Fuel cell system and control method thereof, and vehicle

Abstract

The present invention discloses a fuel cell system and a control method thereof, and a vehicle. The fuel cell system includes a fuel cell stack, an air supply system, a stack cooling system, a controller, and a heating system; the heating system includes a first heating unit, a first switch unit, and a second heating unit; the first end of the first heating unit is electrically connected to the positive electrode of the fuel cell stack, and the second end of the first heating unit is electrically connected to the first end of the first switch unit; the second end of the first switch unit is electrically connected to the first end of the second heating unit, and the second end of the second heating unit is electrically connected to the negative electrode of the fuel cell stack; the first heating unit is used to heat the coolant in the first pipeline; the second heating unit is used to heat at least part of the single cells in the second battery part. The present invention can enable the fuel cell stack to complete self-starting in a low temperature environment using the electric energy generated by it, without the need for an additional power supply, thereby simplifying the structure of the fuel cell system and reducing costs.

Description

Technical Field

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

[0002] A fuel cell is a device that converts chemical energy directly into electrical energy. Proton exchange membrane fuel cell is a type of fuel cell. It has the advantages of low operating temperature, high energy density, and environmental friendliness. It has good commercial prospects in mobile power sources, vehicles and other equipment.

[0003] However, in a low-temperature environment, the water in the fuel cell freezes, causing the fuel cell to be unable to start normally under low-temperature conditions. Summary of the invention

[0004] The present invention provides a fuel cell system and a control method thereof, and a vehicle, which can enable a fuel cell stack to self-start using the electricity generated by it in a low-temperature environment without the need for an additional power supply, thereby simplifying the structure of the fuel cell system and reducing costs.

[0005] According to one aspect of the present invention, a fuel cell system is provided, the fuel cell system comprising: a fuel cell stack, an air supply system connected to an air inlet of the fuel cell stack, a stack cooling system connected to the fuel cell stack through a first pipeline, a controller, and a heating system connected between a positive electrode and a negative electrode of the fuel cell stack;

[0006] The fuel cell stack comprises a first battery unit and a second battery unit, wherein the first battery unit is close to an air inlet of the fuel cell stack, and the second battery unit is located on a side of the first battery unit away from the air inlet; the first battery unit and the second battery unit each comprise at least one single battery;

[0007] The heating system comprises a first heating unit, a first switch unit and a second heating unit; a first end of the first heating unit is electrically connected to the positive electrode of the fuel cell stack, and a second end of the first heating unit is electrically connected to the first end of the first switch unit; a second end of the first switch unit is electrically connected to the first end of the second heating unit, and a second end of the second heating unit is electrically connected to the negative electrode of the fuel cell stack; the first heating unit is used to heat the coolant in the first pipeline; the second heating unit is used to heat at least part of the single cells in the second battery part;

[0008] The controller is connected to the control end of the first switch unit. The controller is used to control the gas supply system to input hydrogen and air into the air inlet of the fuel cell stack, control the first end of the first switch unit to be conductive with the second end thereof, and control the coolant in the stack cooling system to flow in the first pipeline when the temperature of the fuel cell stack is lower than the first set temperature. When the temperature of the coolant in the first pipeline is higher than the second set temperature, the controller controls the heating system to be disconnected from the positive and negative electrodes of the fuel cell stack.

[0009] Optionally, the heating system further includes a second switch unit;

[0010] A first end of the second switch unit is electrically connected to a first end of the first heating unit, a second end of the second switch unit is electrically connected to a second end of the first switch unit, and a control end of the second switch unit is electrically connected to the controller;

[0011] When the first end of the first switch unit is connected to the second end thereof, the controller is used to control the first end of the first switch unit to be disconnected from the second end thereof after at least one single cell in the fuel cell stack is in a reverse polarity state for a duration exceeding a first set duration, and at the same time control the first end of the second switch unit to be connected to the second end thereof and the coolant in the stack cooling system to stop flowing in the first pipeline.

[0012] Optionally, when the first end of the second switch unit is connected to the second end thereof, the controller is used to control the first end of the first switch unit to be connected to the second end thereof when the temperature at the air outlet of the fuel cell stack exceeds a third set temperature, and at the same time control the first end of the second switch unit to be not connected to the second end thereof and the coolant in the stack cooling system to flow in the first pipeline.

