Reactive power compensation and load balancing for unbalanced three-phase four-wire system by a combined system of an SVC and a series active filter

A conibincd reactive power compensation method of a static VAr compensator (SVC) aiid a series activc filter is described for unbalanced three-phase four-wirc distribution fceders with harmonic distortion. The SVC which consists or A-connected thyristor-controlled reactors. Yconnected thyristor-controlled reactors and passive filters, acts as a compensator Tor load balancing and power kictor correction. The small rating active filter is used to improve tlie filtering characteristics or the passive filter in the SVC and suppress possible resonance between the system iinpedancc and the passive filter. Simulation results perfoinied by the clcctroiiiagnctic transients program show that the proposed reactive power compensation configurations can effectivcly balancc currents, correct power factor and eliminate harmonic currents.