Fuel cell fault detection control method and device and vehicle

Abstract

The invention discloses a fuel cell fault detection control method and device and a vehicle, and the method comprises the steps: obtaining the single voltage of each single cell in an electric pile of a fuel cell, and determining the average single voltage according to the average value of each single voltage; according to the difference value between the average single voltage and the minimum single voltage in the single voltages, single voltage deviation is determined, the average single voltage and the single voltages are substituted into a standard deviation formula, and single voltage standard deviation is determined; and if the monomer voltage deviation and the monomer voltage standard deviation meet a preset triggering condition and a change value of the whole vehicle request power of the vehicle within a preset time period is smaller than a preset threshold value, performing fault detection on the fuel cell according to a preset fault detection mode, according to the method, the time for fault detection of the fuel cell is determined through the single voltage deviation, the single voltage standard deviation and the whole vehicle request power, unnecessary fault detection is avoided, the applicability of fault detection is improved, and thus fault detection of the fuel cell is more accurate.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and more specifically, to a fuel cell fault detection control method, device and vehicle. Background Art

[0002] Fuel cells are one of the main forms of hydrogen energy utilization. They are devices that convert the chemical energy of hydrogen into electrical energy. Compared with ordinary internal combustion engines, fuel cells have higher conversion efficiency and only emit water, making them the best technology for hydrogen energy utilization.

[0003] When a fuel cell operates in a fault state, such as a membrane dry fault or a water flooding fault, its output efficiency will decrease. If it is in a fault state for a long time without recovery, it will cause irreversible degradation of the performance of the membrane electrode and the catalyst layer. Therefore, it is necessary to perform fault detection on the fuel cell to prevent the fuel cell from being in a fault state for a long time.

[0004] In the prior art, there are methods of triggering fault detection in the following ways: Method 1 is timed triggering, which automatically triggers detection at fixed intervals. Method 2 is triggered based on fixed special operating conditions, such as triggering detection only under fixed current conditions such as idling conditions and steady-state operating conditions. Method 3 is to trigger detection when the average voltage decreases. However, the trigger conditions of Methods 1 and 2 have poor applicability and low efficiency, and cannot specifically diagnose the operating status of fuel cells that may fail, and timely adjust and feedback. In Method 3, since the performance of the fuel cell itself will fluctuate under different environments, and as the life cycle changes and the life decays, the performance of the fuel cell will become worse and worse. This solution will lead to frequent triggering of invalid detections in the later stage.

[0005] Therefore, how to more accurately detect and control fuel cell faults is a technical problem that needs to be solved. Summary of the invention

[0006] The embodiments of the present application provide a fuel cell fault detection and control method, device and vehicle for more accurately performing fuel cell fault detection and control.

[0007] In a first aspect, a fuel cell fault detection control method is provided, the method comprising: obtaining the cell voltage of each single cell in a fuel cell stack, and determining an average cell voltage according to the average value of each cell voltage; determining a cell voltage deviation according to the difference between the average cell voltage and the minimum cell voltage among the cell voltages, and substituting the average cell voltage and each cell voltage into a standard deviation formula to determine the cell voltage standard deviation; if the cell voltage deviation and the cell voltage standard deviation meet preset trigger conditions, and the change value of the vehicle's whole vehicle request power within a preset time period is less than a preset threshold, performing fault detection on the fuel cell according to a preset fault detection method.

[0008] In a second aspect, a fuel cell fault detection control device is provided, the device comprising: an acquisition module, used to acquire the cell voltage of each single cell in the fuel cell stack, and determine the average cell voltage according to the average value of each cell voltage; a determination module, used to determine the cell voltage deviation according to the difference between the average cell voltage and the minimum cell voltage among the cell voltages, and substitute the average cell voltage and each cell voltage into the standard deviation formula to determine the cell voltage standard deviation; a detection module, used to perform fault detection on the fuel cell according to a preset fault detection method if the cell voltage deviation and the cell voltage standard deviation meet preset trigger conditions, and the change value of the vehicle's whole vehicle request power within a preset time period is less than a preset threshold.

