Control method for air compressor, air compressor and controller

Abstract

The control method for the air compressor system comprises the steps that in the operation process of an air compressor, whether the air compressor is locked or not is judged; when it is judged that the air compressor is locked, the air compressor is controlled to be automatically started; if n times of continuous self-starting are not successful, a fault signal is sent to a related component; otherwise, the air compressor system operates normally; wherein n is an integer greater than or equal to 1. The invention further provides an air compressor system and a controller.

Description

Technical Field

[0001] The present application relates to air compressor technology, and more specifically, to air compressor control technology. Background Art

[0002] Vehicles using fuel cells require air compressors to provide compressed air during operation. Under certain operating conditions, the air compressor may become stalled. Once stalled, a large current may flow through the coil of the air compressor drive motor, causing the motor temperature to rise rapidly, which may damage the air compressor. Summary of the invention

[0003] According to one aspect of the present application, a control method for an air compressor is provided, comprising: during the operation of the air compressor, determining whether the air compressor is stalled; if the air compressor is stalled, controlling the air compressor to self-start; if the self-start fails n times, sending a fault signal to relevant components; otherwise, the air compressor system operates normally; wherein n is an integer greater than or equal to 1. Optionally, n is 3.

[0004] According to the control method for an air compressor of the example of the present application, optionally, the judging whether the air compressor is stalled includes obtaining an actual current of a motor of the air compressor and an actual speed of the motor; based on the actual speed, determining a required current corresponding to the actual speed by a preset model; comparing the actual current with the required current, and determining that the motor is stalled if the actual current is greater than the required current.

[0005] According to the control method for an air compressor system of the example of the present application, optionally, for each self-start, the start parameters are reset; and a signal indicating self-start due to a stall is sent to the relevant components.

[0006] According to another aspect of the present application, an air compressor is also provided. The air compressor includes: an air compressor pump, a motor and a controller, wherein the motor is used to drive the air compressor pump to operate, and the controller is used to execute instructions, and when executing the instructions: during the operation of the air compressor, determine whether the air compressor is blocked; if the air compressor is blocked, control the air compressor to start automatically; if the air compressor fails to start automatically for n consecutive times, send a fault signal to the relevant components; otherwise, control the air compressor to operate normally; wherein n is an integer greater than or equal to 1.

[0007] According to the air compressor of the present application, optionally, it also includes: a current detection component for detecting the actual current of the motor; a speed acquisition component for acquiring the actual speed of the motor; the controller is configured to further determine whether the motor is stalled through the following process when executing the instruction: based on the actual speed, determining the required current corresponding to the actual speed by a preset model; comparing the actual current with the required current, and determining that the air compressor is stalled when the detected actual current is greater than the required current.

[0008] According to various examples of the present application, optionally, when the detected actual current is greater than the required current, the severity of the air compressor jam can be determined based on the difference between the two.

[0009] The air compressor system according to each example of the present application is an air compressor for a fuel cell vehicle.

[0010] A fuel cell system is also provided, which includes any one of the air compressors described herein, or can execute any one of the control methods described herein.

[0011] The present application also provides a controller, which stores instructions so that any one of the methods described above is implemented when the instructions are executed.

[0012] For example, any one of the above control methods for an air compressor according to the present application is executed when the air compressor is running in a steady state, that is, it is executed after the motor of the air compressor enters a steady-state operation from a startup process.

[0013] For example, according to the controller of the air compressor of the present application, the judgment on whether the air compressor is stalled is performed when the air compressor is running in a steady state, that is, after the motor of the air compressor enters a steady-state operation from the startup process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The following will describe the embodiments of the present application in detail with reference to the accompanying drawings so that the present application can be more fully understood, wherein:

[0015] Figure 1 is a structural schematic diagram of an example air compressor system;

[0016] Figure 2 is a flow chart of a control method for an air compressor system according to an example of the present application;

[0017] Figure 3 It is an exemplary process of determining whether a motor is stalled according to the present application;

[0018] Figure 4 It is a structural schematic diagram of an air compressor system according to an example of the present application. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings to clearly and completely describe the implementation methods of the present application. It should be noted that the described implementation methods are only partial implementation methods of the technical scheme of the present application, not all. All other implementation methods obtained by ordinary technicians in this field based on the implementation methods recorded in the application documents without paying creative work are covered by the protection scope of the present application.

[0020] The terms "first", "second", etc. in the specification, claims and drawings of this application are used to distinguish similar objects, rather than to describe a specific order or sequence. In addition, "first" and "second" are used for descriptive purposes only and should not be understood as explicitly or implicitly indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of this application, unless otherwise specified, "multiple" means two or more.

