Working condition control method and device of fuel cell system and electronic equipment

Abstract

The invention relates to the technical field of batteries, and discloses a working condition control method and device of a fuel cell system and electronic equipment, and the method comprises the following steps: determining whether the system power of the fuel cell system meets the whole vehicle power limit or not; responding to the condition that the system power meets the whole vehicle power limit, and determining whether the voltage of the fuel cell stack meets the system voltage constraint or not; in response to the condition that the voltage of the fuel cell stack meets the system voltage constraint, determining whether the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval; and in response to the situation that the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval, controlling the humidity control device to maintain the humidification operation on the fuel cell stack, so that the real-time working condition of the fuel cell is maintained in a flooding state. Therefore, the method can reduce the average monolithic voltage, reduce the output power of the fuel cell stack and prolong the service life of the stack.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular, to a method for controlling the operating conditions of a fuel cell system, a device for controlling the operating conditions of a fuel cell system, an electronic device, and a computer-readable storage medium. Background Art

[0002] In order to enable a fuel cell to meet the power demand on a vehicle, the number of single cells can be increased, or a multi-stack series connection method can be adopted to meet the vehicle's power demand. The idle power of a high-power fuel cell system is relatively high. When the fuel cell charges the power battery, a relatively high net power will increase the charging speed of the power battery, which is likely to cause overcharging of the power battery. The idle condition of a high-power fuel cell system is characterized by high voltage, low water production, and relatively large gas leakage. Among them, a voltage exceeding 0.8V will cause the platinum in the battery catalyst layer to dissolve. When the voltage exceeds 1.2V, the corrosion attenuation rate of the diffusion layer carbon increases significantly, and the corrosion of the carbon carrier in the catalyst layer becomes more serious. The above situations will all exacerbate the stack attenuation and affect the service life of the fuel cell system.

[0003] Currently, the idle scheme adopted for low-rated power fuel cell systems in China is the system zero-power scheme: by increasing the speed of the air compressor, increasing the power consumption of the auxiliary system, reducing the oxygen content, and reducing the output power of the stack, ultimately achieving system zero-power. To extend the service life of the fuel cell and reduce its attenuation, the above scheme can only be used for a short time. However, in a high-rated power fuel cell system, under its idle condition, the average single-cell voltage will be even higher, and compared with a low-rated power fuel cell system, the impact on the stack is greater. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems in the related art to some extent. For this reason, the first object of the present invention is to propose a method for controlling the operating conditions of a fuel cell system. By operating the water pump and the water spraying device under the idle condition, the air circulation loop presents a high-humidity state, and liquid water enters the fuel cell stack. A flooding phenomenon occurs inside the fuel cell stack, reducing the average single-cell voltage at the same current density, reducing the output power of the fuel cell stack, thereby causing the output power of the fuel cell system to decrease to the upper limit of the vehicle power requirement. At the same time, the average single-cell voltage will also be reduced to 0.85V, reducing the platinum corrosion and carbon corrosion caused by high voltage, reducing the stack attenuation, extending the stack life, and meeting the vehicle requirements.

[0005] The second object of the present invention is to propose a device for controlling the operating conditions of a fuel cell system.

[0006] The third object of the present invention is to propose an electronic device.

[0007] The fourth object of the present invention is to provide a computer-readable storage medium.

[0008] To achieve the above object, an embodiment of the first aspect of the present invention provides a method for controlling the operating condition of a fuel cell system, including: when the fuel cell system is operating, in response to receiving an idle condition demand, controlling the current density of the fuel cell stack to a first preset current density, and controlling a humidity control device to perform a humidifying operation on the fuel cell stack so that the real-time operating condition of the fuel cell reaches a flooded state; determining whether the system power of the fuel cell system meets the vehicle power limit; in response to the system power meeting the vehicle power limit, determining whether the voltage of the fuel cell stack meets the system voltage constraint; in response to the voltage of the fuel cell stack meeting the system voltage constraint, determining whether the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval; in response to the system power of the fuel cell system and the voltage of the fuel cell stack reaching a stable state within a preset time interval, controlling the humidity control device to maintain the humidifying operation on the fuel cell stack so that the real-time operating condition of the fuel cell maintains a flooded state.

[0009] In addition, the method for controlling the operating condition of the fuel cell system according to the above embodiment of the present invention may further have the following additional technical features:

[0010] According to some embodiments of the present invention, controlling the humidity control device to perform a humidifying operation on the fuel cell stack so that the real-time operating condition of the fuel cell reaches a flooded state includes: controlling the bypass valve to close to cut off the introduction of a dry air source; controlling the water pump to start so that the water pump extracts stored water from a water source and conveys it to a spraying device; controlling the spraying device to start so that the spraying device sprays the stored water onto the fuel cell stack to perform a humidifying operation on the fuel cell stack; determining whether the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack reaches a first preset range; in response to the impedance phase angle of the electrochemical impedance spectrum reaching the first preset range, determining that the real-time operating condition of the fuel cell reaches a flooded state.

[0011] According to some embodiments of the present invention, the above method further includes: in response to the impedance phase angle of the electrochemical impedance spectrum reaching a second preset range, determining that the real-time operating condition of the fuel cell reaches a normal state.

[0012] According to some embodiments of the present invention, the above method further includes: in response to the impedance phase angle of the electrochemical impedance spectrum reaching a third preset range, determining that the real-time operating condition of the fuel cell reaches a membrane dry state.

[0013] According to some embodiments of the present invention, the first preset range is greater than the second preset range, and the second preset range is greater than the third preset range.

[0014] According to some embodiments of the present invention, the above method further includes: in response to receiving a demand for releasing the idle condition, controlling the current density of the fuel cell stack to a second preset current density, and controlling the humidity control device to perform a dehumidification operation on the fuel cell stack, so that the real-time condition of the fuel cell is out of the flooded state.

[0015] According to some embodiments of the present invention, controlling the humidity control device to perform a dehumidification operation on the fuel cell stack so that the real-time condition of the fuel cell is out of the flooded state includes: controlling to close the water pump and the water spraying device, controlling to open the bypass valve to perform a dehumidification operation on the fuel cell stack; determining whether the impedance phase angle of the electrochemical impedance spectrum is within a first preset range; in response to the impedance phase angle of the electrochemical impedance spectrum being within the first preset range, controlling to increase the rotational speed of the air compressor; in response to the impedance phase angle of the electrochemical impedance spectrum not being within the first preset range, controlling to close the bypass valve, and determining whether the impedance phase angle of the electrochemical impedance spectrum is within a third preset range; in response to the impedance phase angle of the electrochemical impedance spectrum being within the third preset range, controlling to open the water pump and the water spraying device until the impedance phase angle of the electrochemical impedance spectrum is within a second preset range.

[0016] The method for controlling the condition of a fuel cell system according to an embodiment of the present invention includes: when the fuel cell system is operating, in response to receiving a demand for the idle condition, controlling the current density of the fuel cell stack to a first preset current density, and controlling the humidity control device to perform a humidification operation on the fuel cell stack so that the real-time condition of the fuel cell reaches the flooded state; determining whether the system power of the fuel cell system meets the vehicle power limit; in response to the system power meeting the vehicle power limit, determining whether the voltage of the fuel cell stack meets the system voltage constraint; in response to the voltage of the fuel cell stack meeting the system voltage constraint, determining whether the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval; in response to the system power of the fuel cell system and the voltage of the fuel cell stack reaching a stable state within the preset time interval, controlling the humidity control device to maintain the humidification operation on the fuel cell stack so that the real-time condition of the fuel cell maintains the flooded state. Thus, in this method, under the idle condition, the water pump and the water spraying device work, the air circulation loop presents a high humidity state, and liquid water enters the fuel cell stack. There is a flooded phenomenon inside the fuel cell stack, reducing the average single-cell voltage at the same current density, reducing the output power of the fuel cell stack, and thus causing the output power of the fuel cell system to be reduced to the upper limit of the vehicle power requirement. At the same time, the average single-cell voltage will also be reduced to 0.85 V, reducing the platinum corrosion and carbon corrosion caused by high voltage, reducing the degradation of the fuel cell stack, and extending the life of the fuel cell stack to meet the vehicle requirements.

