A Multi-Directional Power Converter for a Hybrid Renewable Energy Distributed Generation System with Battery Storage

Power electronics is the key technology for enabling renewable power generation and dispatching distributed generation (DG) with improved load-side efficiency. This paper presents a multi-directional power converter with a high-frequency isolation transformer for a stand-alone hybrid renewable energy DG system with battery storage. Full-bridge power converters are employed to realize bi-directional power flow among renewable generator, battery storage and load. Detailed analysis is provided for a four-directional power converter in a wind-photovoltaic distributed generation system. In addition, a two loop PI control scheme is proposed to achieve constant output voltage and exact power flow management. Theoretical analyses are verified by simulations in PSPICE and MATLAB