Failure detection method for pressure sensor of fuel cell system

Abstract

The present disclosure proposes a fault recognition method for a pressure sensor of a fuel cell system. The fault identification method comprises the following steps: when the downtime of the fuel cell system is greater than or equal to a downtime threshold value, calculating an average value of pressure values measured by a first pressure sensor, a second pressure sensor, a third pressure sensor and a fourth pressure sensor; comparing the pressure values measured by the first pressure sensor, the second pressure sensor, the third pressure sensor and the fourth pressure sensor with an average value; if the absolute value of the difference value between the pressure value measured by any one of the first pressure sensor, the second pressure sensor, the third pressure sensor and the fourth pressure sensor and the average value is larger than or equal to a third pressure difference threshold value, it is recognized that the corresponding pressure sensor breaks down. According to the fault identification method disclosed by the invention, whether the pressure sensor breaks down or not can be automatically identified before the fuel cell system is started.

Description

Technical Field

[0001] The present disclosure relates to the field of fuel cell systems, and more particularly to a method for identifying faults of a pressure sensor for a fuel cell system, and a computer-readable storage medium including instructions for implementing the method. Background Art

[0002] A fuel cell stack is very sensitive to pressure, especially to the pressure difference between its anode and cathode. During operation, it is usually necessary to control the pressure difference between the anode and cathode within a certain value, for example, to control the pressure difference at about 350 hPa under full power. An excessive pressure difference may tear the proton exchange membrane of the fuel cell, and a too small pressure difference may cause overall under-gassing and reverse polarization, further leading to irreversible damages such as the shedding of the fuel cell catalyst and the perforation of the proton exchange membrane.

[0003] In order to monitor and control the pressure of the fuel cell stack, a pressure sensor is usually provided at each of the cathode inlet, cathode outlet, anode inlet, and anode outlet. If the pressure sensor works properly, its reading will be close to the true pressure value, or the deviation from the true pressure value does not exceed a certain threshold. However, when the sensor drifts or fails, the deviation between its measured value and the true pressure value will be relatively high, which may cause some problems. For example, when the sensor at the cathode outlet fails, such that it measures the true pressure value of 1000 hPa as 1050 hPa, even if the measured pressure difference between the anode and cathode (the pressure difference between the anode and cathode is equal to the pressure at the anode inlet minus the pressure at the cathode outlet) is about 350 hPa at this time, the true pressure difference may already be greater than 350 hPa. As described above, this may cause damage to the proton exchange membrane of the fuel cell. Therefore, it is very necessary to check whether each pressure sensor fails before the fuel cell system starts.

[0004] Currently, the pressure sensor is inspected before leaving the factory, but there is a lack of inspection during subsequent installation and use. If there are imperceptible damages, the life of the fuel cell will be greatly reduced. In addition, sometimes the fault identification is carried out manually. This method requires the interior of the fuel cell stack to be connected to the atmospheric pressure, which will accelerate the aging of the fuel cell catalyst. Therefore, it is necessary to avoid frequent execution of this operation. For this reason, the present disclosure proposes a method for automatically performing fault identification of the pressure sensor. Summary of the Invention

[0005] The method for identifying faults of a pressure sensor for a fuel cell system proposed by the present disclosure can automatically identify whether the pressure sensor fails before the fuel cell system starts.

[0006] Specifically, the present disclosure proposes a method for fault identification of a pressure sensor for a fuel cell system, where the fuel cell system includes: a fuel cell stack; and a first pressure sensor A, a second pressure sensor B, a third pressure sensor C, and a fourth pressure sensor D respectively disposed at the cathode inlet, cathode outlet, anode inlet, and anode outlet of the fuel cell stack. Among them, the fault identification method includes: when the shutdown time t of the fuel cell system is greater than or equal to the shutdown time threshold T, calculating the average value avg of the pressure values measured by the first pressure sensor A, the second pressure sensor B, the third pressure sensor C, and the fourth pressure sensor D; comparing the pressure values measured by the first pressure sensor A, the second pressure sensor B, the third pressure sensor C, and the fourth pressure sensor D with the average value avg; and if the absolute value of the difference between the pressure value measured by any one of the first pressure sensor A, the second pressure sensor B, the third pressure sensor C, and the fourth pressure sensor D and the average value avg is greater than or equal to the third pressure difference threshold ε3, identifying that the corresponding pressure sensor has a fault.

[0007] In one embodiment, the fault identification method further includes: when the shutdown time t of the fuel cell system is less than the shutdown time threshold T, comparing the pressure value measured by the first pressure sensor A with the pressure value measured by the second pressure sensor B; if the absolute value of the difference between the pressure value measured by the first pressure sensor A and the pressure value measured by the second pressure sensor B is greater than or equal to the first pressure difference threshold ε1, identifying that the first pressure sensor A or the second pressure sensor B has a fault.