[0021] As used hereinafter, the words “example” or “exemplarily” or “exemplarily” mean “serving as an example, embodiment, or illustration.” Any embodiment described as “example” or “exemplarily” or “exemplarily” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0022] Figure 1 is a schematic diagram of the structure of an example air compressor system. Figure 1 As shown, the air compressor includes an air compressor pump 10, a drive motor 12 and a controller 14. The drive motor 12 drives the air compressor pump 10 to operate, and the air compressor pump 10 is used to compress air. The controller 14 can be configured to control the motor to work. The controller 14 includes, for example, an air compressor controller EAC.

[0023] Figure 2 This is a flow chart of a control method for an air compressor according to an example of the present application. In step S200, during the operation of the air compressor, it is determined whether the air compressor is stalled. The motor of the air compressor rotates at high speed. A Hall position sensor is usually not provided in a high-speed motor. Instead, an extended Kalman filter (EKF) is used to estimate the rotation speed. When the air compressor is stalled, the rotation speed estimated by the EKF may still exist, so it is impossible to determine the stall based on the motor speed. However, when a stall occurs, the current of the motor will increase. Accordingly, in some examples of the present application, whether the air compressor is stalled is determined based on the change in the current of the motor. The following will be combined with Figure 3Specific description. If the result of judgment in step S200 is that the air compressor is not blocked, then continue to step S200. If the result of judgment in step S200 is that the air compressor is blocked, then proceed to step S202 to control the air compressor to start automatically. In step S204, determine whether the self-start is successful. If the self-start is successful, return to step S200 to continue monitoring whether the air compressor is blocked; otherwise, proceed to step S206. In step S206, the counter recording the number of self-starts is increased by 1 and when the count value of the counter is less than n, return to step S202 and perform self-start again. When the value of the counter reaches n in step S206, that is, the automatic start has failed for n consecutive times, it will no longer return to step S202 for automatic restart, but enter step S208 to send a fault signal to the relevant components. If the air compressor self-starts successfully in step S202, the air compressor continues to operate normally due to the successful start.

[0024] For the self-start performed in step S202, the startup parameters are reset for each self-start. Taking the air compressor starting in a V / F mode that keeps the ratio of the output voltage to the output frequency of the inverter constant as an example, the output voltage and output frequency are reset for each self-start.

[0025] Figure 3 This is an exemplary process for determining whether an air compressor is stalled according to some examples of the present application. Specifically, Figure 3 Indicated Figure 2 A specific implementation process of step S200 in FIG. Figure 3 As shown, in step S300, the actual current and the actual speed of the motor are obtained. As an example, the actual current of the motor can be detected by a current detection circuit or sensed by a current sensor; as for the speed, the estimated actual speed of the motor can be obtained from the EKF, and the present application does not exclude obtaining the actual speed of the motor in other ways.

[0026] In other examples, such as when the air compressor itself has detected or calculated either or both of the actual current and actual speed of the motor, obtaining the actual current of the motor and detecting the actual speed of the motor in step S300 may be performed by obtaining the actual current and actual speed from data already detected by the air compressor.

[0027] In step S304, based on the actual speed, the preset model determines the required current corresponding to the actual speed. The preset model can be a function representing the motor speed and current. In this case, the required current can be calculated by the model according to the actual speed. According to some examples of the present application, the preset model is set to a preset correspondence table, which gives the correspondence between the speed and the required current, that is, according to the detected actual speed, the required current corresponding to the actual speed can be found from the preset correspondence table. Accordingly, in step S304, the required current corresponding to the actual speed can be found from the preset correspondence table according to the actual speed.

[0028] In step S306, the actual current is compared with the determined required current to determine whether the actual current is greater than the required current. If the actual current is greater than the required current, the process proceeds to step S308 to determine that the air compressor is stalled. If the actual current is not greater than the required current, the air compressor is considered to be operating normally, and the process returns to step S306 to compare the next detected current with the actual current. For the case where the actual current is equal to the required current, it can be set according to the actual application. According to the example of this application, the air compressor can be considered to be stalled when the actual current is equal to the required current.

[0029] For example, if the actual speed of the current air compressor is 30000rpm, the actual current detected is 20A. According to the preset corresponding table, when the speed is 30000rpm, the required current is 15A, so it can be determined that a stall has occurred or there is a possibility of a stall. On the contrary, if the actual current detected is 10A, it indicates that the current air compressor is operating normally.

