Power decoupling method for isolated DC to single-phase AC converter using matrix converter

Abstract

This paper presents an isolated DC to single-phase AC converter using a matrix converter for HVDC (higher voltage direct current) power feeding system. The proposed converter comprises a full bridge inverter, a high frequency transformer and a matrix converter and does not use a bulky electrolytic capacitor. Then, in order to reduce a ripple component in a DC bus current caused by the single-phase load, this paper also proposes a power decoupling method. The power decoupling method employs a center-tapped transformer and a small LC buffer instead of additional switches, which aims to achieve high efficiency. Moreover, modulation methods of the full bridge inverter and the matrix converter, and a control strategy of the power decoupling are described. As an experimental result, the power decoupling method reduces the DC bus current ripple to 2/3. In addition, a validity of a parameter design method of the proposed control is confirmed in simulations.