Simulation of a three-phase AC-AC boost converter to compensate for voltage sags

Voltage sags or short term reductions in the voltage levels constitute 68% of all power disturbances. Voltage sags are becoming crucial problems in many process industry plants as well as in rural customers, resulting in lower production and serious equipment damage. A possible method to compensate for voltage sags is to install an AC-AC boost converter that is capable of compensating at a much higher bandwidth than the typical voltage sag event. The AC-AC boost converter of this paper incorporates the use of bi-directional insulated gate bipolar transistors (IGBTs) in a relatively well-understood DC-DC boost converter topology. Most voltage sags are due to a faulted circuit or a major increase of load current. The resulting neutral return current produces an increase in the measured voltage. On a half cycle-by-cycle basis, the peak voltage can be used as feedback where the converter can maintain regulated supply voltage to the end user. Simulation results show that a three-phase AC-AC boost converter may sense and improve the voltage sags and power quality quickly due to the high-speed IGBT switching operations