ACTIVE POWER FILTER FOR HARMONIC AND REACTIVE POWER COMPENSATION IN 3-PHASE, 4-WIRE SYSTEMS SUPPLYING NONLINEAR LOADS

An active power filter (APF) is proposed which eliminates harmonics, c ompensates reactive power and neutral current in a three-phase four-wi re electric system supplying non-linear loads. An insulated-gate-bipol ar-transistor (IGBT)-based pulse-width modulation (PWM) voltage source inverter (VSI) with a DC bus capacitor is employed as an APF. A hyste resis-rule-based carrierless PWM current control technique is used to generate switching signals to the devices of the APF. Three single-pha se diode rectifiers supplying resistive-capacitive loads are considere d as a three-phase non-linear load. A detailed dynamic model of the sc heme is developed to study transient and steady-state behavior of the APF. The proposed APF is found capable to compensate reactive power, n eutral currents and to reduce the harmonics below specific recommendat ions of IEEE-519 standard.