[0013] Optionally, the fuel cell system provided in this embodiment further includes a first temperature sensor and a second temperature sensor;

[0014] The first temperature sensor is used to detect the temperature of the coolant in the first pipeline;

[0015] The second temperature sensor is used to detect the temperature at the air outlet;

[0016] The controller is electrically connected to the first temperature sensor and the second temperature sensor, and is used to obtain the temperature of the coolant and the temperature at the air outlet.

[0017] Optionally, the second heating unit includes a plurality of heating subunits connected in series; the second battery unit includes a plurality of single batteries;

[0018] The heating subunits correspond one-to-one to the single cells in the second battery section;

[0019] The heating subunit is used to heat the corresponding single battery.

[0020] Optionally, the stack cooling system includes a cooling pump;

[0021] The cooling pump is used to control the coolant to flow in the first pipeline.

[0022] Optionally, the heating system further comprises a fuse and a resistor;

[0023] The first end of the fuse is connected to the second end of the first heating unit, and the second end of the fuse is connected to the first end of the first switch unit;

[0024] A first end of the resistor is connected to a first end of the first heating unit, and a second end of the resistor is connected to a first end of the second switch unit.

[0025] Optionally, the first heating unit includes a PCT heater;

[0026] The second heating unit includes a heating resistance wire.

[0027] According to another aspect of the present invention, a control method for a fuel cell system is provided, and the control method is applied to the fuel cell system provided by any embodiment of the present invention;

[0028] The control method comprises:

[0029] When the temperature of the fuel cell stack is lower than the first set temperature, the gas supply system is controlled to input hydrogen and air into the air inlet of the fuel cell stack, the first end of the first switch unit and the second end thereof are controlled to be connected, and the coolant in the stack cooling system is controlled to flow in the first pipeline; when the temperature of the coolant in the first pipeline is higher than the second set temperature, the heating system is controlled to be disconnected from the positive and negative electrodes of the fuel cell stack.

[0030] According to another aspect of the present invention, a vehicle is provided. The vehicle includes the fuel cell system provided by any embodiment of the present invention.

[0031] The present embodiment provides a fuel cell system, in which a heating system is connected between the positive and negative electrodes of a fuel cell stack. The first heating unit in the heating system can heat the coolant in the first pipeline, and the second heating unit in the heating system can heat some of the single cells in the second battery part of the fuel cell stack, wherein the second battery part of the fuel cell stack is located on the side of the first battery part away from the air inlet, and the first battery part of the fuel cell stack is close to the air inlet. When the temperature of the fuel cell stack is lower than the first set temperature, the controller controls the coolant to flow in the first pipeline, and at the same time controls the first heating unit and the second heating unit to work, so that the first heating unit heats the coolant, and the second heating unit heats some of the single cells in the second battery part until the fuel cell stack completes self-starting, that is, until the temperature of the coolant is higher than the second set temperature. After the temperature of the coolant is higher than the second set temperature, the controller controls the first heating unit and the second heating unit to stop working. The fuel cell system provided in the present embodiment can enable the fuel cell stack to complete self-starting in a low temperature environment, and the heating system in the fuel cell system can work normally using the electric energy generated by the fuel cell stack without the need for an additional power supply. In summary, the fuel cell system provided in this embodiment can enable the fuel cell stack to complete self-starting in a low-temperature environment using the electricity it generates without the need for an additional power supply, thereby simplifying the structure of the fuel cell system and reducing costs.

[0032] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 is a structural schematic diagram of a fuel cell system provided according to an embodiment of the present invention;

[0035] Figure 2 is a structural schematic diagram of another fuel cell system provided according to an embodiment of the present invention;

[0036] Figure 3 is a structural schematic diagram of another fuel cell system provided according to an embodiment of the present invention;

[0037] Figure 4is a structural schematic diagram of another fuel cell system provided according to an embodiment of the present invention;