[0008] In one embodiment, the fuel cell system further includes a first valve V1 upstream of the cathode inlet of the fuel cell stack and a second valve V2 downstream of the cathode outlet, and the fault identification method further includes: opening the first valve V1 or the second valve V2 to communicate the cathode of the fuel cell stack with the atmospheric pressure ATM; comparing the pressure values measured by the first pressure sensor A and the second pressure sensor B with the atmospheric pressure ATM, and if the absolute value of the difference between the pressure value measured by the first pressure sensor A or the second pressure sensor B and the atmospheric pressure ATM is greater than or equal to the second pressure difference threshold ε2, identifying that the first pressure sensor A or the second pressure sensor B has a fault.

[0009] In one embodiment, the first valve V1 includes a globe valve for cutting off fluid flow or regulating fluid flow rate, and the second valve V2 includes a backpressure valve for controlling backpressure or cutting off fluid flow.

[0010] In one embodiment, the fault identification method further includes: when the shutdown time t of the fuel cell system is less than the shutdown time threshold T, comparing the pressure value measured by the third pressure sensor C with the pressure value measured by the fourth pressure sensor D; if the absolute value of the difference between the pressure value measured by the third pressure sensor C and the pressure value measured by the fourth pressure sensor D is greater than or equal to the first pressure difference threshold ε1, it is identified that the third pressure sensor C or the fourth pressure sensor D fails.

[0011] In one embodiment, the fuel cell system further includes a third valve V3 located downstream of the anode outlet of the fuel cell stack, and the fault identification method further includes: opening the third valve V3 to connect the anode of the fuel cell stack to the atmospheric pressure ATM; comparing the pressure values measured by the third pressure sensor C and the fourth pressure sensor D with the atmospheric pressure ATM, if the absolute value of the difference between the pressure value measured by the third pressure sensor C or the fourth pressure sensor D and the atmospheric pressure ATM is greater than or equal to the second pressure difference threshold ε2, it is identified that the third pressure sensor C or the fourth pressure sensor D fails.

[0012] In one embodiment, the third valve V3 includes an exhaust and drainage valve for exhausting waste gas or draining water from the anode.

[0013] In one embodiment, the fault identification method further includes: when the shutdown time t of the fuel cell system is greater than or equal to the shutdown time threshold T, comparing the pressure value measured by the first pressure sensor A with the pressure value measured by the second pressure sensor B, and comparing the pressure value measured by the third pressure sensor C with the pressure value measured by the fourth pressure sensor D; if the absolute value of the difference between the pressure value measured by the first pressure sensor A and the pressure value measured by the second pressure sensor B is greater than or equal to the first pressure difference threshold ε1, it is identified that the first pressure sensor A or the second pressure sensor B fails; and if the absolute value of the difference between the pressure value measured by the third pressure sensor C and the pressure value measured by the fourth pressure sensor D is greater than or equal to the first pressure difference threshold ε1, it is identified that the third pressure sensor C or the fourth pressure sensor D fails.

[0014] In one embodiment, the fuel cell system further includes a first valve V1 upstream of the cathode inlet of the fuel cell stack and a second valve V2 downstream of the cathode outlet, and the fault identification method further includes: opening the first valve V1 or the second valve V2 to connect the cathode of the fuel cell stack to the atmospheric pressure ATM; comparing the pressure values measured by the first pressure sensor A and the second pressure sensor B with the atmospheric pressure ATM, and if the absolute value of the difference between the pressure value measured by the first pressure sensor A or the second pressure sensor B and the atmospheric pressure ATM is greater than or equal to a second pressure difference threshold ε2, it is identified that the first pressure sensor A or the second pressure sensor B has failed.

[0015] In one embodiment, the fuel cell system further includes a third valve V3 downstream of the anode outlet of the fuel cell stack, and the fault identification method further includes: opening the third valve V3 to connect the anode of the fuel cell stack to the atmospheric pressure ATM; comparing the pressure values measured by the third pressure sensor C and the fourth pressure sensor D with the atmospheric pressure ATM, and if the absolute value of the difference between the pressure value measured by the third pressure sensor C or the fourth pressure sensor D and the atmospheric pressure ATM is greater than or equal to a second pressure difference threshold ε2, it is identified that the third pressure sensor C or the fourth pressure sensor D has failed.

[0016] In one embodiment, the shutdown time threshold T is greater than or equal to 2 hours.

[0017] In one embodiment, the third pressure difference threshold ε3 is equal to 10 hPa.

[0018] In one embodiment, the first pressure difference threshold ε1 is equal to 20 hPa.

[0019] In one embodiment, the second pressure difference threshold ε2 is equal to 10 hPa.

[0020] The present disclosure also proposes another fault identification method for a pressure sensor of a fuel cell system. The fuel cell system includes: a fuel cell stack; and a first pressure sensor A and a second pressure sensor B respectively disposed at the cathode inlet and the cathode outlet of the fuel cell stack. Wherein, the fault identification method includes: when receiving a start command of the fuel cell system, comparing the pressure value measured by the first pressure sensor A with the pressure value measured by the second pressure sensor B; if the absolute value of the difference between the pressure value measured by the first pressure sensor A and the pressure value measured by the second pressure sensor B is greater than or equal to a first pressure difference threshold ε1, it is identified that the first pressure sensor A or the second pressure sensor B has failed.

