Sorting-algorithm-based Modulation Technique For Voltage Balancing the Floating Capacitors of Modular Multilevel Converters

Abstract

The modular multilevel cascade converter (MMCC) has been emerging as a good solution for medium to high-voltage applications. This paper proposes a modified nearest level control for the MMCCs, aiming at a lower error in the voltages of the submodules and a reduction in the computational effort. To check the feasibility of the proposed technique, a comparison of the results was carried out with the phase-shifted carrier technique. From the proposed solution, $m+1$ voltage levels can been achieved, similar as some applications, besides presenting better results in the voltage balancing of the floating capacitors and the waveform quality of output voltages.