Control method of fuel cell system, program product, control unit, and vehicle

Abstract

The invention relates to a control method for a fuel cell system of a vehicle, and the control method at least comprises the following steps: obtaining the required power of the vehicle for the fuel cell system; when the required power is zero, the charge level and the battery temperature of a power battery of the vehicle are obtained; the state of the fuel cell system is controlled according to the charge level and the cell temperature, when the charge level exceeds a preset first charge level threshold value, the fuel cell system enters a zero-power output mode, and when the charge level exceeds the preset first charge level threshold value, the fuel cell system enters a zero-power output mode; and when the charge level is lower than the first charge level threshold value and the battery temperature is lower than a preset temperature threshold value, the fuel cell system is shut down. The invention also relates to a corresponding computer program product, a fuel cell control unit and a vehicle. The fuel cell system can be prevented from being frequently started and stopped, so that the performance of the fuel cell system is improved, and the service life is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell vehicles, and more particularly to a control method for a fuel cell system for a vehicle. The present invention also relates to a corresponding computer program product, a fuel cell control unit for a fuel cell system for a vehicle, and a corresponding vehicle. Background Art

[0002] In recent years, with the development of society and technology, people's attention to problems such as air pollution and energy loss has increased day by day. A fuel cell is a highly efficient power generation device that directly converts the chemical energy in fuel and oxidant into electrical energy through an electrochemical reaction process without going through a combustion process. Since the reaction products are mainly water and basically no harmful gases are emitted, fuel cells have the significant advantages of being clean and environmentally friendly and can be particularly advantageously used in the vehicle field.

[0003] In a vehicle with a fuel cell system, the fuel cell system and the power battery jointly provide driving power for the vehicle. Among them, during the operation of the vehicle, there is a situation where the required power for the fuel cell system is zero. In response to this situation, existing vehicles usually shut down the fuel cell system. However, the shutdown of the fuel cell system requires going through shutdown processes such as drying, purging, and cooling, and subsequent restart also requires going through startup processes such as heating and humidifying, which results in a relatively long start-stop response time for the fuel cell system. In addition, frequent start-stop will also have an adverse impact on the output performance and service life of the fuel cell system. Summary of the Invention

[0004] Therefore, an object of the present invention is to propose an improved control method for a fuel cell system for a vehicle. Through the control method, the state of the fuel cell system can be targeted controlled when the required power is zero, and the fuel cell system is only shut down when necessary conditions are met, so as to avoid frequent start-stop of the fuel cell system, improve the performance of the fuel cell system, and extend the service life. Another object of the present invention is to propose a corresponding computer program product, a fuel cell control unit for a fuel cell system for a vehicle, and a vehicle.

[0005] According to a first aspect of the present invention, there is provided a control method for a fuel cell system for a vehicle, wherein the control method at least includes the following steps:

[0006] S1: Obtain the required power of the vehicle for the fuel cell system;

[0007] S2: When the required power is zero, obtain the state of charge and battery temperature of the power battery of the vehicle;

[0008] S3: Control the state of the fuel cell system according to the state of charge and the battery temperature. When the state of charge exceeds a preset first state of charge threshold, put the fuel cell system into a zero-power output mode. When the state of charge is lower than the first state of charge threshold and the battery temperature is lower than a preset temperature threshold, shut down the fuel cell system.

[0009] Compared with the prior art, in the control method of the fuel cell system for a vehicle according to the present invention, when the required power of the vehicle for the fuel cell system is zero, the state of the fuel cell system is controlled specifically according to the state of charge of the power battery and the battery temperature. When the state of charge exceeds the first state of charge threshold, the power battery can supply power to the fuel cell system to maintain the continuous operation of the fuel cell system, so that the fuel cell system keeps running and does not output power externally, thus avoiding affecting the energy distribution of the vehicle and preventing the frequent start and stop of the fuel cell system. Only when the state of charge is lower than the first state of charge threshold and the battery temperature is lower than the temperature threshold, the power battery cannot discharge externally due to too low a state of charge, and at the same time cannot be charged due to too low a temperature. In this case, in order to make the output power of the fuel cell system zero, the fuel cell system can only be shut down. Therefore, the state of the fuel cell system can be controlled more precisely when the required power of the vehicle for the fuel cell system is zero, and the fuel cell system is shut down only when necessary conditions are met, thus avoiding the frequent start and stop of the fuel cell system, reducing the response time of the fuel cell system and improving the performance and service life of the fuel cell system.

