Output Power Forecasting And Analysis Of Effect Of Large-scale PVGeneration On Power System

Due to the uncertainty of PV generations, the dispatch plan of traditional generations and control of fracture surface exchange power becomes harder. The Line voltage violation caused by short time fluctuation and periodic variations of sunshine irradiation becomes more frequent. In addition, PV generation are integrated into power system via power electronic inverters without rotational inertia and damping, which is different from traditional generators, bringing new challenges into secure and stability analysis of the power system. Hence, it is meaningful to enhance the study of PV prediction and analyze the influence of large scale of PV generations on power system operation, such as economic dispatch, secure and stability analysis, power quality and etc.This thesis is based on the background of a 20MW PV plant built by Xu Zhou XieXin electric power company.In this thesis, the research is focused on power prediction of large PV plant and the influence of large PV plant on power system. This thesis is organized as follows:Firstly, the research background and significance is introduced, a literature review of PV prediction and PV influence on power system is performed and the research emphasis is determined.Secondly, a modified BP-neural network based power prediction model is established, which outputs the prediction value of PV output power utilizing the history date of the PV plant’s out power and weather conditions.Thirdly, the influence of PV plants on the power system of Xuzhou is analyzed, including reserve capacity, generation schedule, peak pitching, voltage regulation and transient stability of Xu zhou power grid, which is validated by the XieXin 20MW PV plant.Finally, the influence of the XieXin 20MW PV plant on the short circuit capacity, relay protection, power quality of distribution network is studied.