A novel sparse matrix converter with a Z-source network

Abstract

This paper proposes a novel Z-source sparse matrix converter and its modulation strategy. The proposed matrix converter is developed based on the structure of a sparse matrix converter to reduce the number of unipolar turn-off power semiconductors and employs a Z-source network to overcome the inherent drawback of the low voltage transfer ratio of the conventional matrix converter. The proposed modulation strategy utilizes a zero-current commutation method in combination with a Z-source network control scheme, which eliminates the complex commutation problem. The fundamental operation modes are described and its theoretical equation of the overall voltage transfer ratio is derived. A simulation of the overall system is carried out and theoretical calculations and feasibility are verified. The simulation results show that the proposed Z-source sparse matrix converter can achieve unity or higher voltage transfer ratio by controlling shoot-through zero interval (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ) with less numbers of unipolar semiconductor power switches and a simple modulation strategy.