Rotor Fault Identification and Diagnosis of PM Motor

Abstract

The most common rotor faults in a permanent magnet (PM) motor are the permanent magnet demagnetization and rotor eccentricity, and they are difficult to diagnose accurately because they exhibit very similar fault characteristics. However, the means of fixing the PM motor after two kinds of faults are different, and it is necessary to distinguish accurately between the two kinds of faults. To address the difficult of accurately distinguishing between the rotor eccentricity and the permanent magnet demagnetization fault in PM motor, this paper analyzes in depth the spectral changes of stator branch currents of various faults, proposes a rotor fault identification and diagnosis method for faulty PM motor based on motor branch current analysis. Finally, the feasibility and effectiveness of the proposed method is verified by the finite element.