Permanent magnet synchronous motor open phase and current sensor fault detection method and apparatus

Abstract

The application relates to a permanent magnet synchronous motor open-phase and current sensor fault detection method and device. The method comprises the following steps: in the static state of the permanent magnet synchronous motor, the current values between any two phases of the permanent magnet synchronous motor are detected respectively, and the fault condition of the current sensor in the permanent magnet synchronous motor is determined; if the current values detected between any two phases are all zero, the current flag bit is marked as 0, otherwise, the current flag bit is marked as 1; a state quantity is formed according to the flag bit, and the open-phase fault condition is determined according to the state quantity. The method can realize static detection of the open-phase and current sensor fault of the permanent magnet synchronous motor.

Description

Technical Field

[0001] This application relates to the field of synchronous motor testing technology, and in particular to a method and apparatus for detecting phase loss and current sensor faults in permanent magnet synchronous motors. Background Technology

[0002] Phase loss faults are the most common faults in motor drive systems, often caused by a disconnection of one phase of the motor, one phase of the inverter, or poor contact at mechanical terminals. Under phase loss fault conditions, the imbalance of phase currents leads to a decrease in motor performance and efficiency. In extreme cases, it can cause irreversible damage to the motor and drive system. Therefore, fault diagnosis and fault-tolerant control techniques for phase loss faults are crucial for ensuring the reliability of the control system.

[0003] Current phase loss detection methods measure the peak value of each phase current. If the peak value of a particular current differs significantly from the peak values ​​of the other two phases, a fault is identified in that phase. This method only works when the motor is running and cannot detect phase loss faults when the motor is stationary. To overcome the shortcomings of current phase loss detection methods, a phase loss detection method for use when the motor is stationary is proposed. Summary of the Invention

[0004] Therefore, it is necessary to provide a method and device for detecting phase loss and current sensor faults in permanent magnet synchronous motors, addressing the aforementioned technical problems.

[0005] A method for detecting phase loss and current sensor faults in a permanent magnet synchronous motor, the method comprising:

[0006] When the permanent magnet synchronous motor is stationary, the current value between any two phases of the permanent magnet synchronous motor is detected to determine the fault condition of the current sensor in the permanent magnet synchronous motor.

[0007] If only two phases of the circuit are energized, and the detected current values ​​are both zero, then the current flag is set to 0; otherwise, it is set to 1.

[0008] The status quantity is composed of the flag bits, and the phase loss fault condition is determined based on the status quantity.

[0009] In one embodiment, the method further includes arranging the flag bits of any two phases in a preset order to form flag bits.

[0010] In one embodiment, the method further includes: detecting the current value between any two phases of the permanent magnet synchronous motor when the motor is stationary; energizing only phases A and B; if the current value of phase A is 0 and the current value of phase B is not 0, then the current sensor corresponding to phase A is faulty; wherein the permanent magnet synchronous motor includes phases A, B, and C, the path between phases A and B is the AB path, the path between phases B and C is the BC path, and the path between phases A and C is the AC path; if the current value of phase A is not 0 and the current value of phase B is 0, then the current sensor corresponding to phase B is faulty; if the current value of phase A is 0 and the current value of phase B is 0, then the flag bit recording the AB path is 0.

[0011] In one embodiment, the method further includes: detecting whether the corresponding current sensor is faulty by detecting the BC path and the AC path, and recording the flag bits corresponding to the BC path and the AC path.

[0012] In one embodiment, the method further includes determining a three-digit state quantity based on the flag bits of the AB path, BC path, and AC path.

[0013] In one embodiment, the method further includes: setting the state value to 111 when all three phases of the permanent magnet synchronous motor are normal; setting the state value to 000 when all three phases of the permanent magnet synchronous motor are abnormal; setting the state value to 100 when the AB path of the permanent magnet synchronous motor is 1 and the BC and AC paths are both 0; setting the state value to 010 when the BC path of the permanent magnet synchronous motor is 1 and the AB and AC paths are both 0; and setting the state value to 001 when the AC path of the permanent magnet synchronous motor is 1 and the BC and AB paths are both 0. The method further includes determining the phase loss status of the permanent magnet synchronous motor based on the position of the flag bit 0 in the state value.

[0014] In one embodiment, the method further includes performing phase loss detection after replacing the faulty current sensor.

[0015] A device for detecting phase loss and current sensor faults in a permanent magnet synchronous motor, the device comprising:

[0016] The fault detection module is used to detect the current value between any two phases of the permanent magnet synchronous motor when the motor is stationary, and to determine the fault status of the current sensor in the permanent magnet synchronous motor.

