Electric drive system power tube open-circuit fault diagnosis method based on grey prediction theory

Abstract

The invention discloses an open-circuit fault diagnosis method for a power tube of an electric drive system based on a grey prediction theory. The electric drive system comprises a double-winding permanent magnet motor, two sets of three-phase bridge inverters and a fault diagnosis module. The method comprises the following steps of firstly, forming an original sequence of a gray prediction modelby collecting current data; predicting the current value of the next moment by using a mathematical model of grey prediction; and then the difference between the prediction data and the original datais calculated through a fault diagnosis device and compared with a set threshold value so that whether a fault occurs or not is judged, a fault signal is fed back, and the current values at the time of 3T / 4 and the time of T / 2 from the beginning of the fault are detected to judge the fault position. The method is high in reliability, does not need an additional sensor, and can achieve the quick and accurate diagnosis and positioning of the open-circuit fault of the power tube of the electric drive system.

Description

technical field [0001] The invention relates to the field of fault diagnosis of an electric drive system, in particular to a diagnosis method for an open circuit fault of a power tube of an electric drive system based on gray prediction theory. Background technique [0002] With the development of multi-electric, all-electric aircraft and hybrid and pure electric vehicles, the motor drive system has ushered in new development opportunities and challenges. In addition to requiring high power density and high efficiency, it also needs to have high output performance and high reliability. performance, which has become the key to the motor drive system. However, when the electric drive system fails, the motor will run asymmetrically, and the output torque will pulsate, resulting in large mechanical noise, which will lead to the decline of the overall performance of the system, especially the greatly reduced output power, or even malfunction, seriously endangering the The safety...

AI Technical Summary

Problems solved by technology

In the past, the electric drive system relied on calculating the current of one or more cycles to diagnose the fault, which also means that the motor will run more time in the fault state, increasing the loss and risk of the system

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