Generalized Phase-Shift Pulse Width Modulation for Multi-Level Converters

Abstract

In this paper a simplified algorithm for phase-shift pulsed width modulation (PS _ PWM) is generalized for all topologies of multi-level converters and modular multi-level converters (MMC). Fundamentally, proposed method includes simplified algorithm based on analytical model of phase shift that could be applied on all topologies of multi-level converters and MMCs. Each voltage level is generated through comparing a set of carrier signals with the reference waveform. The method is explained for generating three voltage levels and then it is extended to produce n voltage levels at the output of inverters. Eventually, simulation results are presented on different types of multilevel inverters including 5-level H-bridge Neutral point clamped (5L-HNPC), 7-level Packed U-cell (PUC-7) and 15-level cascade H-bridge with 7 cells to validate the performance of the proposed modulation technique.