[0017] The flag determination module is used to mark the current flag as 0 if the detected current values ​​between any two phases are both zero, and otherwise as 1.

[0018] The phase loss detection module is used to form a status quantity based on the flag bits, and to determine the phase loss fault condition based on the status quantity.

[0019] A computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program performing the following steps:

[0020] When the permanent magnet synchronous motor is stationary, the current value between any two phases of the permanent magnet synchronous motor is detected to determine the fault condition of the current sensor in the permanent magnet synchronous motor.

[0021] If the detected current values ​​between any two phases are both zero, then the current flag is set to 0; otherwise, it is set to 1.

[0022] The status quantity is composed of the flag bits, and the phase loss fault condition is determined based on the status quantity.

[0023] A computer-readable storage medium having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0024] When the permanent magnet synchronous motor is stationary, the current value between any two phases of the permanent magnet synchronous motor is detected to determine the fault condition of the current sensor in the permanent magnet synchronous motor.

[0025] If the detected current values ​​between any two phases are both zero, then the current flag is set to 0; otherwise, it is set to 1.

[0026] The status quantity is composed of the flag bits, and the phase loss fault condition is determined based on the status quantity.

[0027] The aforementioned method, apparatus, computer equipment, and storage medium for detecting phase loss and current sensor faults in permanent magnet synchronous motors, when dealing with static phase loss detection, first detect the current sensor fault by measuring the current value between two phases to ensure the accuracy of subsequent phase loss detection. Based on the sensor fault detection, if the current value detected between any two phases is zero, the current flag is marked as 0; otherwise, it is marked as 1. The state quantity is determined based on the output flag, and thus the phase loss fault condition is determined based on the state quantity. This method can perform both sensor fault detection and phase loss detection simultaneously in a static state, greatly improving the reliability of the permanent magnet synchronous motor after power-on. Attached Figure Description

[0028] Figure 1 This is a flowchart illustrating a method for detecting phase loss and current sensor faults in a permanent magnet synchronous motor, as shown in one embodiment.

[0029] Figure 2 This is a structural block diagram of a permanent magnet synchronous motor phase loss and current sensor fault detection device in one embodiment;

[0030] Figure 3 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0032] In one embodiment, such as Figure 1 As shown, a method for detecting phase loss and current sensor faults in a permanent magnet synchronous motor is provided, including the following steps:

[0033] Step 102: With the permanent magnet synchronous motor stationary, detect the current value between any two phases of the permanent magnet synchronous motor to determine the fault condition of the current sensor in the permanent magnet synchronous motor.

[0034] In this step, common methods for detecting phase loss in permanent magnet synchronous motors cannot directly perform phase loss detection when the motor is stationary. The method of this invention first performs sensor fault detection while the motor is stationary, and then performs phase loss detection.

[0035] Step 104: If the current values ​​detected between any two phases are both zero, then mark the current flag bit as 0; otherwise, mark it as 1.

[0036] Step 106: Based on the flag bits, form a status quantity, and determine the phase loss fault condition based on the status quantity.

[0037] In the aforementioned method for detecting phase loss and current sensor faults in permanent magnet synchronous motors, when dealing with static phase loss detection, the current sensor is first checked for faults by measuring the current value between two phases to ensure the accuracy of subsequent phase loss detection. Based on the sensor fault detection, if the current value detected between any two phases is zero, the current flag is set to 0; otherwise, it is set to 1. The state quantity is determined based on the output flag, and the phase loss fault condition is then determined based on the state quantity. This method can perform both sensor fault detection and phase loss detection simultaneously in a static state, greatly improving the reliability of the permanent magnet synchronous motor after power-on.

[0038] In one embodiment, the flag bits of any two phases are arranged in a preset order to form a flag bit. This embodiment differs from the traditional method of using sensor indicators to judge phase loss; instead, it uses statistical flag bits to accurately determine the phase loss status of the permanent magnet synchronous motor under static conditions.

