Daily Solar Irradiance Profile Characterization and Ramp Rate Analysis at Different Time Resolutions

摘要

Characterization of daily solar irradiance profiles and analysis of the fluctuations of the ramp rates exhibited by the power produced by photovoltaic (PV) systems is a crucial topic that adversely affects power quality and reliability especially in weak and island power systems. In this work, a detailed procedure to characterize daily solar irradiance profiles is presented based on the k-means clustering technique and a classification method for daily sky conditions applied to annual global horizontal irradiance (GilI) time series. Both methods were used to analyze the data from a location in Cyprus in order to cluster and characterize the daily GilI profiles. The obtained results of the 3-cluster framework demonstrated that 86 % of the days in a year do not exhibit high ramp rate behavior, while the classification method exhibited that 86.2 % of the year were primarily classified in classes with clear sky and nearly clear sky conditions. Finally, the ramp rate analysis performed demonstrated that time sampling resolution affects the magnitude of the extracted ramp rates.