Maximum utilization of DC link voltage in grid connected hybrid modular multilevel converter

Abstract

This paper presents a five level hybrid modular multilevel converter that consists of full-bridge sub modules & half-bridge sub modules with a ratio of 1:2. Compared to conventional half bridge based modular multilevel converter, Hybrid modular multilevel converter can provide maximum utilization of available DC bus voltage by which transformer less operation can be obtained. Phase-disposition pulse width modulation technique has been utilized for generating the pulses required for the converter. Finally, grid connection of the hybrid modular multilevel converter using vector control scheme was implemented. Capacitor voltage balancing scheme has also been performed in this system. Simulation results have been presented here for validation of the complete system.