Induction motor fault detection by space vector angular fluctuation

A new method of obtaining diagnostic data from induction motors, derived from space vector angular fluctuation, is presented in this paper. It obtains data from stator current by exploring the position of the current space vector in the space vector plane. Variations of the phase angle of the vector are subjected to Fourier transformation and analysed in the frequency domain. The method has been tested on laboratory induction motors with simulated stator faults, rotor resistance unbalance, supply voltage unbalance, as well as with computer simulation. The Goertzel algorithm is employed as a tool for real-time fault monitoring of the frequency domain. In the case of a stator fault, which can develop rapidly, this allows diagnosis within a few cycles. As well as providing a new tool in motor diagnostics, this method is able to detect both stator and rotor faults, and gives a good basis for an integrated induction motor condition monitor.