[0009] In a third aspect, a vehicle is provided, comprising a fuel cell and a fuel cell fault detection and control device as described in the second aspect.

[0010] By applying the above technical scheme, the cell voltage of each single cell in the fuel cell stack is obtained, and the average cell voltage is determined according to the average value of each cell voltage; the cell voltage deviation is determined according to the difference between the average cell voltage and the minimum cell voltage among the cell voltages, and the average cell voltage and each cell voltage are substituted into the standard deviation formula to determine the cell voltage standard deviation; if the cell voltage deviation and the cell voltage standard deviation meet the preset trigger conditions, and the change value of the vehicle's whole vehicle request power within a preset time period is less than the preset threshold, the fuel cell is fault detected according to the preset fault detection method, so that the timing of fuel cell fault detection is determined by the cell voltage deviation, the cell voltage standard deviation and the whole vehicle request power, thereby avoiding unnecessary fault detection, improving the applicability of fault detection, and achieving more accurate fuel cell fault detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0012] Figure 1 A schematic flow chart of a fuel cell fault detection and control method proposed in an embodiment of the present invention is shown;

[0013] Figure 2 A schematic flow chart of a fuel cell fault detection and control method according to another embodiment of the present invention is shown;

[0014] Figure 3A schematic structural diagram of a fuel cell fault detection and control device proposed in an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0016] It should be noted that those skilled in the art will easily think of other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary technical means in the art that are not disclosed in the present application. The specification and examples are only regarded as exemplary, and the true scope and spirit of the present application are indicated by the claims.

[0017] It should be understood that the present application is not limited to the precise structures described below and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

[0018] An embodiment of the present application provides a fuel cell fault detection control method, which determines the timing of fuel cell fault detection through single cell voltage deviation, single cell voltage standard deviation and vehicle power request, thereby avoiding unnecessary fault detection and achieving more accurate fuel cell fault detection.

[0019] like Figure 1 As shown, the method comprises the following steps:

[0020] Step S101, obtaining the cell voltage of each cell in the fuel cell stack, and determining the average cell voltage according to the average value of each cell voltage.

[0021] In this embodiment, the fuel cell is a vehicle-mounted fuel cell, which is mainly composed of a stack, an air subsystem, a hydrogen subsystem and a cooling subsystem, and the stack includes multiple single cells. The working principle of the fuel cell is that hydrogen and oxygen react on both sides of the proton exchange membrane inside the stack to output electrical energy and generate water on the air side.

[0022] The cell voltage of each single battery in the battery stack is obtained, and then the average cell voltage is determined according to the average value of each cell voltage, and then the cell voltage deviation and the cell voltage standard deviation are determined according to each cell voltage and the average cell voltage.

[0023] In some embodiments of the present application, the step of obtaining the cell voltage of each cell in the fuel cell stack includes:

[0024] Acquiring the original single cell voltage of each single cell based on a voltage patrol meter;

[0025] If the original single cell voltage is zero within the preset detection time, or the average voltage of the original single cell voltage within the preset detection time is less than the preset voltage, the original single cell voltage is regarded as an invalid voltage;

[0026] The invalid voltage is removed from each of the original cell voltages to obtain each of the cell voltages.

[0027] In this embodiment, the voltage monitor, namely CVM (Cell Voltage Monitor), is used to collect the voltage of each single cell. First, the original single cell voltage of each single cell is obtained through the voltage monitor, and it is determined whether there is an invalid voltage in each original single cell voltage. If there is, the invalid voltage is removed, and the remaining original single cell voltage in the original single cell voltage is used as each single cell voltage, wherein, if the original single cell voltage is zero within the preset detection time, or the average voltage of the original single cell voltage within the preset detection time is less than the preset voltage, the original single cell voltage is used as the invalid voltage.

