This paper analysis under the conditions of power penetration of PV power system integrated with distribution power network is 0%, 5%, 10%, 15%, 20%, 24.46%, 30%, 35%, 40%, 50%, 60% and 75% respectively, the effects for common bus-bar load forecasting accuracy. Then, designation for the configuration, NWP solving, real-time data collection and PV power system and its cluster power forecasting of short-term PV power forecasting system. In addition, validation for the accuracy of PV power system cluster short-term power forecasting results, and the results indicate that the proposed system is able to explore and technical adaption for the business demand for operator of power grid dispatch department and PV power system.

This study analyses the distributed photovoltaic (PV) power system effects on common short-term load forecasting, based on the proposed power penetration index, and load data reconfiguration method, by using common short-term load-forecasting algorithm under conditions of the distributed PV power system and the power penetration index as 0, 5, 10, 15, 20, 24.46, 30, 35, 40, 50, 60 and 75%, the short-term load-forecasting accuracy obviously decreases. In this research study, the short-term power-forecasting method is proposed in order to offset the power output of distributed PV power systems, and transfer to the original load without the effects of distributed PV power systems or treated as the input information for updated load-forecasting model, this study proposes the short-term power-forecasting algorithm based on the BP neutral network for the typical distributed PV power system through training and validation of the proposed model. The power-forecasting accuracy is analysed and verified for a typical distributed PV power system, and the proposed method is effective in improving the accuracy for load forecasting.

中国目前的光伏发电系统尚以集中式光伏为主,但是很多太阳能资源丰富地区对电力的消纳能力较差,因此分布式光伏日益受到重视.分布式光伏的波动性和随机性导致对其进行功率预测变得十分必要,然而,分布式光伏发电存在的历史数据收集困难、实时监测数据缺乏等问题对功率预测造成了极大的困难.近年来出现了一些将集群功率预测方法应用于风电场群功率预测的研究.因为集群功率预测方法更加关注集群内各区域的功率预测而不是单个电场或电站的功率预测,所以这种方法能够在很大程度上解决分布式光伏发电功率预测的难题.文章概述了目前已有的分布式功率预测方法和集群功率预测方法,分析了这两个方面已有的研究,并指出集群功率预测方法在分布式光伏发电功率预测上的应用前景.

This paper established two types of models of distributed power supply in PSCAD/EMTDC and connected these two power supplies in the power distribution networks with 18 nodes to simulate respectively under specified voltage control and specified power factor strategies. Then, the simulated data was loaded into Matlab to analyze and calculate. It can be concluded that the shorter the distance between the interconnected of photovoltaic plant and the sensitive points, the more significant compensation effect of voltage sag, the amplitude of the voltage sag went down with the temperature increase and went up with the illumination intensity increase. When the threshold value of the voltage sag's 70% was obtained under specified voltage at the sag region and power factor control strategies based on root mean square value method, the connection of photovoltaic plant can effectively slow down the severity of the voltage sag, which makes the possibility of the influence of power distribution network on sensitive equipment largely go down. The bigger the capacity of the photovoltaic cell, the shorter distance between interconnected location and sensitive load, the smaller the sag depth at sensitive load locations, as well as the shorter the duration time of the sag.