Harmonics optimization of the voltage balancing control for multilevel converter/inverter systems

This paper presents a novel control method to lower the harmonic components of the conventional voltage balancing control for the multilevel converters. The harmonic components in the voltage balancing control theory are analyzed in detail. A revised control method based on the line-line voltage redundancy of the three-phase inverter is proposed to lower the harmonic components of both the converter and inverter side. The proposed method can significantly reduce the harmonic components while keeping the switching frequency nearly the same. Simulation and experimental results are provided to show the validity of the theory.