Dynamic Analysis and Controller Design for Standalone Operation of Photovoltaic Power Conditioners with Energy Storage

Energy storage devices are necessary to obtain stable utilization of renewable energysources. When black-out occurs, distributed renewable power sources with energy storage devices canoperate under standalone mode as uninterruptable power supply. This paper proposes a dynamicresponse analysis with small-signal modeling for the standalone operation of a photovoltaic powergeneration system that includes a bidirectional charger/discharger with a battery. Furthermore, itproposes a DC-link voltage controller design of the entire power conditioning system, using thestorage current under standalone operation. The purpose of this controller is to guarantee the stableoperation of the renewable source and the storage subsystem, with the power conversion of a veryefficient bypass-type PCS. This paper presents the operating principle and design guidelines of theproposed scheme, along with performance analysis and simulation. Finally, a hardware prototypeof 1-kW power conditioning system with an energy storage device is implemented, for experimentalverification of the proposed converter system. KCI Citation Count: 12