[0028] By eliminating the invalid voltage in the original single-cell voltage, each single-cell voltage is made to be a valid voltage, and a more accurate average voltage can be obtained based on each single-cell voltage later.

[0029] Step S102, determining a cell voltage deviation according to a difference between the average cell voltage and the minimum cell voltage among the cell voltages, and substituting the average cell voltage and the cell voltages into a standard deviation formula to determine a cell voltage standard deviation.

[0030] In this embodiment, after obtaining the voltages of each cell, the minimum cell voltage among the cell voltages is determined, the minimum cell voltage is subtracted from the average cell voltage to obtain the cell voltage deviation, and then the average cell voltage and each cell voltage are substituted into the standard deviation formula, and the standard deviation is calculated using the standard deviation formula to obtain the cell voltage standard deviation.

[0031] The standard deviation formula is: Wherein, σ is the voltage standard deviation, n is the number of single cell voltages, i represents the sequence number of single cell voltages, and x i represents the voltage of the i-th cell, Indicates the average cell voltage.

[0032] Step S103: If the cell voltage deviation and the cell voltage standard deviation meet the preset trigger condition, and the change value of the vehicle's whole vehicle requested power within the preset time period is less than the preset threshold, the fuel cell is fault detected according to the preset fault detection method.

[0033] In this embodiment, after obtaining the cell voltage deviation and the cell voltage standard deviation, it is determined whether the cell voltage deviation and the cell voltage standard deviation meet the preset trigger condition. If so, it is determined whether the change value of the vehicle's whole vehicle request power within the preset time length is less than the preset threshold value. If it is less than, it means that the state of the fuel cell is relatively stable, and fault detection can be performed. The fuel cell is fault-detected according to the preset fault detection method, wherein the change value of the whole vehicle request power within the preset time length can be determined according to the whole vehicle power request issued by the whole vehicle controller. In this way, the timing of fuel cell fault detection is determined by the cell voltage deviation, the cell voltage standard deviation and the whole vehicle request power, which avoids unnecessary fault detection, improves the applicability of fault detection, and thus realizes more accurate fault detection of the fuel cell.

[0034] Optionally, the preset fault detection method can be a detection method for detecting whether the water content of the membrane in the fuel cell stack is normal, such as electrochemical impedance detection, or it can be a detection method for detecting whether other indicators of the fuel cell are normal. The embodiment of the present application is not limited to this.

[0035] It is understandable that if the cell voltage deviation and the cell voltage standard deviation do not meet the preset trigger conditions, or the change value of the vehicle's entire vehicle request power within a preset time period is not less than a preset threshold, no fault detection is performed on the fuel cell.

[0036] In some embodiments of the present application, the preset trigger condition includes that the cell voltage deviation is greater than a first preset voltage value, and the cell voltage standard deviation is greater than a second preset voltage value.

[0037] In this embodiment, if the cell voltage deviation is greater than the first preset voltage value, and the cell voltage standard deviation is greater than the second preset voltage value, it indicates that there is a high possibility that the fuel cell is faulty. The timing for triggering fault detection is determined based on the preset trigger condition and the vehicle's requested power, thereby performing fault detection more accurately.

[0038] Optionally, the preset trigger condition may also be that a preset calculation value is higher than a preset threshold value, and the preset calculation value is a value obtained by summing the cell voltage deviation and the cell voltage standard deviation, or a value obtained by multiplying them.

[0039] Optionally, the first preset voltage value and the second preset voltage value can be determined based on experience or by designing normal operating conditions and fault injection comparison tests. The first preset voltage value may be higher than the second preset voltage value or lower than the second preset voltage value, or both may be equal. In the specific application scenario of the present application, the first preset voltage value is 30mv and the second preset voltage value is 20mv.

[0040] In some embodiments of the present application, after performing fault detection on the fuel cell in a preset fault detection manner, the method further includes:

[0041] Determining whether the fuel cell has a fault according to the fault detection result;

[0042] If the fault exists, adjusting the operating parameters related to the fault according to the type of the fault;

[0043] When the cell voltage deviation is smaller than the first preset voltage value, and the cell voltage standard deviation is smaller than the second preset voltage value, the operation parameter is stopped from being adjusted.

