PROJECT TITLE :

Topology and Capacitor Voltage Balancing Control of a Symmetrical Hybrid Nine-Level Inverter for High Speed Motor Drives - 2017

ABSTRACT:

So as to increase the output voltage levels and reduce the isolated dc sources, a symmetrical hybrid 9-level inverter for high-speed motor drive applications is presented during this paper. Every phase of this inverter is composed of a five-level dc/dc converter cell and an H-bridge cell. The dc/dc converter is operated at high frequency with low-voltage devices and therefore the H-bridge is operated at basic frequency with high-voltage devices. The 3 phases are connected to a standard dc-link and each drives an isolated winding of an open-winding motor. The operating principles and modulation methodology are introduced. A detailed analysis of the common currents through the flying capacitor and neutral purpose of the dc-link is presented and a capacitor voltage balancing technique based on phase-shifted pulse-width modulation is proposed. Simulation and experimental results are presented to demonstrate the feasibility of this topology and management method.