Power control of a grid-connected hybrid generation system with photovoltaic/wind turbine/battery sources

A grid-connected hybrid distributed generation system, composed of PV(photovoltaic) array, wind turbine and BESS (battery energy storage system), is proposed for various power transfer functions to the distribution network. The proposed system has several operation modes which are normal operation, power dispatching, and power averaging, according to coordinate control of the BESS and grid inverter. PV array and wind turbine are individually controlled to operate at the maximum power point for the most use of renewable energy. The BESS operates as an energy buffer to flexibly shift the generation from the renewable energy sources without excessively frequent shifts between battery charging and discharging. A grid interface inverter regulates the generated power injection into the grid. Developed prototype system design and experimental results are presented to demonstrate the performance and to validate the proposed system during its operation modes.