The Modular Current-Fed High-Frequency Isolated Matrix Converters for Wind Energy Conversion

In this article, a modular current-fed high-frequency transformer isolated matrix converters (CF-HFT-MC) based wind energy conversion system (WECS) is proposed. The CF-HFT-MC module utilizes the high-frequency transformer instead of the line-frequency input transformer, and eliminates the bulky and vulnerable electrolytic capacitors in the WECS. Therefore, the power density, reliability and efficiency of WECS can be increased. Moreover, single-stage power conversion and soft-switching can be achieved in the CF-HFT-MC modules, which can reduce the losses of the system. With the function of electric isolation, the wind turbines can be connected in series through the proposed CF-HFT-MC modules. Thus, the total dc output voltage is increased, which enables the offshore wind farm to be integrated to the current-source-converters based HVdc transmission directly. The modulation, control scheme and power sharing method are analyzed and designed for the proposed CF-HFT-MC based WECS in this article. Both the simulations and the experiments are given to verify the effectiveness of the proposed system.