[0038] Figure 5 It is a flow chart of a control method of a fuel cell system provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0040] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0041] Figure 1 is a schematic diagram of a fuel cell system according to an embodiment of the present invention, with reference to Figure 1The fuel cell system provided in this embodiment includes: a fuel cell stack 110, an air supply system 120 connected to the air inlet of the fuel cell stack 110, a stack cooling system 130 connected to the fuel cell stack 110 through a first pipeline 131, a controller 140, and a heating system 150 connected between the positive electrode S1 and the negative electrode S2 of the fuel cell stack 110; the fuel cell stack 110 includes a first battery section 111 and a second battery section 112, the first battery section 111 is close to the air inlet of the fuel cell stack 110, and the second battery section 112 is located on a side of the first battery section 111 away from the air inlet; the first battery section 111 and the second battery section 112 each include at least one single battery; the heating system 150 includes a first heating unit 151, a first switch unit 152 and a second heating unit 153; the first end of the first heating unit 151 is electrically connected to the positive electrode S1 of the fuel cell stack 110, and the second end of the first heating unit 151 is electrically connected to the first switch unit 1 52 is electrically connected; the second end of the first switch unit 152 is electrically connected to the first end of the second heating unit 153, and the second end of the second heating unit 153 is electrically connected to the negative electrode S2 of the fuel cell stack 110; the first heating unit 151 is used to heat the coolant in the first pipeline 131; the second heating unit 153 is used to heat at least part of the single cells in the second battery part 112; the controller 140 is connected to the control end of the first switch unit 152, and the controller 140 is used to control the gas supply system 120 to input hydrogen and air to the air inlet of the fuel cell stack 110 when the temperature of the fuel cell stack 110 is lower than the first set temperature, control the first end of the first switch unit 152 to be conductive with its second end, and control the coolant in the stack cooling system 130 to flow in the first pipeline 131, and control the heating system 150 to be non-conductive with the positive electrode S1 and the negative electrode S2 of the fuel cell stack 110 when the temperature of the fuel cell stack 110 is lower than the second set temperature.

[0042] Specifically, the fuel cell stack 110 is formed by stacking a plurality of single cells, and the single cells in this embodiment may also be referred to as fuel cells. The plurality of single cells in the fuel cell stack 110 may be connected in series.

[0043] The gas supply system 120 can input hydrogen and air to the fuel cell stack 110 . The fuel cell stack 110 can generate electrical energy after receiving the air and hydrogen, so that the positive electrode S1 and the negative electrode S2 of the fuel cell stack 110 are turned on to generate current.

[0044] The stack cooling system 130 may include a cooling pump 132, which can allow the coolant to flow in the first pipeline 131. The stack cooling system 130 is connected to the liquid inlet S3 and the liquid outlet S4 of the fuel cell stack 110. The coolant flowing in the first pipeline 131 can flow into the fuel cell stack 110 through the liquid inlet S3, and flow out from the liquid outlet S4 of the fuel cell stack 110 to the first pipeline 131. The coolant can perform heat exchange with the fuel cell stack 110. When the temperature of the fuel cell stack 110 is lower than the temperature of the coolant, the coolant flowing in the first pipeline 131 can heat the fuel cell stack 110. When the temperature of the fuel cell stack 110 is higher than the temperature of the coolant, the coolant flowing in the first pipeline 131 can cool the fuel cell stack 110.

[0045] The first set temperature may be lower than -30°C. When the temperature of the fuel cell stack 110 is lower than the first set temperature, after the gas supply system 120 inputs hydrogen and air into the air inlet of the fuel cell stack 110, the electric energy generated by the fuel cell stack 110 cannot meet the working requirements of the high-power device, which may be an electric motor in a car. Therefore, the fuel cell stack 110 needs to be started so that the electric energy generated by it can meet the working requirements of the high-power device.

[0046] After hydrogen and air are input into the air inlet of the fuel cell stack 110, hydrogen and air react chemically to generate heat energy, wherein the temperature of the single cell close to the air inlet is higher than the temperature of the single cell far from the air inlet. The single cell far from the air inlet may have low voltage or even reverse polarity problems due to the low ambient temperature. Therefore, it is necessary to heat some of the single cells far from the air inlet. In this embodiment, the single cells in the second battery section 112 are far from the air inlet, and the single cells in the first battery section 111 are close to the air inlet. The temperature of the single cells in the second battery section 112 is lower than the temperature of the single cells in the first battery section 111. In this embodiment, a second heating unit 153 is provided to heat some of the single cells in the second battery section 112. The second heating unit 153 can be provided on the end plate of the single cell in the second battery section 112.

