A Study on Capacity Credit and ESS Evaluation for WTG and Multi-ESS in Power System

This paper proposes a new method for evaluating Effective Load Carrying Capability (ELCC) and Capacity Credit (CC) of a power system including Wind Turbine Generator (WTG) combined with Multi Energy Storage System (ESS). The WTG can only generate electrical power when the wind is available. Because of the fluctuation of wind speed, WTG generates intermittent power. In the reliability viewpoint of power system, the intermittent power of WTG is similar to the probabilistic characteristics based on the on-off power due to the mechanical availability of conventional generators. Therefore, high penetration of WTG will cause difficulties in power system operation. The high penetration of numerous and large capacity WTG can risk the power system adequacy, quality, and stability. This study develops a new method to assess how much the penetration of WTG can be extended when WTG is combined with ESS. This paper demonstrates various case studies of ELCC and CC of a power system containing WTG combined with Multi ESSs using a model system similar to Jeju island power system in Korea.