Reactive Power Optimization For Distribution Networks With Distributed Power Sources Research

With the proposal of the national "dual carbon" strategic goal,the integration of distributed power sources into the distribution network has become a development trend in the power industry.The integration of distributed power sources into the distribution network has broken the original trend structure of the distribution network and affected the power quality and safe operation of the distribution network system.Reactive power optimization for distribution networks containing distributed power sources can reduce active network losses and improve voltage quality.Therefore,based on existing research,this thesis proposes an improved ant lion algorithm to study static multi-objective reactive power optimization and dynamic single objective reactive power optimization in distribution network systems with distributed power sources.The main content includes the following four aspects:(1)Introduced three common distributed power sources,established grid connection models for three distributed power sources,and equivalent distributed power sources to four types of nodes;In response to the changes in node types of the distribution network system after connecting to distributed power sources,as well as the structural characteristics of the distribution network itself,the forward and backward substitution method is adopted to calculate the power flow of the distribution network;From both theoretical and experimental perspectives,the impact of the output size of distributed power sources and the location of their connection to the distribution network on the distribution network was analyzed,and the optimal capacity and location for grid connection were determined.(2)In response to the drawbacks of the standard ant lion algorithm being prone to local optima and lacking a regeneration mechanism,three improvements have been made to the standard ant lion algorithm: the introduction of Sobol sequences,the introduction of dynamic weight coefficients,and the introduction of Cubic chaotic maps.By testing two unimodal test functions and two multimodal test functions,the results verify that the improved ant lion algorithm has good convergence and speed.(3)Determine the installation position of reactive power compensation devices through the reactive power margin method;A multi-objective optimization mathematical model for static reactive power optimization considering active power loss and node voltage deviation in the distribution network was established using the weighted method.The improved ant lion algorithm and standard ant lion algorithm were used for simulation and solution.The results validate that the improved ant lion algorithm is an effective tool for solving static multi-objective reactive power optimization in distribution networks with distributed power sources.(4)A single objective model for dynamic reactive power optimization of distribution networks considering active network losses has been established.The time-phased optimization method is used to address the fluctuation of distributed power sources and loads,and dynamic reactive power optimization is carried out on the distribution network.Starting from the first period of optimization calculation,reactive power optimization is carried out on the first period to obtain the action and active power loss of the reactive power compensation device in that period.In the next period of optimization calculation,the action of the reactive power compensation device in the previous period is continued,and reactive power optimization is carried out by controlling the output of distributed power sources;By setting relevant thresholds,limit the action of reactive power compensation devices.Through simulation analysis,it has been proven that the dynamic reactive power optimization method can effectively reduce the active power loss of the distribution network within the specified action frequency range of the reactive power compensation device.