[0047] The controller 140 can be electrically connected to the fuel cell stack 110, and the controller 140 can obtain the temperature of the fuel cell stack 110. The controller 140 can also be electrically connected to the stack cooling system 130, and the controller 140 can control the stack cooling system 130 to make the coolant in the first pipeline 131 flow. When the temperature of the fuel cell stack 110 is lower than the first set temperature, the controller 140 controls the gas supply system 120 to input air and hydrogen into the air inlet of the fuel cell stack 110, and controls the first end of the first switch unit 152 to be connected to the second end of the first switch unit 152. The fuel cell stack 110 that receives air and hydrogen can generate electrical energy, and the generated electrical energy can make the heating system 150 work. Since the first end and the second end of the first switch unit 152 are connected, current is generated in the heating system 150, and the first heating unit 151 and the second heating unit 153 can work to generate heat. The first heating unit 151 heats the coolant in the first pipeline 131. Since the coolant flows in the first pipeline 131 when the temperature of the fuel cell stack 110 is lower than the first set temperature, the coolant heated by the first heating unit 151 can heat the fuel cell stack 110, and the second heating unit 153 can also heat some of the single cells in the second battery part 112. The first heating unit 151 and the second heating unit 153 can work simultaneously to quickly increase the temperature of the fuel cell stack 110, so that the fuel cell stack 110 can quickly heat up and complete self-starting in a low temperature environment. When the temperature of the coolant is higher than the second set temperature, it indicates that the fuel cell stack 110 has completed self-starting, and the electric energy generated by the fuel cell stack 110 after self-starting can meet the needs of high-power devices. Therefore, there is no need to heat the fuel cell stack 110 anymore, and the electrical connection between the fuel cell stack 110 and the heating system 150 can be disconnected, that is, when the temperature of the coolant is higher than the second set temperature, the heating system 150 is controlled to have no current, that is, the first end of the first switch unit 152 is controlled to be non-conductive with its second end.

[0048] The present embodiment provides a fuel cell system, in which a heating system is connected between the positive and negative electrodes of a fuel cell stack. The first heating unit in the heating system can heat the coolant in the first pipeline, and the second heating unit in the heating system can heat some of the single cells in the second battery part of the fuel cell stack, wherein the second battery part of the fuel cell stack is located on the side of the first battery part away from the air inlet, and the first battery part of the fuel cell stack is close to the air inlet. When the temperature of the fuel cell stack is lower than the first set temperature, the controller controls the coolant to flow in the first pipeline, and at the same time controls the first heating unit and the second heating unit to work, so that the first heating unit heats the coolant, and the second heating unit heats some of the single cells in the second battery part until the fuel cell stack completes self-starting, that is, until the temperature of the coolant is higher than the second set temperature. After the temperature of the coolant is higher than the second set temperature, the controller controls the first heating unit and the second heating unit to stop working. The fuel cell system provided in the present embodiment can enable the fuel cell stack to complete self-starting in a low temperature environment, and the heating system in the fuel cell system can work normally using the electric energy generated by the fuel cell stack without the need for an additional power supply. In summary, the fuel cell system provided in this embodiment can enable the fuel cell stack to complete self-starting in a low-temperature environment using the electricity it generates without the need for an additional power supply, thereby simplifying the structure of the fuel cell system and reducing costs.

[0049] Optional, Figure 2 is a schematic diagram of a structure of another fuel cell system provided according to an embodiment of the present invention, with reference to Figure 2 The heating system 150 also includes a second switch unit 154; the first end of the second switch unit 154 is electrically connected to the first end of the first heating unit 151, the second end of the second switch unit 154 is electrically connected to the second end of the first switch unit 152, and the control end of the second switch unit 154 is electrically connected to the controller 140; when the first end of the first switch unit 152 and the second end thereof are conductive, the controller 140 is used to control the first end of the first switch unit 152 and the second end thereof to be non-conductive after at least one single cell in the fuel cell stack 110 is in a reverse polarity state for a duration exceeding a first set duration, and at the same time control the first end of the second switch unit 154 and the second end thereof to be conductive and the coolant in the stack cooling system 130 to stop flowing in the first pipeline 131.

