Study Of The Voltage Flicker At The Point Of Common Coupling In Power System And The Influence Of Load Characteristic

With the developing of human society, energy source and enviroment problem has become a pressing problem to be solved for human society's surviving and developing nowadays. Clean and renewable source will become the core of source configuration in future. As a kind of clean, without pollute and renewable source, the wind energy has get more and more attention. In certain sense, wind power is one of the most potential source to be cosmically exploitured in 21 century. There are three models for the wind energy generator operation: independent running, associate with disesel engine or parallel into power system. Thereinto, wind energy generator parallel into power system then transport energy through network can cover the shortage of lower energy density. So it is the most economical and efficiency way to exploiture the wind energy. One problem with wind power installations, is the influence of power quality at the point of common coupling(PCC), mainly cause the voltage fluctuation and flicker. Simultaneity, the overall development of economy produces the variety of loads, thereby studying the voltage fluctuation and flicker at system's PCC which connect with wind farm and the influence of load characteristic become more important.This paper introduces the constitutes of wind energy power system and some important parameters, and find out two factors which closely in relation to the turbine's output power: the turbulent flow and wind speed. Besides, consider the influence of system's capacity of short circuit at PCC, the ratio X/R of network and load characteristic connected to PCC. On the base of the simulation software PSCAD/EMTDC, the established complex load model is used to carry out the simulation test on the standard wind enegy system for different load characteristics at PCC. The simulation results are comparaed with each other. The final analysis indicates that system parameters like the ratio X/R of network, system's capacity of short circuit in PCC and the load characteristic have important influence for the voltage fluctuation and flicker.