Research On Voltage Influence And Optimizing Method Of Distributed Generation Connected To Grid

With the shortage of energy and the increase of user's power consumption,the number of distributed generation(DG)connected to the grid is also increasing,which leads to the increasingly obvious influence on the power quality.Therefore,in order to effectively improve the influence of grid-connected DG on power quality,it is necessary to rationally configure it.This paper focuses on the possible impact of DG grid-connection on system voltage,and then adopts the improved genetic algorithm to optimize the grid-connection of distributed power supply.Firstly,the main factors that influence the voltage quality are the access location,capacity,node type and power factor of DG.Then,it introduces the basic working principles of four kinds of DG,and analyzes the building methods of photovoltaic power generation system and wind power generation system modules.Based on this,it uses DIgSILENT to build its model.Then,by using the established model,this paper simulates and analyzes the influence of various factors of DG grid-connection on voltage deviation and harmonic voltage.The experimental results show that the grid-connected distributed generation has an improving effect on the node voltage.However,it should be properly configured,otherwise the voltage will exceed the limit.Then,the voltage fluctuation of power grid caused by switching of photovoltaic power generation system is simulated and analyzed.The results of many simulation experiments have proved that the largest voltage fluctuation occurs at the DG grid-connection point,Therefore,the grid-connected DG should take measures to suppress the voltage fluctuation.Finally,in view of the voltage quality problem of the distribution network containing DG,the objective function is selected as the loss of the distribution network and node voltage deviation.Based on the corresponding constraints,the mathematical model of DG optimal allocation was established,and a multi-population DNA genetic algorithm was used to optimize it.Then it is verified in the MATLAB software through the IEEE 33 node distribution network,which proves that the algorithm can achieve the purpose of improving the voltage quality of the system and realize the voltage optimization of the system.The thesis has 61 figures,22 tables,70 references.