Study Of Improving Micro-gird’s Electric Power Quality Based On APF

Owing to the application of Distributed Generation(DG) can save energy, protect environment, make sure the safety, reliability and economical efficiency of electricity serving, recent years, more and more investigations and tests of Distributed Generation are being carried out. Along with the development of electrical and electronic technology, energy storage technology and control theory, some system of Distributed Generation have been in implement stage. However, DG’s application brings many influences on original Distribution Network on power quality and relay protection. In order to make use of DG widely, to solve these problems is of first importance.This thesis firstly expound the basic theory of Distributed Generation, discuss the types of DGs, modes of DG’s operation, and control strategy of different DG in different operating mode. The paper lays out analysis on effects in different aspects which DGs have on power system.Based on the influence that DG has on power quality, this thesis focuses on the causes and suppression methods of harmonic wave, theories and structures of Active Power Filter (APF), and its meaning to power quality improvement. At last, This paper use the tool of Matlab/Simulink to carry out emulation analysis to APF, The simulation model adopt the method of harmonic detection based on instantaneous reactive power theory and the control methods of current tracking hysteresis control and triangular carrier control. The simulation results prove that the realization means is feasible and its suppression function is efficacious to Distribution Network.