Grid interface for a wind turbine-fuel cell system

Environmental and sustainability concerns are increasing the importance of distributed generation based on renewable energy sources and its grid integration. This paper proposes a grid interface for a hybrid system composed by fuel cells, a wind turbine and supercapacitors. Such grid interface permits to control the wind turbine energy using a diode rectifier and an intermediate DC boost converter and the low voltage of the supercapacitors-fuel cell system is raised by a voltage-fed full-bridge converter. All these power converters are connected to a DC bus and a supervisory control manages the power flow between them, according to the wind turbine production. A voltage source inverter converts the direct current from the DC bus to alternating current, controlling the reactive energy. The inverter output voltage is filtered and raised by a transformer before being delivered to the grid. This grid interface has a low cost and a fast compensation to disturbances.