[0030] In a further example, the air compressor stall situation can be further subdivided by the difference between the actual current and the required current. Specifically, when the actual current is greater than the required current, the severity of the current stall situation can be determined based on the size of the difference between the two, or in some cases, the likelihood of stall situation. In this case, the number of possible self-starts n may be different.

[0031] In addition, in some possible cases, the air compressor stall determined according to the present application may also indicate that the air compressor is about to stall rather than having stalled, which may depend on the required current set for the motor speed in the preset corresponding table. If the required current is set smaller for the same speed, the determined result may indicate that stalling is about to occur.

[0032] In addition, according to the various embodiments of the present application, the actual speed obtained may be when the motor enters steady-state operation after starting. For example, it is usually a very short T time from when the motor is powered on to when it enters steady-state operation. During the T time, the speed of the motor may be an increasing process. At this time, implementing the examples of the present application, collecting the speed may not correctly reflect the stalling of the air compressor. Therefore, after being implemented in the air compressor, the examples of the present application can be executed within T seconds after the air compressor is started. T seconds is, for example, the startup time of the motor, such as 1 second.

[0033] Back to Figure 2 , in the case of motor stall, in step S202, the air compressor is controlled to start automatically. According to some examples of the present application, for each self-start, the startup parameters will be reset to restart. In addition, during each self-start process, a signal indicating that the air compressor is restarted due to stall can be sent to the relevant components so that they can understand the current situation of the air compressor. As an example, the controller of the air compressor, such as EAC, can set a flag to let other related components know the restart information. For example, a flag is set to indicate whether the air compressor is stalled. When the air compressor is stalled in step S200, the value of the flag is set to True. After the stall is eliminated, the value of the flag is cleared; a flag is set to indicate that the air compressor system is self-starting. When the air compressor is self-starting in step S202, the value of the flag is set to True, so that other related components know that the air compressor is self-starting. After the self-start is completed, the value of the flag is cleared.

[0034] The air compressor in each example of the present application may be an air compressor of a fuel cell vehicle. In such an example, the relevant component is, for example, a controller of a fuel cell control system.

[0035] According to some examples of the present application, a signal indicating that the air compressor is stalled and / or the air compressor is self-starting can also be sent to a display device for display to the user. For example, when the air compressor is an air compressor of a fuel cell vehicle, the signal indicating that the motor is stalled and / or the air compressor is self-starting can be sent to the display screen of the vehicle so that the driver can understand these states of the air compressor.

[0036] According to this combination Figure 2 and Figure 3The described method, when the air compressor is blocked, firstly makes the air compressor self-start, that is, automatically restart, instead of directly reporting the fault, so that the driver of the vehicle using the air compressor does not need to perform the on-off-on operation as soon as the air compressor is blocked, which improves the driving experience. Further, according to each example of the present application, when the air compressor is blocked and self-starts, the number of self-starts is set (for example, the number of starts n is 3 or 2), that is, if the air compressor fails to self-start successfully once, there is a second or third chance to self-start again, which increases the probability of successful self-start; but at the same time, because the number of self-starts is set to a limit, the multiple self-starts of the air compressor of the embodiment of the present application are limited to a reasonable time (that is, to avoid the time when the driver feels the abnormality of the air compressor). In the case of multiple self-starts without results, the fault is immediately notified to the relevant components of the controller of the fuel cell control system, for example, and the fault handling process is entered.

[0037] Figure 4 Schematic diagram of the structure of the air compressor system according to the example of this application. Figure 4 As shown, the air compressor includes an air pump 40, a motor 42, and a controller 44. The motor 42 is used to drive the air pump 40 to operate, and the controller 44 is configured to execute stored instructions. The instructions are stored in a memory, which can be set in the controller 44 or in the air compressor outside the controller 44. During the operation of the air compressor, when the controller 44 executes the instructions, it determines whether the air compressor is blocked. If it is determined that the air compressor is blocked, the air compressor is controlled to start automatically. If the continuous start-up is unsuccessful for n times, a fault signal is sent to the relevant components; if the start-up is successful once within the n consecutive self-starts allowed according to this application, the air compressor enters a normal operating state due to the successful self-start.

[0038] Figure 4 The air compressor system shown can execute the control method for the air compressor described above. Figure 4 The system shown performs the above combined Figure 2 When the method described is executed, the controller implements Figure 2 The process shown.

