A Space Vector Modulation approach for capacitor voltage balancing of Flying Capacitor Converters

Abstract

The capacitor voltage balancing is the main technical challenge of a multi-level Flying Capacitor Converter (FCC). This paper proposes a Space Vector Modulation (SVM)-based voltage balancing strategy that takes the advantage of redundant switching states of an n-level FCC to counteract the voltage drift/imbalance. A cost function minimization approach is proposed to choose the proper redundant switching states to carry out the voltage balancing task. Performance of a four-level FCC under the proposed SVM strategy for various operating conditions is studied and evaluated. The studies demonstrate effectiveness of the proposed SVM strategy to control and maintain voltage balance of the capacitors.