Wind power generation using an unlimited, natural energy is getting an attention regarding environment issues in recent years, and the installed capacity of wind power generation system is increasing at a rapid pace, Resulting in deterioration of power quality especially frequency and voltage. This fact will be a big problem to restrict large capacity of wind farm. This paper proposes a new frequency converter: rotary frequency converter (RFC) to moderate the electric output from wind generation, which is to be installed between a set of wind generators and a grid, providing a smoothed electric output, promoting the wind power generation introduction. This mainly consists of a synchronous machine and the adjustable-speed machine. Independent controls of input/output voltage, active power, and reactive power offer electrical separation between the two networks. Experimental study of prototype model and its characteristics, especially dynamic control is discussed in this paper.