[0044] In this embodiment, the fault detection result is obtained. If a fault exists, the operating parameters related to the fault are adjusted according to the type of fault. During the adjustment process, the cell voltage deviation and the cell voltage standard deviation are continuously obtained. When the cell voltage deviation is less than the first preset voltage value and the cell voltage standard deviation is less than the second preset voltage value, it indicates that the fault is eliminated and the adjustment of the corresponding operating parameters is stopped. By adjusting the corresponding parameters in time when a fault exists, the fuel cell is prevented from being in a faulty state for a long time, thereby further improving the reliability of the fuel cell.

[0045] It is understandable that if there is no fault, no additional parameter adjustment is required, and the current operating state of the fuel cell is maintained. In addition, in order to ensure the stability of the fuel cell, the operating parameters related to the fault are adjusted, specifically, the operating parameters are gradually adjusted according to the preset adjustment range.

[0046] Optionally, those skilled in the art may also compare the cell voltage deviation and the cell voltage standard deviation with other voltage values ​​different from the first preset voltage value and the second preset voltage value, and determine whether to stop adjusting the operating parameters according to the comparison result.

[0047] In some embodiments of the present application, the preset fault detection method is to determine the water content of the membrane in the stack based on electrochemical impedance detection, and determine the type of the fault according to the water content, the type of the fault includes a membrane dry fault and a flooding fault, the operating parameters include the cathode air flow rate of the stack, and / or the inlet or outlet temperature of the coolant of the stack, and the operating parameters related to the fault are adjusted according to the type of the fault, including:

[0048] If the type of the fault is the membrane dry fault, reducing the air flow rate and / or reducing the temperature to increase the water content;

[0049] If the fault type is the flooding fault, the air flow rate is increased, and / or the temperature is increased to reduce the water content.

[0050] In this embodiment, the preset fault detection method is to determine the water content of the membrane in the stack based on electrochemical impedance detection, and determine the type of fault according to the water content. The membrane in the stack is a proton exchange membrane, and the types of faults are membrane dry faults and water flooding faults. If the water content is lower than the preset lower limit, the type of fault is determined to be a membrane dry fault. If the water content is higher than the preset upper limit, the type of fault is determined to be a water flooding fault. If the water content is between the preset lower limit and the preset upper limit, it is determined that there is no fault. The operating parameters related to membrane dry faults and water flooding faults include the cathode air flow rate of the stack, and / or the inlet or outlet temperature of the coolant of the stack. If the type of fault is a membrane dry fault, the air flow rate is reduced, and / or the temperature is reduced to increase the water content. If the type of fault is a water flooding fault, the air flow rate is increased, and / or the temperature is increased to reduce the water content, so as to more accurately adjust the operating parameters.

[0051] In order to ensure the stability of the fuel cell, in some embodiments of the present application, the air flow rate is reduced and / or the temperature is reduced, specifically, the air flow rate is gradually reduced according to the first preset adjustment range, and / or the temperature is gradually reduced by the second preset adjustment range. Correspondingly, the air flow rate is increased and / or the temperature is increased, specifically, the air flow rate is gradually increased according to the first preset adjustment range, and / or the temperature is gradually increased by the second preset adjustment range.

[0052] It should be noted that the specific valves or equipment involved in regulating the air flow and / or temperature are obvious to those skilled in the art and will not be described in detail here. In addition, the operating parameters are not limited to air flow and / or temperature, and those skilled in the art may use other operating parameters for adjustment as needed.

[0053] Optionally, in addition to using electrochemical impedance spectroscopy to determine the water content, the water content may also be determined by any of the following methods: anode side or cathode side flow resistance detection, fuel cell polarization performance detection, fuel cell temperature and humidity parameter sensitivity detection, etc. In the specific application scenario of the present application, electrochemical impedance spectroscopy specifically includes high-frequency electrochemical impedance spectroscopy and low-frequency electrochemical impedance spectroscopy.

