Eight-Switch Power Conditioner for Current Harmonic Compensation and Voltage Sag Mitigation

The nine-switch converter has been proposed recently, and since then, a large number of applications have been investigated, particularly as a substitute to the dual-bridge (back-to-back) converter. The main advantage of the nine-switch converter is its lesser number of switches (9 instead of 12 of the back-to-back converter), which has, as a tradeoff, some restrictions in the total attainable amplitude at its outputs, dependent on the phase shift between its two terminal sets. However, with an appropriately designed control scheme, the nine-switch converter is shown to favorably raise the overall power quality, justifying its role as a power conditioner at a reduced semiconductor cost. The proposed power conditioner has only eight switches, being composed by a unit for voltage sag mitigation and another unit for current harmonic compensation. Simulation and experimental results confirm the validity of the proposed method.