[0021] In one embodiment, the fuel cell system further includes a first valve V1 upstream of the cathode inlet of the fuel cell stack and a second valve V2 downstream of the cathode outlet, and the fault identification method further includes: opening the first valve V1 or the second valve V2 to connect the cathode of the fuel cell stack to the atmospheric pressure ATM; comparing the pressure values measured by the first pressure sensor A and the second pressure sensor B with the atmospheric pressure ATM, and if the absolute value of the difference between the pressure value measured by the first pressure sensor A or the second pressure sensor B and the atmospheric pressure ATM is greater than or equal to a second pressure difference threshold ε2, it is identified that the first pressure sensor A or the second pressure sensor B has failed.

[0022] In one embodiment, the fuel cell system further includes a third pressure sensor C and a fourth pressure sensor D respectively disposed at the anode inlet and the anode outlet of the fuel cell stack, and the fault identification method further includes: when receiving a start command of the fuel cell system, comparing the pressure value measured by the third pressure sensor C with the pressure value measured by the fourth pressure sensor D; if the absolute value of the difference between the pressure value measured by the third pressure sensor C and the pressure value measured by the fourth pressure sensor D is greater than or equal to the first pressure difference threshold ε1, it is identified that the third pressure sensor C or the fourth pressure sensor D has failed.

[0023] In one embodiment, the fuel cell system further includes a third valve V3 downstream of the anode outlet of the fuel cell stack, and the fault identification method further includes: opening the third valve V3 to connect the anode of the fuel cell stack to the atmospheric pressure ATM; comparing the pressure values measured by the third pressure sensor C and the fourth pressure sensor D with the atmospheric pressure ATM, and if the absolute value of the difference between the pressure value measured by the third pressure sensor C or the fourth pressure sensor D and the atmospheric pressure ATM is greater than or equal to a second pressure difference threshold ε2, it is identified that the third pressure sensor C or the fourth pressure sensor D has failed.

[0024] The present disclosure also proposes a computer-readable storage medium, on which instructions are stored, and when the instructions are executed by a processor, the processor is caused to execute the method described in any one of the above.

[0025] Generally speaking, the various embodiments of the present disclosure can be combined and coupled in any possible way within the scope of the present disclosure. These and other aspects, features, and / or advantages of the present disclosure will be apparent and elucidated with reference to the embodiments described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Embodiments of the present disclosure will be described by way of example with reference to the following drawings, in which:

[0027] Figure 1 A schematic diagram of a fuel cell system is shown. The fuel cell system includes a fuel cell stack, and pressure sensors A, B, C, and D are respectively provided at the cathode inlet, cathode outlet, anode inlet, and anode outlet of the fuel cell stack. A first valve V1 is provided upstream of the cathode inlet, a second valve V2 is provided downstream of the cathode outlet, and a third valve V3 is provided downstream of the anode outlet.

[0028] Figure 2 A flowchart of the first part of a method for fault identification of a pressure sensor for a fuel cell system according to an embodiment of the present disclosure is shown; and

[0029] Figure 3 A flowchart of the second part of a method for fault identification of a pressure sensor for a fuel cell system according to an embodiment of the present disclosure is shown.

[0030] It should be understood that the drawings only show one way of implementing the present disclosure and should not be construed as a limitation on other possible embodiments falling within the scope of the appended claims. The protection scope of the present disclosure is only defined by the appended claims. Detailed Embodiments

[0031] A fuel cell system refers to a power generation system with a fuel cell stack as the core and composed of an air system, a hydrogen system, a water / heat management system, an electric control system, etc. The fuel cell system can be used as a driving power source or auxiliary power for vehicles, yachts, aerospace, and underwater power equipment, etc., and converts the chemical energy of reactants into electrical energy and heat energy through an electrochemical reaction.

[0032] Generally, in order to control the pressure of a fuel cell stack, a fuel cell system includes several pressure controllers. Figure 1 A schematic diagram of a fuel cell system is shown, in which pressure sensors A, B, C, and D are respectively provided at the cathode inlet, cathode outlet, anode inlet, and anode outlet of the fuel cell stack. Sensor A is used to measure the air pressure at the cathode inlet of the fuel cell stack, sensor B is used to measure the air pressure at the cathode outlet of the fuel cell stack, sensor C is used to measure the hydrogen pressure at the anode inlet of the fuel cell stack, and sensor D is used to measure the hydrogen pressure at the anode outlet of the fuel cell stack. These four pressure sensors A, B, C, and D are all communicatively connected to the fuel cell control unit FCCU, as shown by the dashed lines in the figure, so that the FCCU can receive the measured pressure values from each sensor and control the fuel cell system based on the received pressure values. Figure 1The fuel cell system shown also includes: a first valve V1 upstream of the cathode inlet, which is, for example, a globe valve for cutting off fluid flow or regulating fluid flow rate; a second valve V2 downstream of the cathode outlet, which is, for example, a backpressure valve for controlling the backpressure of the fuel cell stack or cutting off fluid flow; and a third valve V3 downstream of the anode outlet, which is, for example, an exhaust and drain valve for anode purge to discharge waste gas and water in the anode flow channel. When the first valve V1 or the second valve V2 is opened, the cathode of the fuel cell system is in communication with the atmospheric pressure, and when the third valve V3 is opened, the anode of the fuel cell system is in communication with the atmospheric pressure. When the fuel cell system is shut down, the above-mentioned first valve V1, second valve V2, and third valve V3 are all closed to prevent outside air from entering the interior of the fuel cell system and having an adverse effect on related structural components.