[0054] In addition, the water generated by the reaction in the stack is discharged in two ways. The first is that the water generated on the air side is directly carried away by the air. The temperature, flow rate and pressure of the air will affect the water carrying capacity. The second is that the water generated on the air side will penetrate into the hydrogen side through the proton exchange membrane. The water on the hydrogen side needs to be discharged to the outside of the system by opening the tail drain valve. Therefore, as an alternative, the operating parameters include the tail drain valve opening time, and / or the speed of the hydrogen circulation pump, and / or the inlet or outlet water temperature of the cooling water, and / or the cathode air flow rate. If the fault type is a membrane dry fault, the tail drain valve opening time is shortened, and / or the speed of the hydrogen circulation pump is increased, and / or the water temperature is reduced, and / or the air flow rate is reduced. If the fault type is a flooding fault, the tail drain valve opening time is extended, and / or the speed of the hydrogen circulation pump is reduced, and / or the water temperature is increased, and / or the air flow rate is increased.

[0055] The fuel cell fault detection control method in the embodiment of the present application obtains the cell voltage of each single cell in the fuel cell stack, and determines the average cell voltage according to the average value of each cell voltage; determines the cell voltage deviation according to the difference between the average cell voltage and the minimum cell voltage among the cell voltages, and substitutes the average cell voltage and each cell voltage into the standard deviation formula to determine the cell voltage standard deviation; if the cell voltage deviation and the cell voltage standard deviation meet the preset trigger conditions, and the change value of the vehicle's whole vehicle request power within a preset time period is less than a preset threshold, the fuel cell is fault detected according to the preset fault detection method, and the timing of fuel cell fault detection is determined by the cell voltage deviation, the cell voltage standard deviation and the whole vehicle request power, thereby avoiding unnecessary fault detection, improving the applicability of fault detection, and achieving more accurate fuel cell fault detection.

[0056] In order to further explain the technical idea of ​​the present invention, the technical solution of the present invention is now described in combination with specific application scenarios.

[0057] The embodiment of the present application proposes a fuel cell fault detection control method, which obtains the cell voltage of each cell in the fuel cell stack, determines the average cell voltage according to the average value of each cell voltage, determines the cell voltage deviation V1 according to the difference between the average cell voltage and the minimum cell voltage among the cell voltages, and substitutes the average cell voltage and each cell voltage into the standard deviation formula to determine the cell voltage standard deviation V2. Figure 2 As shown, the following processes are also included:

[0058] Determine whether V1>30mv, if so, determine whether V2>20mv, otherwise do not perform electrochemical impedance detection, if V2>20mv, determine whether the vehicle's requested power has not changed suddenly, if so, perform electrochemical impedance detection and enter fault detection mode, otherwise do not perform electrochemical impedance detection, wherein, if the change value of the vehicle's requested power within the preset time is less than the preset threshold, it is determined that the vehicle's requested power has not changed suddenly.

[0059] After electrochemical impedance spectroscopy is performed and the fault detection mode is entered, there are three detection results: normal state, membrane dry fault and water flooding fault.

[0060] If it is in normal state, it means that the water content of the membrane in the fuel cell stack is normal, there is no fault, and there is no feedback adjustment, that is, the current operating state of the fuel cell is maintained and the fault detection mode is exited.

[0061] If it is a membrane dry fault, it means that the water content of the membrane in the fuel cell stack is lower than the preset lower limit, then reduce the air flow and temperature to increase the fuel water content, and continue to detect V1 and V2. If V1 is less than 30mv and V2 is less than 20mv, exit the fault detection mode, where the air flow is the cathode air flow into the stack, and the temperature is the inlet or outlet temperature of the cooling water of the fuel cell stack.

