unit is connected to the positive output of the DC-DC power module of the fuel cell system via a first high-voltage contactor and to the negative output of the DC-DC power module via a second high-voltage contactor. The second end of the first resistance heating unit is connected to the positive output via a third high-voltage contactor. The first end of the second resistance heating unit is connected to the positive output terminal via the third high-voltage contactor, and the second end of the second resistance heating unit is connected to the negative output terminal. The second end of the first resistance heating unit is connected to the first end of the second resistance heating unit; When the fuel cell system is in an emergency shutdown state, the first high-voltage contactor opens, the second high-voltage contactor closes, and the third high-voltage contactor closes. When the fuel cell system is in a shutdown idling state, the first high-voltage contactor is open, the second high-voltage contactor is open, and the third high-voltage contactor is closed; when the fuel cell system is in a low-temperature cold start state, the first high-voltage contactor is closed, the second high-voltage contactor is open, and the third high-voltage contactor is open.

2. The high-voltage electric heater for a fuel cell system according to claim 1, characterized in that, It also includes a controller, which is connected to the control terminals of the first high-voltage contactor, the second high-voltage contactor and the third high-voltage contactor respectively; The controller is used to control the first high-voltage contactor to open, the second high-voltage contactor to close, and the third high-voltage contactor to close when the fuel cell system is in an emergency shutdown state; to control the first high-voltage contactor to open, the second high-voltage contactor to open, and the third high-voltage contactor to close when the fuel cell system is in a shutdown idling state; and to control the first high-voltage contactor to close, the second high-voltage contactor to open, and the third high-voltage contactor to open when the fuel cell system is in a low-temperature cold start state.

3. The high-voltage electric heater for a fuel cell system according to claim 1, characterized in that, The first resistance heating unit includes three heating tubes connected in parallel, and the second resistance heating unit includes three heating tubes connected in parallel, all of which have the same resistance.

4. The high-voltage electric heater for a fuel cell system according to claim 1, characterized in that, The power supply interfaces of the control coils of the first and second high-voltage contactors are interlocked to prevent the first and second high-voltage contactors from closing simultaneously.

5. The high-voltage electric heater for a fuel cell system according to claim 2, characterized in that, The controller is integrated into the DC-DC controller of the fuel cell system.

6. The high-voltage electric heater for a fuel cell system according to claim 1, characterized in that, The high-voltage electric heater is suitable for commercial vehicles and passenger vehicles.

7. A control method for a high-voltage electric heater for a fuel cell system, applied to the high-voltage electric heater for a fuel cell system as described in any one of claims 1-6, characterized in that, include: Obtain the status of the fuel cell system; When the fuel cell system is in an emergency shutdown state, the first resistance heating unit and the second resistance heating unit are respectively connected to the output terminal of the DC-DC power module; When the fuel cell system is in a stopped idling state, the second resistance heating unit is connected to the output terminal of the DC-DC power module. When the fuel cell system is in a low-temperature cold start state, the first resistance heating unit and the second resistance heating unit are connected in series and then connected to the output terminal of the DC-DC power module.

8. An electronic device, characterized in that, include: processor; Memory used to store the processor's executable instructions; The processor is configured to execute the control method for a high-voltage electric heater for a fuel cell system as described in claim 7.

9. A computer-readable storage medium, characterized in that, When the instructions in the computer-readable storage medium are executed by the processor of the electronic device, the electronic device is able to perform the control method for the high-voltage electric heater of the fuel cell system as described in claim 7.

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