Single Phase High Frequency AC Link DC/AC Converter for Photovoltaic Systems

Abstract

In this article, an isolated high-frequency AC link bidirectional AC/DC Push-Pull converter is proposed for photovoltaic systems. Conventional DC/AC converters, such as back-to-back converters, are multi-stages converter with a common DC link. These converters due to their huge DC link capacitor, despite the simplicity of control, have some drawbacks such as high size and volume, low reliability and short life span, and fault ride-through (FRT) problems. In this article, a DC/AC converter with high-frequency AC link and transformer is proposed for the integration of photovoltaic (PV) arrays to a single-phase AC grid or load. The presented converter, beside the reduced number of active switches and cost, due to the lack of intermediate bulky energy storage element, has none of the conventional converter disadvantages. Modulation and commutation techniques of the proposed converter are also presented. The performance of the proposed system is proved using simulation in the MATLAB/SIMULINK environment and using a laboratory setup.