[0062] If it is a flooding fault, it means that the water content of the membrane in the fuel cell stack is higher than the preset upper limit. In this case, increase the air flow and temperature to reduce the water content, and continue to detect V1 and V2. If V1 is less than 30mv and V2 is less than 20mv, exit the fault detection mode.

[0063] Corresponding to the fuel cell fault detection control method in the embodiment of the present application, the embodiment of the present application also proposes a fuel cell fault detection control device, such as Figure 3 As shown, the device includes: an acquisition module 301, used to acquire the cell voltage of each single cell in the fuel cell stack, and determine the average cell voltage according to the average value of each cell voltage; a determination module 302, used to determine the cell voltage deviation according to the difference between the average cell voltage and the minimum cell voltage among the cell voltages, and substitute the average cell voltage and each cell voltage into the standard deviation formula to determine the cell voltage standard deviation; a detection module 303, used to perform fault detection on the fuel cell according to a preset fault detection method if the cell voltage deviation and the cell voltage standard deviation meet the preset trigger condition, and the change value of the vehicle's whole vehicle request power within a preset time period is less than a preset threshold.

[0064] In a specific application scenario, the preset trigger condition includes that the cell voltage deviation is greater than a first preset voltage value, and the cell voltage standard deviation is greater than a second preset voltage value.

[0065] In a specific application scenario, the device also includes an adjustment module, which is used to: determine whether the fuel cell has a fault based on the fault detection result; if the fault exists, adjust the operating parameters related to the fault according to the type of the fault; when the cell voltage deviation is less than the first preset voltage value and the cell voltage standard deviation is less than the second preset voltage value, stop adjusting the operating parameters.

[0066] In a specific application scenario, the preset fault detection method is to determine the water content of the membrane in the fuel cell stack based on electrochemical impedance detection, and determine the type of the fault according to the water content. The types of faults include membrane dry faults and water flooding faults. The operating parameters include the cathode air flow rate of the fuel cell stack, and / or the inlet or outlet temperature of the coolant of the fuel cell stack. The adjustment module is specifically used to: if the type of the fault is the membrane dry fault, reduce the air flow rate, and / or reduce the temperature to increase the water content; if the type of the fault is the water flooding fault, increase the air flow rate, and / or increase the temperature to reduce the water content.

[0067] In a specific application scenario, the acquisition module 301 is specifically used to: acquire the original single cell voltage of each single cell battery based on a voltage patrol meter; if the original single cell voltage is zero within a preset detection time, or the average voltage of the original single cell voltage within the preset detection time is less than a preset voltage, the original single cell voltage is used as an invalid voltage; remove the invalid voltage from each original single cell voltage to acquire each single cell voltage.

[0068] The fuel cell fault detection control device in the embodiment of the present application includes: an acquisition module, which is used to acquire the cell voltage of each single cell in the fuel cell stack, and determine the average cell voltage according to the average value of each cell voltage; a determination module, which is used to determine the cell voltage deviation according to the difference between the average cell voltage and the minimum cell voltage among the cell voltages, and substitute the average cell voltage and each cell voltage into the standard deviation formula to determine the cell voltage standard deviation; a detection module, which is used to perform fault detection on the fuel cell according to a preset fault detection method if the cell voltage deviation and the cell voltage standard deviation meet the preset trigger conditions, and the change value of the vehicle's whole vehicle request power within a preset time period is less than a preset threshold value, and determine the timing of fuel cell fault detection through the cell voltage deviation, the cell voltage standard deviation and the whole vehicle request power, thereby avoiding unnecessary fault detection and improving the applicability of fault detection, thereby achieving more accurate fuel cell fault detection.

[0069] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk), etc.

[0070] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0071] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A fuel cell fault detection and control method, characterized in that: The method comprises: Obtaining the cell voltage of each cell in the fuel cell stack, and determining the average cell voltage according to the average value of each cell voltage; Determine a cell voltage deviation according to a difference between the average cell voltage and a minimum cell voltage among the cell voltages, and substitute the average cell voltage and the cell voltages into a standard deviation formula to determine a cell voltage standard deviation; If the cell voltage deviation and the cell voltage standard deviation meet the preset trigger conditions, and the change value of the vehicle's entire vehicle requested power within a preset time period is less than a preset threshold, the fuel cell is fault detected according to a preset fault detection method.

