Rotor fault detection system for inverter driven induction motor using currents signal

In this paper, the induction motor rotor fault diagnosis system using current signals which are measured using axis-transformation method is presented. In inverter-fed motor drives unlike line-driven motor drives the stator currents are rich in harmonics and therefore fault diagnosis using stator current is not trivial. The current signals for rotor fault diagnosis need precise and high resolution information, which means the diagnosis system demands additional hardware such as low pass filter, high resolution ADC, encoder and etc. Therefore, the proposed axis-transformation method is expected to contribute to low cost fault diagnosis system in inverter-fed motor drives without the need for encoder and any additional hardware. In order to confirm validity of the developed algorithms, various experiments for rotor faults are tested and the line current spectrum of each faulty situation using Park transformation is compared with the results obtained from fast Fourier transforms.