Space vector modulation for a single-phase converter with parallel legs using virtual vectors concept

Abstract

This paper explores the space vector modulation for voltage fed converters with multiple parallel coupled legs. The proposed modulation strategy allows the synthesis of multilevel equivalent PWM voltage patterns with reduced total harmonic distortion. In addition, thanks to the use of virtual vectors concept, it is possible to establish the voltage limits required to ensure equal current sharing between adjacent legs, avoiding saturation of the coupled inductors. Furthermore the developed modulation approach provides a degree of freedom to select switching sequences that minimizes the inner high frequency leg current ripple. The proposed space vector modulation is demonstrated for a single phase converter, however it can be easy generalized for three phase counterpart. Simulation results are presented to support the developed analysis demonstrating the very good performance of the proposed modulation technique.