Method and apparatus for diagnosing fuel cell controller proportional valve stick

Abstract

The application provides a fuel cell controller proportional valve sticking diagnosis method and device. The fuel cell controller proportional valve sticking diagnosis method comprises the following steps: monitoring the values of the Bypass proportional valve duty cycle and the hydrogen inlet stack pressure P2 during the stable current point operation of the fuel cell; obtaining the average hydrogen inlet stack pressure C before the exhaust valve is opened, the minimum value D of the hydrogen inlet stack pressure after the exhaust valve is opened, and the maximum value F of the Bypass proportional valve PWM after the exhaust valve is opened; judging whether the Bypass proportional valve works normally; if the Bypass proportional valve does not work normally, judging whether the Bypass proportional valve has sticking phenomenon; if the Bypass proportional valve has sticking phenomenon, prohibiting the opening of the exhaust valve, sending the PWM excitation to the Bypass proportional valve, and collecting the corresponding information of the PWM excitation; judging whether the Bypass proportional valve is stuck based on the collected corresponding information of the PWM excitation, and sending the proportional valve sticking fault signal. The purpose of reducing the damage caused by the proportional valve failure to the system and improving the reliability of the fuel cell system is achieved.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, and in particular relates to a diagnostic method and apparatus for a proportional valve stuck in a fuel cell controller. Background Technology

[0002] Hydrogen fuel cell vehicles are promising new energy vehicles with advantages such as short refueling time and long driving range. A fuel cell system typically includes a fuel cell stack and peripheral components for hydrogen, air, and cooling. The stack includes a proton exchange membrane, catalyst layer, gas diffusion layer, and bipolar plates. Because the membrane electrode assembly (MEA) in the stack requires high stability of the gas supply pressure, the fuel cell is highly sensitive to pressure fluctuations in the hydrogen injection system. Currently, fuel cell hydrogen injection systems typically use proportional valves to meterly supply hydrogen. Existing technology mainly controls hydrogen pressure, but if the proportional valve jams or fails during operation, as an actuator, there is no fault feedback mechanism. The proportional valve fault can only be detected after the fuel cell hydrogen system experiences overpressure, requiring disassembly and inspection. This leads to the problem of undetected proportional valve faults causing damage to the fuel cell system and affecting its reliability. Summary of the Invention

[0003] In view of the problems existing in the prior art, the present invention provides a diagnostic method and device for proportional valve sticking in fuel cell controllers, which at least partially solves the problem of proportional valve failure causing damage to fuel cell systems in the prior art.

[0004] In a first aspect, embodiments of this disclosure provide a diagnostic method for a stuck proportional valve in a fuel cell controller. The fuel cell hydrogen control device includes an ejector, a main proportional valve, and a bypass proportional valve. The method includes:

[0005] During operation at the fuel cell steady current point, monitor the duty cycle of the Bypass proportional valve and the value of hydrogen inlet pressure P2.

[0006] During a complete exhaust valve operation cycle, the PWM of the Bypass proportional valve and the hydrogen inlet pressure P2 are collected to calculate the average hydrogen inlet pressure C before the exhaust valve opens, the minimum hydrogen inlet pressure D after the exhaust valve opens, and the maximum PWM value F of the Bypass proportional valve after the exhaust valve opens. The exhaust valve is installed on the tailpipe of the fuel cell.

[0007] Determine whether the bypass proportional valve is working properly based on the hydrogen inlet pressure C, the minimum hydrogen inlet pressure D, and the maximum PWM value F.

[0008] If the bypass proportional valve is not working properly, determine whether the bypass proportional valve is stuck based on the hydrogen inlet pressure C, the minimum value of the hydrogen inlet pressure D, and the maximum value of the PWM.

[0009] If the bypass proportional valve gets stuck, the exhaust valve will be prevented from opening. At the same time, a PWM excitation will be sent to the bypass proportional valve and the corresponding PWM excitation information will be collected.

[0010] Based on the collected PWM excitation response information, it is determined whether the bypass proportional valve is stuck or malfunctioning, and then a proportional valve stuck fault signal is sent.

