A fuel cell system solenoid fault detection method, device and electronic equipment

Abstract

This application provides a method, apparatus, and electronic device for detecting solenoid valve faults in a fuel cell system, relating to the field of fuel cell technology. The method includes: when the auxiliary hydrogen injection is not in operation, comparing the current absolute pressure deviation with a set threshold to obtain a comparison result, where the absolute pressure deviation is the difference between the actual pressure and the theoretical pressure at the ejector inlet; based on the comparison result, determining whether both the exhaust valve and the drain valve have a normally open fault; if neither the exhaust valve nor the drain valve has a normally open fault, determining whether the drain valve has a normally closed fault based on the liquid level indicated by a liquid level sensor, and determining whether the exhaust valve has a normally closed fault based on the pressure change at the ejector inlet before and after the exhaust valve is opened. By employing the above-mentioned method, apparatus, and electronic device for detecting solenoid valve faults in a fuel cell system, the problems of low detection accuracy and high detection cost are solved.

Description

Technical Field

[0001] This application relates to the field of fuel cell technology, and more specifically, to a method, apparatus, and electronic device for detecting solenoid valve faults in a fuel cell system. Background Technology

[0002] The basic working principle of a fuel cell is that hydrogen and oxygen undergo an electrochemical reaction in the presence of a catalyst, converting chemical energy into electrical energy. The only reactant is water. To ensure the normal operation of the fuel cell's power generation reaction, an exhaust valve and a drain valve are typically installed on the hydrogen side of the fuel cell in a vehicle. Both exhaust and drain valves are solenoid valves and lack internal fault feedback functionality. When the exhaust or drain valve malfunctions and fails to open, the engine will experience a voltage drop, preventing further power generation. However, there are many reasons for a voltage drop in the engine, making it difficult to pinpoint the specific cause. Currently, two methods are commonly used to determine if the exhaust or drain valve is malfunctioning: First, by observing the increase in the hydrogen injection duty cycle when the exhaust or drain valve is normally open; second, by adding a flow meter at the hydrogen inlet of the fuel cell system and observing the flow rate changes when the exhaust or drain valve is opened and closed.

[0003] However, in the first method, the hydrogen injection duty cycle is related not only to the flow rate but also to the resistance of the hydrogen injector solenoid valve. The resistance of the solenoid valve increases with the temperature of the nozzle during operation, leading to low accuracy in detecting solenoid valve malfunctions. In the second method, the added flow meter is expensive, resulting in high costs for solenoid valve malfunction detection. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a method, device and electronic device for detecting solenoid valve faults in a fuel cell system, so as to solve the problems of low detection accuracy and high detection cost when detecting solenoid valve faults.

[0005] In a first aspect, embodiments of this application provide a method for detecting solenoid valve faults in a fuel cell system, including:

[0006] When the auxiliary hydrogen injection is not in operation, the absolute pressure deviation at the current moment is compared with the set threshold to obtain the comparison result. The absolute pressure deviation is the difference between the actual pressure and the theoretical pressure at the ejector inlet.

[0007] Based on the comparison results, determine whether both the exhaust valve and the drain valve have a normally open fault;

[0008] If neither the vent valve nor the drain valve is normally open, determine whether the drain valve is normally closed based on the liquid level indicated by the liquid level sensor, and determine whether the vent valve is normally closed based on the pressure change at the ejector inlet before and after the vent valve is opened.

[0009] Optionally, the set threshold includes a first set threshold and a second set threshold. Based on the comparison result, it is determined whether both the exhaust valve and the drain valve have a normally open fault, including: if the absolute pressure deviation is greater than or equal to the first set threshold, it is determined that both the exhaust valve and the drain valve have a normally open fault; if the absolute pressure deviation is less than or equal to the second set threshold, it is determined that neither the exhaust valve nor the drain valve has a normally open fault.

[0010] Optionally, after comparing the absolute pressure deviation at the current moment with the set threshold, the method further includes: if the absolute pressure deviation is between the first set threshold and the second set threshold, then starting from the new current moment, selecting consecutive target solenoid valve opening cycles as multiple first opening cycles; for each first opening cycle, determining the first actual pressure difference value corresponding to the first opening cycle; determining whether each first actual pressure difference value is greater than the target theoretical pressure difference value, where the target theoretical pressure difference value is the pressure difference at the ejector inlet before and after the target solenoid valve opens; if all first actual pressure difference values ​​are greater than the target theoretical pressure difference value, then determining that the target solenoid valve is in a normal state; otherwise, determining that the target solenoid valve has a normally open fault.

[0011] Optionally, determining whether the drain valve has a normally closed fault based on the liquid level status indicated by the liquid level sensor includes: obtaining the liquid level status indicated by the liquid level sensor after the drain valve has finished opening; if the liquid level status changes from high to low after the drain valve has finished opening, determining that the drain valve does not have a normally closed fault; if the liquid level status remains high after the drain valve has finished opening, shortening the drain cycle, and determining whether the drain valve has a normally closed fault based on the change in liquid level status after shortening the drain cycle.

