| Photovoltaic grid connected power generation as the main way of the newenergy on the word,evelopment rapiddly.Although the domestic and international research in photovoltaic power generation has a lot of achievements,But in some of the key technical aspects, there are still many problems to be solved.If the grid contains grid connected photovoltaic power generation unit,we have to consider the uncertainty,effects of intermittent power on the grid fully.This paper first research in grid connected photovoltaic power station of Jiangsu area,Choose the typical photovoltaic power station to analysis operating characteristics.To further understand the characteristics of photovoltaic power station in Jiangsu.First consider the power characteristics of a single photovoltaic power station,inc luding active power output characteristics under different weather conditions,Output fluctuation characteristics,The output characteristics of probability distribution,The maximum output of time distribution characteristics,The random distribution characteristics of output fluctuations,Analysis of output correlation under different time scales of a single photovoltaic power station,and effect of grid on voltage distribution network.then analysis the output characteristics of photovoltaic power plants,the correlation and the influence on the output voltage..Analysis voltage limit problem, when many PV connet the grid.Then put forward the accurate prediction can reduce the bad influence of photovoltaic grid connected photovoltaic brings to the safe and stable operation of power grid.Power prediction part,firstly introduces several common methods of photovoltaic powerprediction,and then put forward the combined forecasting method..Combination forecasting method in this paper is a combination forecasting method based on variance-covariance.Three single forecasting method were introduced in this paper to use in the combination forecast method:Artificial neural network prediction method,prediction method based on Markov chain,based on the similarity day of photovoltaic power generation,and least squares support vector machine prediction. Finally,the combination forecasting method based on variance-covariance.The average error in xiexin PV can be seen that the combination forecasting method is more accurate. |