[0011] Optionally, the step of determining whether the bypass proportional valve is working properly based on the hydrogen inlet pressure C, the minimum hydrogen inlet pressure D, and the maximum PWM value F includes:

[0012] Determine whether the minimum hydrogen inlet pressure C-D is less than the first set value a, and whether the maximum value F is less than the upper limit of the proportional valve operation f;

[0013] If the minimum hydrogen inlet pressure C-D is less than the first set value a, and the maximum value F is less than the upper limit of the proportional valve's operation, then the bypass proportional valve will operate normally.

[0014] Otherwise, the bypass proportional valve will malfunction.

[0015] Optionally, if the bypass proportional valve malfunctions, determining whether the bypass proportional valve is stuck based on the hydrogen inlet pressure C, the minimum hydrogen inlet pressure D, and the maximum PWM value F includes:

[0016] Then determine whether the minimum value D of the hydrogen inlet pressure C is greater than the second set value b, and whether the maximum value F is equal to the upper limit of the proportional valve operation f;

[0017] If the minimum hydrogen inlet pressure C-D is greater than the second set value b, and the maximum value F is equal to the upper limit of the proportional valve's operation f, then it is preliminarily considered that the bypass proportional valve is stuck.

[0018] Optionally, the bypass proportional valve is sent with a PWM excitation value of d and an excitation time of B.

[0019] Optionally, the acquisition of PWM excitation information includes:

[0020] The average value G of the hydrogen infeed pressure P2 during PWM excitation is collected.

[0021] Optionally, determining whether the bypass proportional valve is stuck or malfunctioning based on the collected PWM excitation response information includes:

[0022] If the absolute value of the average value G - hydrogen inlet pressure C is greater than the second set value b, the proportional valve is determined to be stuck and malfunctioning.

[0023] In a second aspect, embodiments of this disclosure also provide a diagnostic device for a stuck proportional valve in a fuel cell controller, using any of the methods described in the first aspect, including: an ejector, a main proportional valve, a bypass proportional valve, and an exhaust valve;

[0024] The outlet of the main proportional valve is connected to the ejector and the inlet, the outlet of the Bypass proportional valve is connected to the outlet of the ejector, the inlets of the main proportional valve and the Bypass proportional valve are connected to the hydrogen source, the outlet of the ejector is connected to the fuel cell stack, and the exhaust valve is installed on the tailpipe of the fuel cell stack.

[0025] Thirdly, embodiments of this disclosure also provide fuel cells that use any of the methods described in the first aspect.

[0026] Fourthly, embodiments of this disclosure also provide a vehicle that uses any of the methods described in the first aspect.

[0027] Fifthly, embodiments of this disclosure also provide a power device that uses any of the methods described in the first aspect.

[0028] This invention provides a diagnostic method and apparatus for proportional valve sticking in a fuel cell controller. The diagnostic method utilizes periodic active detection to check whether the proportional valve is in normal working order. When a proportional valve malfunctions, it can be detected promptly, thereby reducing the damage caused by proportional valve failure to the system and improving the reliability of the fuel cell system. Attached Figure Description

[0029] The above and other objects, features and advantages of this disclosure will become more apparent from the accompanying drawings, in which like reference numerals generally denote like parts.

[0030] Figure 1 A schematic block diagram of a diagnostic device for a proportional valve stuck in a fuel cell controller provided in an embodiment of this disclosure;

[0031] Figure 2 A flowchart of a diagnostic method for proportional valve sticking in a fuel cell controller provided in an embodiment of this disclosure. Detailed Implementation

[0032] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0033] It should be understood that the following specific examples illustrate the implementation of this disclosure, and those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0034] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0035] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this disclosure. The illustrations only show the components related to this disclosure and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0036] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0037] Hydrogen proportional valve: In a fuel cell hydrogen system, an injector that can be electrically controlled to proportionally adjust the hydrogen flow rate.

[0038] FCU: Fuel Cell Controller

[0039] Main proportional valve: Hydrogen proportional valve connected to the ejector

[0040] Bypass hydrogen injection: a hydrogen proportioning valve directly connected to the fuel cell.

