A New Inverter Topology to Improve the Performance of Pole-phase Modulated Induction Motor Drive by Minimizing Circulating/Common Mode Currents

The paper gives an new inverter topology to improve the performance of pole-phase modulated induction motor drive (PPM-IMD) by minimizing circulating/common mode currents. The pole phase modulation technique usually gives wide speed-torque ranges and operation to IMD. Specifically, the PPM technique operates the IMD in wide pole ranges i.e., from high-pole to low-pole mode. However, especially in high-pole operation there exists high torque ripples. The torque ripples are due to by reason high-space harmonics in stator winding. The harmonics are attributable to the circulating currents/common mode currents (CMC). The CMC are resultant of inverter common mode voltage (CMV). The proposed inverter topology minimizes the CMV by decoupling the DC bus and load during active high states of the switches. The paper mainly concentrates on the 3-phase mode CMV minimization. The proposed inverter topology minimizes the transition that comes due to switch junction capacitance effect. The minimization in CMV improves the drive performance by minimizing the torque ripple in high-pole mode. In addition, the proposed topology minimizes the switch losses as all switches in the inverter are turned ‘on’ during DC-decoupling/freewheeling period. The ANSYS designed 3HP, 415V, 12-pole IMD is exported to Ansys Twin-Builder environment and results are presented for proposed inverter topology. The simulation results validate the minimization of CMV and improvement in the drive performance by the proposed new inverter topology.