[0033] During normal operation, due to the pressure losses in the cathode flow field and the anode flow field, and the air pressure in the anode flow field being controlled to be higher than that in the cathode flow field, the pressure values measured by these four pressure sensors are different. As the power provided by the fuel cell increases, the difference in these pressure values also increases.

[0034] The inventors of the present application found that although the pressure values measured by the pressure sensors vary greatly during operation, after shutdown, since the anode gas and the cathode gas no longer flow, the pressure loss caused by the flow field is 0. Therefore, the pressures at the anode inlet and the anode outlet will become the same in a short time, and the pressures at the cathode inlet and the cathode outlet will also become substantially the same in a short time.

[0035] The inventors of the present application also found that when the shutdown time exceeds a certain threshold, due to the mutual penetration between the cathode gas and the anode gas, the pressures at the anode inlet, the anode outlet, the cathode inlet, and the cathode outlet will become substantially the same.

[0036] For example, Table 1 below lists the pressure values measured by the pressure sensors of a certain model of fuel cell system under different operating conditions. Among them, all four pressure sensors are operating normally, and the measured pressure values are close to the true pressure values.

[0037] Table 1 Pressure values measured under different operating conditions

[0038]

[0039] As can be seen from the table, when the fuel cell system operates at full power, the pressure difference between the anode inlet and the anode outlet is 123 hPa; the pressure difference between the cathode inlet and the cathode outlet is 259 hPa; and the pressure difference between the anode and the cathode is 345 hPa. When the fuel cell system operates at idle power, the pressure difference between the anode inlet and the anode outlet is 49 hPa; the pressure difference between the cathode inlet and the cathode outlet is 40 hPa; and the pressure difference between the anode and the cathode is 108 hPa.

[0040] However, when the fuel cell system operates at a certain power between full power and idle power and then shuts down, at the moment of shutdown, the pressure difference between the anode inlet and the cathode outlet is 7 hPa, and the pressure difference between the cathode inlet and the cathode outlet is 3 hPa. When the shutdown reaches 12.8 s, the pressure difference between the anode inlet and the anode outlet is only 3 hPa, and the pressure difference between the cathode inlet and the cathode outlet is only 1 hPa. After the shutdown reaches 5 h, the pressure values at the anode inlet, anode outlet, cathode inlet, and cathode outlet are in the range of 923 - 932 hPa, and the differences between them are all less than 10 hPa.

[0041] Based on the above findings, the inventors of the present application proposed a method for fault identification of pressure sensors for a fuel cell system. This method can automatically identify whether each pressure sensor fails before the fuel cell system starts. According to the method of the present disclosure, it can be implemented by the above fuel cell control unit FCCU. Since the fuel cell control unit FCCU and its communication connections with each sensor are existing configurations, therefore, this method can be only an improvement at the software level without adding additional hardware. Alternatively, this method can also be implemented by a separate control unit.

[0042] The following will refer to Figure 2 and Figure 3 to describe this method in detail. Among them, Figure 2 shows the flowchart of the first part of this method, Figure 3 shows the flowchart of the second part of this method. The above first part and second part can be selected according to the shutdown time of the fuel cell system. In addition, these two parts are not mutually exclusive. For example, when the shutdown time is long, the first part and the second part can be executed simultaneously. As long as a fault is identified according to one of the parts, the faulty sensor is replaced, thereby reducing the risk of false negatives in the identification result. This will be described in detail below.

[0043] Refer to Figure 1 and Figure 2, when the FCCU receives a start command, it will judge the relationship between the shutdown time t of the fuel cell system and the shutdown time threshold T. If the shutdown time t is less than the shutdown time threshold T, it means that the shutdown time is still short, and in this case, the method proceeds according to the first part. Based on historical data, the shutdown time threshold T can be selected to be greater than or equal to 2 h, and for example, it is 4 h or 5 h.