[0017] The second objective of the present invention is to provide a working condition control device for a fuel cell system. When in the idle condition, the water pump and the water spraying device operate, the air circulation loop is in a high humidity state, and liquid water enters the fuel cell stack. Waterlogging occurs inside the fuel cell stack, reducing the average single-cell voltage at the same current density and the output power of the fuel cell stack, thereby causing the output power of the fuel cell system to decrease to the upper limit of the vehicle power requirement. At the same time, the average single-cell voltage also decreases to 0.85 V, reducing platinum corrosion and carbon corrosion caused by high voltage, reducing the degradation of the fuel cell stack, and extending the life of the fuel cell stack to meet the vehicle requirements.

[0018] To achieve the above objective, an embodiment of the second aspect of the present invention provides a working condition control device for a fuel cell system, including: a control module configured to, when the fuel cell system is operating, in response to receiving an idle condition demand, control the current density of the fuel cell stack to a first preset current density, and control the humidity control device to humidify the fuel cell stack so that the real-time working condition of the fuel cell reaches a waterlogging state; a determination module configured to determine whether the system power of the fuel cell system meets the vehicle power limit; a first response module configured to, in response to the system power meeting the vehicle power limit, determine whether the voltage of the fuel cell stack meets the system voltage constraint; a second response module configured to, in response to the voltage of the fuel cell stack meeting the system voltage constraint, determine whether the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval; and a third response module configured to, in response to the system power of the fuel cell system and the voltage of the fuel cell stack reaching a stable state within a preset time interval, control the humidity control device to continue humidifying the fuel cell stack so that the real-time working condition of the fuel cell maintains the waterlogging state.

[0019] The operating condition control device of a fuel cell system according to an embodiment of the present invention includes: a control module configured to, when the fuel cell system is operating, in response to receiving an idle condition demand, control the current density of the fuel cell stack to a first preset current density, and control a humidity control device to perform a humidifying operation on the fuel cell stack so that the real-time operating condition of the fuel cell reaches a flooded state; a determination module configured to determine whether the system power of the fuel cell system meets the vehicle power limit; a first response module configured to, in response to the system power meeting the vehicle power limit, determine whether the voltage of the fuel cell stack meets the system voltage constraint; a second response module configured to, in response to the voltage of the fuel cell stack meeting the system voltage constraint, determine whether the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval; a third response module configured to, in response to the system power of the fuel cell system and the voltage of the fuel cell stack reaching a stable state within a preset time interval, control the humidity control device to maintain the humidifying operation on the fuel cell stack so that the real-time operating condition of the fuel cell maintains the flooded state. Thus, in this device, under the idle condition, the water pump and the water spraying device work, the air circulation loop presents a high humidity state, and liquid water enters the fuel cell stack. A flooding phenomenon appears inside the fuel cell stack, reducing the average single-cell voltage at the same current density and reducing the output power of the fuel cell stack, thereby causing the output power of the fuel cell system to decrease to the upper limit of the vehicle power requirement. At the same time, the average single-cell voltage will also decrease to 0.85V, reducing the platinum corrosion and carbon corrosion caused by high voltage, reducing the stack degradation, extending the stack life, and meeting the vehicle requirements.

[0020] To achieve the above object, an embodiment of the third aspect of the present invention proposes an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the above-mentioned operating condition control method of the fuel cell system.

[0021] The electronic device according to an embodiment of the present invention, by executing the above-mentioned operating condition control method of the fuel cell system, under the idle condition, the water pump and the water spraying device work, the air circulation loop presents a high humidity state, and liquid water enters the fuel cell stack. A flooding phenomenon appears inside the fuel cell stack, reducing the average single-cell voltage at the same current density and reducing the output power of the fuel cell stack, thereby causing the output power of the fuel cell system to decrease to the upper limit of the vehicle power requirement. At the same time, the average single-cell voltage will also decrease to 0.85V, reducing the platinum corrosion and carbon corrosion caused by high voltage, reducing the stack degradation, extending the stack life, and meeting the vehicle requirements.

[0022] To achieve the above object, an embodiment of the fourth aspect of the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to implement the above-described operating condition control method of the fuel cell system.

[0023] According to the computer-readable storage medium of the embodiment of the present invention, by executing the above-described operating condition control method of the fuel cell system, when in the idle condition, the water pump and the water spraying device operate, the air circulation loop presents a high humidity state, and liquid water enters the fuel cell stack. Water flooding occurs inside the fuel cell stack, reducing the average single cell voltage at the same current density, reducing the output power of the fuel cell stack, thereby causing the output power of the fuel cell system to drop to the upper limit of the vehicle power requirement. At the same time, the average single cell voltage also drops to 0.85 V, reducing platinum corrosion and carbon corrosion caused by high voltage, reducing stack degradation, and extending the stack life to meet the vehicle requirements.

[0024] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A block diagram of a fuel cell system according to some embodiments of the present invention;

[0026] Figure 2 An architecture diagram of signal and control transmission of a fuel cell stack according to some embodiments of the present invention;

[0027] Figure 3 A flowchart of an operating condition control method of a fuel cell system according to some embodiments of the present invention;

[0028] Figure 4 A flowchart of an operating condition control method of a fuel cell system according to some other embodiments of the present invention;

[0029] Figure 5 A flowchart of an operating condition control method of a fuel cell system according to still some other embodiments of the present invention;

[0030] Figure 6 A block diagram of an operating condition control device of a fuel cell system according to some embodiments of the present invention;

[0031] Figure 7 A block diagram of an electronic device according to some embodiments of the present invention.

[0032] Description of the Reference Numerals:

[0033] 100 - Fuel cell system, 67 - Fuel cell stack, 6 - First fuel cell stack, 7 - Second fuel cell stack, 20 - Water pump, 21 - Water spraying device, 14 - Bypass valve, 15 - Humidifying device, 13 - Three - way valve, 9 - Hydrogen circulation pump, 8 - Drain valve, 2 - Shut - off valve, 3 - Proportioning valve, 45 - Ejector assembly, 4 - First ejector, 5 - Second ejector, 11 - Air compressor, 12 - Inter - cooler, 17 - Shut - off valve, 18 - Water separator, 16 - Back - pressure valve, 19 - Water source, 10 - Air source, 1 - Hydrogen source, 32 - DC / DC module, 33 - Electrochemical impedance spectroscopy analysis module, and 34 - Operating condition control module. Detailed implementation manners

[0034] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to specific embodiments and the accompanying drawings.

[0035] It should be noted that unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present invention should have the ordinary meanings understood by those of ordinary skill in the field to which the present invention belongs. The "first", "second", and similar terms used in the embodiments of the present invention do not indicate any order, quantity, or importance, but are only used to distinguish different components. The terms such as "including" or "comprising" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left", "right", etc. are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0036] As mentioned in the background technology section, in order to make the fuel cell meet the power requirements on the car, the number of single cells can be increased, or multiple stacks can be connected in series to meet the power requirements of the whole vehicle. The idle power of the high-power fuel cell system is relatively high. When the fuel cell charges the power battery, the higher net power will increase the charging speed of the power battery, which is easy to cause the power battery to overcharge. The idle condition of the high-power fuel cell system has the characteristics of high voltage, low water production, and large gas permeation. Among them, the voltage exceeding 0.8V will cause the platinum of the battery catalyst layer to dissolve. When the voltage exceeds 1.2V, the corrosion decay rate of the diffusion layer carbon increases significantly, and the corrosion of the catalyst layer carbon carrier increases. The above situations will aggravate the decay of the stack and affect the service life of the fuel cell system. Therefore, the average single-chip voltage is generally set not to exceed 0.85V. The fuel cell charges the power battery in the idle state, so the vehicle end will require the fuel cell idle power demand to have an upper limit to prevent the charging speed from being too fast, causing the power battery to be fully charged in a short time, thereby causing the power battery to be overcharged and cause spontaneous combustion and explosion.