[0012] Optionally, the presence of a normally closed fault in the drain valve is determined based on the change in liquid level after shortening the drain cycle, including: after shortening the drain cycle, selecting consecutive new drain valve opening cycles as multiple second opening cycles; for each second opening cycle, determining the corresponding second actual pressure difference value; if the liquid level changes from high to low during the multiple second opening cycles, the drain valve is determined to be in normal condition; if the liquid level does not decrease during the multiple second opening cycles and each second actual pressure difference value is less than the second theoretical pressure difference value, the drain valve is determined to have a normally closed fault, where the second theoretical pressure difference value is the pressure difference at the ejector inlet before and after the drain valve is opened; if the liquid level does not decrease during the multiple second opening cycles and there is a second actual pressure difference value greater than or equal to the second theoretical pressure difference value among the multiple second actual pressure difference values, the drain valve is determined not to have a normally closed fault, but the liquid level sensor is faulty.

[0013] Optionally, the presence of a normally closed fault in the exhaust valve is determined based on the pressure change at the ejector inlet before and after the exhaust valve is opened. This includes: selecting consecutive new exhaust valve opening cycles as multiple third opening cycles starting from the latest current moment; determining the third actual pressure difference value corresponding to each third opening cycle; if all the third actual pressure difference values ​​are less than the first theoretical pressure difference value, then the exhaust valve is determined to have a normally closed fault, where the first theoretical pressure difference value is the pressure difference at the ejector inlet before and after the exhaust valve is opened; if there is a third actual pressure difference value among the multiple third actual pressure difference values ​​that is greater than or equal to the first theoretical pressure difference value, then the exhaust valve is determined to be in a normal state.

[0014] Optionally, the actual differential pressure value corresponding to each opening cycle is determined in the following way: For each opening cycle, multiple pre-opening pressure values ​​and multiple post-opening pressure values ​​are obtained. Each pre-opening pressure value is the pressure value at the ejector inlet within a first preset time interval before the target solenoid valve opens in the opening cycle, and each post-opening pressure value is the pressure value at the ejector inlet within a second preset time interval after the target solenoid valve opens in the opening cycle. The average value of the multiple pre-opening pressure values ​​is taken as the average pre-pressure value, and the average value of the multiple post-opening pressure values ​​is taken as the average post-pressure value. The difference between the average pre-pressure value and the average post-pressure value is taken as the actual differential pressure value corresponding to the opening cycle.

[0015] Secondly, embodiments of this application also provide a solenoid valve fault detection device for a fuel cell system, the device comprising:

[0016] The numerical comparison module is used to compare the current absolute pressure deviation with a set threshold when the auxiliary hydrogen injection is not in operation, and obtain the comparison result. The absolute pressure deviation is the difference between the actual pressure and the theoretical pressure at the ejector inlet.

[0017] The first fault determination module is used to determine, based on the comparison results, whether both the exhaust valve and the drain valve have a normally open fault.

[0018] The second fault determination module is used to determine whether the drain valve has a normally closed fault based on the liquid level status indicated by the liquid level sensor if neither the exhaust valve nor the drain valve has a normally open fault, and to determine whether the exhaust valve has a normally closed fault based on the pressure change at the ejector inlet before and after the exhaust valve is opened.

[0019] Thirdly, embodiments of this application also provide an electronic device, including: a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the memory via the bus. When the machine-readable instructions are executed by the processor, the steps of the above-described fuel cell system solenoid valve fault detection method are performed.

[0020] Fourthly, embodiments of this application also provide a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the steps of the above-described fuel cell system solenoid valve fault detection method.

[0021] The embodiments of this application bring the following beneficial effects:

[0022] This application provides a method, apparatus, and electronic device for detecting solenoid valve faults in a fuel cell system. It can determine whether both the exhaust valve and drain valve have a normally open fault based on the difference between the actual and theoretical pressure at the ejector inlet. If neither has a normally open fault, it further determines whether the drain valve has a normally closed fault based on the liquid level. It also determines whether the exhaust valve has a normally closed fault based on the pressure value at the ejector inlet. This eliminates the need to use a flow meter and hydrogen injection duty cycle for solenoid valve fault detection. Compared to existing fuel cell system solenoid valve fault detection methods, this method solves the problems of low detection accuracy and high detection costs.

[0023] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A flowchart of the solenoid valve fault detection method for a fuel cell system provided in an embodiment of this application is shown;

[0026] Figure 2 A schematic diagram of the structure of the fuel cell hydrogen subsystem provided in the embodiments of this application is shown;

[0027] Figure 3 A schematic diagram of the structure of the solenoid valve fault detection device for a fuel cell system provided in an embodiment of this application is shown;

[0028] Figure 4 A schematic diagram of the structure of the electronic device provided in the embodiments of this application is shown. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. Based on the embodiments of this application, every other embodiment obtained by those skilled in the art without inventive effort falls within the scope of protection of this application.

[0030] It is worth noting that prior to this application, the basic working principle of fuel cells was that hydrogen and oxygen underwent an electrochemical reaction in the presence of a catalyst, converting chemical energy into electrical energy; the only reactant was water. The purity of hydrogen in automotive fuel cells is required to be above 99.99%, and the hydrogen concentration on the hydrogen side where the reaction occurs inside the fuel cell is generally required to be above 80%. The chemical reaction on the air side generates water. As the amount of water increases, it diffuses from the cathode to the anode (hydrogen side) of the fuel cell. Nitrogen and other impurity gases from the air also diffuse from the cathode. Excessive water on the anode side will block the channels between hydrogen and the catalyst surface. Excessive nitrogen and other impurity gases will reduce the hydrogen concentration on the anode side, decreasing the amount of hydrogen on the catalyst surface. Both of these situations will affect the fuel cell's power generation reaction. Therefore, it is necessary to add an exhaust valve and a drain valve on the hydrogen side. The exhaust valve is used to remove accumulated impurity gases, and the drain valve is used to remove excess water, ensuring that the hydrogen concentration and water content on the anode side are within the normal required range. However, both the exhaust valve and the drain valve are solenoid valves and lack internal fault feedback functionality. When the exhaust valve or drain valve fails to open due to an abnormality, the engine will experience a voltage drop, preventing it from generating electricity. However, there are many reasons for a voltage drop in the engine, making it difficult to pinpoint whether the problem lies with the exhaust valve or drain valve, or something else. Furthermore, when the exhaust valve and drain valve are constantly open, it can cause excessively high hydrogen concentrations in the exhaust, leading to hydrogen safety issues.