[0044] In the first part, the FCCU compares the pressure value measured by pressure sensor A with the pressure value measured by pressure sensor B, and judges the relationship between the absolute value of the difference between the pressure value measured by pressure sensor A and the pressure value measured by pressure sensor B and the first pressure difference threshold ε1. If the absolute value of the difference is less than the first pressure difference threshold ε1, it means that the pressure values measured by pressure sensor A and pressure sensor B can reflect the actual pressure value, so it can be considered that neither pressure sensor A nor pressure sensor B has failed. If the absolute value of the difference is greater than or equal to the first pressure difference threshold ε1, it means that either pressure sensor A or pressure sensor B has failed, because at this time, the pressure values at the cathode inlet and the cathode outlet should not differ too much. At the same time, the FCCU compares the pressure value measured by pressure sensor C with the pressure value measured by pressure sensor D, and judges the relationship between the absolute value of the difference between the pressure value measured by pressure sensor C and the pressure value measured by pressure sensor D and the first pressure difference threshold ε1. If the absolute value of the difference is less than the first pressure difference threshold ε1, it means that the pressure values measured by pressure sensor C and pressure sensor D can reflect the actual pressure value, so it can be considered that neither pressure sensor C nor pressure sensor D has failed. If the absolute value of the difference is greater than or equal to the first pressure difference threshold ε1, it means that either pressure sensor C or pressure sensor D has failed. The reason for using the same pressure difference threshold ε1 for pressure sensors A, B and pressure sensors C, D is that usually, the pressure sensors A, B, C, D used are of the same type. The first pressure difference threshold ε1 can be, for example, 20 hPa.

[0045] When none of the pressure sensors A, B, C, D has failed, the FCCU can normally start the fuel cell system. If any group (A and B are a group, C and D are a group) of the pressure sensors A, B, C, D may have failed, the method will continue in order to identify which specific pressure sensor has failed.

[0046] For the case where pressure sensor A or pressure sensor B fails, the method includes: opening the first valve V1 or the second valve V2 to connect the cathode of the fuel cell stack to the atmospheric pressure. Thus, the pressure at the cathode of the fuel cell stack will become close to the atmospheric pressure ATM in a short time. That is to say, the pressures at the cathode inlet and the cathode outlet will also become close to the atmospheric pressure ATM in a short time. Subsequently, the method includes: comparing the pressure value measured by pressure sensor A with the atmospheric pressure ATM, and judging the relationship between the absolute value of the difference between the pressure value measured by pressure sensor A and the atmospheric pressure ATM and the second pressure difference threshold ε2. The second pressure difference threshold ε2 can be, for example, 10 hPa. If the absolute value of the difference is less than the second pressure difference threshold ε2, it indicates that the pressure value measured by pressure sensor A can basically reflect the actual pressure value, so it can be considered that pressure sensor A has not failed. If the absolute value of the difference is greater than or equal to the second pressure difference threshold ε2, it indicates that pressure sensor A has failed. At this time, the FCCU can issue a fault indication signal and stop starting the fuel cell system. The fault indication signal can be a sound or light indication signal. Subsequently, the operator can replace pressure sensor A according to the fault indication signal. The method also includes performing the above method steps for pressure sensor A on pressure sensor B. If the absolute value of the difference between the pressure value measured by pressure sensor B and the atmospheric pressure ATM is less than the second pressure difference threshold ε2, it indicates that pressure sensor B has not failed. If it is greater than or equal to the second pressure difference threshold ε2, it indicates that pressure sensor B has failed. At this time, the FCCU can issue a fault indication signal and stop starting the fuel cell system. Those skilled in the art will understand that the fault indication signal issued for pressure sensor B can be different from the fault indication signal issued for pressure sensor A, so that the operator can distinguish which specific sensor has failed and perform subsequent replacement based on this distinction.

[0047] For the case where pressure sensor C or pressure sensor D fails, the method includes: opening the third valve V3 to connect the anode of the fuel cell stack to the atmospheric pressure. Thus, the pressure at the anode of the fuel cell stack will become close to the atmospheric pressure ATM in a short time. That is to say, the pressures at the anode inlet and the anode outlet will also become close to the atmospheric pressure ATM in a short time. Subsequently, the method includes: comparing the pressure value measured by pressure sensor C with the atmospheric pressure ATM, and determining the relationship between the absolute value of the difference between the pressure value measured by pressure sensor C and the atmospheric pressure ATM and the second pressure difference threshold ε2. If the absolute value of the difference is less than the second pressure difference threshold ε2, it indicates that the pressure value measured by pressure sensor C can reflect the actual pressure value, so it can be considered that pressure sensor C has not failed. If the absolute value of the difference is greater than or equal to the second pressure difference threshold ε2, it indicates that pressure sensor C has failed. At this time, the FCCU can issue a fault indication signal and stop starting the fuel cell system. The method also includes performing the above method steps for pressure sensor D to identify whether pressure sensor D has failed.

[0048] As shown above, as long as any one of the pressure sensors A, B, C, and D is identified as having failed, the FCCU stops starting the fuel cell system and issues a corresponding fault indication signal for the operator to replace. Only when each of the pressure sensors A, B, C, and D has not failed will the FCCU normally start the fuel cell system.

