Research And Implementation On Key Techniques Of Three-phase Three-line Shunt Active Power Filter

The electricity is one of the most important source of energy in modernindustry,it is the main power to the development of the national economy. Alongwith the wide application of all kinds of electric equipment enhance industrialproduction and quality of life,at the same time, it brings a lot of power qualityproblems, the harmonic pollution and reactive power is one of the mainperformance. Active power filter can realize harmonic suppression and reactivecompensation, so it has a good application prospects in power quality control field.This paper studies the key techniques and implementation of the three-phasethree-line parallel active power filter, the following aspects are the major work.First introduces power quality standards and the harmonic harm, then putforward by use the active power filter on the reactive power compensation andharmonic control. In the paper, the working principle and the main circuit structureof the active power filter are studied, the mathematical models of APF in staticthree-phase coordinates and in rotary two-phase coordinates are made.In this paper, the reactive current and active current analysis based oninstantaneous reactive power theory are studied. According to the asymmetriccomponent method,the harmonic and negative sequence current detection methodsis proposed; Through introduce low-pass filter to the q channel of three-phaselocked loop to achieve the tracking of the network voltage. Compare Movingaverage sliding window filter and Butterworth filter, Show that the former better.Based on traditional PI control of active power filter are analyzed, through thesimulation experiments show that the method is not good at the field of theharmonic current compensation.So the composite repetitive control strategies isadopted to control the compensating current,and Each part of the control strategyare given. The subsection PI control is used to realize the voltage of dc sidestability.According to the requested function of APF, planning the system hardwarestructure, design sampling and controller circuit board, write software program.The APF model machine is builded to do the experiment of reactive powercompensation and harmonic control. The experimental results show that the key technology of the active power filter which this paper described is effective.