[0037] The higher the rated power of the fuel cell system, the greater the system power at the rated idle speed. Therefore, for high rated power fuel cell systems (greater than 300kW), different manufacturers have different standards for idle speed conditions. 1. The idle speed condition is set at a system power of 0kw, and the average single-chip voltage is close to 1V. 2. The idle speed condition is set at a current density of 0.1A / cm 2 3. The idle condition is set when the average single-chip voltage is less than 0.85V and the system power is less than the set power.

[0038] For the first case, the high voltage generated will accelerate the dissolution of platinum and the corrosion of carbon, aggravating the attenuation of the battery stack, which is not conducive to long-term use. For the second case, the idle condition is set at a current density of 0.1A / cm 2 In low-rated power fuel cell systems, the average cell voltage is less than 0.85 V, which can reduce the attenuation of the fuel cell. In high-rated power fuel cell systems, the current density is 0.1 A / cm 2 Nearby, its single-chip average voltage will exceed 0.85V, accelerating the dissolution of platinum in the catalyst layer, affecting the catalytic decomposition of hydrogen, and accelerating the attenuation of the fuel cell. For the third case mentioned above, it is more applicable in low-rated power fuel cells, while in high-rated power fuel cell systems, if the average single-chip voltage is lower than 0.85V, the fuel cell system power will be higher, exceeding the upper limit of the required power at idle speed on the vehicle side, and may cause overcharging of the power battery. In summary, the idle power of a high-rated power fuel cell system is constrained by the average single-chip voltage and the idle power demand of the vehicle side.

[0039] In the process of implementing the present invention, the applicant found that currently, the idling scheme adopted for low-rated power fuel cell systems in China is the system zero-power scheme: by increasing the rotational speed of the air compressor, increasing the power consumption of the auxiliary system, reducing the oxygen content, and reducing the output power of the fuel cell stack, ultimately achieving system zero-power. To extend the service life of the fuel cell and reduce the attenuation of the fuel cell, the above scheme can only be used for a short time. However, in a high-rated power fuel cell system, during its idling condition, the average single-cell voltage will be higher, and it has a greater impact on the fuel cell stack compared to a low-rated power fuel cell system. Therefore, the above scheme is not applicable to high-rated power fuel cells.

[0040] Thus, the present invention can operate the water pump and the water spraying device under the idling condition, making the air circulation loop in a high-humidity state and accompanied by liquid water entering the fuel cell stack. There is a flooding phenomenon inside the fuel cell stack, reducing the average single-cell voltage at the same current density, reducing the output power of the fuel cell stack, thereby causing the output power of the fuel cell system to be reduced to the upper limit of the vehicle power requirement. At the same time, the average single-cell voltage will also be reduced to 0.85 V, reducing the platinum corrosion and carbon corrosion caused by high voltage, reducing the stack attenuation, extending the stack life, and meeting the vehicle requirements.

[0041] The following describes a method for controlling the working conditions of a fuel cell system, a device for controlling the working conditions of a fuel cell system, an electronic device, and a storage medium proposed in an embodiment of the present invention with reference to the accompanying drawings.

[0042] Reference Figure 1 , is a block schematic diagram of a fuel cell system according to some embodiments of the present invention.

[0043] The fuel cell system 100 of the present invention includes a fuel cell stack 67 and a humidity control device.

[0044] The fuel cell stack 67 includes a first fuel cell stack 6 and a second fuel cell stack 7. The humidity control device includes a water circuit component and a gas circuit component.

[0045] The water circuit component includes a water pump 20 and a water spraying device 21. Among them, the water spraying device 21 can be an atomizing water sprayer, and the water spraying device 21 is used to spray water mist on the fuel cell stack 67 to humidify the fuel cell stack 67. The water inlet of the water pump 20 is connected to a water source 19, where the water source 19 can be used to provide water. For example, the water source 19 can be a water tank or a small river, etc. The water outlet of the water pump 20 is connected to the water inlet of the water spraying device 21, and the water spraying ports of the water spraying device 21 are respectively connected to the first fuel cell stack 6 and the second fuel cell stack 7.

[0046] The gas circuit component includes an air circulation loop, a bypass valve 14, and a humidifying device 15.

[0047] The air circulation loop includes a three-way valve 13. The inlet of the three-way valve 13 is connected to the air source 10 through the air circulation loop. Here, the air source 10 can be used to supply air. For example, the air source 10 can be the ambient atmosphere. The first outlet of the three-way valve 13 is connected to the inlet of the bypass valve 14. The outlet of the bypass valve 14 is respectively connected to the first fuel cell stack 6 and the second fuel cell stack 7. The second outlet of the three-way valve 13 is connected to the inlet of the humidifying device 15. Here, the humidifying device 15 is used to humidify the fuel cell stacks 6 and 7. For example, the humidifying device 15 can be a humidifier. The outlet of the humidifying device 15 is connected to the fuel cell stacks 6 and 7.

[0048] The fuel cell system 100 further includes a hydrogen circulation loop.

[0049] The hydrogen circulation loop includes a hydrogen circulation component, a hydrogen circulation pump 9, and a drain valve 8. Here, the hydrogen circulation component includes a shut-off valve 2, a proportional valve 3, and an ejector assembly 45. The ejector assembly 45 includes a first ejector 4 and a second ejector 5. The hydrogen source 1 is connected to the hydrogen inlet of the fuel cell stacks 6 and 7 through the hydrogen circulation component. Here, the hydrogen source 1 is used to supply hydrogen. For example, the hydrogen can be a gas cylinder. The water-vapor outlet of the fuel cell stacks 6 and 7 is connected to the water-vapor inlet of the drain valve 8. The outlet of the drain valve 8 is connected to the inlet of the hydrogen circulation pump 9. The outlet of the hydrogen circulation pump 9 is respectively connected to the first ejector 4 and the second ejector 5. The water outlet of the drain valve 8 is connected to the water source 19. The outlet of the hydrogen source 1 is successively connected to the inlets of the first ejector 4 and the second ejector 5 through the shut-off valve 2 and the proportional valve 3. The outlets of the first ejector 4 and the second ejector 5 are respectively connected to the hydrogen inlets of the first fuel cell stack 6 and the second fuel cell stack 7.

[0050] The air circulation loop further includes an air compressor 11, an intercooler 12, a shut-off valve 17, and a water separator 18.

[0051] The inlet of the air compressor 11 is connected to the air source 10. The outlet of the air compressor 11 is connected to the inlet of the intercooler 12. The outlet of the intercooler 12 is connected to the inlet of the three-way valve 13. The third outlet of the three-way valve 13 is connected to the water-vapor inlet of the water separator 18 through the shut-off valve 17. The outlet of the water separator 18 is connected to the air source 10. The water outlet of the water separator 18 is connected to the water source 19.

[0052] The humidity control device further includes a back pressure valve 16. The inlet of the back pressure valve 16 is connected to the humidifying device 15. The outlet of the back pressure valve 16 is connected to the water-vapor inlet of the water separator 18.

[0053] The fuel cell system 100 further includes a DC / DC module 32, which is configured to record the voltage signal, current signal, and stack parameters of the fuel cell stack 67. The stack parameters may be rated power, peak power, current density, voltage efficiency, operating life, maximum operating temperature, operating ambient temperature, and thermal stability, etc. The DC / DC module 32 then sends the voltage signal, current signal, and stack parameters of the fuel cell stack 67 to the electrochemical impedance spectroscopy analysis module 33.

