Abstract: This paper presents the hardware implementation of the bidirectional LLC resonant converter used for renewable energy sources and energy storage systems with automatic mode transition. Out of the various bi-directional DC-DC converters, LLC resonant converters have gained an immense interest due its simple structure, buck/boost operation capability and narrow switching frequency variation range and higher efficiency than other converters. With this proposed new bi-directional LLC resonant dc-dc converter, the power flow direction and output power of the proposed converter can be changed automatically and continuously, which is attractive for energy storage systems to keep the dc-bus voltage constant and to keep the balance of energy. The desired characteristics of the proposed topology will obtained and analyzed. The analysis of the proposed Power flow converters for Distributed Generation with automatic bidirectional Transition will be carried out using MATLAB simulation package and the results will be verified by the construction of prototype model.

Keywords: Distributed Generation (DG), Renewable energy sources(RES), Energy storage systems, LLC resonant converter &automatic transition.