[0050] Specifically, the single cell is in a reverse polarity state, indicating that the positive and negative electrodes of the single cell are reversed, and the original negative electrode in the single cell becomes the positive electrode, and the original positive electrode becomes the negative electrode. When the first end of the first switch unit 152 is connected to the second end of the first switch unit 152, the gas supply system 120 inputs hydrogen and air to the air inlet of the fuel cell stack 110, and the stack cooling system 130 controls the coolant to flow in the first pipeline 131. Before the temperature of the coolant is higher than the second set temperature and when the first end of the first switch unit 152 is connected to the second end thereof, the voltage of the single cell in the second battery unit 112 will rise or fall.

[0051] When the first end of the first switch unit 152 is connected to the second end of the first switch unit 152, the first heating unit 151 heats the coolant in the first pipeline 131, and the second heating unit 153 heats some of the single cells in the second battery part 112. In this state, if the controller 140 detects that at least one single cell in the fuel cell stack 110 has a reverse polarity problem, and the duration of the reverse polarity problem exceeds the first set time, which can be in the range of 2 minutes to 5 minutes, it indicates that the voltage in the fuel cell stack 110 is too low and cannot continue to meet the power demand of the first heating unit 151 and the second heating unit 153 working at the same time. At this time, it is necessary to reduce the load in the heating system 150. The load in the heating system 150 can be reduced by controlling only the second heating unit 153 in the heating system 150 to work, that is, the controller 140 controls the switch in the first switch unit 152 to be disconnected, and controls the switch in the second switch unit 154 to be closed, so that only the second heating unit 153 heats the fuel cell stack 110. When the first heating unit 151 stops heating the coolant, there is no need to allow the coolant in the first pipeline 131 to flow, and the controller 140 can control the stack cooling system 130 to stop the coolant in the first pipeline 131 from flowing.

[0052] Optional, continue to refer to Figure 2 When the first end of the second switch unit 154 is connected to the second end thereof, the controller 140 is used to control the first end of the first switch unit 152 to be connected to the second end thereof when the temperature at the air outlet of the fuel cell stack 110 exceeds the third set temperature, and at the same time control the first end of the second switch unit 154 to be not connected to the second end thereof and the coolant in the stack cooling system 130 to flow in the first pipeline 131.

[0053] Specifically, the second battery unit 112 is close to the air outlet. The air outlet and the air inlet are respectively located on both sides of the fuel cell stack 110. The conduction between the first end of the second switch unit 154 and its second end indicates that the switch in the second switch unit 154 is closed. When the switch in the second switch unit 154 is closed, the switch in the first switch unit 152 is disconnected. When the switch in the second switch unit 154 is closed, if the controller 140 detects that the temperature at the air outlet exceeds the third set temperature, which may be 90°C, it indicates that the temperature in the fuel cell stack 110 is too high and the fuel cell stack 110 needs to be cooled by the coolant. At this time, the controller 140 controls the switch in the second switch unit 154 to be disconnected, controls the switch in the first switch unit 152 to be closed, and at the same time enables the stack cooling system 130 to flow the coolant in the first pipeline 131, so that the coolant cools the temperature of the fuel cell stack 110. When the switch in the first switch unit 152 is closed and the switch in the second switch unit 154 is open, if the controller 140 detects again that at least one single cell in the fuel cell stack 110 is in the reverse polarity state for a duration exceeding the first set duration, the switch in the first switch unit 152 is controlled to be open and the switch in the second switch unit 154 is controlled to be closed.

[0054] Optional, Figure 3 is a schematic diagram of a structure of another fuel cell system provided according to an embodiment of the present invention, with reference to Figure 3 The fuel cell system provided in this embodiment also includes a first temperature sensor 160 and a second temperature sensor 170; the first temperature sensor 160 is used to detect the temperature of the coolant in the first pipeline 131; the second temperature sensor 170 is used to detect the temperature at the air outlet; the controller 140 is electrically connected to the first temperature sensor 160 and the second temperature sensor 170, and the controller 140 is used to obtain the temperature of the coolant and the temperature at the air outlet.

[0055] Specifically, the controller 140 controls the switch in the first switch unit 152 to be opened or closed, and the switch in the second switch unit 154 to be opened or closed according to the signal transmitted by the first temperature sensor 160 and the signal transmitted by the second temperature sensor 170. When the controller 140 detects that the temperature of the coolant is higher than the second set temperature, it controls the switch in the first switch unit 152 to be opened and the switch in the second switch unit 154 to be opened. After the switch in the first switch unit 152 and the switch in the second switch unit 154 are both opened, the high-power device can be electrically connected to the positive electrode S1 and the negative electrode S2 of the fuel cell stack 110. The first temperature sensor 160 can be connected to the first pipeline 131, and the temperature of the coolant is detected by detecting the temperature of the first pipeline 131. The second temperature sensor 170 can be located at the air outlet to detect the temperature at the air outlet.