[0041] like Figure 1As shown, the fuel cell system employs an ejector and two proportional valves. The main proportional valve opens first, targeting the pressure at position P2, while the bypass proportional valve closes. This, in conjunction with the ejector, supplies hydrogen to the fuel cell stack at points of lower operating current. When the fuel cell operating current increases, and the main proportional valve alone cannot meet the system's hydrogen consumption, it switches to targeting P1, primarily providing hydrogen return flow to the stack and simultaneously replenishing it with hydrogen. The bypass proportional valve opens after the main proportional valve's control target switch, continuously supplying hydrogen to the fuel cell stack. The hydrogen pressure is maintained above air pressure throughout the fuel cell system's operation to ensure the stack operates at a consistently high efficiency.

[0042] A proportional valve is a valve body driven by current. The electromagnetic force generated by the supply current keeps the proportional valve hovering around a certain opening degree. Generally, automotive controllers use voltage control, with the supply current controlled by a duty cycle. This means the controller's PWM (Pulse Width Modulation) has a linear relationship with the supply current, and this relationship increases or decreases proportionally with the supply voltage.

[0043] In the hydrogen supply system of a fuel cell, during normal operation of the fuel cell, the main proportional valve and the bypass proportional valve correspond to a stable duty cycle at each operating point of the fuel cell.

[0044] The fuel cell system outlet has a periodically opening and closing exhaust valve to discharge the nitrogen generated by the reaction inside the fuel cell system. When the exhaust valve is open, the Bypass proportional valve increases the hydrogen flow rate to maintain the stability of the fuel cell hydrogen system pressure.

[0045] Two situations where a proportional valve becomes stuck:

[0046] 1. The proportional valve is stuck in the closed position and cannot be opened.

[0047] 2. The proportional valve is stuck in the middle position between 0-100%, and the opening degree of the proportional valve cannot be changed by adjusting the magnitude of the drive current.

[0048] This embodiment discloses a diagnostic method for a stuck proportional valve in a fuel cell controller. The fuel cell hydrogen control device includes an ejector, a main proportional valve, and a bypass proportional valve. The method includes:

[0049] During operation at the fuel cell steady current point, monitor the duty cycle of the Bypass proportional valve and the value of hydrogen inlet pressure P2.

[0050] During a complete exhaust valve operation cycle, the PWM of the Bypass proportional valve and the hydrogen inlet pressure P2 are collected to calculate the average hydrogen inlet pressure C before the exhaust valve opens, the minimum hydrogen inlet pressure D after the exhaust valve opens, and the maximum PWM value F of the Bypass proportional valve after the exhaust valve opens. The exhaust valve is installed on the tailpipe of the fuel cell.

[0051] Determine whether the bypass proportional valve is working properly based on the hydrogen inlet pressure C, the minimum hydrogen inlet pressure D, and the maximum PWM value F.

[0052] If the bypass proportional valve is not working properly, determine whether the bypass proportional valve is stuck based on the hydrogen inlet pressure C, the minimum value of the hydrogen inlet pressure D, and the maximum value of the PWM.

[0053] If the bypass proportional valve gets stuck, the exhaust valve will be prevented from opening. At the same time, a PWM excitation will be sent to the bypass proportional valve and the corresponding PWM excitation information will be collected.

[0054] Based on the collected PWM excitation response information, it is determined whether the bypass proportional valve is stuck or malfunctioning, and then a proportional valve stuck fault signal is sent.

[0055] Optionally, the step of determining whether the bypass proportional valve is working properly based on the hydrogen inlet pressure C, the minimum hydrogen inlet pressure D, and the maximum PWM value F includes:

[0056] Determine whether the minimum hydrogen inlet pressure C-D is less than the first set value a, and whether the maximum value F is less than the upper limit of the proportional valve operation f;

[0057] If the minimum hydrogen inlet pressure C-D is less than the first set value a, and the maximum value F is less than the upper limit of the proportional valve's operation, then the bypass proportional valve will operate normally.

[0058] Otherwise, the bypass proportional valve will malfunction.

