Isolation of Rotor Asymmetry Fault in Induction Machines through Sign-based Rotating Reference Frame and Generalized Goertzel Algorithm

Detection of rotor asymmetry faults (RAFs) in induction machines (IMs) based on stator current signature of machine due to the presence of low-frequency load torque oscillation (LTOs) can cause false alarm (FM). Therefore, isolating the RAFs from the LTOs can improve the condition-based monitoring system. The methods discussed in the past generally require three-phase current and voltage of stator windings information along with machine angular velocity. In this paper, a new method based on single phase machine data is presented. In this regard, a virtual rotating reference frame based on Hilbert transform is provided which do not need the angular velocity of machine. In order to improve the output spectrum resolution and low computational cost, the proposed method is combined with the Gortzel algorithm. The proposed method is tested and evaluated by synthetic data and then evaluated by means of experimental results. The results show that this method can isolate the RAFs indices from LTOs, effectively.