A three-phase active power filter for harmonic and reactive power compensation

In this paper, a 3-phase active power filter (APF) is presented to eliminate harmonics and to compensate the reactive power of an uncontrolled rectifier with capacitive loading taken as nonlinear load. An APF is realized using a 3-phase voltage source inverter (VSI) with DC bus capacitor. Reference source currents are estimated using P-I control over DC bus voltage and 3-phase source voltages. Command currents of the APF are obtained with reference source currents and load currents. A hysteresis based carrierless PWM current control over the command currents of the APF is used to derive gating signals to the devices of APF. Modeling and performance characteristics of an 18 kW APF to meet the IEEE-519 standards are presented.