The application of power electronic promotes neoteric power system

however

it also bring serious harmonic pollution

In this paper the harmfulness of the var power and the high-order harmonic of the power system are discussed. It points out that the status of var compensation is tightly dependent upon the harmonic restraining; the paper analyses the advantages and disadvantages of passive power filter technology and simply introduces the system forming and working principals of active power filter. The applied actualities and developnent forecasts of power electronic in power system

the funfdemental principle and of APFC based power electronics are discussed in this article. The paper also analyses some new technologies and tendency to solve var compensation and harmonic restraining problem

and draws some reasonable conclusion.