[0031] Currently, two common methods are used to determine if an exhaust or drain valve is malfunctioning: First, by monitoring the increase in hydrogen injection duty cycle when the exhaust or drain valve is normally open; second, by adding a flow meter at the hydrogen inlet of the fuel cell system and monitoring flow changes during valve opening and closing. However, the first method estimates hydrogen flow using the hydrogen injection duty cycle and the MAP (Mean Assurance Map) of the hydrogen injector. But the hydrogen injection duty cycle is not only related to flow rate but also to the resistance of the hydrogen injector solenoid valve, which increases with nozzle temperature. Furthermore, the MAP cannot be calibrated in real-time. Additionally, flow changes caused by the exhaust or drain valve opening have little impact on the hydrogen injection duty cycle, leading to false alarms and inaccurate solenoid valve detection. The second method requires expensive flow meters, and currently, there are no automotive-grade hydrogen flow meters available for onboard hydrogen flow monitoring; adding a flow meter is only suitable for laboratory scenarios.

[0032] Based on this, embodiments of this application provide a method for detecting solenoid valve faults in a fuel cell system, which improves detection accuracy and reduces detection costs when performing solenoid valve fault detection.

[0033] Please see Figure 1 , Figure 1 This is a flowchart illustrating a method for detecting solenoid valve faults in a fuel cell system, as provided in an embodiment of this application. Figure 1 As shown in the embodiments of this application, the method for detecting solenoid valve faults in a fuel cell system includes:

[0034] Step S101: When the auxiliary hydrogen injection is not in operation, compare the current absolute pressure deviation with the set threshold and obtain the comparison result.

[0035] In this step, the absolute pressure deviation is the difference between the actual pressure at the ejector inlet and the theoretical pressure. The absolute pressure deviation changes over time. Taking the current time as T1 as an example, the theoretical pressure is denoted as P0, and the actual pressure is denoted as P... act The absolute pressure deviation at the current time T1 is denoted as: P T1 Then P T1 =P act -P0.

[0036] The set threshold is a calibration value, determined during operation through calibration using a normally open exhaust valve and / or drain valve. The set threshold includes a first set threshold and a second set threshold. The first set threshold is obtained by calibrating the pressure at the ejector inlet when both the exhaust valve and drain valve are open simultaneously. The first set threshold is denoted as P. highThe second set threshold is obtained by calibrating the pressure at the ejector inlet when the exhaust valve or drain valve is open. The second set threshold is denoted as: P. mid .

[0037] In this embodiment, the fuel cell system solenoid valve fault detection method is applied to the controller of the fuel cell system, which is used to detect faults in the drain valve and exhaust valve of the fuel cell system. The fuel cell system includes a hydrogen subsystem and a controller. A fuel cell may refer to a fuel cell in a hydrogen-powered vehicle.

[0038] The following reference Figure 2 This section will introduce the operation process of the hydrogen subsystem in a fuel cell system.

[0039] Figure 2 A schematic diagram of the structure of the fuel cell hydrogen subsystem provided in the embodiments of this application is shown.

[0040] like Figure 2 As shown, the fuel cell hydrogen subsystem includes a battery pack (PACK), main hydrogen injection, auxiliary hydrogen injection (bypass hydrogen injection), ejector, water distribution unit, vent valve, drain valve, sensors P-0, P-1, P-2, and P-3, and related pipelines. The PACK includes the fuel cell stack, wiring harness, etc., and the fuel cell stack is used for power generation. Sensor P-0 is a pressure sensor at the hydrogen injection inlet; sensor P-1 is a pressure sensor at the ejector inlet; sensor P-2 is a pressure sensor at the ejector outlet; and sensor P-3 is an ultrasonic liquid level sensor.

[0041] Here, the fuel cell hydrogen subsystem is also called the fuel cell engine hydrogen subsystem. Sensor P-0 is used to collect the pressure at the hydrogen injection inlet, sensor P-1 is used to collect the pressure at the ejector inlet, sensor P-2 is used to collect the pressure at the junction of the ejector and auxiliary hydrogen injection, and sensor P-3 is used to detect the liquid level at the water distribution device. When the liquid level is high, the drain valve is opened to drain the water.

[0042] Specifically, when a vehicle operates at high power, such as when traveling at high speeds, the demand for hydrogen also increases. If the main hydrogen injection and ejector alone cannot provide sufficient hydrogen flow, the auxiliary hydrogen injection will supplement the insufficient hydrogen flow. Therefore, the auxiliary hydrogen injection will only intervene when the high-power main hydrogen injection cannot provide enough hydrogen flow; otherwise, the auxiliary hydrogen injection will not operate.

