Research On Method Of Harmonics Detection For Active Power Filter Applied In Single Phase Load

A lot of electric components produce various degrees of harmonies in the power system. It's serious that it affects the power quality. the harmonic problem has become the most critical task so as to ensure a high level of power quality nowadays, and a lot of attention has been paid to the harmonic problem.Active power filter is one of the most effective approaches for suppressing the harmonic at present. Active power filter mainly consists of two parts, the first is current operation circuit, and the second is compensation current circuit. This thesis lays emphasis on the research of part one, and deeply analyzing how to accurately detect the harmonic component.The thesis explains the relevant concepts, causes and harm of harmonic in chapter 1 to bring into the subject. This thesis introduces two methods of reduce harmonic: reduce the sources of harmonic and set power filter devices, power filter devices mostly are PF(Passive Filter) and APF(Active Power Filter). the classification t, theory and advantages of power devices are expounded In chapter 2, especially APF, Then highlighting the development of APF at home and abroad, defining the main task of the thesis: take deep study on the technology of APF and focus on analyzing two methods of harmonic detection, based on which, to design a harmonic detection system used in APF.The description of harmonic detecting method based on Fast Fourier Transformer and Phase Discrimination Principle are in the chapter 3, and their simulations of MATLAB/Simulink are made in order to verify the accuracy and reliability in chapter 4. The hardware and the software of data collection system are then designed base on the simulation in chapter 5. Finally all the work of this dissertation is summarized and the future research work is prospected in chapter 6.