[0054] The fuel cell system 100 further includes an electrochemical impedance spectroscopy analysis module 33, which is configured to determine the electrochemical impedance spectrum of the fuel cell stack 67 based on the voltage signal, current signal, and stack parameters of the fuel cell stack 67 sent by the DC / DC module 32, and then send the electrochemical impedance spectrum to the operating condition control module 34.

[0055] The fuel cell system 100 further includes an operating condition control module 34, which is configured to determine the real-time operating condition of the fuel cell stack 67 based on the electrochemical impedance spectrum sent by the electrochemical impedance spectroscopy analysis module 33, and control the humidity control device according to the real-time operating condition so that the real-time operating condition of the fuel cell stack 67 meets the target operating condition requirements.

[0056] In some embodiments, referring to Figure 2 , which is a schematic diagram of the signal and control transmission architecture of a fuel cell stack according to some embodiments of the present invention, the voltage signal, current signal, and stack parameters output by the first fuel cell stack 6 and the second fuel cell stack 7 are transmitted to the DC / DC module 32. The DC / DC module 32 transmits the voltage and current signals to the operating condition control module 34, and the DC / DC module 32 transmits the stack parameters to the electrochemical impedance spectroscopy analysis module 33. The electrochemical impedance spectroscopy analysis module 33 processes the stack parameters, and the operating condition control module 34 determines the humidity status of the first fuel cell stack 6 and the second fuel cell stack 7 (mainly determines whether the first fuel cell stack 6 and the second fuel cell stack 7 are flooded and membrane dried). When the vehicle demand is transmitted to the operating condition control module 34, the operating condition control module 34 processes the signal and transmits it to the DC / DC module 32. Finally, the DC / DC module 32 controls the first fuel cell stack 6 and the second fuel cell stack 7 to perform power output.

[0057] Among them, the first fuel cell stack 6 is used to convert the chemical energy of hydrogen and oxygen into electrical energy; the second fuel cell stack 7 is used to convert the chemical energy of hydrogen and oxygen into electrical energy; the water pump 20 is used to pump out the stored water in the water source 19; the water spraying device 21 is used to spray water mist on the first fuel cell stack 6 and the second fuel cell stack 7 to humidify the first fuel cell stack 6 and the second fuel cell stack 7; the bypass valve 14 is used to adjust the flow rate of the coolant to ensure uniform temperature of the first fuel cell stack 6 and the second fuel cell stack 7; the humidifying device 15 is used to humidify the first fuel cell stack 6 and the second fuel cell stack 7; the three-way valve 13 is used to control the flow direction of the coolant; the hydrogen circulation pump 9 is used to circulate the unreacted hydrogen at the outlets of the first fuel cell stack 6 and the second fuel cell stack 7 to the inlets to improve the hydrogen utilization rate, and at the same time circulate the water vapor to the inlets to play a humidifying role; the drain valve 8 is used to drain the water in the first fuel cell stack 6 and the second fuel cell stack 7; the shut-off valve 2 is used to control the on-off of hydrogen; the proportional valve 3 is used to adjust the hydrogen pressure entering the first fuel cell stack 6 and the second fuel cell stack 7 to adapt to different operating conditions; the first ejector 4 is used to suck in and discharge the unreacted hydrogen and water vapor; the second ejector 5 is used to suck in and discharge the unreacted hydrogen and water vapor; the air compressor 11 is used to provide high-pressure air for the first fuel cell stack 6 and the second fuel cell stack 7 to ensure sufficient oxygen supply; the intercooler 12 is used to lower the high-temperature air at the outlet of the air compressor 11; the shut-off valve 17 is used to control the on-off of air; the water separator 18 is used to separate the moisture in the air to prevent moisture from entering the first fuel cell stack 6 and the second fuel cell stack 7; the back pressure valve 16 is used to maintain the pressure stability of the stored water or gas in the fuel cell system 100 to prevent pressure fluctuations; the water source 19 is used to provide stored water; the air source 10 is used to provide air; the hydrogen source 1 is used to provide hydrogen.

[0058] Thus, the fuel cell system 100 of the present invention includes a first fuel cell stack 6, a second fuel cell stack 7, a water pump 20, a water spraying device 21, a bypass valve 14, a humidifying device 15, a three-way valve 13, a hydrogen circulation pump 9, a drain valve 8, a shut-off valve 2, a proportional valve 3, a first ejector 4, a second ejector 5, an air compressor 11, an intercooler 12, a shut-off valve 2, a water separator 18, a back pressure valve 16, a water source 19, an air source 10, a hydrogen source 1, a DC / DC module 32, an electrochemical impedance spectroscopy analysis module 33, and a working condition control module 34.

[0059] Hydrogen passes through the hydrogen source 1, via the shut-off valve 2 and the proportional valve 3, and simultaneously passes through the first ejector 4 and the second ejector 5, and enters the first fuel cell stack 6 and the second fuel cell stack 7 respectively. At this time, the mixture discharged from the first fuel cell stack 6 and the second fuel cell stack 7 contains hydrogen, nitrogen, water vapor and liquid water. The mixture discharged from the stack passes through the drain valve 8 to drain the liquid water into the water source 19, and the remaining mixed gas re-enters the first ejector 4 and the second ejector 5 through the hydrogen circulation pump 9.

[0060] Air passes through the air source 10, passes through the air compressor 11, and enters the intercooler 12 and converges into the three-way valve 13 respectively. One path of the three-way valve 13 can pass through the three-way valve 13 or the humidifying device 15 and enter the first fuel cell stack 6 and the second fuel cell stack 7; the other path of the three-way valve 13 passes through the shut-off valve 17 and the water separator 18, and the gas part is directly discharged into the air source 10. The gas discharged from the first fuel cell stack 6 and the second fuel cell stack 7 passes through the humidifying device 15, the back pressure valve 16, and the water separator 18, and is finally discharged to the air source 10. Among them, the liquid water part enters the water source 19.

[0061] The stored water in the water source 19 can, according to the working conditions, enter the first fuel cell stack 6 and the second fuel cell stack 7 together with the air through the water pump 20 and the water spraying device 21, which can meet the vehicle power requirements under the idle condition, and can also greatly reduce the attenuation of the fuel cell and extend the life of the fuel cell system 100.

[0062] Reference Figure 3 , is a flowchart of the working condition control method of the fuel cell system according to some embodiments of the present invention.

[0063] As Figure 3 shown, the working condition control method of the fuel cell system according to the embodiments of the present invention may include the following steps:

[0064] S301, when the fuel cell system is running, in response to receiving the idle condition demand, control the current density of the fuel cell stack to the first preset current density, and control the humidity control device to humidify the fuel cell stack so that the real-time working condition of the fuel cell reaches the flooded state. Among them, the first preset current density can be set according to the actual situation.

[0065] Specifically, when the fuel cell system is operating, the vehicle controller sends an idle condition demand to the operating condition control module. When the operating condition control module receives the idle condition demand sent by the vehicle controller, since when the vehicle needs the fuel cell to output greater power, it is necessary to increase the current density to meet the power output. At this time, the operating condition control module will change the current density through a series of operations to adjust the output power of the fuel cell, that is, the operating condition control module controls the DC / DC module to adjust the current density of the fuel cell stack to the first preset current density. In order to make the interior of the fuel cell stack contain liquid water and reduce the output power of the fuel cell stack, the operating condition control module controls the humidity control device to humidify the fuel cell stack so that the real-time operating condition of the fuel cell reaches the flooded state. Among them, the flooded state refers to a fault state in which excessive liquid water accumulates inside the fuel cell stack, causing the gas diffusion layer and the catalyst layer to be covered by liquid water, thereby hindering the transmission and diffusion of reaction gases (such as hydrogen and oxygen), and ultimately affecting the performance of the fuel cell stack.