[0043] As the flow rate of hydrogen entering the fuel cell stack increases, the pressure at the ejector tip also increases significantly. Under normal operation, there is a correlation between the ejector inlet pressure (the pressure collected by sensor P-1) and the fuel cell output current. When the exhaust valve or drain valve is open, the ejector inlet pressure will be significantly higher than when it is closed. By analyzing the change in ejector inlet pressure with the opening / closing of the exhaust valve or drain valve, it is possible to detect whether there are any abnormalities in the exhaust valve or drain valve, thus enabling fault detection of the exhaust valve and drain valve.

[0044] In this embodiment, after the engine starts, it first checks whether the auxiliary hydrogen injection is in operation. If the auxiliary hydrogen injection is in operation, the exhaust valve and drain valve fault detection is not performed. If the auxiliary hydrogen injection is not in operation, the exhaust valve and drain valve fault detection begins. The current output current at the moment the fault detection begins is obtained. For example, if the current output current is 100A, the theoretical pressure P0 at the ejector inlet corresponding to 100A is obtained from the ejector's MAP diagram or the test calibration value. Simultaneously, the actual pressure P at the ejector inlet is collected through sensor P-1. act , will P act The difference between P0 and P0 is taken as the absolute pressure deviation. Then, the absolute pressure deviation is compared with the first set threshold and the second set threshold to obtain the comparison result.

[0045] Step S102: Based on the comparison results, determine whether both the exhaust valve and the drain valve have a normally open fault.

[0046] In this step, the comparison result between the absolute pressure deviation and the set threshold is divided into three cases. The first case is that the absolute pressure deviation P T1 P is between the first set threshold and the second set threshold. mid <P T1 <P high The second type is when the absolute pressure deviation is greater than or equal to the first set threshold, i.e., P. T1 ≥P high The third type is where the absolute pressure deviation is less than or equal to the second set threshold, i.e., P. T1 ≤P mid .

[0047] For the first case, after step S101, the steps include: step a1, step a2, step a3, and step a4.

[0048] Step a1: If the absolute pressure deviation is between the first set threshold and the second set threshold, then starting from the new current moment, select consecutive target solenoid valve opening cycles as multiple first opening cycles.

[0049] If P mid<P T1 <P high This indicates a malfunction in either the exhaust valve or the drain valve. To determine which solenoid valve is faulty, further investigation is needed. Therefore, multiple consecutive first opening cycles are selected. If the target solenoid valve is a drain valve, the first opening cycle consists of multiple consecutive cycles before and after the drain valve opens; if the target solenoid valve is an exhaust valve, the first opening cycle consists of multiple consecutive cycles before and after the exhaust valve opens.

[0050] Step a2: For each first opening cycle, determine the first actual pressure difference value corresponding to that first opening cycle.

[0051] Assuming the number of first opening cycles is N, then the first actual pressure difference value corresponding to each first opening cycle is determined, and the first actual pressure difference value is denoted as: P. diff1 A total of N first actual pressure difference values ​​P can be obtained. diff1 .

[0052] It should be noted that the first actual pressure difference value is a variable, which is calculated and updated in real time before and after each opening of the exhaust valve. The updated P is used in each judgment. diff1 The actual pressure difference value obtained at different times is different.

[0053] Step a3: Determine whether each first actual pressure difference value is greater than the target theoretical pressure difference value.

[0054] Here, the target theoretical pressure difference is the pressure difference at the ejector inlet before and after the target solenoid valve opens, denoted as ΔP. ​​The target theoretical pressure difference includes a first theoretical pressure difference and a second theoretical pressure difference. If the target solenoid valve is an exhaust valve, the target theoretical pressure difference is the pressure difference at the ejector inlet before and after the exhaust valve opens, i.e., the first theoretical pressure difference, denoted as ΔP1. If the target solenoid valve is a drain valve, the target theoretical pressure difference is the pressure difference at the ejector inlet before and after the drain valve opens, i.e., the second theoretical pressure difference, denoted as ΔP2.

[0055] Specifically, for each P diff1 Determine the P diff1 Whether it is greater than ΔP, a total of N comparison results can be obtained.

[0056] Step a4: If all the first actual differential pressure values ​​are greater than the target theoretical differential pressure value, then the target solenoid valve is determined to be in a normal state; otherwise, the target solenoid valve is determined to have a normally open fault.

[0057] When the target solenoid valve is an exhaust valve, if N P diff1If all N values ​​are greater than ΔP1, then the exhaust valve is confirmed to be normal, while the drain valve has a normally open fault; if N values ​​of P1 are greater than ΔP1, then the exhaust valve is normal, while the drain valve has a normally open fault. diff1 There is any P diff1 If the value is less than or equal to ΔP1, then the drain valve is normal, but the air vent valve has a normally open fault.

[0058] When the target solenoid valve is a drain valve, if N P diff1 If all values ​​are greater than ΔP2, then the drain valve is normal, but the air vent valve has a normally open fault; if N values ​​of P2 are greater than ΔP2, then the drain valve is normal, but the air vent valve has a normally open fault. diff1 There is any P diff1 If the value is less than or equal to ΔP2, then the exhaust valve is normal, but the drain valve has a normally open fault.

[0059] Once the fault is identified, the corresponding fault code is reported, and the corresponding fault tolerance scheme is executed.

[0060] For the second and third cases, step S102 includes: step b1 and step b2.

[0061] Step b1: If the absolute pressure deviation is greater than or equal to the first set threshold, it is determined that both the exhaust valve and the drain valve have a normally open fault.

[0062] If P T1 ≥P high If the exhaust valve and drain valve are both leaking, it indicates that both the exhaust valve and drain valve are normally open. In this case, it is necessary to report the normally open exhaust valve fault, the normally open drain valve fault, and the serious hydrogen leakage fault, and immediately perform the shutdown operation.

