Static eccentricity fault detection in induction motors using wavelet packet decomposition and Gyration radius

In this paper, Finite Element Magnetic (FEM) method is used for modeling an induction motor before and after rotor eccentricity fault. The imbalance magnetic field in the air gap affects the stator current sinusoidal shape. The wavelet packet decomposition and Gyration radius methods are applied on the distorted current and torque signals respectively for the fault detection. The results of the two methods are consistent and reliable in eccentricity fault detection. In addition, by increasing the eccentricity severity for the static fault, both the energy of nodes and radius of phase space diagram of FEM diagram increase. Hence these two indices were used to measure the severity degrees of the static eccentricity fault.