Fault model and performance evaluation of an inverter-fed permanent magnet synchronous motor under winding shorted turn and inverter switch open

Abstract

To analyse influences under various fault conditions, a fault model of an inverter-fed permanent magnet (PM) synchronous motor drive that can be used for a performance assessment of a diagnostic algorithm is presented. For fault conditions of a drive system, a short-circuited turn in the stator winding, switching device open in pulse width modulated inverter and the isolation between the inverter and motor are considered. Even though the conventional dq model is widely used to control an AC motor, it cannot be used directly for the analysis of a motor fault, since three-phase balanced condition does not hold under such conditions, and thus, it is not easy to obtain phase voltage inputs of motor from the pole voltage. To overcome this limitation, a fault model of an inverter-fed PM synchronous motor is derived using the line voltage, which can be effectively used to evaluate the performance of a fault detection algorithm. A test motor producing short-circuited turn in the stator winding is built. The validity of the proposed fault model is verified through the comparative simulations and experiments using digital signal processor TMS320F28335 under various fault conditions.