New control method for regulating state-of-charge of a battery in hybrid wind power/battery energy storage system

Although wind power generation has been introduced continuously in Japan, it is of considerable concern that, an intermittent power output would have affected interconnected grids. As an approach for the output fluctuation, authors are making a research in smoothing out a short-term fluctuation using a hybrid system of a battery energy storage system and a wind farm. In order to operate the hybrid system, the charging-level of the battery has to be regulated not to exceed its operable range. This paper presents a control system called as "State-Of-Charge Feed Back control" to keep the charging level of the battery within its proper range while the battery energy storage system smoothes out output fluctuation of a wind farm Furthermore, this paper clarifies fundamental characteristics oi the control to show its effectiveness through a theoretical study and numerical simulations.