Online Stator Inter-Turn Short Circuit Faults Detection in Interior PMSM Drives

In order to improve reliability and minimize maintenance effort of ac electric drives, online fault diagnosis represents an important tool. This paper proposes a detection algorithm for stator inter-turn short circuit (ITSC) faults in permanent magnet synchronous motor drives designed for online operation. Specifically, the focus is on main traction drive of a railway vehicle, where the emphasis is put on simple non-invasive implementation with no need for specialized hardware. Moreover, the goal is to achieve high reliability despite variable operational conditions which are typical in traction drive (load, speed, temperature, etc.). The algorithm is implemented using standard current sensors together with control hardware which combines the commonly available digital signal processor (DSP) and field programmable gate array (FPGA) to accelerate the calculations. Experimental testing is used to validate the proposed online detector on a laboratory prototype of an IPMSM drive, and the results are compared to selected state of the art diagnostic algorithm.