DC-Decoupled based Multi-phase Inverter Topology for Electronic Pole-changing Induction Motor Drive

This paper proposes a DC-Decoupled based multi-phase inverter (DCDMI) topology for electronic-pole changing (E-PC) induction motor drive (IMD) system. The given E-PC IMD with flexible wide speed and torque ranges, operates in two modes: 3-φ,12-pole and 9-φ, 4-pole mode. However, during the operation of E-PC IMD, a prevalent torque ripple exists, especially in high-pole mode. Torque ripples are due to harmonics in the stator periphery. The harmonics are attributed to common-mode current (CMC) produced by common-mode voltage (CMV) of the inverter that drives IMD. Consequently, this results in deterioration of drive performance. This paper proposes a new inverter topology for E-PC IMD, which minimizes the transitions in CMV both operating modes. Subsequently, the CMC in the stator periphery is minimized in both the modes. The required analysis and derivation for the expression of terminal voltages are also presented in this manuscript. Further, in the proposed system an interleaved switching strategy which is integrated with the DC-decoupling technique improves the over-all performance in 3-φ mode. To validate the results of the proposed DCDMI topology, a 36-slot 3.0HP 3-φ, 12-pole IM is designed, simulated, and analyzed in an Ansys environment. Simulated results are corroborated by experimentation.