PROJECT TITLE :

Multilevel Dodecagonal Voltage Space Vector Structure Generation for Open-End Winding IM Using a Single DC Source

ABSTRACT:

In this paper, a replacement inverter topology is proposed for generating a multilevel dodecagonal voltage house vector structure for open-finish winding induction motor (IM) employing a single dc source. Dodecagonal voltage space vector structure eliminates fifth- and seventh-order harmonic voltages from part voltage output and hence eliminates the fifth- and seventh-order harmonic currents through the motor leading to removal of the dominant sixth-order torque ripple generation within the motor over the entire modulation vary. Multilevel house vector structure generates output voltage with better THD and low dv/dt. In the proposed topology, 2 3-level inverters drive an open-end winding IM, one inverter from each side. DC-link of primary inverter is from a dc supply that delivers the complete active power, whereas the secondary inverter dc-link is maintained by a capacitor, which is self balanced throughout the inverter operation. The PWM scheme implemented ensures low switching frequency for primary inverter. Secondary inverter operates at a little dc-link voltage. Hence, switching losses are small for both primary and secondary inverters. Experimental results show the elimination of fifth- and seventh-order harmonic voltages over the whole modulation vary, validating effectiveness of the proposed multilevel inverter theme.