[0039] In one embodiment, when the permanent magnet synchronous motor (PMSM) is stationary, the current values ​​between any two phases of the PMSM are detected. If the current value of phase A is 0, while the current value of phase B is not 0, the current sensor corresponding to phase A is faulty. The PMSM includes phases A, B, and C. The path between phases A and B is the AB path, the path between phases B and C is the BC path, and the path between phases A and C is the AC path. If the current value of phase A is not 0 and the current value of phase B is 0, the current sensor corresponding to phase B is faulty. If the current value of phase A is 0 and the current value of phase B is 0, the flag bit of the AB path is recorded as 0. In this embodiment, static fault detection of the current sensors can be performed. Simultaneously with static fault detection, if the fault cannot be determined, the presence of a missing phase in the PMSM can be determined by recording the flag bit.

[0040] In one embodiment, a three-digit state variable is determined based on the flag bits of the AB, BC, and AC paths.

[0041] In one embodiment, when all three phases of the permanent magnet synchronous motor are normal, the state value is set to 111; when all three phases of the permanent magnet synchronous motor are abnormal, the state value is set to 000; when the AB path of the permanent magnet synchronous motor is 1, and the BC and AC paths are both 0, the state value is set to 100; when the BC path of the permanent magnet synchronous motor is 1, and the AB and AC paths are both 0, the state value is set to 010; when the AC path of the permanent magnet synchronous motor is 1, and the BC and AB paths are both 0, the state value is set to 001. The phase loss condition of the permanent magnet synchronous motor is determined based on the position of flag bit 0 in the state value. In this embodiment, by corresponding the state of each flag bit with the phase loss fault, the phase loss fault can be directly determined after detecting the corresponding state value, greatly improving the efficiency of phase loss detection.

[0042] In one embodiment, phase loss detection is performed after the faulty current sensor is replaced.

[0043] It should be understood that, although Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0044] In one embodiment, such as Figure 2 As shown, a phase loss and current sensor fault detection device for a permanent magnet synchronous motor is provided, comprising: a fault detection module 202, a flag bit determination module 204, and a phase loss detection module 206, wherein:

[0045] The fault detection module 202 is used to detect the current value between any two phases of the permanent magnet synchronous motor when the permanent magnet synchronous motor is stationary, and to determine the fault condition of the current sensor in the permanent magnet synchronous motor.

[0046] The flag determination module 204 is used to mark the current flag as 0 if the detected current values ​​between any two phases are both zero, and otherwise as 1.

[0047] The phase loss detection module 206 is used to determine the phase loss fault condition based on the status quantity composed of the flag bits.

[0048] In one embodiment, the phase loss detection module 206 is further configured to arrange the flag bits of any two phases in a preset order to form a flag bit.

[0049] In one embodiment, the fault detection module 202 is further configured to detect the current value between any two phases of the permanent magnet synchronous motor when the motor is stationary; if the current value of phase A is 0 and the current value of phase B is not 0, then the current sensor corresponding to phase A is faulty; wherein the permanent magnet synchronous motor includes phase A, phase B and phase C, the path between phase A and phase B is the AB path, the path between phase B and phase C is the BC path, and the path between phase A and phase C is the AC path; if the current value of phase A is not 0 and the current value of phase B is 0, then the current sensor corresponding to phase B is faulty; if the current value of phase A is 0 and the current value of phase B is 0, then the flag bit recording the AB path is 0.

[0050] In one embodiment, the flag determination module 204 further detects the BC path and AC path to confirm whether the corresponding current sensor is faulty, and records the flags corresponding to the BC path and AC path.

[0051] In one embodiment, the phase loss detection module 206 is further configured to: set the status value to 111 when all three phases of the permanent magnet synchronous motor are normal; set the status value to 000 when all three phases of the permanent magnet synchronous motor are abnormal; set the status value to 100 when the AB path of the permanent magnet synchronous motor is 1 and the BC and AC paths are both 0; set the status value to 010 when the BC path of the permanent magnet synchronous motor is 1 and the AB and AC paths are both 0; and set the status value to 001 when the AC path of the permanent magnet synchronous motor is 1 and the BC and AB paths are both 0. The phase loss status of the permanent magnet synchronous motor is determined according to the position of the flag bit 0 in the status value.

[0052] In one embodiment, the phase loss detection module 206 is also used to perform phase loss detection after the faulty current sensor is replaced.

[0053] Specific limitations regarding the phase loss and current sensor fault detection device for permanent magnet synchronous motors can be found in the limitations of the phase loss and current sensor fault detection method for permanent magnet synchronous motors mentioned above, and will not be repeated here. Each module in the aforementioned phase loss and current sensor fault detection device for permanent magnet synchronous motors can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in hardware or independently of the processor in a computer device, or stored in software in the memory of a computer device, so that the processor can call and execute the corresponding operations of each module.

