Research On Reactive Power Planning Of Distribution Network Taking Into Account The Correlation Of Distributed Power Sources

With the rapid development of economy and society,the demand for electricity is growing rapidly,and people's demand for power quality is constantly improving.At the same time,the fossil fuels are widely used in the traditional centralized power supply,the global energy crisis occurs frequently,and the environmental pollution problem is aggravating,which can not meet the needs of sustainable development of the future society.As an emerging energy utilization method,distributed generation(DG)has the advantages of environmental protection,economy and flexibility,which will become an effective measure to alleviate these problems.However,the outputs of DG on the basis of wind power generation are mainly affected by natural factors,and their outputs have certain randomness and correlation.When it is connected to the distribution network,it will have an important impact on the planning,operation and control of the system.Therefore,reactive power planning of distribution network considering the correlation of DG output becomes very important.Firstly,this paper briefly introduces the basic concept,classification and working principle of DG,then theoretically analyzes the impact of DG connected to the network on the power distribution network,and meanwhile takes into account of the randomness of the outputs of DG on the basis of wind power generation,thus introducing two methods of constructing the probability model of the outputs of the wind power generation.Secondly,considering the correlation of the muti-dimensional wind turbine output in the same region,the paper adopts the optimal vine Copula model for correlation modeling,and makes a comparison with the single vine Copula model thorough an example to verify the accuracy of the correlation modeling.Finally,this paper establishes a reactive power planning model for the distribution network based on chance constraint,calculates the probabilistic load flow through the point estimation,and makes reactive power planning with the improved particle swarm optimization algorithm.The paper takes the IEEE33 node system as an example to obtain the reactive power planning scheme under various conditions.The results validate the effectiveness and accuracy of the proposed reactive power planning model involving the influence of DG,providing a reference to ensure the stable,safe and economical operation of the system.