[0049] Alternatively, it is also possible to stop starting the fuel cell stack when it is identified that the first group of pressure sensors A and B or the second group of pressure sensors C and D has failed, and then perform subsequent identification steps to identify which specific pressure sensor has failed.

[0050] The above fault identification method first divides pressure sensors A and B into the first group and pressure sensors C and D into the second group for identification. If the identification result is that none of them has failed, the fuel cell system can be normally started. Only when the first group or the second group has failed will one or more of the first valve V1, the second valve V2, and the third valve V3 be opened to connect the anode or the cathode of the fuel cell stack to the atmospheric pressure for subsequent identification. Therefore, compared with the method adopted in the prior art, the probability of the identification method having an adverse impact on the relevant structure is greatly reduced.

[0051] Then refer to Figure 1 and Figure 3 , when the shutdown time t is greater than or equal to the shutdown time threshold T, it indicates that the shutdown time is long enough and the permeation between the cathode gas and the anode gas has been basically completed. Therefore, the pressure values at the cathode inlet, the cathode outlet, the anode inlet, and the anode outlet are close to being equal. At this time, the method proceeds according to the second part.

[0052] In the second part, the FCCU will calculate the average value of the pressure values measured by pressure sensors A, B, C, and D, and then compare the pressure values measured by each sensor with this average value avg to determine the relationship between the absolute value of the difference between the pressure values measured by each pressure sensor and this average value avg and the third pressure difference threshold ε3. This third pressure difference threshold ε3 can be, for example, 10 hPa. If the absolute value of the difference between the pressure value measured by each of pressure sensors A, B, C, and D and the average value avg is less than the third pressure difference threshold ε3, it indicates that none of pressure sensors A, B, C, and D has failed. At this time, the FCCU can normally start the fuel cell system. On the contrary, if the absolute value of the difference between the pressure value measured by any one of pressure sensors A, B, C, and D and the average value avg is greater than or equal to the third pressure difference threshold ε3, it indicates that the corresponding pressure sensor has failed. At this time, the FCCU can issue a fault indication to inform the operator which pressure sensor has failed and stop starting the fuel cell system. Since the probability of a pressure sensor of the fuel cell system failing is small, and it usually does not happen that two or more pressure sensors fail simultaneously, the above fault identification method can effectively identify the failed sensor. Thus, the operator can replace the failed sensor in time, thereby achieving precise control of the fuel cell system and avoiding damage to it.

[0053] Figure 3 The fault identification method given in the second part shown Figure 2 is simpler than the fault identification method given in the first part shown, and it avoids communicating the anode or cathode with the atmosphere. However, it will be understood that, if necessary, when the downtime t is greater than or equal to the downtime threshold T, the first part described above with reference to Figure 2 can be additionally or alternatively used to identify faults in the pressure sensor. When additionally using the first part to identify faults, as long as a fault is identified according to one of the parts, the failed sensor is replaced, thereby reducing the risk of false negatives in the identification result.

[0054] The above reference Figure 2 and Figure 3 have described in detail the fault identification method for the pressure sensor of the fuel cell system according to the present disclosure. The present disclosure also proposes a computer-readable storage medium. Instructions are stored on this computer-readable storage medium. When these instructions are executed by the processor of a computer, the steps of the above fault identification method can be performed.

[0055] Although the present disclosure has been described in connection with the above specific embodiments, it should not be construed as being limited in any way to the presented examples. The scope of the present disclosure is defined by the appended claims. In the context of the claims, the term "comprising" or "including" does not exclude other possible elements or steps. Additionally, references such as "a" or "an" should not be construed as excluding a plurality. The use of reference signs of elements shown in the drawings in the claims should also not be construed as limiting the scope of the present disclosure. Furthermore, the various features mentioned in different claims may be advantageously combined, and the mention of these features in different claims does not exclude the combination of these features being possible and advantageous. Moreover, the "first", "second", "third", "fourth", etc. used in the present disclosure are only used to distinguish the relevant components from each other, and are not intended to confer any priority-related attributes on them.

Claims

1. A method for fault identification of a pressure sensor for a fuel cell system, characterized in that, The fuel cell system includes: a fuel cell stack; and a first pressure sensor (A), a second pressure sensor (B), a third pressure sensor (C), and a fourth pressure sensor (D) respectively disposed at the cathode inlet, cathode outlet, anode inlet, and anode outlet of the fuel cell stack. Wherein, the fault identification method includes: When the shutdown time (t) of the fuel cell system is greater than or equal to the shutdown time threshold (T), calculate the average value (avg) of the pressure values measured by the first pressure sensor (A), the second pressure sensor (B), the third pressure sensor (C), and the fourth pressure sensor (D); Compare the pressure values measured by the first pressure sensor (A), the second pressure sensor (B), the third pressure sensor (C), and the fourth pressure sensor (D) with the average value (avg); and If the absolute value of the difference between the pressure value measured by any one of the first pressure sensor (A), the second pressure sensor (B), the third pressure sensor (C), and the fourth pressure sensor (D) and the average value (avg) is greater than or equal to the third pressure difference threshold (ε3), it is identified that the corresponding pressure sensor has a fault.

