A novel control method for a combined system using active power filter and static var compensator

As a compromise between economy and good performance, this paper adopts the combined system using active power filter (APF) and static var compensator (SVC) to compensate reactive power and harmonic currents simultaneously. The SVC is constructed by fixed capacitor (FC) and thyristor controlled reactor (TCR), and the APF is constructed by a voltage source converter and its filter reactor. SVC acts as a classic reactive power compensator for load balancing and power factor correction, and APF is used to compensate the harmonic current. The analysis and comparisons are studied for several combined systems in detail, while the control methods of APF and SVC and SVC's construct are taken into account. And then an outstanding combined system and its control method are proposed. The steady state and dynamic waveforms show that good performance and system stability of the combined system are achieved.