PROJECT TITLE:

A Quad Two-Level Inverter Configuration for Four-Pole Induction-Motor Drive with Single DC Link - 2015

ABSTRACT:

A multilevel inverter topology for a four-pole induction-motor drive is presented during this paper, which is built using the induction-motor stator winding arrangement. A single dc source with a less magnitude compared with typical 5-level inverter topologies is utilized in this topology. Therefore, power balancing issues (that are major challenges in conventional multilevel inverters) are minimized. As this configuration uses one dc source, it provides a path for zero-sequence currents as a result of of the zero-sequence voltages gift in the output, that can flow through the motor phase winding and Power Electronic switches. To minimize these zero-sequence currents, sine-triangle pulsewidth modulation (SPWM) is employed, that will shift the lower order harmonics close to to switching frequency within the linear modulation region. But, within the case of overmodulation, harmonic voltages can be introduced shut to the fundamental frequency. During this regard, a modified SPWM technique is proposed in this paper to operate the drive within the overmodulation region up to the modulation index of two/v3. The proposed quad 2-level inverter topology is experimentally verified with a laboratory prototype on a four-pole 5-hp induction motor. Experimental results show the effectiveness of the proposed topology in the entire linear modulation region and the overmodulation region.