A reconfigurable dual three phase PMSM with insulation monitoring

Inter Turn Short Circuit (ITSC) faults in conventional PMSM drives are difficult to detect early due to weak fault signatures. This paper proposes a novel reconfigurable dual three-phase Permanent Magnet Synchronous Machine (PMSM) drive architecture designed to enhance incipient fault detection. The machine drive operates in six phase mode when maximum power is needed and transitions to three-phase mode. In three-phase operation mode, one winding set is energized while the other is isolated and repurposed as a passive search winding in partial load. These two winding sets are arranged in a bifilar manner in which tooth-coils are interleaved in a way that the turns of the first set are physically adjacent to those of the second. Any turn-to-turn short circuit then becomes a connection between the two winding sets. The analysis and simulation results show that incipient ITSC detection is achievable using only phase current measurements. The proposed drive can be particularly attractive for safety-critical applications where peak power is demanded for short duration.