CN-121995186-A - Multi-phase motor IGBT open-circuit fault identification method, system and storage medium

CN121995186ACN 121995186 ACN121995186 ACN 121995186ACN-121995186-A

Abstract

The present disclosure provides a method, a system and a storage medium for identifying an IGBT open circuit fault of a multiphase motor, and relates to the technical field of motor control, wherein the method comprises the steps of obtaining an actual rotation speed of the multiphase motor; when the actual rotating speed is smaller than the set rotating speed threshold value, a second diagnosis strategy is started, and the second diagnosis strategy is used for positioning the fault phase with the IGBT open-circuit fault based on the duty ratio of each phase and the current of each phase of the multiphase motor and generating an IGBT open-circuit fault identification result containing the fault phase. According to the method, different diagnosis strategies are dynamically selected according to the motor rotation speed, so that the accuracy of fault positioning can be effectively improved, the occurrence of misdiagnosis is avoided, and the accurate identification of the IGBT open-circuit fault under all working conditions is realized.

Inventors

MENG HUIBIN
LI QIANG
LIU WENLIANG
ZHUANG XUHUI
ZHANG ZHENGQING

Assignees

潍柴动力股份有限公司

Dates

Publication Date: 20260508
Application Date: 20251222

Claims (10)

1. The method for identifying the open-circuit fault of the IGBT of the multiphase motor is applied to a motor driver electrically connected with the multiphase motor and is characterized by comprising the following steps of: acquiring the actual rotating speed of the multiphase motor; When the actual rotating speed is larger than a set rotating speed threshold value, a first diagnosis strategy is started, wherein the first diagnosis strategy is used for carrying out harmonic analysis and positioning on fault phases with IGBT open-circuit faults based on current of each phase of the multi-phase motor; when the actual rotating speed is smaller than a set rotating speed threshold value, a second diagnosis strategy is started, wherein the second diagnosis strategy is used for positioning a fault phase with IGBT open circuit fault based on the duty ratio and the current of each phase of the multiphase motor, and And generating an IGBT open-circuit fault identification result containing the fault phase.
2. The method of claim 1, wherein the first diagnostic strategy is configured to: acquiring each phase current of the multiphase motor; judging whether each phase current of the multi-phase motor meets a preset first constraint condition for preventing the first diagnosis strategy from being positioned by mistake; When each phase current of the multiphase motor meets the first constraint condition, performing VSD coordinate transformation on each phase current of the multiphase motor to obtain current components of an xy harmonic plane; generating a harmonic current total amplitude based on the current components of the xy harmonic plane, and And when the total amplitude of the harmonic current is larger than a preset fault judgment current threshold value, matching based on the current component of the xy harmonic plane and the corresponding relation between the preset fault phase and the harmonic current track, and positioning the fault phase.
3. The method of claim 2, wherein determining whether each phase current of the multi-phase motor meets a preset first constraint for preventing the first diagnostic strategy from being mispositioned comprises: Taking absolute values of all phases of currents of the multi-phase motor respectively, and accumulating to generate accumulated current values of all phases; Sequencing the accumulated current values of each phase to obtain a maximum accumulated current value and a minimum accumulated current value; judging whether the maximum accumulated current value is larger than the product of the minimum accumulated current value and the motor phase number to verify the first constraint condition, and And if the maximum accumulated current value is larger than the product of the minimum accumulated current value and the motor phase number, judging that each phase current of the multi-phase motor meets the first constraint condition.
4.A method according to any one of claims 1-3, wherein the second diagnostic strategy is configured to: acquiring the duty ratio of each phase of the multiphase motor; judging whether the duty ratio of each target phase of the multiphase motor meets a preset second constraint condition for preventing the second diagnosis strategy from being positioned by mistake; Acquiring the actual current of the target phase when the duty ratio meets the second constraint condition; Identifying whether the IGBT open-circuit fault occurs in the target phase based on the actual current, generating an IGBT open-circuit fault diagnosis result of the target phase, and And positioning the fault phase based on the IGBT open-circuit fault diagnosis result of each target phase.
5. The method of claim 4, wherein determining whether the duty cycle satisfies a second constraint preset to prevent the second diagnostic strategy from being mispositioned comprises: judging whether the duty ratio of the target phase is in a set range or not and the duration of the duty ratio of the target phase in the set range exceeds a set time or not to verify the second constraint condition; if yes, determining that the duty ratio satisfies the second constraint condition, and And if not, judging that the duty ratio does not meet the second constraint condition.
6. The method of claim 4, wherein the identifying whether the target phase has an IGBT open circuit fault based on the actual current comprises: Determining that the target phase has an IGBT open circuit fault in response to the actual current being less than a preset current determination threshold, and And responding to the actual current which is larger than or equal to a preset current judgment threshold value, and judging that the target phase has no IGBT open circuit fault.
7. A method according to claim 2 or 3, further comprising: acquiring each phase voltage of the multiphase motor; generating a fault judgment current threshold initial value based on each phase voltage of the multi-phase motor; Acquiring actual operation parameters of the multiphase motor, wherein the actual operation parameters comprise actual rotation speed and actual torque, and And adjusting the initial value of the fault judgment current threshold based on the actual operation parameters to generate a final fault judgment current threshold.
8. A method according to any one of claims 1-3, further comprising: after detecting a hardware driving fault signal of the motor driver, generating a control instruction for acquiring the actual rotating speed of the multiphase motor so as to start IGBT open circuit fault identification; Generating a fault signal based on the fault phase located by the first diagnostic strategy or the second diagnostic strategy; verifying whether the time sequence stability of the fault signal meets the set standard, and And when the time sequence stability of the fault signal meets a set standard, a control instruction for generating the IGBT open circuit fault identification result is sent out.
9. An IGBT open circuit fault identification system for a multiphase motor for a motor drive electrically connected to the multiphase motor, comprising: An acquisition unit configured to acquire an actual rotation speed of the multiphase motor; The first processing unit is configured to start a first diagnosis strategy when the actual rotating speed is larger than a set rotating speed threshold value, wherein the first diagnosis strategy is used for carrying out harmonic analysis and positioning on a fault phase with IGBT open-circuit fault based on each phase current of the multi-phase motor; a second processing unit configured to start a second diagnosis strategy when the actual rotation speed is smaller than a set rotation speed threshold value, wherein the second diagnosis strategy is used for positioning a fault phase with IGBT open circuit fault based on each phase duty ratio and each phase current of the multiphase motor, and And a result generation unit configured to generate an IGBT open-circuit fault identification result containing the fault phase.
10. A storage medium storing a program or instructions which, when executed by a processor, implement the steps of the method of any one of claims 1 to 8.

