Inter-Turn Short-Circuit Fault Diagnosis Method for Dual Three-Phase PMSM Based on Voltage Demodulation

This article proposed an inter-turn short-circuit (ITSC) fault diagnosis method for dual three-phase permanent magnet synchronous motor (DTPPMSM) based on voltage demodulation. The method is established based on the extraction and analysis of 2nd harmonics of d- and q-axis voltage caused by ITSC fault. This article analyzed the influence of ITSC fault on d- and q-axis voltage and pinpointed the relationship between the amplitudes of 2nd voltage harmonics and ITSC fault severity. On this basis, the 2nd harmonics of d- and q-axis voltage are extracted and properly transformed in time domain to form a fault indicator, thus achieving a quantitative and online diagnosis of ITSC fault severity. The correctness of the proposed method is verified by both finite element analysis (FEA)-based field-circuit coupling method and prototype experiments.