[0010] Exemplarily, when the idle state of the vehicle lasts for more than a preset first time threshold, the required power is zero; and / or when the state of charge of the power battery exceeds a preset second state of charge threshold, the required power is zero; and / or when the vehicle is running in a pure electric mode powered by the power battery alone, the required power is zero.

[0011] Exemplarily, in step S3, when the fuel cell system remains in the zero-power output mode for more than a second time threshold, exit the zero-power output mode and shut down the fuel cell system.

[0012] Exemplarily, in step S2, when the required power is not zero, make the fuel cell system operate normally.

[0013] Exemplarily, in step S3, when the state of charge is lower than the first state of charge threshold and the battery temperature is higher than the temperature threshold, recalculate the required power according to the state of charge and make the fuel cell system operate normally to charge the power battery.

[0014] Exemplarily, in the zero-power output mode, the power battery supplies electrical energy to the fuel cell system to at least drive the hydrogen circulation pump of the fuel cell system and continuously consume the remaining oxygen in the fuel cell stack of the fuel cell system, wherein the output power of the fuel cell system is zero.

[0015] According to a second aspect of the present invention, there is provided a computer program product, which includes a computer program, wherein when the computer program is executed by one or more than one processor, the processor can execute the control method according to the present invention.

[0016] According to a third aspect of the present invention, there is provided a fuel cell control unit for a fuel cell system of a vehicle, wherein the fuel cell control unit is configured to be communicatively connected to a vehicle control unit of the vehicle and a battery management system of a power battery for the vehicle and execute the control method according to the present invention by using the computer program product according to the present invention.

[0017] According to a fourth aspect of the present invention, there is provided a vehicle, which at least includes:

[0018] - A fuel cell system, which at least has a fuel cell stack, an air supply subsystem, a hydrogen supply subsystem and a fuel cell control unit according to the present invention;

[0019] - A power battery, which is electrically connected to the fuel cell system through a DCDC converter and has a battery management system, and the battery management system is configured to detect the state of charge and battery temperature of the power battery;

[0020] - A vehicle control unit, which is configured to output the required power of the vehicle for the fuel cell system,

[0021] wherein the fuel cell control unit is communicatively connected to the battery management system and the vehicle control unit respectively.

[0022] Exemplarily, the vehicle control unit determines the driving state of the vehicle according to the wheel speed detected by a wheel speed sensor and determines the required power based on the driving state. Description of the Drawings

[0023] Hereinafter, the present invention will be described in more detail by referring to the drawings, and the principles, features and advantages of the present invention can be better understood. The drawings include:

[0024] Figure 1 A schematic block diagram of a vehicle showing an exemplary embodiment according to the present invention;

[0025] Figure 2 A schematic flowchart showing a control method for a fuel cell system for a vehicle according to an exemplary embodiment of the present invention is shown. Detailed implementation manners

[0026] In order to make the technical problems to be solved, technical solutions and beneficial technical effects of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and multiple exemplary embodiments.

[0027] It should be understood that in this text, expressions such as "first", "second", etc. are only for descriptive purposes, and should not be construed as indicating or implying relative importance, nor should they be construed as implicitly indicating the number of the indicated technical features. Features defined with "first" and "second" may explicitly or implicitly include at least one of such features.

[0028] In this specification, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate member, or the communication inside two elements. For those of ordinary skill in the art, the meanings of the above terms in this disclosure can be understood according to the circumstances.

[0029] Figure 1 A schematic block diagram of a vehicle 100 according to an exemplary embodiment of the present invention is shown. Here, the vehicle 100 is configured as a fuel cell vehicle.

