Multi–Port High–Frequency AC–Link and Indirect Matrix Converters: A Generalized Structure

Abstract

Conventional multi–stage AC/DC/DC, AC/DC/AC, DC/DC/DC, and DC/DC/AC converters are two ports converters used to connect a resource or load to an AC or DC grid. To connect several loads or resources to a grid, these converters can easily be extended to a multi– port converter through a common DC–link, with simplified control and a reduced number of active switches. However, DC–link huge energy storage component increases the converter volume and cost and reduces its lifetime and reliability. On the other hand, most of the resources with these types of converters have fault ride–through problems and the DC–link voltage increases during the grid–side faults. The indirect matrix converter is a two–port high–frequency AC–link (HFAC) converter without any intermediate energy storage component, which can be used to connect just a single source or load to a grid. In this paper, a generalized extension of a two–port indirect matrix converter (and the other HFAC converters) to a multi–port converter is proposed. The modulation method, voltage and current gains, and the reactive power limitation of the proposed structure are also presented. Performances of the proposed structure and its modulation strategy are verified through simulation in MATLAB/SIMULINK environment.