The Method Of Reducing Higher Harmonic Of PWM Rectifier Based On Distributional Multiple Technique

Electric power is one of product who is using in large scope , high value and more quantity in modern society. As the development of science skill, the elements which cause the power quality have increased continuously. The problem that making the electric equipment can't be supplied electricity is the problem of power quality , which affects human life and the running of GDP's safe directly.The power quality include frequency, harmonics wave, voltage deviation, voltage dip and rising, voltage fluctuating and flashing, unbalance of three kinds of voltage and voltage's changing, specially, with application of advanced digital AC varied -speed system in industry, the influence of harmonics it produced to the public power system can't be ignored.There are many ways and methods to decrease harmonics, many articles introduce the method of decreasing harmonics based on multiplex technology. This article introduces one method to decrease harmonics, author refers it "method of decreasing harmonics based on distributed multiplex technology.This article expounds the problem of harmonics in cool rolling mill(CRM) which author serviced, harmonics produced by AC varied -speed system damaged many equipments. Firstly, the article specifies concisely the machnism of harmonics because IGBT convert (following called convert) adopts PWM method. Next, the article analysis the problem of harmonics by test data in job site, and then, the article introduces this settlement method and its principle. Finally, the article also proves the efficiency of this method by comparing harmonics data which be tested before parameter adjustment and behind it. After observation and measurement for long time, power quality achieved the desired results .