[0030] As Figure 1As shown, vehicle 100 includes a fuel cell system 10, which is the main energy source of vehicle 100 and generates electrical energy through the electrochemical reaction of hydrogen and oxygen in the air. Among them, the fuel cell system 10 has a fuel cell stack 11, which is composed of a plurality of fuel cell monomers stacked on top of each other. The fuel cell monomer has a membrane electrode assembly and bipolar plates arranged on both sides of the membrane electrode assembly. The oxidation-reduction reaction of hydrogen and oxygen takes place in the membrane electrode assembly. In addition, the fuel cell system 10 also has an air supply subsystem 12 and a hydrogen supply subsystem 13. The air supply subsystem is configured to supply air as the cathode gas to the cathode of the fuel cell stack 11 and is provided with a compressor, which is configured to drive and compress air. The hydrogen supply subsystem is configured to supply hydrogen as the anode gas to the anode of the fuel cell stack 11 and is provided with a hydrogen circulation pump, which is configured to drive high-pressure hydrogen to flow in the fuel cell system 10. Among them, the operation of both the air supply subsystem 12 and the hydrogen supply subsystem 13 requires the consumption of electrical energy. In addition, the fuel cell system 10 also has a fuel cell control unit 14, which is electrically connected to the fuel cell stack 11, the air supply subsystem 12, and the hydrogen supply subsystem 13 respectively and is configured to control the operation of the fuel cell system 10. It is also possible that the fuel cell system 10 has other components considered meaningful by those skilled in the art, such as humidifying components and heating components, etc.

[0031] As Figure 1 shown, vehicle 100 includes a power battery 20, which is electrically connected to the fuel cell system 10 through a DCDC converter 21 and jointly provides driving energy for vehicle 100 with the fuel cell system 10. Among them, through the boosting effect of the DCDC converter 21, the fuel cell system 10 can deliver the generated electrical energy to the power battery 20 and store it in the power battery 20. The power battery further supplies electrical energy to the high-voltage loads of vehicle 100 to drive vehicle 100 to operate normally. In contrast, the power battery 20 can also deliver electrical energy reversely to the fuel cell system 10 to maintain the operation of the fuel cell system 10. Here, vehicle 100 can exemplarily have a pure electric mode and a hybrid mode. In the pure electric mode, only the power battery 20 supplies electrical energy to the power-consuming loads of vehicle 100, while in the hybrid mode, the fuel cell system 10 and the power battery 20 jointly supply electrical energy to the power-consuming loads of vehicle 100. Here, the power battery 20 is provided with a battery management system 22. Through the battery management system, the state of the power battery 20 can be monitored and problems such as overcharging and over-discharging can be prevented. Among them, the battery management system 22 can detect the state of charge level and battery temperature of the power battery 20.

[0032] AsFigure 1 As shown, vehicle 100 further includes a vehicle control unit 30. The vehicle control unit is a key part of the electric control system of vehicle 100 and is configured to implement functions such as vehicle-wide energy distribution and motor drive control. Through the vehicle control unit 30, the utilization efficiency of the electric energy generated by the fuel cell system 10 and the power battery 20 can be maximized. Here, the vehicle control unit 30 can output the required power of vehicle 100 for the fuel cell system 10.

[0033] As Figure 1 shown, the fuel cell control unit 14 of the fuel cell system 10 is communicatively connected to the battery management system 22 of the power battery 20 and the vehicle control unit 30 respectively. Among them, the fuel cell control unit 14 can execute a control method for the fuel cell system 10 of vehicle 100 by using a computer program product according to the present invention. The computer program product includes a computer program. When the computer program is executed by one or more than one processor, the processor can execute the control method according to the present invention.

[0034] Figure 2 Fig. shows a schematic flow chart of a control method for the fuel cell system 10 of vehicle 100 according to an exemplary embodiment of the present invention. Here, the control method is executed by the fuel cell control unit 14 of the fuel cell system 10.

[0035] As Figure 2 shown, the control method according to the present invention at least includes the following steps:

[0036] S1: Obtain the required power of vehicle 100 for the fuel cell system 10 from the vehicle control unit 30;

[0037] S2: When the obtained required power is zero, obtain the state of charge and battery temperature of the power battery 20 of vehicle 100 from the battery management system 22 of the power battery 20;

[0038] S3: Control the state of the fuel cell system 10 according to the state of charge and battery temperature of the power battery 20. Among them, when the state of charge exceeds a preset first state of charge threshold, such as 30%, the power battery 20 can supply power to the fuel cell system 10 to maintain the continuous operation of the fuel cell system 10, so that the fuel cell system 10 enters a zero power output mode. In the zero power output mode, the fuel cell system 10 continuously operates and the external output power is zero. When the state of charge is lower than the first state of charge threshold and the battery temperature is lower than a preset temperature threshold, such as 0 °C, the power battery 20 can neither discharge nor charge, so that the fuel cell system 10 shuts down. Here, the first state of charge threshold and the temperature threshold can be obtained from experimental data and / or empirical data and stored in the fuel cell control unit 14 in advance.