[0066] S302, determine whether the system power of the fuel cell system meets the vehicle power limit.

[0067] Specifically, after the real-time operating condition of the fuel cell reaches the flooded state, determine whether the system power of the fuel cell system meets the vehicle power limit. When the system power of the fuel cell system meets the vehicle power limit, it can indicate that the system power of the fuel cell system has reached the requirement; when the system power of the fuel cell system does not meet the vehicle power limit, it can indicate that the operating condition control module still needs to adjust the humidity control device to humidify the fuel cell stack (that is, adjust the rotation speed of the water pump and the lift of the spraying device) so that the system power of the fuel cell system reaches the requirement.

[0068] S303, in response to the system power meeting the vehicle power limit, determine whether the voltage of the fuel cell stack meets the system voltage constraint.

[0069] Specifically, when the system power of the fuel cell system meets the vehicle power limit, determine again whether the voltage of the fuel cell stack meets the system voltage constraint. When the voltage of the fuel cell stack meets the system voltage constraint, it can indicate that the voltage of the fuel cell stack meets the requirement; when the voltage of the fuel cell stack does not meet the system voltage constraint, it can indicate that the operating condition control module still needs to adjust the humidity control device to humidify the fuel cell stack (that is, adjust the rotation speed of the water pump and the lift of the spraying device) so that the voltage of the fuel cell stack meets the system voltage constraint.

[0070] S304, in response to the voltage of the fuel cell stack meeting the system voltage constraint, determine whether the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval.

[0071] Specifically, when the voltage of the fuel cell stack satisfies the system voltage constraint, it is further determined whether the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval. When the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within the preset time interval, it can indicate that the system power of the fuel cell system and the voltage of the fuel cell stack will not change within a certain period of time, and the system power of the fuel cell system and the voltage of the fuel cell stack meet the requirements of the fuel cell system, maintaining the humidifying operation of the humidity control device on the fuel cell stack (i.e., maintaining the rotation speed of the water pump and the lift of the water spraying device); when the system power of the fuel cell system and the voltage of the fuel cell stack do not reach a stable state within the preset time interval, it can indicate that the system power of the fuel cell system and the voltage of the fuel cell stack will still change (increase or decrease), and the system power of the fuel cell system and the voltage of the fuel cell stack are unstable, which will affect the service life of the fuel cell. At this time, the humidifying operation of the humidity control device on the fuel cell stack is adjusted (i.e., adjusting the rotation speed of the water pump and the lift of the water spraying device).

[0072] S305, in response to the system power of the fuel cell system and the voltage of the fuel cell stack reaching a stable state within a preset time interval, control the humidity control device to maintain the humidifying operation on the fuel cell stack so that the real-time working condition of the fuel cell maintains a flooded state.

[0073] Specifically, when the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval, in order to maintain the humidity of the fuel cell stack, the working condition control module controls the humidity control device to maintain the humidifying operation on the fuel cell stack so that the real-time working condition of the fuel cell maintains a flooded state, reducing the attenuation of the fuel cell stack and extending the service life of the fuel cell system. When the system power of the fuel cell system and the voltage of the fuel cell stack do not reach a stable state within the preset time interval, the working condition control module continues to control the humidity control device to perform the humidifying operation on the fuel cell stack so that the real-time working condition of the fuel cell reaches a flooded state.

[0074] In some embodiments, after the real-time working condition of the fuel cell reaches a flooded state, it is determined whether the voltage of the fuel cell stack satisfies the system voltage constraint. When the voltage of the fuel cell stack satisfies the system voltage constraint, it is further determined whether the system power of the fuel cell system satisfies the vehicle power limit.

[0075] In some embodiments of the present invention, controlling a humidity control device to perform a humidifying operation on a fuel cell stack so that the real-time operating condition of the fuel cell reaches a flooded state includes: controlling to close a bypass valve to cut off the introduction of a dry air source; controlling to turn on a water pump so that the water pump extracts stored water from a water source and conveys it to a water spraying device; controlling to turn on the water spraying device so that the water spraying device sprays the stored water onto the fuel cell stack to perform a humidifying operation on the fuel cell stack; determining whether the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack reaches a first preset range; in response to the impedance phase angle of the electrochemical impedance spectrum reaching the first preset range, determining that the real-time operating condition of the fuel cell reaches a flooded state. Wherein, the first preset range can be set according to actual situations.

[0076] Specifically, in order to make the inside of the fuel cell stack contain liquid water and reduce the output power of the fuel cell stack, since the dry air source can reduce the liquid water inside the fuel cell stack, the operating condition control module needs to control to close the bypass valve to cut off the introduction of the dry air source, control the humidifying device to always remain open, control to turn on the water pump so that the water pump extracts stored water from the water source and conveys it to the water spraying device, so that the water spraying device sprays the stored water onto the fuel cell stack to make the incoming stack gas reach a super-humid state to perform a humidifying operation on the fuel cell stack so that the real-time operating condition of the fuel cell reaches a flooded state. At this time, the fuel cell stack decays, at this current density, the voltage value decreases, and the output power of the fuel cell stack decreases. Then, the impedance phase angle of the electrochemical impedance spectrum can be obtained through a lock-in amplifier or a spectrum analyzer. According to the impedance phase angle of the electrochemical impedance spectrum, the water content of the fuel cell stack can be judged, that is, the larger the impedance phase angle of the electrochemical impedance spectrum, the more water content in the fuel cell stack; the smaller the impedance phase angle of the electrochemical impedance spectrum, the less water content in the fuel cell stack. Comparing the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack with the first preset range, the electrochemical impedance spectrum analysis module judges whether the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack reaches the first preset range. When the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack reaches the first preset range, it can indicate that the water content in the fuel cell stack is relatively large, that is, the water content in the fuel cell stack can flood the fuel cell stack, which can make the real-time operating condition of the fuel cell reach a flooded state, reduce the average single-cell voltage at the same current density, and reduce the output power of the fuel cell stack, thereby causing the output power of the fuel cell system to be reduced to the upper limit of the vehicle power requirement. At the same time, the average single-cell voltage will also be reduced to 0.85V, reducing platinum corrosion and carbon corrosion caused by high voltage, reducing stack decay, extending the stack life, and meeting vehicle requirements.

[0077] In some embodiments of the present invention, the above method further includes: in response to the impedance phase angle of the electrochemical impedance spectrum reaching a second preset range, determining that the real-time operating condition of the fuel cell reaches a normal state. Wherein, the second preset range can be set according to actual situations.

[0078] Specifically, the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack is compared with the second preset range, and the electrochemical impedance spectrum analysis module determines whether the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack reaches the second preset range. When the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack reaches the second preset range, it can indicate that the water content of the fuel cell stack is neither too much nor too little, that is, the water content of the fuel cell stack cannot submerge the fuel cell stack, and the real-time operating condition of the fuel cell can reach a normal state.

[0079] In some embodiments of the present invention, the method further includes: in response to the impedance phase angle of the electrochemical impedance spectrum reaching a third preset range, determining that the real-time operating condition of the fuel cell reaches a membrane dry state. The third preset range can be set according to actual conditions.

[0080] The first preset range is larger than the second preset range, and the second preset range is larger than the third preset range.

[0081] Specifically, the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack is compared with the third preset range, and the electrochemical impedance spectrum analysis module determines whether the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack reaches the third preset range. When the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack reaches the third preset range, it can indicate that the water content of the fuel cell stack is low, that is, the water content of the fuel cell stack is not enough to submerge the fuel cell stack, and the real-time operating condition of the fuel cell can reach a membrane dry state, wherein the membrane dry state refers to a fault state in which the water content of the proton exchange membrane in the proton exchange membrane fuel cell is too low, resulting in a significant decrease in proton conductivity, affecting the normal operation of the battery.