[0059] Optionally, if the bypass proportional valve malfunctions, determining whether the bypass proportional valve is stuck based on the hydrogen inlet pressure C, the minimum hydrogen inlet pressure D, and the maximum PWM value F includes:

[0060] Then determine whether the minimum value D of the hydrogen inlet pressure C is greater than the second set value b, and whether the maximum value F is equal to the upper limit of the proportional valve operation f;

[0061] If the minimum hydrogen inlet pressure C-D is greater than the second set value b, and the maximum value F is equal to the upper limit of the proportional valve's operation f, then it is preliminarily considered that the bypass proportional valve is stuck.

[0062] Optionally, the bypass proportional valve is sent with a PWM excitation value of d and an excitation time of B.

[0063] Optionally, the acquisition of PWM excitation information includes:

[0064] The average value G of the hydrogen infeed pressure P2 during PWM excitation is collected.

[0065] Optionally, determining whether the bypass proportional valve is stuck or malfunctioning based on the collected PWM excitation response information includes:

[0066] If the absolute value of the average value G - hydrogen inlet pressure C is greater than the second set value b, the proportional valve is determined to be stuck and malfunctioning.

[0067] In a specific scenario, such as Figure 2 The exhaust valve operates periodically during fuel cell operation. The exhaust valve operating time period is A, and the exhaust valve opening time is B. That is, within the time period A, the exhaust valve is open for B and closed for AB.

[0068] During the fuel cell's operation at the steady current point, the duty cycle of the Bypass proportional valve and the hydrogen inlet pressure P2 are monitored. Within a complete exhaust valve operating cycle, the PWM of the Bypass proportional valve and the hydrogen inlet pressure P2 are collected. The average hydrogen inlet pressure C before the exhaust valve opens, the minimum hydrogen inlet pressure D after the exhaust valve opens, and the maximum PWM F of the proportional valve after the exhaust valve opens are calculated.

[0069] When the bypass proportional valve is working normally, CD should be less than a (a is a calibrable quantity that varies with different systems) and F should be less than the upper limit of the proportional valve components themselves.

[0070] If, after the exhaust valve opens, CD is greater than b (b is a calibrable quantity that varies with different systems) and F is equal to the upper limit of the proportional valve components' working capacity f, then it is preliminarily considered that the proportional valve is stuck.

[0071] At this time, the fuel cell current point is kept unchanged, the exhaust valve is prohibited from opening, and a PWM excitation is given to Bypass with an excitation value of d and an excitation time of B. At the same time, the average value G of the hydrogen inlet pressure P2 during the process is collected.

[0072] If the absolute value of GC is greater than b (calibrated value), the proportional valve is determined to be stuck and a proportional valve stuck fault is reported.

[0073] This embodiment also discloses a fuel cell, using the diagnostic method for proportional valve sticking in a fuel cell controller disclosed in this embodiment.

[0074] This embodiment also discloses a vehicle using the diagnostic method for the proportional valve sticking of the fuel cell controller disclosed in this embodiment.

[0075] This embodiment also discloses a power unit that uses the diagnostic method for proportional valve sticking in a fuel cell controller disclosed in this embodiment. The power unit includes devices such as motors.

[0076] The basic principles of this disclosure have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details for implementation.

[0077] In this disclosure, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Words such as "including," "comprising," "having," etc., are open-ended terms meaning "including but not limited to," and are used interchangeably with them. The terms "or" and "and" as used herein refer to the terms "and / or," and are used interchangeably with them unless the context explicitly indicates otherwise. The term "such as" as used herein refers to the phrase "such as but not limited to," and is used interchangeably with it.

[0078] Additionally, as used herein, the “or” used in a list of items beginning with “at least one” indicates a separate list, such that a list of, for example, “at least one of A, B, or C” means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word “exemplary” does not imply that the described example is preferred or better than other examples.

[0079] It should also be noted that in the systems and methods of this disclosure, the components or steps can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions to this disclosure.

[0080] Various changes, substitutions, and modifications can be made to the technology described herein without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of this disclosure is not limited to the specific aspects of the processes, machines, manufactures, events, means, methods, and actions described above. Currently existing or later-developed processes, machines, manufactures, events, means, methods, or actions that perform substantially the same function or achieve substantially the same result as the corresponding aspects described herein can be utilized. Therefore, the appended claims include such processes, machines, manufactures, events, means, methods, or actions within their scope.

