Applications and Modulation Methods for Modular Converters Enabling Unequal Cell Power Sharing

Abstract

Modular converters based on the connection of multiple power cells have become a competitive solution for many applications achieving high performance with reduced production and maintenance cost. However, their performance is degraded if the power modules present an unbalanced operation which is a common case in some applications and/or when they implement active thermal control methods. Variable-angle carrier-based PWM strategies face this challenge minimizing the negative impact of unequal power sharing among the cells by improving the output waveforms harmonic quality what has a direct impact on the output filters and/or components’ lifetime.