Method and device for handling locked-rotor of air compressor

Abstract

The application discloses an air compressor rotor stall processing method and device, wherein the method comprises the following steps: detecting that the rotor of an air compressor is currently in a stall state; stopping the operation of the air compressor; judging whether the air compressor meets restart conditions; and if the air compressor meets the restart conditions, restarting the air compressor.

Description

Technical Field

[0001] This application relates to the field of fuel cell technology, and in particular to a method and apparatus for dealing with a stalled air compressor rotor in a fuel cell system. Background Technology

[0002] A fuel cell system mainly consists of a fuel cell stack, an electric air compressor (EAC), a hydrogen supply module, and a cooling system. The electric air compressor draws in fresh air via an electric motor and then delivers the compressed air to the fuel cell stack to participate in the reaction.

[0003] As a systemic fault, rotor stall manifests as the motor outputting torque while the rotor speed is 0 rpm. This can be caused by rotor step loss, excessive motor load, mechanical failure, or bearing damage or wear.

[0004] In the field of traditional electric motors, rotor position sensors are typically used to determine whether the rotor is stalled. However, because the rotor speed of an air compressor can reach up to 120 rpm, the center point of the air bearing will shift during high-speed rotation, causing the rotor position sensor to be unable to effectively monitor the rotor's operating status continuously. Furthermore, when the air compressor uses a Kalman filter algorithm to estimate the rotor speed, misjudgments may occur in some cases: for example, the rotor may be stalled, but the inverter may still determine that the rotor is operating normally.

[0005] When a rotor stalls, the power factor becomes extremely low, and the maximum current (called the rotor stall current) can reach several times the rated current. In this situation, if the stall is not resolved promptly and the motor is not stopped, the motor is highly susceptible to burnout. Therefore, a timely and effective rotor stall handling solution is essential. Summary of the Invention

[0006] This application discloses a method and apparatus for dealing with rotor stall in an air compressor, which can solve or optimize the aforementioned problems.

[0007] Therefore, according to one aspect of this application, a method for handling a stalled air compressor rotor is disclosed, comprising the following steps: detecting that the air compressor rotor is currently in a stalled state; stopping the air compressor operation; determining whether the air compressor meets the restart conditions; and restarting the air compressor if the air compressor meets the restart conditions.

[0008] According to an exemplary embodiment of this application, a method for detecting that the rotor of an air compressor is currently in a stalled state is as follows: the effective current of the current motor exceeds a preset threshold. According to an exemplary embodiment of this application, the step of stopping the air compressor further includes resetting the estimated rotor speed of the air compressor to zero.

[0009] According to an exemplary embodiment of this application, the method for resetting the estimated rotor speed of the air compressor to zero is as follows: starting a timer when the rotor is detected to be in a stalled state; adjusting the inverter to a non-ready state; and after a preset time, adjusting the inverter to a ready state.

[0010] According to an exemplary embodiment of this application, the method for determining whether the air compressor meets the restart conditions is as follows: the air compressor meets the restart conditions by determining the cause of the rotor stall.

[0011] According to an exemplary embodiment of this application, if the rotor operates normally after being restarted, the cause of the rotor stall is determined to be a loss of synchronization during startup; if the rotor does not operate normally after being restarted, the cause of the rotor stall is determined to be a mechanical failure.

[0012] According to an exemplary embodiment of this application, if the cause of rotor stall is determined to be startup synchronism failure, the air compressor is considered to meet the restart conditions; if the cause of rotor stall is determined to be mechanical failure, the air compressor is considered to not meet the restart conditions.

[0013] According to another aspect of this application, an air compressor operation control unit is provided, which is configured to: receive information that the rotor of the air compressor is currently in a stalled state; send an instruction to stop the operation of the air compressor; obtain a judgment result on whether the air compressor meets the restart conditions; and if the air compressor meets the restart conditions, instruct the air compressor to restart.

[0014] According to another aspect of this application, an air compressor rotor stall handling device is provided, comprising: a detection unit for detecting that the air compressor rotor is currently in a stall state; a stop unit for stopping the air compressor operation; a judgment unit for judging whether the air compressor meets the restart conditions; and a restart unit for restarting the air compressor if the air compressor meets the restart conditions.

[0015] According to another aspect of this application, a computer-readable storage medium is provided that stores a computer program, which, when executed, causes a processor to perform any of the methods described above.