[0081] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0082] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this disclosure to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A method for diagnosing sticking of a proportional valve in a fuel cell controller, the fuel cell hydrogen control device comprising an ejector, a main proportional valve, and a bypass proportional valve, characterized in that, The methods include: During operation at the fuel cell steady current point, monitor the duty cycle of the Bypass proportional valve and the value of hydrogen inlet pressure P2. During a complete exhaust valve operation cycle, the PWM of the Bypass proportional valve and the hydrogen inlet pressure P2 are collected to calculate the average hydrogen inlet pressure C before the exhaust valve opens, the minimum hydrogen inlet pressure D after the exhaust valve opens, and the maximum PWM value F of the Bypass proportional valve after the exhaust valve opens. The exhaust valve is installed on the tailpipe of the fuel cell. Determine whether the bypass proportional valve is working properly based on the hydrogen inlet pressure C, the minimum hydrogen inlet pressure D, and the maximum PWM value F. If the bypass proportional valve is not working properly, determine whether the bypass proportional valve is stuck based on the hydrogen inlet pressure C, the minimum hydrogen inlet pressure D, and the maximum PWM value F. If the bypass proportional valve gets stuck, the exhaust valve will be prevented from opening. At the same time, a PWM excitation will be sent to the bypass proportional valve and the corresponding PWM excitation information will be collected. Based on the collected PWM excitation response information, determine whether the bypass proportional valve is stuck or malfunctioning, and then send a proportional valve stuck fault signal. The method for determining whether the bypass proportional valve is working properly based on the hydrogen inlet pressure C, the minimum hydrogen inlet pressure D, and the maximum PWM value F includes: Determine whether the minimum hydrogen inlet pressure C-D is less than the first set value a, and whether the maximum value F is less than the upper limit of the proportional valve operation f; If the minimum hydrogen inlet pressure C-D is less than the first set value a, and the maximum value F is less than the upper limit of the proportional valve's operation, then the bypass proportional valve will operate normally. Otherwise, the bypass proportional valve will malfunction. If the bypass proportional valve malfunctions, the determination of whether the bypass proportional valve is stuck is based on the hydrogen inlet pressure C, the minimum hydrogen inlet pressure D, and the maximum PWM value F, including: Then determine whether the minimum value D of the hydrogen inlet pressure C is greater than the second set value b, and whether the maximum value F is equal to the upper limit of the proportional valve operation f; If the minimum hydrogen inlet pressure C-D is greater than the second set value b, and the maximum value F is equal to the upper limit of the proportional valve's operation f, then it is preliminarily considered that the bypass proportional valve is stuck.

2. The diagnostic method for proportional valve sticking in a fuel cell controller according to claim 1, characterized in that, The bypass proportional valve is given a PWM excitation, the excitation value is d, and the excitation time is B.

3. The diagnostic method for proportional valve sticking in a fuel cell controller according to claim 2, characterized in that, The acquisition of PWM excitation information includes: The average value G of the hydrogen infeed pressure P2 during PWM excitation is collected.

4. The diagnostic method for proportional valve sticking in a fuel cell controller according to claim 3, characterized in that, The method of determining whether the bypass proportional valve is stuck or malfunctioning based on the collected PWM excitation response information includes: If the absolute value of the average value G - hydrogen inlet pressure C is greater than the second set value b, the proportional valve is determined to be stuck and malfunctioning.

5. A diagnostic device for a stuck proportional valve in a fuel cell controller, using the method described in any one of claims 1 to 4, characterized in that, include: Ejector, main proportional valve, bypass proportional valve, and exhaust valve; The outlet of the main proportional valve is connected to the ejector and the inlet, the outlet of the Bypass proportional valve is connected to the outlet of the ejector, the inlets of the main proportional valve and the Bypass proportional valve are connected to the hydrogen source, the outlet of the ejector is connected to the fuel cell stack, and the exhaust valve is installed on the tailpipe of the fuel cell stack.

6. A fuel cell, characterized in that, Use the method described in any one of claims 1 to 4.

7. A vehicle, characterized in that, Use the method described in any one of claims 1 to 4.

8. A power unit, characterized in that, Use the method described in any one of claims 1 to 4.

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