Multi-input DC-AC converter for renewable energy applications

This paper proposes a high frequency link multi-input DC-AC converter for renewable energy applications. It consists of a boost converter for interfacing uni-directional sources and bi-directional buck-boost converter for interfacing the storage system. An LLC resonant converter is used to further boost the DC voltage and convert DC into high frequency AC. Finally, a cycloconverter is used to convert from high frequency AC to line frequency. The features of the proposed system include reduced number of power conversion stages, low part count, high frequency operation. High frequency switching losses are eliminated using soft switching technique, thereby reducing the magnetics and heat sink requirements. This results in lower cost and higher efficiency. Simulation results are presented to validate the proposed converter configuration and its control performance.