New functionalities of the unified power quality conditioner

Power quality problems have received much attention because of their bad economical impacts on both utilities and customers. Current harmonics are the most common power quality problem, while the voltage sag is the most severe. This paper introduces new functionalities for the unified power quality conditioner (UPQC), which never introduced before by one mitigating device (UPQC). This device can suppress current harmonics and compensate the current unbalance, which might be produced in the distribution system. It also mitigates different voltage sags, which might result from different faults in the system. The performance of the proposed UPQC is verified by digital simulation results PSCAD/EMTDC.