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

Multilevel diode clamped converters have accepted more and more concentration recently due to its adaptability to high-power and high-voltage applications. The DC capacitor voltage balance problem is very important yet difficult to handle among the problems concerning DCC. 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.