Controller design of power conditioning systems with energy storage device for renewable energy source under stand-alone operation

With depletion of fossil fuels and environmental contamination, it has become important to use renewable energy. For the stable utilization of the renewable energy sources, energy storage device must be employed. The renewable and distributed power sources with energy storages can operate under stand-alone mode such as uninterruptable power supply when black-out occurs. This paper proposed a dynamic response modeling for a renewable power generation systems including a bidirectional charger/discharger for battery, and also suggests the DC-link voltage controller design of the charger/discharger under stand-alone operation in order to analyze a method for guaranteeing the stable operation while fully utilizing the power from the energy storage device. In this paper, the operation principle and design guidelines of the proposed scheme are presented, along with the performance analysis and simulation using MATLAB and PSIM simulation. Finally, 1kW power conditioning system with energy storage device hardware prototype has been implemented for experimental verification of the proposed converter system.