Description

Multi-phase motor IGBT open-circuit fault identification method, system and storage medium Technical Field The disclosure belongs to the technical field of motor control, and particularly relates to a multiphase motor IGBT open circuit fault identification method, a multiphase motor IGBT open circuit fault identification system and a multiphase motor IGBT open circuit fault identification storage medium. Background IGBT faults of motor drives are largely divided into short-circuit faults and open-circuit faults. When the IGBT fails, the type and the position of the failure need to be identified in time. The short-circuit fault is short in time, usually several microseconds, which is difficult to detect, so that a hardware protection circuit such as a fast fuse is connected in series in the motor driver to convert the short-circuit fault into an open-circuit fault for processing. After the open circuit fault occurs, the motor driver can still continue to operate in a short time, however, if the current of other healthy switches is increased and the heat is serious due to the fact that the current is not detected in time, secondary faults can be caused when the current is serious, and huge economic loss is caused. In the related art, research on motor driver fault diagnosis focuses on IGBT open circuit fault identification. In the related art, the method for identifying the open-circuit fault of the IGBT mostly monitors the harmonic content of phase current through software to identify the fault phase. The method has the following defects that firstly, only the fault characteristics shown by the harmonic current mapped to a static coordinate system are used, so that the method is narrow in application scene, secondly, the difference of harmonic content under different working conditions is large, a diagnosis threshold value is difficult to accurately calibrate, misdiagnosis is easy to occur, current is close to direct current when the rotating speed is close to 0, the method is not suitable for identifying IGBT open-circuit faults through the harmonic content any more, and thirdly, depending on filter setting, misdiagnosis can occur when the chip calculation force is insufficient or the filter parameter setting is incorrect. Disclosure of Invention The disclosure provides a multiphase motor IGBT open-circuit fault identification method, a multiphase motor IGBT open-circuit fault identification system and a multiphase motor IGBT open-circuit fault storage medium, and aims to solve the technical problem that the IGBT open-circuit fault cannot be accurately identified under the full working condition by the related technology to at least a certain extent. At least one embodiment of the present disclosure provides a multi-phase motor IGBT open circuit fault identification method applied to a motor driver electrically connected to a multi-phase motor, including: acquiring the actual rotating speed of the multiphase motor; When the actual rotating speed is larger than a set rotating speed threshold value, a first diagnosis strategy is started, wherein the first diagnosis strategy is used for carrying out harmonic analysis and positioning on fault phases with IGBT open-circuit faults based on current of each phase of the multi-phase motor; when the actual rotating speed is smaller than a set rotating speed threshold value, a second diagnosis strategy is started, wherein the second diagnosis strategy is used for positioning a fault phase with IGBT open circuit fault based on the duty ratio and the current of each phase of the multiphase motor, and And generating an IGBT open-circuit fault identification result containing the fault phase. The IGBT open-circuit fault identification method suitable for the multiphase motor, particularly the six-phase motor, has the advantages that the IGBT open-circuit fault identification method suitable for the multiphase motor is provided, the actual rotation speed change of the multiphase motor can generate obvious influence on a harmonic plane, different diagnosis strategies are dynamically selected according to the actual rotation speed, the occurrence of the condition of misdiagnosis can be effectively avoided, fault characteristics are more comprehensively captured, the possibility of missing detection is reduced, the accuracy of fault location is improved, the accuracy and coverage of an IGBT open-circuit fault identification result are effectively improved, and therefore the overall diagnosis capability of a system is enhanced. The diagnosis method based on the rotation speed self-adaption is not only beneficial to improving the speed of fault identification, but also can further improve the accuracy of diagnosis, and ensures that the system can realize rapid and reliable fault detection under various working conditions. In a method provided by at least one embodiment of the present disclosure, the first diagnostic strategy is configured to: acquiring each phase current of the