[0082] In some embodiments of the present invention, the method further includes: in response to receiving a request to release the idle condition, controlling the current density of the fuel cell stack to a second preset current density, and controlling the humidity control device to perform a dehumidification operation on the fuel cell stack so that the real-time condition of the fuel cell is out of the flooded state. The second preset current density can be set according to the situation.

[0083] Specifically, the vehicle controller will send a request to release the idle condition to the operating condition control module. When the operating condition control module receives the request to release the idle condition sent by the vehicle controller, because when the vehicle requires the fuel cell to output a larger power, the current density needs to be increased to meet the power output. At this time, the operating condition control module will change the current density through a series of operations to adjust the output power of the fuel cell, that is, the operating condition control module controls the DC / DC module to adjust the current density of the fuel cell stack to a second preset current density. In order to reduce the liquid water contained in the fuel cell stack, the operating condition control module controls the humidity control device to dehumidify the fuel cell stack to reduce the humidity of the fuel cell stack and to remove the real-time operating condition of the fuel cell from the flooded state.

[0084] In some embodiments of the present invention, the humidity control device is controlled to perform a dehumidification operation on the fuel cell stack to make the real-time operating condition of the fuel cell out of the flooded state, including: controlling to close the water pump and the water spraying device, and controlling to open the bypass valve to perform a dehumidification operation on the fuel cell stack; determining whether the impedance phase angle of the electrochemical impedance spectrum is within a first preset range; in response to the impedance phase angle of the electrochemical impedance spectrum being within the first preset range, controlling to increase the speed of the air compressor; in response to the impedance phase angle of the electrochemical impedance spectrum not being within the first preset range, controlling to close the bypass valve, and determining whether the impedance phase angle of the electrochemical impedance spectrum is within a third preset range; in response to the impedance phase angle of the electrochemical impedance spectrum being within the third preset range, controlling to open the water pump and the water spraying device until the impedance phase angle of the electrochemical impedance spectrum is within the second preset range.

[0085] Specifically, in order to reduce the liquid water contained in the fuel cell stack, the operating condition control module needs to control the closing of the water pump and the water spraying device to stop the water pump from continuing to pump water and the water spraying device from continuing to spray water into the fuel cell stack, and control the opening of the bypass valve to introduce a dry air source to dry the water in the fuel cell stack for dehumidifying the fuel cell stack. The bypass valve can be equivalent to a "hair dryer". When there is more water in the fuel cell stack, the "hair dryer" can blow the water in the fuel cell stack to reduce the humidity of the fuel cell stack. Then, the water content of the fuel cell stack can be judged according to the impedance phase angle of the electrochemical impedance spectrum. The impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack is compared with the first preset range, and the electrochemical impedance spectrum analysis module judges whether the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack reaches the first preset range. When the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack reaches the first preset range, it can indicate that the water content of the fuel cell stack is relatively high, that is, the water content of the fuel cell stack can flood the fuel cell stack. In order to prevent the real-time operating condition of the fuel cell from reaching the waterlogging state, since the greater the rotational speed of the air compressor, the faster the evaporation rate of the water inside the fuel cell stack, at this time, control is carried out to increase the rotational speed of the air compressor to increase the drainage speed of the fuel cell stack and reduce the water content of the fuel cell stack. Then, the electrochemical impedance spectrum analysis module continues to judge whether the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack is not within the first preset range. When the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack is not within the first preset range, it can indicate that the humidity of the fuel cell stack has been reduced and the water in the fuel cell stack has decreased, but there is still a part of water inside the fuel cell stack. In order to continue to reduce the water content of the fuel cell stack, at this time, control is carried out to close the bypass valve and introduce a dry air source to dry the water in the fuel cell stack.

[0086] Compare the impedance phase angle of the electrochemical impedance spectrum with the third preset range. The electrochemical impedance spectrum analysis module continues to determine whether the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack is within the third preset range. When the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack is within the third preset range, it can indicate that the water content of the fuel cell stack is relatively low, that is, the water content of the fuel cell stack is not sufficient to submerge the fuel cell stack, which can bring the real-time working condition of the fuel cell to the membrane dry state. In order to bring the real-time working condition of the fuel cell to the normal state, it is necessary to humidify the battery stack. At this time, control the water pump and the water spraying device to be turned on, and control the humidifying device to always remain on, so that the water pump extracts stored water from the water source and transports it to the water spraying device, so that the water spraying device sprays the stored water onto the fuel cell stack to humidify the fuel cell stack. The electrochemical impedance spectrum analysis module continues to determine whether the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack is within the second preset range. When the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack is within the second preset range, it can indicate that the water content of the fuel cell stack is just right, so that the real-time working condition of the fuel cell reaches the normal state. At this time, control the water pump and the water spraying device to be turned off to stop the water pump from continuing to pump water and the water spraying device from continuing to spray water onto the fuel cell stack.

[0087] As a specific embodiment, as Figure 4 shown, the flowchart of the working condition control method of the fuel cell system of the present invention may include the following steps:

[0088] S401, in response to receiving an idle working condition demand.

[0089] S402, control the current density of the fuel cell stack to the first preset current density.

[0090] S403, control the bypass valve to be closed.

[0091] S404, control the water pump to be turned on and control the water spraying device to be turned on.

[0092] S405, determine whether the system power of the fuel cell system meets the vehicle power limit. If yes, execute step S406; if no, execute step S408.

[0093] S406, determine whether the voltage of the fuel cell stack meets the system voltage constraint. If yes, execute step S407; if no, execute step S408.

[0094] S407, whether the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval. If yes, execute step S409; if no, execute step S408.

[0095] S408, adjust the rotational speed of the water pump and the lift of the water spraying device.

[0096] S409, maintaining the rotation speed of the water pump and the lift of the water spray device.

[0097] As another specific embodiment, Figure 5 As shown, the flowchart of the operating condition control method of the fuel cell system of the present invention may include the following steps:

[0098] S501, responding to receiving a request to release an idle condition.

[0099] S502, controlling the current density of the fuel cell stack to a second preset current density.

[0100] S503, control to shut down the water pump and the water spraying device.

[0101] S504, control to open the bypass valve.

[0102] S505, determining whether the impedance phase angle of the electrochemical impedance spectrum is within a first preset range. If yes, executing step S506; if no, executing step S507.

[0103] S506, controlling to increase the rotation speed of the air compressor.

[0104] S507, controlling the bypass valve to close.

[0105] S508, determining whether the impedance phase angle of the electrochemical impedance spectrum is within a third preset range. If yes, executing step S509; if no, returning to step S503.

[0106] S509, controlling to start the water pump and the water spraying device until the impedance phase angle of the electrochemical impedance spectrum is within a second preset range.

[0107] Therefore, flooding will cause the fuel cell stack to decay. However, short-term flooding can be recovered by simply draining the water in the fuel cell stack. Therefore, this solution can meet the power constraints and voltage constraints of the idle condition, and can also reduce the decay of the fuel cell stack and extend the life of the fuel cell system. By increasing the intake humidity and liquid water, the fuel cell stack is flooded and the fuel cell decays, thereby reducing the voltage and idle power of the fuel cell system to avoid high voltage-induced platinum decay and carbon decay of the catalyst layer. The idle power meets the idle power requirements of the vehicle. Therefore, when the fuel cell system is working normally, the excess water is discharged to make the fuel cell stack reach a suitable humidity state, and the fuel cell stack can be restored to its original state. This solution can both reduce the decay of the fuel cell and meet the idle power requirements of the vehicle.

