I. Introduction
Although it is widely recognized that wind power generation is clean and environmental friendly as well as increasingly competitive, but wind turbine power plant is highly capital-invested and relies on the intermittent and unpredictable nature of the wind. The major concerns is that wind power can be neither storable nor scheduling so that the wind generation may not coincide with electricity demand. Consequently, electric utility would have to add more capacity reserve in the presence of wind wind power generation.