2. The method according to claim 1, characterized in that The preset trigger condition includes that the cell voltage deviation is greater than a first preset voltage value, and the cell voltage standard deviation is greater than a second preset voltage value.

3. The method according to claim 2, characterized in that After performing fault detection on the fuel cell in a preset fault detection manner, the method further includes: Determining whether the fuel cell has a fault according to the fault detection result; If the fault exists, adjusting the operating parameters related to the fault according to the type of the fault; When the cell voltage deviation is smaller than the first preset voltage value, and the cell voltage standard deviation is smaller than the second preset voltage value, the operation parameter is stopped from being adjusted.

4. The method according to claim 3, characterized in that The preset fault detection method is to determine the water content of the membrane in the stack based on electrochemical impedance detection, and determine the type of the fault according to the water content, the type of the fault includes a membrane dry fault and a flooding fault, the operating parameters include the cathode air flow rate of the stack, and / or the inlet or outlet temperature of the coolant of the stack, and the operating parameters related to the fault are adjusted according to the type of the fault, including: If the type of the fault is the membrane dry fault, reducing the air flow rate and / or reducing the temperature to increase the water content; If the fault type is the flooding fault, the air flow rate is increased, and / or the temperature is increased to reduce the water content.

5. The method according to claim 1, characterized in that The step of obtaining the cell voltage of each cell in the fuel cell stack includes: Acquiring the original single cell voltage of each single cell based on a voltage patrol meter; If the original single cell voltage is zero within the preset detection time, or the average voltage of the original single cell voltage within the preset detection time is less than the preset voltage, the original single cell voltage is regarded as an invalid voltage; The invalid voltage is removed from each of the original single-cell voltages to obtain each of the single-cell voltages.

6. A fuel cell fault detection and control device, characterized in that: The device comprises: An acquisition module, used to acquire the cell voltage of each cell in the fuel cell stack, and determine the average cell voltage according to the average value of each cell voltage; A determination module, used to determine a cell voltage deviation according to a difference between the average cell voltage and a minimum cell voltage among the cell voltages, and to substitute the average cell voltage and the cell voltages into a standard deviation formula to determine a cell voltage standard deviation; The detection module is used to perform fault detection on the fuel cell according to a preset fault detection method if the single cell voltage deviation and the single cell voltage standard deviation meet the preset trigger condition and the change value of the vehicle's whole vehicle requested power within a preset time period is less than a preset threshold.

7. The device according to claim 6, characterized in that The preset trigger condition includes that the cell voltage deviation is greater than a first preset voltage value, and the cell voltage standard deviation is greater than a second preset voltage value.

8. The device according to claim 7, characterized in that The device also includes a regulating module, which is used to: Determining whether the fuel cell has a fault according to the fault detection result; If the fault exists, adjusting the operating parameters related to the fault according to the type of the fault; When the cell voltage deviation is smaller than the first preset voltage value, and the cell voltage standard deviation is smaller than the second preset voltage value, the operation parameter is stopped from being adjusted.

9. The device according to claim 8, characterized in that The preset fault detection method is to determine the water content of the membrane in the stack based on electrochemical impedance detection, and determine the type of the fault according to the water content, the type of fault includes membrane dry fault and flooding fault, the operating parameters include the cathode air flow rate of the stack, and / or the inlet or outlet temperature of the coolant of the stack, and the regulating module is specifically used for: If the type of the fault is the membrane dry fault, reducing the air flow rate and / or reducing the temperature to increase the water content; If the fault type is the flooding fault, the air flow rate is increased, and / or the temperature is increased to reduce the water content.

10. A vehicle, characterized in that: It comprises a fuel cell and a fuel cell fault detection and control device as described in any one of claims 6 to 9.

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