Study On Power System Harmonics And Its Suppression Technology

With the development of the power system and the opening of the electricity market, the Power quality problem is receiving increasing attention. The Pollution of the harmonies to the grid is increasingly severe, owing to the prevalence of the non-linear loads (harmonic sources).So, the harmonic and its suppression technology is becoming the topic of common concern world wide.The active power filter is a kind of new power electronics device used for dynamic suppression of harmonics capable of compensating for the harmonics with variable magnitude and frequency, which can over come the disadvantages of such traditional approaches of harmonic suppression as PPF.This thesis conducts research of the harmonic detection method of the three-phase three-line parallel active power filter the harmonic current detection method i_p-i_q based on the instantaneous reactive power theory , and performs simulation analyses in two different cases i.e., the steady system and the abrupt load changes.This thesis conducts research of the controlling method of the current of the parallel active power filter, and chooses the Hysteresis Current Control manner as the controlling strategy.Finally , this thesis develops a three-phase three-line parallel active power filter with the above harmonic detection approach and controlling method , and conducts simulation experiments with Matlab , whose results verify the good compensation characteristics and performance of the filtering device.