[0063] Step b2: If the absolute pressure deviation is less than or equal to the second set threshold, it is determined that neither the exhaust valve nor the drain valve is normally open.

[0064] If P T1 ≤P mid If the air pressure is normal, it means that neither the exhaust valve nor the drain valve is leaking, confirming that neither the exhaust valve nor the drain valve is normally open.

[0065] Step S103: If neither the vent valve nor the drain valve has a normally open fault, determine whether the drain valve has a normally closed fault based on the liquid level status indicated by the liquid level sensor, and determine whether the vent valve has a normally closed fault based on the pressure change at the ejector inlet before and after the vent valve is opened.

[0066] In this step, since neither the exhaust valve nor the drain valve has a normally open fault, it is necessary to continue testing for a normally closed fault. Because the methods for testing normally closed faults in the exhaust valve and the drain valve are different, the order in which they are tested can be disregarded. The exhaust valve can be tested first, followed by the drain valve, or vice versa.

[0067] If the drain valve has a normally closed fault, it will be reflected in the liquid level status of the level sensor. Therefore, the presence of a normally closed fault in the drain valve can be determined based on the liquid level status indicated by the level sensor. Additionally, the pressure change at the ejector inlet before and after the vent valve is opened can be used to further determine if the vent valve has a normally closed fault.

[0068] In an optional embodiment, step S103, determining whether the drain valve has a normally closed fault based on the liquid level status indicated by the liquid level sensor, includes steps c1, c2, and c3.

[0069] Step c1: Obtain the liquid level status indicated by the liquid level sensor after the drain valve has finished opening.

[0070] When performing a normally closed fault detection on the drain valve, the vent valve needs to be closed, and the drain valve should be opened according to its opening frequency. When the drain valve closes after opening, the liquid level indicated by sensor P-3 should be acquired. The liquid level status includes high and low.

[0071] Step c2: If the liquid level changes from high to low after the drain valve is opened, it is determined that the drain valve does not have a normally closed fault.

[0072] If the ultrasonic level sensor changes the liquid level from high to low after the drain valve is opened and closed, it indicates that the drain valve can open and drain normally, and there is no normally closed fault in the drain valve.

[0073] Step c3: If the liquid level is still high after the drain valve is opened, shorten the drain cycle. Based on the change in liquid level after shortening the drain cycle, determine whether the drain valve has a normally closed fault.

[0074] If the ultrasonic level sensor still indicates a high liquid level after the drain valve is opened and closed, it is necessary to further confirm whether the drain valve is not open, whether the ultrasonic level sensor itself is faulty, or whether the previous drainage was insufficient.

[0075] To further confirm why the liquid level remains unchanged, the drainage cycle needs to be shortened to observe the changes in the liquid level during the shortened drainage cycle.

[0076] In an optional embodiment, step c3 includes: step c31, step c32, step c33, step c34, and step c35.

[0077] Step c31: After shortening the drainage cycle, select consecutive new drainage valve opening cycles as multiple second opening cycles.

[0078] After adjusting the drainage cycle, a series of consecutive drain valve opening cycles starting from the new current time T2 are selected as the second opening cycle. For example, before shortening the drainage cycle, each drain valve opening cycle was 30 seconds, with each cycle opening for 1 second. After shortening the drainage cycle, each drain valve opening cycle is 3 seconds, with each cycle opening for 1 second. Three consecutive cycles of opening, totaling 9 seconds in duration, constitute the three second opening cycles. The second opening cycle is part of the drain valve opening cycle. Those skilled in the art can choose the number of consecutive opening cycles based on actual circumstances; this application does not impose any limitations on this.

[0079] Step c32: For each second opening cycle, determine the second actual pressure difference value corresponding to that second opening cycle.

[0080] Taking the above example, for each of the three second opening cycles, calculate the change in the average pressure at the ejector inlet before and after the drain valve opens. This change in average pressure is the second actual pressure difference value, denoted as P. diff2 .

[0081] Step c33: If the liquid level changes from high to low during multiple second opening cycles, it is determined that the drain valve is in normal condition.

[0082] If the liquid level changes from high to low during the above three drain valve opening processes, it indicates that the drain valve can drain normally, thus confirming that the drain valve is in normal condition.

[0083] Step c34: If the liquid level does not decrease and each second actual pressure difference value is less than the second theoretical pressure difference value during multiple second opening cycles, it is determined that the drain valve has a normally closed fault.

[0084] Here, the second theoretical pressure difference value is the pressure difference at the ejector inlet before and after the drain valve is opened.

[0085] If the liquid level remains high during the above three drain valve opening processes and the corresponding P in each second opening cycle is... diff2 If all values ​​are less than ΔP2, it indicates that the drain valve cannot drain normally, thus confirming that the drain valve has a normally closed fault.

[0086] Step c35: If, during multiple second opening cycles, the liquid level does not decrease and there is a second actual pressure difference value among multiple second actual pressure difference values ​​that is greater than or equal to the second theoretical pressure difference value, it is determined that the drain valve does not have a normally closed fault, but the liquid level sensor has a fault.

[0087] If the liquid level remains high during the above three drain valve opening processes and there is a second opening cycle corresponding to P diff2If the value is greater than or equal to ΔP2, it indicates that the drain valve can drain normally, thus confirming that the drain valve does not have a normally closed fault. The lack of change in liquid level is due to a fault in the liquid level sensor. Report the liquid level sensor fault and adjust the working mode of the drain valve to a fixed periodic opening, that is, return to the working mode before the drainage cycle was shortened.

