Hybrid 3-level converter for high performance induction machine drive

Abstract

This paper investigates a hybrid multilevel converter for an induction machine drive. It is performed through the add of a 1-phase 3-levels FC-based leg to a classical 3-phases 3-levels NPC converter. The aim of the additional leg is to provide NPC legs with an active neutral point and, consequently, avoids the neutral point voltage unbalance issue. To ensure a balanced flying capacitor voltage and a constant neutral point, a strategy control of the FC leg is developed and an appropriate LC filter is proposed. The converter is simulated feeding a 1.5kW induction machine. Experimental results of the converter feeding a 1.5kW induction machine show the effectiveness of the developed control of FC leg and the proposed topology.