A novel DC voltage balancing scheme of five-level converters based on reference-decomposition SVPWM

Multilevel diode clamped converter (DCC) has gained more and more focus nowadays due to its adaptability to high-power and high-voltage applications. Among the problems concerning DCC, the DC capacitor voltage balancing problem is of great significance yet difficult to resolve. In this paper, the DC voltage of a five-level DCC is balanced using an object function optimizing scheme based on a proposed novel and simple DC current model. This paper also proposes a combination of the voltage balancing scheme with reference-decomposition SVM method, thus realize a novel and effective DC voltage balancing scheme. Analytical and Simulation results of a five-level diode-clamped converter are given to validate the feasibility of the proposed scheme.