[0039] According to the example of the present application, the air compressor also includes a current detection component 400 and a speed acquisition component 402. The current detection component 400 detects the actual current of the motor, which can be implemented as a current detection circuit or a current sensor. The speed acquisition component 402 acquires the actual speed of the motor. In some examples, the speed acquisition component 402 is a speed estimation model, such as an EKF estimation model. In other examples, any one or all of the current detection component 400 and the speed acquisition component 402 can be existing components of the air compressor itself.

[0040] Further, when executing the instruction, the controller 44 executes the above combined Figure 3 The process described above is used to determine the motor stall condition and will not be repeated here.

[0041] The air compressor according to each example of the present application may be implemented in a fuel cell vehicle as an air compressor for the fuel cell vehicle.

[0042] According to some examples of the present application, the controller 44 may also send a signal indicating that the motor is stalled and / or the air compressor is self-starting to a display device for display to the user. For example, when the air compressor is an air compressor of a fuel cell vehicle, the signal indicating that the motor is stalled and / or the air compressor is self-starting may be sent to the display screen of the vehicle so that the driver can understand these states of the air compressor system.

[0043] The present application also provides a controller, which is configured to execute instructions in a memory so as to implement any one of the control methods described above when the instructions are executed.

[0044] The present application also provides a fuel cell system, which includes any one of the air compressors described above, or the fuel cell system is configured to execute any one of the control methods described above.

[0045] Although various embodiments of the present application have been shown and described in detail to illustrate the principles of the present application, it should be understood that the various embodiments and their features can be combined with each other without conflict to achieve new implementations, and such implementations should be included in the scope claimed by the present application. In addition, the present application can also be implemented in other ways that do not deviate from the spirit of the present application.

Claims

1. A control method for an air compressor, characterized in that: The method comprises: During the operation of the air compressor, determining whether the air compressor is blocked; When it is determined that a stall occurs, controlling the air compressor to start automatically; If the self-start fails for n times in a row, a fault signal is sent to the relevant components; otherwise, the air compressor operates normally; Here, n is an integer greater than or equal to 1.

2. The control method according to claim 1, characterized in that: The step of determining whether the air compressor is blocked includes: Obtaining the actual current of the motor of the air compressor and the actual speed of the motor; Based on the actual speed, determining a required current corresponding to the actual speed by a preset model; The actual current is compared with the required current, and when the detected actual current is greater than the required current, it is determined that the air compressor is blocked.

3. The control method according to claim 2, characterized in that: When the actual current obtained is greater than the required current, the severity of the air compressor stall is determined according to the difference between the two.

4. The control method according to claim 1, characterized in that: The n is 3.

5. The control method according to claim 2, characterized in that: For each self-start, the start parameters are reset; and a signal indicating self-start due to stall is sent to the relevant components.

6. The control method according to claim 1, characterized in that: The method is performed when the air compressor operates in a steady state.

7. The control method according to any one of claims 1 to 6, characterized in that: The air compressor is an air compressor for a fuel cell vehicle.

8. An air compressor, characterized in that: The air compressor comprises: Air compressor; A motor, used for driving the air compressor to operate; A controller for executing instructions to: During the operation of the air compressor, determining whether the air compressor is blocked; When it is determined that the air compressor is blocked, controlling the air compressor to start automatically; If the self-start fails for n times in a row, a fault signal is sent to the relevant components; otherwise, the control air compressor operates normally; Here, n is an integer greater than or equal to 1.

9. The air compressor according to claim 8, characterized in that: The air compressor also includes: A current detection component, used for detecting the actual current of the motor; A rotation speed acquisition component, used to acquire the actual rotation speed of the motor; The controller is configured to further determine whether the air compressor is stalled by the following process when executing the instruction: Based on the actual speed, determining a required current corresponding to the actual speed by a preset model; The actual current is compared with the required current, and when the detected actual current is greater than the required current, it is determined that the air compressor is blocked.

10. The air compressor according to claim 8, characterized in that: The n is 3.

11. The air compressor according to claim 9, characterized in that: The controller is configured to: For each auto-start, reset the startup parameters; and, A signal indicating self-start due to stall is sent to the related components.

12. The air compressor according to claim 11, characterized in that: The air compressor is an air compressor for a fuel cell vehicle.

13. A fuel cell system, characterized in that: The fuel cell system includes the air compressor according to any one of claims 8 to 12, or the fuel cell system is configured to execute the control method according to any one of claims 1 to 7.

14. A controller, configured to execute instructions stored in a memory, and to implement the control method according to any one of claims 1 to 7 when executing the instructions.

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