[0056] Optionally, the second heating unit includes a plurality of heating sub-units connected in series; the second battery unit includes a plurality of single cells; the heating sub-units correspond one-to-one to the single cells in the second battery unit; and the heating sub-units are used to heat the corresponding single cells.

[0057] Specifically, when all the single cells in the second battery unit need to be heated, a heating subunit can be provided for each single cell in the second battery unit so that the heating subunit heats its corresponding single cell, thereby improving the heating rate of the single cells in the second battery unit and making the heating rate of the single cells in the second battery unit basically consistent, so that each single cell is heated evenly.

[0058] Optionally, the stack cooling system includes a cooling pump; the cooling pump is used to control the flow of coolant in the first pipeline.

[0059] Specifically, the cooling pump may be connected to the controller, and the controller controls the cooling pump to operate so that the coolant flows in the first pipeline.

[0060] Optional, Figure 4 is a schematic diagram of a structure of another fuel cell system provided according to an embodiment of the present invention, with reference to Figure 4 The heating system 150 also includes a fuse FU and a resistor R1; the first end of the fuse FU is connected to the second end of the first heating unit 151, and the second end of the fuse FU is connected to the first end of the first switch unit 152; the first end of the resistor R1 is connected to the first end of the first heating unit 151, and the second end of the resistor R1 is connected to the first end of the second switch unit 154.

[0061] Specifically, the first switch unit 152 includes a first switch K1, a first end of the first switch K1 is electrically connected to the second end of the fuse FU, a second end of the first switch K1 is electrically connected to the first end of the second heating unit 153, and a control end of the first switch K1 is electrically connected to the controller 140. The second switch unit 154 includes a second switch K2, a first end of the second switch K2 is electrically connected to the second end of the resistor R1, a second end of the second switch K2 is electrically connected to the first end of the second heating unit 153, and a control end of the second switch K2 is electrically connected to the controller 140. When the first switch K1 is closed, the fuse FU is used to prevent excessive current from burning the first heating unit 151 and the second heating unit 153. The resistor R1 is used for current limiting. When the first switch K1 is disconnected and the second switch K2 is closed, the resistor R1 can prevent the current in the heating system 150 from burning the second heating unit 153.

[0062] Optionally, the first heating unit includes a PCT heater; the second heating unit includes a heating resistance wire.

[0063] Specifically, the PCT heater has the characteristics of fast heating rate and high heating efficiency, etc. The heating resistance wire has the characteristics of low cost and easy acquisition, etc.

[0064] This embodiment also provides a control method for a fuel cell system, and the control method is applicable to the fuel cell system provided by any embodiment of the present invention.

[0065] Figure 5 is a flow chart of a control method of a fuel cell system provided according to an embodiment of the present invention, with reference to Figure 5 , the control method comprises the following steps:

[0066] S110, detecting the temperature of the fuel cell stack.

[0067] S120. When the temperature of the fuel cell stack is lower than the first set temperature, the gas supply system is controlled to input hydrogen and air into the air inlet of the fuel cell stack, the first end of the first switch unit and the second end thereof are controlled to be conductive, and the coolant in the stack cooling system is controlled to flow in the first pipeline. When the temperature of the coolant in the first pipeline is higher than the second set temperature, the heating system is controlled to be disconnected from the positive and negative electrodes of the fuel cell stack.

[0068] The control method of the fuel cell system provided in this embodiment has corresponding beneficial effects as the fuel cell system provided in any embodiment of the present invention. For technical details not elaborated in this embodiment, please refer to the fuel cell system provided in any embodiment of the present invention.

[0069] This embodiment also provides a vehicle, which includes the fuel cell system provided by any embodiment of the present invention.

[0070] Specifically, the vehicle in this embodiment further includes an electric motor, which is electrically connected to the fuel cell system, and the fuel cell system can supply power to the electric motor.

