Operation features of a reduced matrix converter for offshore wind power

The reduced matrix converter (RMC) implemented in offshore wind power conversion system is investigated in this paper. The RMC is built with 6 bi-directional switches, and the losses produced by these switches are compared under different conditions. Each bi-directional switch is made up by two RB-IGBTs in antiparallel, and it is studied how the special structure of the RB-IGBT will affect the total losses of the switch. The entire offshore wind power conversion system is modeled in PSIM. The first conversion stage after the wind turbine is direct ac-ac conversion by the reduced matrix converter. Thereafter a high frequency square wave voltage is fed into a transformer. Due to the high frequency, the transformer will have reduced weight, which is an important aspect of the lightweight and compact component requirements for offshore wind turbine installations. After the transformer the second conversion stage is carried out. This is done by a full-bridge converter where the output is dc voltage, for enabling series connection of wind turbines in dc. The study is aimed at the achievement of an energy efficient converter, with high power density and reliability.