[0088] In an optional embodiment, step S103 determines whether the exhaust valve has a normally closed fault based on the pressure change at the ejector inlet before and after the exhaust valve is opened, including steps d1, d2, d3, and d4.

[0089] Step d1: Starting from the latest current moment, select consecutive new exhaust valve opening cycles as multiple third opening cycles.

[0090] When performing a normally closed fault detection on the exhaust valve, the drain valve needs to be closed, while the exhaust valve is controlled to open. The moment when the normally closed fault detection of the exhaust valve is performed is taken as the latest current time T3. Starting from the current time T3, a series of consecutive exhaust valve opening cycles are selected as the third opening cycle. For example, three consecutive exhaust valve opening cycles are selected as the third opening cycle, which is part of the exhaust valve opening cycle.

[0091] Step d2: For each third opening cycle, determine the third actual pressure difference value corresponding to that third opening cycle.

[0092] Taking the above example, for each of the three third opening cycles, calculate the change in the average pressure at the ejector inlet before and after the exhaust valve opens. This change in average pressure is the third actual pressure difference value, denoted as P. diff3 .

[0093] Step d3: If multiple third actual pressure difference values ​​are all less than the first theoretical pressure difference value, then it is determined that the exhaust valve has a normally closed fault.

[0094] Here, the first theoretical pressure difference value is the pressure difference at the ejector inlet before and after the exhaust valve is opened.

[0095] If, during the above three exhaust valve opening processes, P corresponds to each exhaust valve opening cycle... diff3 If all values ​​are less than ΔP1, it indicates that the exhaust valve cannot open normally, thus confirming that the exhaust valve has a normally closed fault.

[0096] Step d4: If there is a third actual pressure difference value among the multiple third actual pressure difference values ​​that is greater than or equal to the first theoretical pressure difference value, then it is determined that the exhaust valve is in normal condition.

[0097] If, during the above three exhaust valve opening processes, at least one exhaust valve opening cycle corresponding to P occurs...diff3 If the value is greater than or equal to ΔP1, it means that the exhaust valve can exhaust normally, thus confirming that the exhaust valve is in normal condition.

[0098] It should be noted that when the normally closed fault detection is performed on the exhaust valve first, and then on the drain valve, the second opening cycle is the exhaust valve opening cycle, and the third opening cycle is the drain valve opening cycle. Correspondingly, the second actual pressure difference value is the change in the average pressure at the ejector inlet before and after the exhaust valve opens. Simultaneously, the second actual pressure difference value is compared with the first theoretical pressure difference value to determine whether the exhaust valve has a normally closed fault. The third actual pressure difference value is the change in the average pressure at the ejector inlet before and after the drain valve opens. Simultaneously, the third actual pressure difference value is compared with the second theoretical pressure difference value to determine whether the drain valve has a normally closed fault.

[0099] In an optional embodiment, the actual differential pressure value corresponding to each opening cycle is determined by the following steps: e1, e2, and e3.

[0100] Step e1: For each opening cycle, obtain multiple pre-opening pressure values ​​and multiple post-opening pressure values ​​corresponding to that opening cycle.

[0101] Here, the pressure value before each opening is the pressure value at the ejector inlet within the first preset time interval before the target solenoid valve opens in the opening cycle, and the pressure value after each opening is the pressure value at the ejector inlet within the second preset time interval after the target solenoid valve opens in the opening cycle.

[0102] Each activation cycle includes multiple first activation cycles, multiple second activation cycles, and multiple third activation cycles.

[0103] Taking the target solenoid valve as an example of a single first opening cycle of the exhaust valve, according to the opening frequency of the exhaust valve, each time the exhaust valve opens, multiple pressure values ​​at the ejector inlet are calculated within the first preset time interval of 100ms before the exhaust valve opens. This pressure value is the pre-opening pressure value corresponding to the first opening cycle, and the pre-opening pressure value corresponding to the first opening cycle is denoted as: P b1 Simultaneously, multiple pressure values ​​at the ejector inlet are calculated within a second preset time interval of 200ms after the exhaust valve opens. These pressure values ​​are the post-opening pressure values ​​corresponding to the first opening cycle, denoted as P. a1 Additionally, the pressure value before opening corresponding to the second opening cycle is denoted as: P. b2 The pressure value after the second opening cycle is denoted as: P a2 The pressure value before opening corresponding to the third opening cycle is denoted as: P b3 The pressure value after the third opening cycle is denoted as: P a3Those skilled in the art can select the specific duration of the first preset time interval and the second preset time interval according to the actual situation, and this application does not impose any restrictions here.

[0104] Taking a single first opening cycle of the target solenoid valve as a drain valve as an example, according to the opening frequency of the drain valve, each time the drain valve opens, multiple pressure values ​​at the ejector inlet are calculated within a first preset time interval of 100ms before the drain valve opens. For example, a pressure value is obtained every 10ms within 100ms, for a total of 10 pressure values. This pressure value is the pre-opening pressure value corresponding to the first opening cycle. At the same time, multiple pressure values ​​at the ejector inlet are calculated within a second preset time interval of 200ms after the drain valve opens. This pressure value is the post-opening pressure value corresponding to the first opening cycle.

[0105] The calculation methods for the pre-opening pressure value and post-opening pressure value corresponding to the second and third opening cycles are the same as those for the first opening cycle, except for the time difference. The calculation methods for the pre-opening pressure value and post-opening pressure value corresponding to the second and third opening cycles will not be repeated here.