[0071] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0072] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fuel cell system, characterized in that: include: A fuel cell stack, an air supply system connected to an air inlet of the fuel cell stack, a stack cooling system connected to the fuel cell stack via a first pipeline, a controller, and a heating system connected between a positive electrode and a negative electrode of the fuel cell stack; The fuel cell stack comprises a first battery unit and a second battery unit, wherein the first battery unit is close to an air inlet of the fuel cell stack, and the second battery unit is located on a side of the first battery unit away from the air inlet; the first battery unit and the second battery unit each comprise at least one single battery; The heating system comprises a first heating unit, a first switch unit and a second heating unit; a first end of the first heating unit is electrically connected to the positive electrode of the fuel cell stack, and a second end of the first heating unit is electrically connected to the first end of the first switch unit; a second end of the first switch unit is electrically connected to the first end of the second heating unit, and a second end of the second heating unit is electrically connected to the negative electrode of the fuel cell stack; the first heating unit is used to heat the coolant in the first pipeline; the second heating unit is used to heat at least part of the single cells in the second battery part; The controller is connected to the control end of the first switch unit, and is used to control the gas supply system to input hydrogen and air to the air inlet of the fuel cell stack, control the first end of the first switch unit to be connected to the second end thereof, and control the coolant in the stack cooling system to flow in the first pipeline when the temperature of the fuel cell stack is lower than the first set temperature, and control the heating system to be disconnected from the positive electrode and the negative electrode of the fuel cell stack when the temperature of the coolant in the first pipeline is higher than the second set temperature; The heating system further comprises a second switch unit; A first end of the second switch unit is electrically connected to a first end of the first heating unit, a second end of the second switch unit is electrically connected to a second end of the first switch unit, and a control end of the second switch unit is electrically connected to the controller; When the first end of the first switch unit is connected to the second end thereof, the controller is used to control the first end of the first switch unit to be disconnected from the second end thereof after at least one single cell in the fuel cell stack is in a reverse polarity state for a duration exceeding a first set duration, and at the same time control the first end of the second switch unit to be connected to the second end thereof and the coolant in the stack cooling system to stop flowing in the first pipeline.

2. The fuel cell system according to claim 1, characterized in that: When the first end of the second switch unit is connected to the second end thereof, the controller is used to control the first end of the first switch unit to be connected to the second end thereof when the temperature at the air outlet of the fuel cell stack exceeds a third set temperature, and at the same time control the first end of the second switch unit to be disconnected from the second end thereof and the coolant in the stack cooling system to flow in the first pipeline.

3. The fuel cell system according to claim 2, characterized in that: Also including a first temperature sensor and a second temperature sensor; The first temperature sensor is used to detect the temperature of the coolant in the first pipeline; The second temperature sensor is used to detect the temperature at the air outlet; The controller is electrically connected to the first temperature sensor and the second temperature sensor, and is used to obtain the temperature of the coolant and the temperature at the air outlet.

4. The fuel cell system according to claim 1, characterized in that: The second heating unit includes a plurality of heating sub-units connected in series; the second battery unit includes a plurality of single batteries; The heating subunits correspond one-to-one to the single cells in the second battery section; The heating subunit is used to heat the corresponding single battery.

5. The fuel cell system according to claim 1, characterized in that: The stack cooling system includes a cooling pump; The cooling pump is used to control the coolant to flow in the first pipeline.

6. The fuel cell system according to claim 1, characterized in that: The heating system also includes a fuse and a resistor; The first end of the fuse is connected to the second end of the first heating unit, and the second end of the fuse is connected to the first end of the first switch unit; A first end of the resistor is connected to a first end of the first heating unit, and a second end of the resistor is connected to a first end of the second switch unit.

7. The fuel cell system according to claim 1, characterized in that: The first heating unit comprises a PCT heater; The second heating unit includes a heating resistance wire.

8. A control method for a fuel cell system, characterized in that: A fuel cell system as claimed in any one of claims 1 to 7; The control method comprises: When the temperature of the fuel cell stack is lower than the first set temperature, the gas supply system is controlled to input hydrogen and air into the air inlet of the fuel cell stack, the first end of the first switch unit and the second end thereof are controlled to be connected, and the coolant in the stack cooling system is controlled to flow in the first pipeline; when the temperature of the coolant in the first pipeline is higher than the second set temperature, the heating system is controlled to be disconnected from the positive and negative electrodes of the fuel cell stack.

9. A vehicle, characterized in that: A fuel cell system comprising any one of claims 1 to 7.

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