중성선 전류 제거를 위한 3상 4선식 능동 전력 필터

Neutral line current elimination method for Active power filter of three phase four-wire power system

This paper proposes a design method using PQR instantaneous power theory on the active power filter, unbalanced nonlinear load condition and unbalanced source voltage condition in three-phase four-wire systems. For reduction of current harmonics and neutral current, the control structure including repetitive controller is proposed and controller gain is designed. For fully-digital implementation, ramp comparison PWM method was adopted. Simulation results verify good performance of the proposed current control strategy on the shunt APFs.