Study of winding inter turn short circuit effect on permanent magnet synchronous motor performance

Abstract

Single phase winding’s inter turn short circuit is a common fault in permanent magnet synchronous motor, the short circuit will cause the change of the motor performance to various degrees. In this paper, a 70 kW permanent magnet motor is taken as an example, and ANSYS Maxwell software is used to establish the model of permanent magnet synchronous motor. The inter turn short circuit fault is simulated by reducing the number of turns of the coil. With the help of the software’s powerful electromagnetic field analysis ability and post-processing function, the fault influence on stator winding phase current, electromotive force, torque fluctuation and iron loss, copper loss effect are studied; the current signal is extracted to analyze the relationship between the changes and it is concluded that the amplitude of the third harmonic (150 Hz) of the current increases with the increase of the number of inter-turn short circuit of the A-phase stator. The result can provide the basis for early stage fault diagnosis of the inter turn short circuit.