[0108] In summary, the operating condition control method for a fuel cell system according to an embodiment of the present invention includes: when the fuel cell system is operating, in response to receiving an idle condition demand, controlling the current density of the fuel cell stack to a first preset current density, and controlling the humidity control device to humidify the fuel cell stack so that the real-time operating condition of the fuel cell reaches a flooded state; determining whether the system power of the fuel cell system meets the vehicle power limit; in response to the system power meeting the vehicle power limit, determining whether the voltage of the fuel cell stack meets the system voltage constraint; in response to the voltage of the fuel cell stack meeting the system voltage constraint, determining whether the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval; in response to the system power of the fuel cell system and the voltage of the fuel cell stack reaching a stable state within the preset time interval, controlling the humidity control device to maintain the humidifying operation on the fuel cell stack so that the real-time operating condition of the fuel cell maintains the flooded state. Thus, in this method, under the idle condition, the water pump and the water spraying device work, the air circulation loop presents a high humidity state, and liquid water enters the fuel cell stack. There is a flooded phenomenon inside the fuel cell stack, reducing the average single cell voltage at the same current density and reducing the output power of the fuel cell stack, thereby causing the output power of the fuel cell system to decrease to the upper limit of the vehicle power requirement. At the same time, the average single cell voltage will also decrease to 0.85 V, reducing the platinum corrosion and carbon corrosion caused by high voltage, reducing the stack attenuation, extending the stack life, and meeting the vehicle requirements.

[0109] It should be noted that the method of the embodiment of the present invention can be executed by a single device, such as a computer or a server. The method of this embodiment can also be applied to a distributed scenario and completed by multiple devices cooperating with each other. In this case of the distributed scenario, one of the multiple devices can only execute one or more steps of the method of the embodiment of the present invention, and these multiple devices will interact with each other to complete the above method.

[0110] It should be noted that some embodiments of the present invention have been described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be executed in a different order from that in the above embodiments and still achieve the desired results. Additionally, the processes depicted in the drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0111] Corresponding to the above embodiment, the present invention also proposes an operating condition control device for a fuel cell system.

[0112] As Figure 6As shown, the operating condition control device of the fuel cell system according to the embodiment of the present invention includes: a control module 610 , a determination module 620 , a first response module 630 , a second response module 640 and a third response module 650 .

[0113] Among them, the control module 610 is configured to control the current density of the fuel cell stack to a first preset current density in response to receiving an idle condition requirement when the fuel cell system is running, and control the humidity control device to perform a humidification operation on the fuel cell stack so that the real-time operating condition of the fuel cell reaches a flooded state; the determination module 620 is configured to determine whether the system power of the fuel cell system meets the power limit of the entire vehicle; the first response module 630 is configured to determine whether the voltage of the fuel cell stack meets the system voltage constraint in response to the system power meeting the power limit of the entire vehicle; the second response module 640 is configured to determine whether the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval in response to the voltage of the fuel cell stack meeting the system voltage constraint; the third response module 650 is configured to control the humidity control device to maintain the humidification operation on the fuel cell stack in response to the system power of the fuel cell system and the voltage of the fuel cell stack reaching a stable state within a preset time interval, so that the real-time operating condition of the fuel cell maintains a flooded state.

[0114] In some embodiments of the present invention, the control module 610 is further configured to: control the closing of the bypass valve to cut off the introduction of the dry air source; control the opening of the water pump so that the water pump draws stored water from the water source and delivers it to the water spraying device; control the opening of the water spraying device so that the water spraying device sprays the stored water to the fuel cell stack to humidify the fuel cell stack; determine whether the impedance phase angle of the electrochemical impedance spectrum of the fuel cell stack reaches a first preset range; in response to the impedance phase angle of the electrochemical impedance spectrum reaching the first preset range, determine that the real-time operating condition of the fuel cell reaches a flooded state.

[0115] In some embodiments of the present invention, the control module 610 is further configured to: in response to the impedance phase angle of the electrochemical impedance spectrum reaching a second preset range, determine that the real-time operating condition of the fuel cell reaches a normal state.

[0116] In some embodiments of the present invention, the control module 610 is further configured to: in response to the impedance phase angle of the electrochemical impedance spectrum reaching a third preset range, determine that the real-time operating condition of the fuel cell reaches a membrane dry state.

[0117] In some embodiments of the present invention, the control module 610 is further configured to: in response to receiving a demand to release the idle condition, control the current density of the fuel cell stack to a second preset current density, and control the humidity control device to dehumidify the fuel cell stack so that the real-time operating condition of the fuel cell is out of the flooded state.

[0118] In some embodiments of the present invention, the control module 610 is further configured to: control the water pump and the water spraying device to be turned off, and control the bypass valve to be opened to perform a dehumidification operation on the fuel cell stack; determine whether the impedance phase angle of the electrochemical impedance spectrum is within a first preset range; in response to the impedance phase angle of the electrochemical impedance spectrum being within the first preset range, control the rotational speed of the air compressor to be increased; in response to the impedance phase angle of the electrochemical impedance spectrum not being within the first preset range, control the bypass valve to be closed, and determine whether the impedance phase angle of the electrochemical impedance spectrum is within a third preset range; in response to the impedance phase angle of the electrochemical impedance spectrum being within the third preset range, control the water pump and the water spraying device to be turned on until the impedance phase angle of the electrochemical impedance spectrum is within a second preset range.

[0119] It should be noted that for the details not disclosed in the operating condition control device of the fuel cell system according to the embodiments of the present invention, please refer to the details disclosed in the operating condition control method of the fuel cell system according to the embodiments of the present invention, and will not be elaborated herein.

[0120] In summary, the operating condition control device of the fuel cell system according to the embodiments of the present invention includes: a control module configured to, when the fuel cell system is operating, in response to receiving an idle condition demand, control the current density of the fuel cell stack to a first preset current density, and control the humidity control device to perform a humidification operation on the fuel cell stack so that the real-time operating condition of the fuel cell reaches a flooded state; a determination module configured to determine whether the system power of the fuel cell system meets the vehicle power limit; a first response module configured to, in response to the system power meeting the vehicle power limit, determine whether the voltage of the fuel cell stack meets the system voltage constraint; a second response module configured to, in response to the voltage of the fuel cell stack meeting the system voltage constraint, determine whether the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval; a third response module configured to, in response to the system power of the fuel cell system and the voltage of the fuel cell stack reaching a stable state within a preset time interval, control the humidity control device to maintain the humidification operation on the fuel cell stack so that the real-time operating condition of the fuel cell is maintained in a flooded state. Thus, in this device, under the idle condition, the water pump and the water spraying device work, the air circulation loop presents a high-humidity state, and liquid water enters the fuel cell stack. A flooding phenomenon occurs inside the fuel cell stack, reducing the average single-cell voltage at the same current density and reducing the output power of the fuel cell stack, thereby causing the output power of the fuel cell system to decrease to the upper limit of the vehicle power requirement. At the same time, the average single-cell voltage will also decrease to 0.85 V, reducing platinum corrosion and carbon corrosion caused by high voltage, reducing the degradation of the fuel cell stack, and extending the life of the fuel cell stack to meet the vehicle requirements.

[0121] For the convenience of description, when describing the above system, it is divided into various modules according to functions and described separately. Of course, when implementing the present invention, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0122] The system of the above embodiment is used to implement the corresponding method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be elaborated here.

[0123] Corresponding to the above embodiment, the present invention also proposes an electronic device.

[0124] Referring to Figure 7 , which is a block diagram of an electronic device according to some embodiments of the present invention, showing a more specific schematic diagram of the hardware structure of the electronic device provided in this embodiment. The electronic device may include: a processor 710, a memory 720, an input / output interface 730, a communication interface 740, and a bus 750. Among them, the processor 710, the memory 720, the input / output interface 730, and the communication interface 740 are communicatively connected to each other inside the electronic device through the bus 750.

[0125] The processor 710 may be implemented in a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, etc., and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0126] The memory 720 may be implemented in the form of a ROM (Read Only Memory), a RAM (Random Access Memory), a static storage device, a dynamic storage device, etc. The memory 720 may store an operating system and other application programs. When implementing the technical solutions provided in the embodiments of this specification through software or firmware, the relevant program codes are stored in the memory 720 and are called and executed by the processor 710.