[0016] To gain a further understanding of the features and technical content of this application, please refer to the following detailed description and accompanying drawings. However, the drawings are provided for reference and illustration only and are not intended to limit the scope of this application. Attached Figure Description

[0017] The foregoing and other aspects of this application will be more fully understood and appreciated through the following detailed description with reference to the accompanying drawings, in which:

[0018] Figure 1This is a schematic block diagram of an air compressor stall treatment apparatus according to one embodiment of this application;

[0019] Figure 2 This is a flowchart of an air compressor stall handling method according to one embodiment of this application;

[0020] Figure 3 This is a flowchart of a method for zeroing the estimated rotor speed according to one embodiment of this application. Detailed Implementation

[0021] To help those skilled in the art to accurately understand the subject matter claimed in this application, the specific embodiments of this application are described in detail below with reference to the accompanying drawings.

[0022] See Figure 1 The diagram shown is a schematic block diagram of an air compressor stall treatment apparatus according to one embodiment of this application. Figure 1 The air compressor rotor stall treatment device 10 includes:

[0023] The detection unit 100 is used to detect whether the rotor of the air compressor is currently in a stalled state. In this specific embodiment, the method for detecting that the rotor of the air compressor is currently in a stalled state is as follows: the detection unit 100 detects that the effective current of the current motor exceeds a preset threshold. It can be understood that, as described herein, detecting that the effective current of the current motor exceeds a preset threshold means that the effective current exceeds the range of the prescribed safety standard. In different embodiments, the preset threshold for effective current may vary to some extent depending on the different safety standards adopted or the different operating conditions of the motor.

[0024] Stop unit 200 stops the air compressor from running. When the rotor is detected to be in a stalled state, the stop unit immediately stops the air compressor from running, preventing the motor from outputting torque and avoiding damage to the motor.

[0025] The judgment unit 300 determines whether the air compressor, after being shut down, meets the restart conditions.

[0026] If the judgment unit 300 determines that the air compressor meets the restart conditions, the restart unit 400 restarts the air compressor.

[0027] In some embodiments, the air compressor rotor stall handling device 10 may further include a prompting unit 500, which outputs an alarm signal if the air compressor is deemed not to meet the restart conditions. Accordingly, the inverter will be adjusted to an error state, and restarting the air compressor will be prohibited.

[0028] See Figure 2 The diagram shown is a flowchart of an air compressor stall handling method according to one embodiment of this application. Figure 2 The method for handling a stalled rotor in an air compressor includes the following steps:

[0029] Step S100: It is detected that the rotor of the air compressor is currently in a stalled state;

[0030] Step S200: Stop the air compressor.

[0031] Step S300: Determine whether the air compressor meets the restart conditions; and

[0032] Step S400: If the air compressor meets the restart conditions, restart the air compressor.

[0033] It is understood that there can be multiple methods for detecting whether the air compressor rotor is stalled in step S100. In this specific embodiment, the method for detecting that the air compressor rotor is currently stalled is: detecting that the effective current of the current motor exceeds a preset threshold. That is, the effective current exceeds the range of the specified safety standard. This method overcomes the problem of rotor position being out of monitoring when the rotor rotates at high speed due to the displacement of the air bearing center point during stall detection using a rotor position sensor.

[0034] Upon detecting a rotor stall, the air compressor is immediately stopped in step S200. In some embodiments, this step further includes resetting the estimated rotor speed of the air compressor to zero. This is to prevent misjudgments that may occur when the air compressor simultaneously uses a Kalman filter algorithm to estimate the rotor speed. In such cases, although the rotor is stalled, the inverter still considers the rotor to be operating normally. Therefore, it is best to forcibly reset the current estimated rotor speed to zero at this stage to avoid affecting subsequent judgments.

[0035] See Figure 3 As shown, in some embodiments, the sub-steps for resetting the estimated rotor speed of the air compressor to zero are: step S201, starting a timer when the rotor is detected to be in a stalled state; step S202, adjusting the inverter to a non-ready state; and step S203, adjusting the inverter to a ready state after a preset time. The preset time is approximately 1 to 2 seconds, to ensure the air compressor reaches complete stillness after shutdown.

