Diagnosis and Remediation of Single-Turn Short Circuit in a Multiphase FSCW PM Machine Based on T-type Equivalent Circuit

Single-turn short circuit (STSC) refers to the most severe turn fault condition in which the number of shorted turns is only one. Since winding inductance is proportional to the square of number of turns, STSC suffers from significantly large circulating current inside the faulted turn. The objective of this article is to provide practical approaches that enable fault detection and postfault operation. A previously developed T-type equivalent circuit laid a solid foundation for the proposed methods. High-frequency injection and signal processing method are carried out for reliable online fault diagnosis, while postfault operation is based on shorting the remaining turns as well as instantaneous power balance theory. Experimental results confirm the effectiveness of the proposed methods.