CN-121994501-A - Fault diagnosis method for electric drive, electric drive system and new energy vehicle

CN121994501ACN 121994501 ACN121994501 ACN 121994501ACN-121994501-A

Abstract

The invention provides a fault diagnosis method of an electric drive, an electric drive system and a new energy vehicle, wherein the fault diagnosis method of the electric drive comprises the steps of obtaining a vibration signal acquired by a vibration sensor arranged on an integrated shell of the electric drive; and if the number of times that the N-order fault index exceeds the index threshold table within a preset duration reaches a frequency limit value, determining that the electric drive has faults and sending out fault signals. So configured, the vibration signal can be converted into an N-order fault index quantity, so that the early mechanical fault of the electric drive can be detected by comparison with an index quantity threshold value table. Further, when the number of times that the N-order fault index exceeds reaches the number limit value, the fault of the electric drive is determined, and a fault signal is sent out, so that non-fault vibration signals introduced by road conditions or working conditions can be effectively filtered, and reliability and practicability of fault diagnosis are improved.

Inventors

ZHANG CHI
SHI JIA
YANG GUANGHAO
WANG YUXUE
Cheng Linqian
MENG ZHIJIN
LI LINJIAN
SHEN WENQING
ZHANG YONG

Assignees

联合汽车电子有限公司

Dates

Publication Date: 20260508
Application Date: 20241101

Claims (10)

1. A fault diagnosis method of an electric drive, comprising: acquiring a vibration signal acquired by a vibration sensor arranged on an integrated shell of the electric drive; Converting the vibration signal into an N-order fault index quantity, and comparing the N-order fault index quantity with a preset index quantity threshold value table; if the number of times that the N-order fault index exceeds the index threshold table reaches a frequency limit value within a preset duration, determining that the electric drive has faults, and sending out fault signals.
2. The method of claim 1, wherein the step of converting the vibration signal into an N-order fault index amount comprises: calculating to obtain a characteristic parameter representing the running state of the electric drive based on the vibration signal; And carrying out Fourier transform on the characteristic parameters based on the motor rotation speed to obtain N fault index quantities with different orders.
3. The method according to claim 2, wherein the characteristic parameter is calculated based on the vibration signal in a period of time and a motor rotation speed in the period of time.
4. The method of claim 2, wherein the characteristic parameter comprises kurtosis or a crest factor.
5. The method of claim 1, wherein the index amount threshold table is calibrated in advance based on the electric drive.
6. The method for diagnosing a failure of an electric drive according to claim 1, wherein the method for diagnosing a failure of an electric drive is repeatedly performed periodically with a period of 0.01s to 3600s.
7. The failure diagnosis method of an electric drive according to claim 1, the fault diagnosis method of the electric drive is characterized by further comprising the following steps: and judging the occurrence position of the fault according to the corresponding relation between the fault index quantity of each order in the N-order fault index quantity and the mechanical characteristic of the electric drive.
8. The method of claim 1, wherein the step of converting the vibration signal into an N-order fault index amount and comparing the N-order fault index amount with a preset index amount threshold value table comprises: And comparing the fault index quantity of each order in the N-order fault index quantity with a corresponding threshold value in the index quantity threshold value table, wherein the fault index quantity of any order exceeds the corresponding threshold value, namely judging that the N-order fault index quantity exceeds the index quantity threshold value table.
9. An electric drive system is characterized by comprising an electric drive, a vibration sensor and a fault detection module, wherein the electric drive at least comprises a motor, a motor controller and a speed reducer, the motor, the controller and the speed reducer are provided with an integrated shell, the vibration sensor is arranged on the integrated shell and is in communication connection with the fault detection module, and the fault detection module is configured to perform fault diagnosis on the electric drive according to the fault diagnosis method of the electric drive.
10. A new energy vehicle, characterized by comprising an electric drive system according to claim 9.

Description

Fault diagnosis method for electric drive, electric drive system and new energy vehicle Technical Field The invention relates to the technical field of new energy vehicles, in particular to an electric drive fault diagnosis method, an electric drive system and a new energy vehicle. Background In current new energy vehicles, the electric drive system lacks a reliable solution for active detection of early mechanical failure, which typically does not manifest itself until the failure is severe enough to affect the power output. This often results in an enlarged fault, damaging other components. Disclosure of Invention The invention aims to provide an electric drive fault diagnosis method, an electric drive system and a new energy vehicle, so as to solve the problem that the existing electric drive system lacks detection of early mechanical failure. In order to solve the above technical problems, the present invention provides a fault diagnosis method for an electric drive, which includes: acquiring a vibration signal acquired by a vibration sensor arranged on an integrated shell of the electric drive; Converting the vibration signal into an N-order fault index quantity, and comparing the N-order fault index quantity with a preset index quantity threshold value table; if the number of times that the N-order fault index exceeds the index threshold table reaches a frequency limit value within a preset duration, determining that the electric drive has faults, and sending out fault signals. Optionally, the step of converting the vibration signal into an N-order fault index amount includes: calculating to obtain a characteristic parameter representing the running state of the electric drive based on the vibration signal; And carrying out Fourier transform on the characteristic parameters based on the motor rotation speed to obtain N fault index quantities with different orders. Optionally, the characteristic parameter is calculated based on the vibration signal in a time period and the motor rotation speed in the time period. Optionally, the characteristic parameter comprises kurtosis or a crest factor. Optionally, the index amount threshold table is calibrated in advance based on the electric drive. Optionally, the fault diagnosis method of the electric drive is repeatedly executed periodically, and the period is 0.01 s-3600 s. Optionally, the fault diagnosis method of the electric drive further includes: and judging the occurrence position of the fault according to the corresponding relation between the fault index quantity of each order in the N-order fault index quantity and the mechanical characteristic of the electric drive. Optionally, the step of converting the vibration signal into an N-order fault indicator and comparing the N-order fault indicator with a preset indicator threshold table includes: And comparing the fault index quantity of each order in the N-order fault index quantity with a corresponding threshold value in the index quantity threshold value table, wherein the fault index quantity of any order exceeds the corresponding threshold value, namely judging that the N-order fault index quantity exceeds the index quantity threshold value table. The invention further provides an electric drive system which comprises an electric drive, a vibration sensor and a fault detection module, wherein the electric drive at least comprises a motor, a motor controller and a speed reducer, the motor, the controller and the speed reducer are provided with an integrated shell, the vibration sensor is arranged on the integrated shell and is in communication connection with the fault detection module, and the fault detection module is configured to conduct fault diagnosis on the electric drive according to the fault diagnosis method of the electric drive. In order to solve the technical problems, the invention also provides a new energy vehicle which comprises the electric drive system. In summary, in the fault diagnosis method, the electric drive system and the new energy vehicle for the electric drive, the fault diagnosis method for the electric drive comprises the steps of obtaining vibration signals acquired by vibration sensors arranged on an integrated shell of the electric drive, converting the vibration signals into N-order fault index amounts, comparing the N-order fault index amounts with a preset index amount threshold value table, and if the times of the N-order fault index amounts exceeding the index amount threshold value table reach a frequency limit value within a preset duration, determining that faults exist in the electric drive, and sending out fault signals. So configured, vibration signals collected by vibration sensors provided on the integrated housing can be converted into N-order fault index amounts, so as to compare with the index amount threshold value table and detect early mechanical faults of the electric drive. Furthermore, by counting the number of times that the N-order fault index