PROJECT TITLE :

A Star-Channel Modular Multilevel Converter for Zero/Low Fundamental Frequency Operation without Injecting Common-Mode Voltage - 2017

ABSTRACT:

This paper proposes a star-channel modular multilevel converter (MMC). It overcomes the zero/low-basic-frequency operation issues of standard MMC whereas not injecting the common-mode voltage (CMV). The proposed converter is characterised by the cross connections of higher three arms and lower 3 arms through two sets of star-channel branches. These star-channel branches rebalance the ability among 3 part legs, resulting in minimized submodule capacitor voltage ripples even at zero/low-fundamental-frequency operation without CMV injection. This feature enables the proposed converter to interface medium/high-voltage DC and variable-frequency AC systems. A 4160-V one-MW simulation model is performed in MATLAB/Simulink, and a 208-V five-kW experimental setup is made in the lab. Both of the simulation and experimental results verify the feasibility of the proposal.