An Estimation Method of Cross-Correlation Function using Spatio-Temporal Attenuation Model for Photovoltaic Generation Power Fluctuation Analysis

Abstract

Power output fluctuation of high penetration renewable energy such as photovoltaic generation (PV) may cause negative impact on electric power systems. Accordingly, quantitative analysis of the fluctuation characteristics in consideration of smoothing effect of solar radiation intensity is necessary to accurately evaluate the negative impact. Estimation of a spatial and temporal cross-correlation function of the solar radiation intensity is inevitable for this analysis. Under this requirement, we propose a novel estimation method of the cross-correlation function. The proposed method allows, by using three pyranometers only, the accurate estimation of the cross-correlation function between any point and a point at which a pyranometer is installed. The accurate estimation is enabled by considering an anisotropic effect of wind directions in a “spatio-temporal attenuation model”. We confirmed the high accuracy of the proposed method by using practical data obtained from pyranometers installed in Sakai Solar Power Plant for its one year operation from January to December 2012.