Estimation of Position and Shorted Turns Percentage of an Inter-Turn Short Circuit in Interior Permanent Magnet Synchronous Machines Based on a Current Observer and Stationary Reference Frame Tracking

This paper presents a method to detect and diagnose an inter-turn short circuit in interior permanent magnet synchronous machines. The proposed method detects the inter-turn short circuit fault using a current observer to estimate a disturbance related to the fault, defined as a fault index current. The fault index current estimates in the rotor reference frame have information about the location and the percentage of shorted turns. A novel stationary frame tracking technique is proposed to simultaneously determine the fault index current in the stationary frame and the fault position. Look-up tables are implemented to correlate the stationary frame fault index current magnitude to the percentage of shorted turns, providing an estimate of the percentage of shorted turns. Simulation and experimental results are shown throughout the paper to analyze and validate the proposed technique.