[0039] Thus, the state of the fuel cell system 10 can be controlled more precisely when the required power of the vehicle for the fuel cell system 10 is zero. The fuel cell system is only shut down when necessary conditions are met, i.e., the state of charge is lower than the first state of charge threshold and the battery temperature is lower than the temperature threshold. Otherwise, the fuel cell system 10 operates in a zero-power output mode, which can effectively avoid frequent start-stop of the fuel cell system, reduce the start-stop response time of the fuel cell system 10, and improve the performance and service life of the fuel cell system 10.

[0040] Exemplarily, within the framework of the present invention, in the zero-power output mode of the fuel cell system 10, the power battery 20 supplies electrical energy to the fuel cell system 10 to at least drive the hydrogen circulation pump of the hydrogen supply subsystem 13 to work intermittently at a relatively low speed and continuously consume the remaining oxygen in the fuel cell stack 11. Wherein, the electrical energy generated by the fuel cell system 10 is used to drive other components of the fuel cell system 100, so that the output power of the fuel cell system 10 is zero. It is also possible here that the electrical energy supplied by the power battery 20 is also used to drive the air compressor in the air supply subsystem 12 to supply air to the fuel cell stack 11 at a relatively low flow rate.

[0041] Exemplarily, the vehicle control unit 30 determines the required power for the fuel cell system 10 according to the driving state of the vehicle 100. For example, when the vehicle is in an idle state and lasts for more than a preset first time threshold, such as 30 seconds, it is determined that the required power for the fuel cell system 10 is zero. For this purpose, the vehicle control unit 30 can, for example, judge the driving state of the vehicle 100 according to the wheel speed detected by the wheel speed sensor, and determine the required power based on the driving state. Wherein, when the wheel speed is zero, the vehicle 100 is in an idle state. However, it is also possible that when the state of charge of the power battery 20 exceeds a preset second state of charge threshold, such as 90%, the fuel cell system 10 does not need to charge the power battery 20, and it is determined that the required power for the fuel cell system 10 is zero. In addition, it can also be considered that when the vehicle 100 is driving in a pure electric mode powered by the power battery 20 alone, it is determined that the required power for the fuel cell system 10 for the fuel cell system 10 is zero. Here, the first time threshold and the second state of charge threshold can also be obtained from experimental data and / or empirical data and pre-stored in the vehicle control unit 30.

[0042] Exemplarily, in step S2, when the required power for the fuel cell system 10 output by the vehicle control unit 30 is not zero, the fuel cell system 10 operates normally, wherein the operating state of the fuel cell system 10 is adjusted depending on the acquired required power. For example, when the vehicle 100 is in an idle state and the required power corresponds to the idle power, such as 5 - 7 kW, the fuel cell system 10 operates in an idle mode, in which the air supply subsystem 12 and the hydrogen supply subsystem 13 of the fuel cell system 10 operate at low power and the current generated by the fuel cell stack 11 is reduced to a smaller value to reduce the damage to the fuel cell stack 11.

[0043] Exemplarily, in step S3, when the fuel cell system remains in the zero - power output mode for more than a second time threshold, such as 60 seconds, the zero - power output mode is exited and the fuel cell system 10 is shut down. By setting the second time threshold, both the delayed shutdown of the fuel cell system 10 can be achieved, thus avoiding the frequent start - stop of the fuel cell system 10, and the excessive consumption of the reaction gases in the fuel cell system 10 can be prevented.

[0044] Exemplarily, in step S3, when the state of charge of the power battery 20 is lower than a first state - of - charge threshold, such as 30%, and the battery temperature is higher than a temperature threshold, such as 0 °C, the state of charge of the power battery 20 is relatively low and the fuel cell system 10 can charge the power battery 20. The battery management system 22 sends a signal about the state of charge to the vehicle control unit 30, and the vehicle control unit recalculates the required power for the fuel cell system 10 according to the state of charge and makes the fuel cell system 10 operate normally to charge the power battery 20.