[0106] Step e2: Take the average of the multiple pressure values ​​before opening as the average of the front pressure, and take the average of the multiple pressure values ​​after opening as the average of the rear pressure.

[0107] Calculate multiple P b1 The average value of the front pressure corresponding to the first opening cycle is obtained by averaging the values ​​of ... bf1 Calculate multiple P a1 The average value of the first opening cycle is obtained by averaging the values ​​of the first and second opening cycles. The average value of the first pressure is denoted as P. af1 .

[0108] Calculate multiple P b2 The average value of the front pressure corresponding to the second opening cycle is obtained by averaging the values ​​of ... bf2 Calculate multiple P a2 The average value of the pressure after the second opening cycle is obtained by averaging the values ​​of ... af2 .

[0109] Calculate multiple P b3 The average value of the front pressure corresponding to the third opening cycle is obtained by averaging the values ​​of ... bf3 Calculate multiple P a3 The average value of the pressure after the third opening cycle is obtained by averaging the values ​​of ... af3 .

[0110] Step e3: The difference between the average front pressure and the average rear pressure is taken as the actual pressure difference value corresponding to this opening cycle.

[0111] The first actual pressure difference is P. diff1 Then P diff1 =P af1 -P bf1 The second actual pressure difference is P. diff2 Then P diff2 =P af2 -P bf2 The third actual pressure difference is P. diff3 Then P diff3 =P af3 -P bf3 .

[0112] Compared with existing methods for detecting solenoid valve faults in fuel cell systems, this application can determine whether both the exhaust valve and the drain valve have a normally open fault based on the difference between the actual pressure and the theoretical pressure at the ejector inlet. If neither has a normally open fault, it further determines whether the drain valve has a normally closed fault based on the liquid level and whether the exhaust valve has a normally closed fault based on the pressure value at the ejector inlet. This eliminates the need to use a flow meter and hydrogen injection duty cycle for solenoid valve fault detection, thus solving the problems of low detection accuracy and high detection cost in solenoid valve fault detection.

[0113] Based on the same inventive concept, this application also provides a fuel cell system solenoid valve fault detection device corresponding to the fuel cell system solenoid valve fault detection method. Since the principle of the device in this application is similar to the fuel cell system solenoid valve fault detection method described above, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be described again.

[0114] Please see Figure 3 , Figure 3 This is a schematic diagram of a solenoid valve fault detection device for a fuel cell system provided in an embodiment of this application. Figure 3 As shown, the fuel cell system solenoid valve fault detection device 200 includes:

[0115] The numerical comparison module 201 is used to compare the current absolute pressure deviation with a set threshold when the auxiliary hydrogen injection is not in operation, and obtain the comparison result. The absolute pressure deviation is the difference between the actual pressure and the theoretical pressure at the ejector inlet.

[0116] The first fault determination module 202 is used to determine, based on the comparison results, whether both the exhaust valve and the drain valve have a normally open fault.

[0117] The second fault determination module 203 is used to determine whether the drain valve has a normally closed fault based on the liquid level status indicated by the liquid level sensor if neither the exhaust valve nor the drain valve has a normally open fault, and to determine whether the exhaust valve has a normally closed fault based on the pressure value change at the ejector inlet before and after the exhaust valve is opened.

[0118] Please see Figure 4 , Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 4 As shown, the electronic device 300 includes a processor 310, a memory 320, and a bus 330.

[0119] The memory 320 stores machine-readable instructions executable by the processor 310. When the electronic device 300 is running, the processor 310 and the memory 320 communicate via the bus 330. When the machine-readable instructions are executed by the processor 310, they can perform the operations described above. Figure 1 The steps of the fuel cell system solenoid valve fault detection method in the method embodiment shown are specifically implemented in the method embodiment and will not be repeated here.

[0120] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, can perform the above-described actions. Figure 1 The steps of the fuel cell system solenoid valve fault detection method in the method embodiment shown are specifically implemented in the method embodiment and will not be repeated here.

[0121] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0122] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0123] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0124] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0125] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0126] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The scope of protection of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A fuel cell system solenoid valve failure detection method characterized by, include: When the auxiliary hydrogen injection is not in operation, the absolute pressure deviation at the current moment is compared with a set threshold to obtain the comparison result. The absolute pressure deviation is the difference between the actual pressure and the theoretical pressure at the ejector inlet. Based on the comparison results, determine whether both the exhaust valve and the drain valve have a normally open fault; If neither the vent valve nor the drain valve has a normally open fault, determine whether the drain valve has a normally closed fault based on the liquid level status indicated by the liquid level sensor, and determine whether the vent valve has a normally closed fault based on the pressure change at the ejector inlet before and after the vent valve is opened. The step of determining whether the drain valve has a normally closed fault based on the liquid level status indicated by the liquid level sensor includes: After the drain valve has finished opening, obtain the liquid level status indicated by the liquid level sensor; If the liquid level changes from high to low after the drain valve has finished opening, it is determined that the drain valve does not have a normally closed fault. If the liquid level is still high after the drain valve is opened, the drain cycle is shortened, and the change in liquid level after the drain cycle is shortened is used to determine whether the drain valve has a normally closed fault. The step of determining whether the exhaust valve has a normally closed fault based on the pressure change at the ejector inlet before and after the exhaust valve is opened includes: Starting from the latest current moment, select consecutive new exhaust valve opening cycles as multiple third opening cycles; For each third opening cycle, determine the corresponding third actual pressure difference value; If multiple third actual pressure difference values ​​are all less than the first theoretical pressure difference value, it is determined that the exhaust valve has a normally closed fault. The first theoretical pressure difference value is the pressure difference of the ejector inlet treatment before and after the exhaust valve is opened. If there is a third actual pressure difference value among multiple third actual pressure difference values ​​that is greater than or equal to the first theoretical pressure difference value, then the exhaust valve is determined to be in normal condition.

