PUBLICATIONS

 This paper proposes a novel two-step active highfrequency injection algorithm for open-circuit switch fault diagnosis in open-end winding (OEW) IPMSM drives fed by a common DC bus. Conventional passive methods, based on current distortion, can identify the indistinguishable faulty pair but fail to pinpoint the specific switch at zero or low speeds due to the topology’s structural symmetry and the lack of backelectromotive force. To overcome this, the proposed speedindependent high-frequency injection technique injects specific unipolar pulses designed according to the faulty pair. This active test identifies a unique response, characterized by an unintentional amplification versus a blocking of the response current, to precisely locate the single faulty switch. This ensures suitability for system operation across all speed ranges. The validity of the proposed algorithm is verified through simulation.