REDUCTION TOTAL HARMONIC DISTORTION (THD) WITH ACTIVE POWER FILTER

Abstract

Unlike passive harmonic filters, modern active harmonic filters have multiple functions, such as harmonic filtering, reactive-power control for power factor correction and voltage regulation, load balancing and voltage-flicker reduction. The proposed power system is a combination of three-phase voltage supply, full wave uncontrolled rectifier, active filter and R-L inductive load. Full wave uncontrolled rectifier produces 3th, 5th, 7th, 11th, 13th, 15th, 17th, 19th, etc. harmonics components. An active filter is used to reduce the total harmonic distortion of the input current (THDI) of the full wave uncontrolled rectifier. Power system is modeled by using Matlab/Simulink program. Simulation results show that both the harmonics are eliminated and the THD value is reduced. THDI was measured % 45.61 in power system. After filtering, it was measured as % 4.491. As a result of using active filter value of THDI is reduced by 41.119 % in power system.