2. The method of claim 1, wherein, The set threshold includes a first set threshold and a second set threshold. Determining whether both the exhaust valve and the drain valve have a normally open fault based on the comparison result includes: If the absolute pressure deviation is greater than or equal to the first set threshold, it is determined that both the exhaust valve and the drain valve have a normally open fault. If the absolute pressure deviation is less than or equal to the second set threshold, it is determined that neither the exhaust valve nor the drain valve has a normally open fault.

3. The method of claim 2, wherein, After comparing the absolute pressure deviation at the current moment with the set threshold, the method further includes: If the absolute pressure deviation is between the first set threshold and the second set threshold, then starting from the new current moment, a series of consecutive target solenoid valve opening cycles are selected as multiple first opening cycles. For each first opening cycle, determine the first actual pressure difference value corresponding to that first opening cycle; Determine whether each first actual pressure difference value is greater than the target theoretical pressure difference value, where the target theoretical pressure difference value is the pressure difference at the ejector inlet before and after the target solenoid valve is opened; If all the first actual differential pressure values ​​are greater than the target theoretical differential pressure value, then the target solenoid valve is determined to be in normal condition; otherwise, the target solenoid valve is determined to have a normally open fault.

4. The method of claim 1, wherein, The step of determining whether the drain valve has a normally closed fault based on the liquid level change after shortening the drainage cycle includes: After shortening the drainage cycle, select consecutive new drainage valve opening cycles as multiple second opening cycles; For each second opening cycle, determine the corresponding second actual pressure difference value; If the liquid level changes from high to low during the plurality of second opening cycles, it is determined that the drain valve is in a normal state; If, during the plurality of second opening cycles, the liquid level does not decrease and each second actual pressure difference value is less than the second theoretical pressure difference value, it is determined that the drain valve has a normally closed fault. The second theoretical pressure difference value is the pressure difference at the ejector inlet before and after the drain valve is opened. If, during the plurality of second opening cycles, the liquid level does not decrease and there is a second actual pressure difference value among the plurality of second actual pressure difference values ​​that is greater than or equal to the second theoretical pressure difference value, it is determined that the drain valve does not have a normally closed fault, but the liquid level sensor has a fault.

5. The method according to claim 3 or 4, characterized in that, The actual differential pressure value corresponding to each opening cycle is determined using the following method: For each opening cycle, multiple pre-opening pressure values ​​and multiple post-opening pressure values ​​are obtained. Each pre-opening pressure value is the pressure value at the ejector inlet within a first preset time interval before the target solenoid valve opens in the opening cycle, and each post-opening pressure value is the pressure value at the ejector inlet within a second preset time interval after the target solenoid valve opens in the opening cycle. The average value of the multiple pressure values ​​before opening is taken as the average front pressure, and the average value of the multiple pressure values ​​after opening is taken as the average rear pressure. The difference between the average front pressure and the average rear pressure is taken as the actual pressure difference value corresponding to the opening cycle.

6. A fuel cell system solenoid valve failure detection device characterized by comprising: include: The numerical comparison module is used to compare the absolute pressure deviation at the current moment with a set threshold when the auxiliary hydrogen injection is not in operation, and to obtain the comparison result. The absolute pressure deviation is the difference between the actual pressure and the theoretical pressure at the ejector inlet. The first fault determination module is used to determine, based on the comparison results, whether both the exhaust valve and the drain valve have a normally open fault. The second fault determination module is used to determine whether the drain valve has a normally closed fault based on the liquid level state indicated by the liquid level sensor if neither the exhaust valve nor the drain valve has a normally open fault, and to determine whether the exhaust valve has a normally closed fault based on the pressure value change at the ejector inlet before and after the exhaust valve is opened. The second fault determination module is specifically used for: After the drain valve has finished opening, obtain the liquid level status indicated by the liquid level sensor; If the liquid level changes from high to low after the drain valve has finished opening, it is determined that the drain valve does not have a normally closed fault. If the liquid level is still high after the drain valve is opened, the drain cycle is shortened, and the change in liquid level after the drain cycle is shortened is used to determine whether the drain valve has a normally closed fault. Starting from the latest current moment, select consecutive new exhaust valve opening cycles as multiple third opening cycles; For each third opening cycle, determine the corresponding third actual pressure difference value; If multiple third actual pressure difference values ​​are all less than the first theoretical pressure difference value, it is determined that the exhaust valve has a normally closed fault. The first theoretical pressure difference value is the pressure difference of the ejector inlet treatment before and after the exhaust valve is opened. If there is a third actual pressure difference value among multiple third actual pressure difference values ​​that is greater than or equal to the first theoretical pressure difference value, then the exhaust valve is determined to be in normal condition.

7. An electronic device, comprising: include: The device includes a processor, a storage medium, and a bus, wherein the storage medium stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor communicates with the storage medium via the bus, and the processor executes the machine-readable instructions to perform the steps of the fuel cell system solenoid valve fault detection method as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, performs the steps of the fuel cell system solenoid valve fault detection method as described in any one of claims 1 to 5.

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