Model-Based Severity Monitoring for Interturn Short Circuit Faults in Symmetrical Six-Phase PMSMs Using Subspace Current Residuals

This article proposes a novel model-based method for severity level monitoring of interturn short-circuit faults (ISCFs) using the
xy
subspace current residuals in symmetrical six-phase permanent magnet synchronous machines. For six-phase control system, the six-phase currents are usually mapped onto the
dq
and
xy
subspaces by vector space decomposition. The behavior in each subspace is affected by ISCF. In order to avoid PM flux linkage error reducing the performance of model-based method, the fault indicator is generated using the
xy
subspace current residuals. The proposed method has a high signal-to-noise ratio by extracting a fundamental signal instead of the second harmonic. Moreover, the proposed fault indicator can be obtained by simple signal processing without the use of spectral analysis tools or lots of filters. Experimental results show the effectiveness of proposed method for different fault severities and operating conditions.