[0127] The input / output interface 730 is used to connect to an input / output module to implement information input and output. The input / output module may be configured as a component in the electronic device (not shown in the figure) or externally connected to the electronic device to provide corresponding functions. Among them, the input electronic device may include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output electronic device may include a display, a speaker, a vibrator, an indicator light, etc.

[0128] The communication interface 740 is used to connect to a communication module (not shown in the figure) to enable communication and interaction between this electronic device and other electronic devices. The communication module can achieve communication through wired means (such as USB, network cable, etc.) or through wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0129] The bus 750 includes a path for transmitting information between various components of the electronic device (such as the processor 710, the memory 720, the input / output interface 730, and the communication interface 740).

[0130] It should be noted that although the above electronic device only shows the processor 710, the memory 720, the input / output interface 730, the communication interface 740, and the bus 750, in the specific implementation process, this electronic device may also include other components necessary for normal operation. In addition, those skilled in the art can understand that the above electronic device may also only include the components necessary to implement the solution of the embodiments of this specification, and does not necessarily include all the components shown in the figure.

[0131] The electronic device of the above embodiment is used to implement the corresponding method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be elaborated here.

[0132] Based on the same inventive concept, corresponding to the method of any of the above embodiments, the present invention also provides a computer-readable storage medium. The computer-readable storage medium stores computer instructions, and the computer instructions are used to cause a computer to execute the method of any of the above embodiments.

[0133] The above computer-readable storage medium can be any available medium or data storage device that a computer can access, including but not limited to magnetic memories (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO), etc.), optical memories (such as CDs, DVDs, BDs, HVDs, etc.), and semiconductor memories (such as ROM, EPROM, EEPROM, non-volatile memories (NANDFLASH), solid-state drives (SSD)), etc.

[0134] The computer instructions stored in the storage medium of the above embodiment are used to cause a computer to execute the method of any of the above exemplary method parts, and have the beneficial effects of the corresponding method embodiments, which will not be elaborated here.

[0135] In addition, although the operations of the method of the present invention are described in a specific order in the drawings, this is not a requirement or implication that these operations must be performed in that specific order, or that all of the operations shown must be performed to achieve the desired result. On the contrary, the order of the steps depicted in the flowchart can be changed. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step for execution, and / or one step may be decomposed into multiple steps for execution.

[0136] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), and the like.

[0137] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present invention should be of the ordinary meaning understood by those of ordinary skill in the art to which the present invention pertains. The "first", "second", and similar terms used in the embodiments of the present invention do not denote any order, quantity, or importance, but are merely used to distinguish different components. Words such as "comprising" or "including" mean that the elements or items appearing before the word cover the elements or items listed after the word and their equivalents, without excluding other elements or items. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0138] Although the spirit and principles of the present invention have been described with reference to several specific embodiments, it should be understood that the present invention is not limited to the specific embodiments disclosed, and the division of various aspects does not mean that the features in these aspects cannot be combined for benefits. This division is only for the convenience of expression. The present invention aims to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the appended claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A method for controlling an operating condition of a fuel cell system, characterized in that: include: When the fuel cell system is running, in response to receiving an idle condition requirement, controlling the current density of the fuel cell stack to a first preset current density, and controlling the humidity control device to perform a humidification operation on the fuel cell stack so that the real-time operating condition of the fuel cell reaches a flooded state; Determining whether the system power of the fuel cell system meets the vehicle power limit; In response to the system power satisfying a vehicle power limit, determining whether a voltage of the fuel cell stack satisfies a system voltage constraint; In response to the voltage of the fuel cell stack satisfying the system voltage constraint, determining whether the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval; In response to the system power of the fuel cell system and the voltage of the fuel cell stack reaching a stable state within a preset time interval, the humidity control device is controlled to maintain a humidification operation on the fuel cell stack so that the real-time operating condition of the fuel cell maintains the flooding state.

2. The operating condition control method of the fuel cell system according to claim 1, characterized in that: The step of controlling the humidity control device to perform a humidification operation on the fuel cell stack so that the real-time operating condition of the fuel cell reaches a flooded state includes: Control and close the bypass valve to cut off the introduction of dry air source; Controlling the water pump to start, so that the water pump draws stored water from the water source and delivers it to the water spraying device; Controlling the water spray device to start, so that the water spray device sprays the stored water to the fuel cell stack to perform a humidification operation on the fuel cell stack; Determining whether an impedance phase angle of an electrochemical impedance spectrum of the fuel cell stack reaches a first preset range; In response to the impedance phase angle of the electrochemical impedance spectrum reaching a first preset range, it is determined that the real-time operating condition of the fuel cell reaches a flooded state.

3. The operating condition control method of the fuel cell system according to claim 2, characterized in that: The method further comprises: In response to the impedance phase angle of the electrochemical impedance spectrum reaching a second preset range, it is determined that the real-time operating condition of the fuel cell reaches a normal state.

4. The operating condition control method of the fuel cell system according to claim 3, characterized in that: The method further comprises: In response to the impedance phase angle of the electrochemical impedance spectrum reaching a third preset range, it is determined that the real-time operating condition of the fuel cell reaches a membrane dry state.

5. The operating condition control method of the fuel cell system according to claim 4, characterized in that: The first preset range is larger than the second preset range, and the second preset range is larger than the third preset range.

6. The operating condition control method of the fuel cell system according to claim 5, characterized in that: The method further comprises: In response to receiving a request to release the idle condition, the current density of the fuel cell stack is controlled to a second preset current density, and the humidity control device is controlled to perform a dehumidification operation on the fuel cell stack to remove the real-time condition of the fuel cell from a flooded state.

7. The operating condition control method of the fuel cell system according to claim 6, characterized in that: The step of controlling the humidity control device to perform a dehumidification operation on the fuel cell stack so as to remove the real-time working condition of the fuel cell from a flooded state includes: Controlling to close the water pump and the water spray device, and controlling to open the bypass valve, so as to perform a dehumidification operation on the fuel cell stack; determining whether the impedance phase angle of the electrochemical impedance spectroscopy is within a first preset range; In response to the impedance phase angle of the electrochemical impedance spectrum being within a first preset range, controlling to increase the rotation speed of the air compressor; In response to the impedance phase angle of the electrochemical impedance spectrum not being within the first preset range, controlling the bypass valve to close, and determining whether the impedance phase angle of the electrochemical impedance spectrum is within a third preset range; In response to the impedance phase angle of the electrochemical impedance spectrum being within a third preset range, the water pump and the water spray device are controlled to be turned on until the impedance phase angle of the electrochemical impedance spectrum is within a second preset range.

8. A fuel cell system operating condition control device, characterized in that: include: a control module configured to control the current density of the fuel cell stack to a first preset current density in response to receiving an idle operating condition requirement when the fuel cell system is running, and control the humidity control device to perform a humidification operation on the fuel cell stack so that the real-time operating condition of the fuel cell reaches a flooded state; A determination module, configured to determine whether the system power of the fuel cell system meets the vehicle power limit; A first response module, configured to determine whether the voltage of the fuel cell stack satisfies a system voltage constraint in response to the system power satisfying a vehicle power constraint; a second response module, configured to determine whether the system power of the fuel cell system and the voltage of the fuel cell stack reach a stable state within a preset time interval in response to the voltage of the fuel cell stack satisfying the system voltage constraint; The third response module is configured to control the humidity control device to maintain humidification operation on the fuel cell stack in response to the system power of the fuel cell system and the voltage of the fuel cell stack reaching a stable state within a preset time interval, so that the real-time operating condition of the fuel cell maintains the flooded state.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the operating condition control method of the fuel cell system as described in any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium storing computer instructions, characterized in that: The computer instructions are used to enable the computer to implement the operating condition control method of the fuel cell system according to any one of claims 1 to 7.

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