Rotor fault detection in inverter drive systems using inverter input current analysis

Broken rotor bar/ end-ring is a common fault in squirrel cage induction motors and has been thoroughly investigated in the case of AC grid supply. In this paper, this type of fault is studied in case of inverter driven motor. Induction motor is driven using scalar Volts/ Hz control method. Motor stator current and inverter input current spectra are studied for frequency components due to fault. Inverter input current spectrum gives the ability of fault detection and severity classification, even under low load and low motor severity fault condition in steady-state more easily than using motor stator current data, as it has the capability to produce advantage in variable frequency operation.