An improved carrier-based SVPWM method using leg voltage redundancies in generalized cascaded multilevel inverter topology

Abstract

The carrier-based space vector pulse width modulation (SVPWM), which is considered as simple and efficient PWM technology, can be also used in multilevel inverters. The method was originally designed for the two-level inverter and developed to the diode-clamped multilevel inverter structure. However it may be noted that it also causes bad switch utilization in cascaded multilevel inverters. This paper introduces an improved carrier-based SVPWM scheme, which is fully suitable for cascaded multilevel inverter topologies because it can achieve the optimized switch utilization through the redistribution of the triangular carrier waves considering leg voltage redundancies while having the advantages of the conventional carrier-based SVPWM. Using experimental results, the superior performance of new PWM method is shown.