Reliability and efficiency-based energy storage sizing from the aspect of system frequency

A major concern for wind farm connection to power systems is large variation of power output caused by the variability and unpredictability of wind speed. For a power system with high wind power penetration, the frequency control process of conventional generators (CGs) to match load and wind power variation becomes an important operation issue. Energy storage systems play an important role in solving the problem. This paper proposes an analytical technique to select the optimal size of battery storage system (BSS) for a power system based on operational reliability analysis and frequency control process. According to optimal size of BSS, the optimal size of state of charge (SOC) and depth of discharge (DOD) are selected to achieve the minimal frequency variation for the fixed wind farm.