Application of active power filtering control technology in restraining a harmonic

With the pollution of harmonic getting more and more serious in power system, its harmfulness and administration begin to motivate people´s attention. Because the harmonic problems in power system are so complicated and make an accurate analysis is difficult. These present situation can be improved by introducing reliable and accurate monitor and analytic methods, among which active power filtering technology is an efficient one. This paper mainly center on three active power filtering methods which are based on PWM, harmonic decoupling control and generalized integral iterative. The paper makes systematically summaries to every theory and analyzes the merit, demerit and the sphere of application respectively. All of these methods lay the groundwork for choosing appropriate active filters, so as to mitigate harmonic and improve the power quality of electric prides.