A Novel Phase-shifted Carrier PWM and Voltage Balancing Control Scheme for Enhancing Dynamic Performance of Modular Multilevel Converter

Abstract

Even though classical control based pulse-width modulation has a superior steady state performance and stable switching state, it suffers from some drawbacks. The dynamic performance of the classical control methods with proportional-integral or proportional-resonant controllers is unsatisfactory and the requirement of proportional-integral parameters tuning procedure makes designing the controller more complex. In this paper, we propose a novel phase-shifted carrier pulse-width modulation method and capacitor voltage balancing control aimed at medium-voltage applications. The proposed control method eliminates the requirement of the tedious proportional-integral parameters tuning procedure and improves the dynamic performance compared to the conventional phase-shifted carrier pulse-width modulation-based proportional-integral controller method. Simulations were conducted to demonstrate the proposed method s properness.