Capacity credit and reasonable ESS evaluation of power system including WTG combined with battery energy storage system

Abstract

This paper proposes a new method for evaluating Effective Load Carrying Capability(ELCC) and capacity credit(C.C.) of power system including Wind Turbine Generator(WTG) combined with Battery Energy Storage System(BESS). WTG can only generate electricity power when the fuel (wind) is available. Because of fluctuation of wind speed, WTG generates intermittent power. In view point of reliability of power system, intermittent power of WTG is similar with probabilistic characteristics based on power on-off due to mechanical availability of conventional generator. Therefore, high penetration of WTG will occur difficulties in power operation. The high penetration of numerous and large capacity WTG can make risk to power system adequacy, quality and stability. Therefore, the penetration of WTG is limited in the world. In recent, it is expected that BESS installed at wind farms may smooth the wind power fluctuation. This study develops a new method to assess how much is penetration of WTG able to extended when Wind Turbine Generator(WTG) is combined with Battery Energy Storage System(BESS). In this paper, the assessment equation of capacity credit of WTG combined with BESS is formulated newly. The simulation program, is called GNRL-ESS, is developed in this study. This paper demonstrates a various case studies of ELCC and capacity credit(C.C.) of power system containing WTG combined with BESS using model system as similar as Jeju island power system. The case studies demonstrate that not only reasonable BESS capacity for a WTG but also permissible penetration percent of WTG combined with BESS and reasonable WTG capacity for a BESS can be decided. Copyright ? The Korean Institute of Electrical Engineers.