2. The method for fault identification of a pressure sensor for a fuel cell system according to claim 1, characterized in that, The fault identification method further includes: When the shutdown time (t) of the fuel cell system is less than the shutdown time threshold (T), compare the pressure value measured by the first pressure sensor (A) with the pressure value measured by the second pressure sensor (B); If the absolute value of the difference between the pressure value measured by the first pressure sensor (A) and the pressure value measured by the second pressure sensor (B) is greater than or equal to the first pressure difference threshold (ε1), it is identified that the first pressure sensor (A) or the second pressure sensor (B) has a fault.

3. The method for fault identification of a pressure sensor for a fuel cell system according to claim 2, characterized in that, The fuel cell system further includes a first valve (V1) upstream of the cathode inlet of the fuel cell stack and a second valve (V2) downstream of the cathode outlet, and the fault identification method further includes: Open the first valve (V1) or the second valve (V2) so that the cathode of the fuel cell stack is in communication with the atmospheric pressure (ATM); Compare the pressure values measured by the first pressure sensor (A) and the second pressure sensor (B) with the atmospheric pressure (ATM). If the absolute value of the difference between the pressure value measured by the first pressure sensor (A) or the second pressure sensor (B) and the atmospheric pressure (ATM) is greater than or equal to the second pressure difference threshold (ε2), it is identified that the first pressure sensor (A) or the second pressure sensor (B) has a fault.

4. The method for fault identification of a pressure sensor for a fuel cell system according to claim 3, characterized in that, The first valve (V1) includes a globe valve for cutting off fluid flow or regulating fluid flow rate, and the second valve (V2) includes a back pressure valve for controlling back pressure or cutting off fluid flow.

5. The method for fault identification of a pressure sensor for a fuel cell system according to claim 1, characterized in that, The fault identification method further includes: When the shutdown time (t) of the fuel cell system is less than the shutdown time threshold (T), compare the pressure value measured by the third pressure sensor (C) with the pressure value measured by the fourth pressure sensor (D); If the absolute value of the difference between the pressure value measured by the third pressure sensor (C) and the pressure value measured by the fourth pressure sensor (D) is greater than or equal to the first pressure difference threshold (ε1), a failure of the third pressure sensor (C) or the fourth pressure sensor (D) is identified.

6. The method for fault identification of a pressure sensor for a fuel cell system according to claim 5, characterized in that, The fuel cell system further includes a third valve (V3) located downstream of the anode outlet of the fuel cell stack, and the failure identification method further includes: Opening the third valve (V3) to connect the anode of the fuel cell stack to the atmospheric pressure (ATM); Comparing the pressure values measured by the third pressure sensor (C) and the fourth pressure sensor (D) with the atmospheric pressure (ATM). If the absolute value of the difference between the pressure value measured by the third pressure sensor (C) or the fourth pressure sensor (D) and the atmospheric pressure (ATM) is greater than or equal to the second pressure difference threshold (ε2), a failure of the third pressure sensor (C) or the fourth pressure sensor (D) is identified.

7. The method for fault identification of the pressure sensor for a fuel cell system according to claim 6, wherein The third valve (V3) includes an exhaust and drainage valve for exhausting waste gas or draining water from the anode.

8. The method for fault identification of a pressure sensor for a fuel cell system according to claim 1, characterized in that, The failure identification method further includes: When the shutdown time (t) of the fuel cell system is greater than or equal to the shutdown time threshold (T), comparing the pressure value measured by the first pressure sensor (A) with the pressure value measured by the second pressure sensor (B), and comparing the pressure value measured by the third pressure sensor (C) with the pressure value measured by the fourth pressure sensor (D); If the absolute value of the difference between the pressure value measured by the first pressure sensor (A) and the pressure value measured by the second pressure sensor (B) is greater than or equal to the first pressure difference threshold (ε1), a failure of the first pressure sensor (A) or the second pressure sensor (B) is identified; and if the absolute value of the difference between the pressure value measured by the third pressure sensor (C) and the pressure value measured by the fourth pressure sensor (D) is greater than or equal to the first pressure difference threshold (ε1), a failure of the third pressure sensor (C) or the fourth pressure sensor (D) is identified.

9. The method for fault identification of a pressure sensor for a fuel cell system according to claim 8, characterized in that, The fuel cell system further includes a first valve (V1) located upstream of the cathode inlet of the fuel cell stack and a second valve (V2) located downstream of the cathode outlet, and the failure identification method further includes: Opening the first valve (V1) or the second valve (V2) to connect the cathode of the fuel cell stack to the atmospheric pressure (ATM); Comparing the pressure values measured by the first pressure sensor (A) and the second pressure sensor (B) with the atmospheric pressure (ATM). If the absolute value of the difference between the pressure value measured by the first pressure sensor (A) or the second pressure sensor (B) and the atmospheric pressure (ATM) is greater than or equal to the second pressure difference threshold (ε2), a failure of the first pressure sensor (A) or the second pressure sensor (B) is identified.

