Parameter determination for reducing ESS capacity in PV power smoothing control using spline function

This paper comprehensively evaluates the PV power smoothing control method using the spline function. As a result of the verification, it is shown that the ESS capacity can be reduced while maintaining the smoothing effect by PV power smoothing control with energy control and limiting fluctuation rate control. Based on the charging/discharging power of the ESS and the operating conditions of the ESS, the section time that achieves both improvement of the smoothing effect and reduction of the ESS capacity is determined to be 1500 s. Then, the rated capacity of the ESS for a rated power of 1.75MW PV system is 1128 kWh. This is 49.6% of the rated capacity of the ESS, which is required in the PV power smoothing control method with fluctuation rate control. As a result of comparing the proposed method and the moving average method, the proposed method improved the smoothing effect by 49.8% compared to the moving average method.