Loading Margin Enhancement in Power System via FACTS Devices Hybrid Structure

The FACTS (Flexible AC Transmission System) devices have been considered as excellent controllers in a power system for better reliability and transmission capacity on a long-term and cost-effective basis. In this paper, a novel power flow controller topology is proposed for FACTS in order to improve static voltage stability characteristics and loading margin enhancement. Employing hybrid topology of FACTS devices enables use of converters to enhance the functionality of existing equipment in a power system. Since existing equipment is fully utilized, the hybrid topology requires considerably lower total converter ratings compared to the UPFC. This paper presents a power injection model (PIM) of hybrid power flow controller for power flow and voltage stability analysis. P-V curves are constructed to calculate loadability margins. Static voltage stability margin enhancement using hybrid topology of FACTS device is compared in the IEEE 6-bus and 14-bus test system. The results used to demonstrate the effectiveness and performance of this model.