A study of the impacts of power fluctuations generated from large PV systems

Installing large grid-connected photovoltaic systems is a new trend in many countries, especially the developed countries. These systems have a number of positive and negative technical impacts on the operation of the electric network. Thus, careful studies should be carried out prior to installing these systems. One of the main characteristics of PV systems that has to be considered when studying their impacts is the fluctuations in their output power. These fluctuations require careful analysis so as to predict their effect on different electric quantities of the feeder under study. The use of typical patterns of PV power in power flow analysis is one way to analyze the impacts of fluctuations. However, so far, there is no specific criterion on how to choose these patterns. In this paper, we propose a criterion that can be used to choose the typical patterns for each season. The number of patterns can be specified by the user based on the inspection of the patterns. The usefulness of the proposed criterion is illustrated through a case study, where the impacts of fluctuations on different quantities of the feeder under study are presented and discussed.