Research On The Optimization Decision-making Of Connecting Small-capacity Distributed Power Sources To Distribution Networks

With the development of clean energy,the proportion of distributed generation connected to distribution network is greatly increased.DG access to the distribution network can improve the voltage reliability,and different access locations and capacities have different impacts on the distribution network.The determination of location and capacity of DG connected to distribution network can be divided into laboratory theoretical calculation and engineering practice approximate calculation,which are different and related to each other.In the laboratory theoretical calculation,the power output and load are determined by the relevant models and parameters.Therefore,the location and capacity of the distributed generation connected to the distribution network can be obtained in theory.In engineering practice,if the total capacity of DG connected to a distribution network is small,and the power load of the distribution network itself is not large,even if the optimal configuration scheme can be obtained in theory,the error of the obtained configuration scheme is still large because the more accurate parameters of distributed generation and load model cannot be given in the planning and design.In engineering practice,a variety of planning schemes are often proposed in advance based on empirical data,so it is necessary to study the scheme decision of small capacity distributed generation access to distribution network.In view of the randomness and fluctuation of distributed generation and load output,this paper proposes to simulate wind power output with two parameter Weibull distribution and photovoltaic power generation with beta distribution function,and establishes load model.In order to accurately calculate the location and capacity of distributed generation(DG)connected to distribution network,considering the decreasing trend of price subsidy of DG,a multi-objective optimization model with total project profit,distribution network loss and total node voltage deviation as objective functions is constructed.At the same time,the improved multi-objective particle swarm optimization algorithm is used to solve the established model,and the final optimization scheme is obtained.Finally,the IEEE-69 bus distribution network system is taken as an example for analysis.In order to meet the decision-making needs of engineering practice,a comprehensive decision-making model is proposed by adding grey correlation coefficient on the basis of prospect theory,and a multi-objective decision-making model with investment cost,electricity price income and network loss reduction rate as decision-making functions is constructed.Taking IEEE-69 bus system as an example,the optimal combination schemeof different load types is determined by the comprehensive decision-making model in the planning and design scheme.The results show that the final decision-making scheme can provide important guidance for the location and capacity determination of distributed generation and the optimization decision-making of small capacity distributed generation.