[0054] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 3 As shown, the computer device includes a processor, memory, network interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The network interface is used to communicate with external terminals via a network connection. When the computer program is executed by the processor, it implements a method for detecting phase loss and current sensor faults in a permanent magnet synchronous motor. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device casing, or an external keyboard, touchpad, or mouse.

[0055] Those skilled in the art will understand that Figure 3The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0056] In one embodiment, a computer device is provided, including a memory and a processor, the memory storing a computer program, the processor executing the computer program to implement the steps of the method described above.

[0057] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described above.

[0058] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0059] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for detecting phase loss and current sensor faults in a permanent magnet synchronous motor, characterized in that, The method includes: When the permanent magnet synchronous motor is stationary, energize any two phases and detect the current value between any two phases of the permanent magnet synchronous motor to determine the fault condition of the current sensor in the permanent magnet synchronous motor. If the detected current values ​​between any two phases are both zero, then the current flag is set to 0; otherwise, it is set to 1. The status quantity is composed of the flag bits, and the phase loss fault condition is determined based on the status quantity. With the permanent magnet synchronous motor stationary, the current values ​​between any two phases of the permanent magnet synchronous motor are detected to determine the fault condition of the current sensor in the permanent magnet synchronous motor, including: With the permanent magnet synchronous motor stationary, the current value between any two phases of the permanent magnet synchronous motor is detected respectively. When the current value of phase A is 0, and the current value of phase B is not 0, the current sensor corresponding to phase A is faulty; wherein, the permanent magnet synchronous motor includes phase A, phase B and phase C, the path between phase A and phase B is AB path, the path between phase B and phase C is BC path, and the path between phase A and phase C is AC path. If the current value of phase A is not 0 and the current value of phase B is 0, then the current sensor corresponding to phase B is faulty. When the current value of phase A is 0 and the current value of phase B is 0, the flag bit recording the AB path is 0.

2. The method according to claim 1, characterized in that, The state quantity is composed of the aforementioned flag bits, including: Arrange the flag bits of any two phases in a preset order to form a flag bit.

3. The method according to claim 1, characterized in that, The method further includes: It also checks the BC and AC paths to confirm whether the corresponding current sensors are faulty, and records the flag bits corresponding to the BC and AC paths.

4. The method according to claim 3, characterized in that, The method further includes: The three-digit state variable is determined based on the flags of the AB, BC, and AC pathways.

5. The method according to claim 4, wherein a state quantity is composed based on the flag bits, and a phase loss fault condition is determined based on the state quantity, comprising: When all three phases of the permanent magnet synchronous motor are normal, the status variable is set to 111; When all three phases of the permanent magnet synchronous motor are abnormal, the status variable is set to 000; When the AB path of the permanent magnet synchronous motor is 1, and the BC path and AC path are both 0, then the state variable is set to 100. When the BC path of the permanent magnet synchronous motor is 1, and the AB and AC paths are both 0, the state variable is set to 010. When the AC path of the permanent magnet synchronous motor is 1, and the BC path and AB path are both 0, then the state variable is set to 001. The phase loss status of the permanent magnet synchronous motor is determined based on the position of flag bit 0 in the state quantity.

6. The method according to any one of claims 1 to 5, characterized in that, The method further includes: After replacing the faulty current sensor, perform a phase loss detection.

7. A device for detecting phase loss and current sensor faults in a permanent magnet synchronous motor, characterized in that, The device includes: The fault detection module is used to detect the current value between any two phases of the permanent magnet synchronous motor when the motor is stationary, and to determine the fault status of the current sensor in the permanent magnet synchronous motor. The flag determination module is used to mark the current flag as 0 if the detected current values ​​between any two phases are both zero, and otherwise as 1. The phase loss detection module is used to form a status quantity based on the flag bits, and to determine the phase loss fault condition based on the status quantity. The fault detection module is also used to detect the current value between any two phases of the permanent magnet synchronous motor when the motor is stationary. If the current value of phase A is 0 and the current value of phase B is not 0, then the current sensor corresponding to phase A is faulty. The permanent magnet synchronous motor includes phases A, B, and C. The path between phases A and B is the AB path, the path between phases B and C is the BC path, and the path between phases A and C is the AC path. If the current value of phase A is not 0 and the current value of phase B is 0, then the current sensor corresponding to phase B is faulty. If the current value of phase A is 0 and the current value of phase B is 0, then the flag bit recording the AB path is set to 0.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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