State-of-charge optimising control approach of battery energy storage system for wind farm

In recent years, configuring battery energy storage system (BESS) in wind farm has become the most popular method to smooth wind power fluctuation. The effectiveness of wind power fluctuation smoothing relies on the charging/discharging power control and state of charge (SOC) regulation of BESS. This study proposed a novel optimising SOC control approach for BESS in wind farm which could regulate wind power fluctuation in a suitable level and maintain SOC in an optimal range by utilising the wind power prediction information. A wind power prediction-based optimal SOC calculation module is designed to obtain an optimal range of SOC which makes BESS have enough capacity to smooth wind power fluctuation in a finite future period of time. It takes minimising over-charging and over-discharging time as optimisation objectives and biggest variations of wind farm outputting power within 1 and 10 min as restraint. A fuzzy self-adjusting of filter-based real-time control module is designed to smooth the wind power fluctuation in real time and regulate SOC to the optimal range. Finally, the effectiveness of the proposed approach was demonstrated through implementing it in wind power smoothing control simulation experiments.