10. The method for fault identification of the pressure sensor for a fuel cell system according to claim 8, characterized in that, The fuel cell system further includes a third valve (V3) located downstream of the anode outlet of the fuel cell stack, and the fault identification method further includes: Opening the third valve (V3) to connect the anode of the fuel cell stack to the atmospheric pressure (ATM); Comparing the pressure values measured by the third pressure sensor (C) and the fourth pressure sensor (D) with the atmospheric pressure (ATM). If the absolute value of the difference between the pressure value measured by the third pressure sensor (C) or the fourth pressure sensor (D) and the atmospheric pressure (ATM) is greater than or equal to a second pressure difference threshold (ε2), it is identified that the third pressure sensor (C) or the fourth pressure sensor (D) has failed.

11. The method for fault identification of a pressure sensor for a fuel cell system according to any one of claims 1-10, characterized in that, The shutdown time threshold (T) is greater than or equal to 2 hours.

12. The method for fault identification of a pressure sensor for a fuel cell system according to any one of claims 1-10, characterized in that, The third pressure difference threshold (ε3) is equal to 10 hPa.

13. The method for fault identification of a pressure sensor for a fuel cell system according to any one of claims 2-10, characterized in that, The first pressure difference threshold (ε1) is equal to 20 hPa.

14. A method for identifying a fault of a pressure sensor for a fuel cell system according to any one of claims 3-4, 6-7, and 9-10, characterized in that, The second pressure difference threshold (ε2) is equal to 10 hPa.

15. A method for fault identification of a pressure sensor for a fuel cell system, characterized in that, The fuel cell system includes: a fuel cell stack; and a first pressure sensor (A) and a second pressure sensor (B) respectively provided at the cathode inlet and the cathode outlet of the fuel cell stack. Wherein, the fault identification method includes: When receiving a start command of the fuel cell system, comparing the pressure value measured by the first pressure sensor (A) with the pressure value measured by the second pressure sensor (B); If the absolute value of the difference between the pressure value measured by the first pressure sensor (A) and the pressure value measured by the second pressure sensor (B) is greater than or equal to a first pressure difference threshold (ε1), it is identified that the first pressure sensor (A) or the second pressure sensor (B) has failed.

16. The method for fault identification of a pressure sensor for a fuel cell system according to claim 15, characterized in that, The fuel cell system further includes a first valve (V1) located upstream of the cathode inlet of the fuel cell stack and a second valve (V2) located downstream of the cathode outlet, and the fault identification method further includes: Opening the first valve (V1) or the second valve (V2) to connect the cathode of the fuel cell stack to the atmospheric pressure (ATM); Comparing the pressure values measured by the first pressure sensor (A) and the second pressure sensor (B) with the atmospheric pressure (ATM). If the absolute value of the difference between the pressure value measured by the first pressure sensor (A) or the second pressure sensor (B) and the atmospheric pressure (ATM) is greater than or equal to a second pressure difference threshold (ε2), it is identified that the first pressure sensor (A) or the second pressure sensor (B) has failed.

17. The method for fault identification of a pressure sensor for a fuel cell system according to claim 15, characterized in that, The fuel cell system further includes a third pressure sensor (C) and a fourth pressure sensor (D) respectively provided at the anode inlet and the anode outlet of the fuel cell stack, and the fault identification method further includes: When receiving a start command of the fuel cell system, comparing the pressure value measured by the third pressure sensor (C) with the pressure value measured by the fourth pressure sensor (D); If the absolute value of the difference between the pressure value measured by the third pressure sensor (C) and the pressure value measured by the fourth pressure sensor (D) is greater than or equal to the first differential pressure threshold (ε1), a failure of the third pressure sensor (C) or the fourth pressure sensor (D) is identified.

18. The method for identifying a fault of a pressure sensor for a fuel cell system according to claim 17, characterized in that, The fuel cell system further includes a third valve (V3) located downstream of the anode outlet of the fuel cell stack, and the failure identification method further includes: Opening the third valve (V3) to connect the anode of the fuel cell stack to the atmospheric pressure (ATM); Comparing the pressure values measured by the third pressure sensor (C) and the fourth pressure sensor (D) with the atmospheric pressure (ATM). If the absolute value of the difference between the pressure value measured by the third pressure sensor (C) or the fourth pressure sensor (D) and the atmospheric pressure (ATM) is greater than or equal to the second differential pressure threshold (ε2), a failure of the third pressure sensor (C) or the fourth pressure sensor (D) is identified.

19. A computer-readable storage medium, characterized in that, Instructions are stored on the computer-readable storage medium, which, when executed by a processor, cause the processor to execute the method according to any one of claims 1-18.

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