Inter-turn fault detection in PM synchronous machines by physics-based EMF estimation

Inter-turn short circuit fault (ISCF) detection, in permanent magnet synchronous machines (PMSM) was developed using a physics-based back electromotive force (EMF) estimator. The electro-thermal saturation-dependent model of the machine was employed in the heart of the open loop estimator. The fault detection system works based on the difference between the estimated EMF and a reference EMF. A 0.8 (kW) PMSM machine was studied experimentally under different ISCF and operational contingencies. The results show acceptable performance in fault detection for wide speed range even in the presence of harmonic loads and dynamic eccentricities.