Estimation of total power output fluctuation of high penetration photovoltaic power generation system

This study proposes a method to estimate the standard deviation (STD) of total power output fluctuation of high penetration photovoltaic power generation system (HP-PVS) dispersed in large area, so that the impact of HP-PVS on the load frequency control is discussed. First, by using the data of horizontal global insolation observed at 5 points in 25 km × 25 km area, the practical usefulness of STD is evaluated by comparing the STD with the maximum fluctuation width. Then, two key factors of the proposed model are discussed; the distance with which the insolation fluctuations at two points can be considered as independent, and the practical usefulness of the central limit theorem to estimate the STD of ensemble average fluctuation of insolation. Finally, assuming the geographical distribution of residential PVS, the STD of total power output fluctuation of HP-PVS dispersed in the service area of electric power utility is evaluated.