Harmonic analysis of the output voltage of parallel multilevel converters with clamping diodes under different methods of PWM

Multilevel semiconductor converters with clamping diodes are used in various fields of electrical and power engineering that require relatively high operating voltages (1–20 kV). These include energy storage systems, static compensators, power active filters, power generation systems, and others. However, the high installed capacity of electrical systems demands implementing a parallel (modular) connection of converters. In this context, one of the factors affecting the quality of the conversion of electrical power in parallel connection is PWM, namely, the form of reference signals and their relative phase shift relative to each other. This article provides harmonic analysis of the output voltage of parallel multilevel converters with clamping diodes at various ways of implementing the PWM. The results of comparing the output voltage harmonic coefficients for different parallel converters for the triangular and sawtooth reference signals are provided.