Low cost 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 for axis-transformation and speed which is estimated using current information are presented. In inverter-fed motor drives the stator currents have much harmonics components and therefore fault diagnosis using stator current is difficult. The current and speed signal 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. Therefore, the proposed method are 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 and speed estimation method are compared with the results obtained from fast Fourier transforms.