[0036] In step S300, it is determined whether the air compressor meets the restart conditions. Specifically, this is done by determining the cause of the rotor stall. In this specific embodiment, if the rotor operates normally after being restarted, the cause of the previous rotor stall is determined to be a startup synchronization failure; if the rotor still does not operate normally after being restarted, the cause of the previous rotor stall is determined to be a mechanical failure.

[0037] Furthermore, if the cause of rotor stall is determined to be startup malfunction, then the air compressor itself is considered to have no fault requiring repair and meets the restart conditions, and can be restarted in the next step; conversely, if the cause of rotor stall is determined to be mechanical fault, then the air compressor is considered not to meet the restart conditions.

[0038] Therefore, in step S400, if the air compressor meets the restart conditions, the air compressor is restarted. Optionally, if the air compressor is deemed not to meet the restart conditions, restarting the air compressor is prohibited, and an alarm signal can be output to adjust the inverter to an error state to alert the operator.

[0039] In addition, this application also provides an air compressor operation control unit, which is configured to: receive information that the rotor of the air compressor is currently in a stalled state; send an instruction to stop the operation of the air compressor; obtain a judgment result on whether the air compressor meets the restart conditions; and, if the air compressor meets the restart conditions, instruct the air compressor to restart.

[0040] This application also provides a computer-readable storage medium storing a computer program that, when executed, causes a processor to perform any of the methods described above.

[0041] While this application has been shown and described based on specific embodiments, it is not limited to the details shown. Rather, various details of this application may be modified within the scope of the claims and their equivalents.

Claims

1. A method for handling rotor stall in an air compressor, characterized in that, The steps include the following: The air compressor rotor has been detected to be in a stalled state. Stop the air compressor from running; Determine whether the air compressor meets the restart conditions; as well as If the air compressor meets the restart conditions, restart the air compressor; in, Determine whether the air compressor meets the restart conditions by identifying the cause of the rotor stall: If the rotor operates normally after the air compressor is restarted, it is determined that the reason for the rotor stall is the start-up failure, and the air compressor meets the restart conditions accordingly. If the rotor does not operate normally after the air compressor is restarted, it is determined that the rotor is stalled due to a mechanical failure, and the air compressor does not meet the restart conditions.

2. The rotor stall handling method as described in claim 1, characterized in that, The method to detect that the rotor of the air compressor is currently in a stalled state is: detecting that the effective current of the current motor exceeds a preset threshold.

3. The rotor stall handling method as described in claim 1, characterized in that, The step of stopping the air compressor also includes resetting the estimated rotor speed of the air compressor to zero.

4. The rotor stall handling method as described in claim 3, characterized in that, The method for resetting the estimated rotor speed of the air compressor to zero is as follows: The timer starts when the rotor is detected to be in a stalled state. Adjust the inverter to an unready state; as well as After a preset time, the inverter will be adjusted to a ready state.

5. An air compressor operation control unit, characterized in that, include: Receive information that the air compressor rotor is currently in a stalled state; Send a command to stop the air compressor; Obtain the result of determining whether the air compressor meets the restart conditions; as well as If the air compressor meets the restart conditions, instruct the air compressor to restart; in, Determine whether the air compressor meets the restart conditions by identifying the cause of the rotor stall: If the rotor operates normally after the air compressor is restarted, it is determined that the reason for the rotor stall is the start-up failure, and the air compressor meets the restart conditions accordingly. If the rotor does not operate normally after the air compressor is restarted, it is determined that the rotor is stalled due to a mechanical failure, and the air compressor does not meet the restart conditions.

6. A device for treating a stalled air compressor rotor, characterized in that, include: The detection unit detected that the air compressor rotor is currently in a stalled state; Stop unit, stop the air compressor operation; The judgment unit determines whether the air compressor meets the restart conditions; as well as The restart unit restarts the air compressor if the air compressor meets the restart conditions. in, Determine whether the air compressor meets the restart conditions by identifying the cause of the rotor stall: If the rotor operates normally after the air compressor is restarted, it is determined that the reason for the rotor stall is the start-up failure, and the air compressor meets the restart conditions accordingly. If the rotor does not operate normally after the air compressor is restarted, it is determined that the rotor is stalled due to a mechanical failure, and the air compressor does not meet the restart conditions.

7. A computer-readable storage medium storing a computer program that, when executed, causes a processor to perform the method as described in any one of claims 1 to 4.

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