[0045] Here, the control method for the fuel cell system 10 of the vehicle 100 according to the present invention is executed by the fuel cell control unit 14 without changing the vehicle control unit 30 of the vehicle 100, which can significantly reduce the coordination difficulty between the vehicle control unit 30 and the fuel cell control unit 14 and simplify the implementation of the control method.

[0046] The foregoing explanation of the embodiments only describes the present invention within the framework of the examples. Of course, as long as it is technically meaningful, the various features of the embodiments can be freely combined with each other without departing from the framework of the present invention.

[0047] For those skilled in the art, other advantages and alternative embodiments of the present invention are obvious. Therefore, the present invention in its broader sense is not limited to the specific details, representative structures, and exemplary embodiments shown and described. On the contrary, those skilled in the art can make various modifications and substitutions without departing from the basic spirit and scope of the present invention.

Claims

1. A control method for a fuel cell system (10) of a vehicle (100), characterized in that, the control method at least includes the following steps: S1: Obtain the required power of the vehicle (100) for the fuel cell system (10); S2: When the required power is zero, obtain the state of charge and the battery temperature of the power battery (20) of the vehicle (100); S3: Control the state of the fuel cell system (10) according to the state of charge and the battery temperature, wherein when the state of charge exceeds a preset first state of charge threshold, the fuel cell system (10) enters a zero-power output mode, and when the state of charge is lower than the first state of charge threshold and the battery temperature is lower than a preset temperature threshold, the fuel cell system (10) is shut down.

2. The control method according to claim 1, characterized in that, when the idle state of the vehicle (100) lasts for more than a preset first time threshold, the required power is zero; and / or when the state of charge of the power battery (20) exceeds a preset second state of charge threshold, the required power is zero; and / or when the vehicle (100) is traveling in a pure electric mode powered solely by the power battery (20), the required power is zero.

3. The control method according to claim 1 or 2, characterized in that, in step S3, when the fuel cell system (10) remains in the zero-power output mode for more than a second time threshold, exit the zero-power output mode and shut down the fuel cell system (10).

4. The control method according to any one of the foregoing claims, characterized in that, in step S2, when the required power is not zero, the fuel cell system (10) operates normally.

5. The control method according to any one of the foregoing claims, characterized in that, in step S3, when the state of charge is lower than the first state of charge threshold and the battery temperature is higher than the temperature threshold, recalculate the required power according to the state of charge and make the fuel cell system (10) operate normally to charge the power battery (20).

6. The control method according to any one of the foregoing claims, characterized in that, in the zero-power output mode, the power battery (20) supplies electric energy to the fuel cell system (10) to at least drive the hydrogen circulation pump of the fuel cell system (10) to work and continuously consume the remaining oxygen in the fuel cell stack (11) of the fuel cell system (10), wherein the output power of the fuel cell system (10) is zero.

7. A computer program product, which includes a computer program, wherein, when the computer program is executed by one or more than one processor, the processor can execute the control method according to any one of claims 1-6.

8. A fuel cell control unit (14) for a fuel cell system (10) of a vehicle (100), characterized in that, The fuel cell control unit (14) is configured to be communicatively connected to the vehicle control unit (30) of the vehicle (100) and the battery management system (22) for the power battery (20) of the vehicle (100), and execute the control method according to any one of claims 1 to 6 by using the computer program product according to claim 7.

9. A vehicle (100), characterized in that the vehicle (100) at least includes: - A fuel cell system (10), the fuel cell system at least having a fuel cell stack (11), an air supply subsystem (12), a hydrogen supply subsystem (13), and a fuel cell control unit (14) according to claim 8; - A power battery (20), the power battery is electrically connected to the fuel cell system (10) through a DCDC converter (21) and has a battery management system (22), the battery management system is configured to be suitable for detecting the charge level and battery temperature of the power battery (20); - A vehicle control unit (30), the vehicle control unit is configured to be suitable for outputting the required power of the vehicle (100) for the fuel cell system (10), wherein the fuel cell control unit (14) is communicatively connected to the battery management system (22) and the vehicle control unit (30) respectively.

10. The vehicle (100) according to claim 9, characterized in that the vehicle control unit (30) judges the driving state of the vehicle (100) according to the wheel speed detected by the wheel speed sensor, and determines the required power based on the driving state.

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