Research On The Influence Of Wind Power Grid Connection On Power Quality Of Power System

Under the concept of environmental protection and national green consumption,wind energy,as a renewable clean energy,is increasingly favored by countries around the world,and wind power related technology has been developed rapidly.However,due to the randomness and intermittency of wind energy and the use of nonlinear power electronics in wind power system,wind power network will bring a series of power quality problems to power system.Especially in recent years,with the increasing permeability of wind power in the power grid,the influence on the power system is more and more important,even threatening the safe and stable operation of the power system.Therefore,it is of great significance to study the influence of wind power grid on power quality and evaluation method.Firstly,the research significance and background of this paper are given,and the current situation of wind power development at home and abroad is analyzed in combination with the global and Chinese wind power development history in recent years.In this paper,the voltage stability and harmonics of the fan are studied,and the research status of the comprehensive evaluation method of power quality is analyzed.Then,the paper also introduces different types of wind power system and power quality standard,with emphasis on the mathematical model and working principle of double feed fan.This paper studies the influence factors and mechanism of wind power grid connection on the voltage stability of the system,builds the grid-connected model of doubly-fed fan on the Matlab/Simulink platform,and studies the voltage stability of the fan after grid-connected under different wind conditions,load switching,fault and so on.At the same time,the simulation proves that the reactive power compensation device SVG beneficial to the recovery of the system voltage.Furthermore,the harmonic source of the doubly-fed fan is analyzed,and the harmonic current at the outlet of the fan is analyzed by simulation,and the filtering effect of the APF on the wind grid system is verified.Finally,the game theory combination weighting method is used to improve the comprehensive evaluation method of power quality,the subjective weighting method adopts the improved AHP method,and the objective weighting method adopts the entropy weight method.The correctness and feasibility of the combined weighting method are verified by the calculation results of examples and three weighting methods.