Comparison of different control actions for small signal stability of a UPFC equipped SMIB system

The power system is a dynamic system that is constantly being subjected to disturbances. It is important that these disturbances do not drive the system to unstable conditions. The Unified Power Flow Controller (UPFC), which is a FACTS device, simultaneously controls the real and reactive power flows on a transmission line as well as regulates voltage at the bus where it is connected. This device creates a tremendous quality impact on power system stability. In this paper, a systematic approach based on phase compensation technique, Robust control technique and Fuzzy logic control technique for designing Unified Power Flow Controller (UPFC) based damping controllers (based on m_B and m_E) have been considered. Investigations on comparing the response of controllers based on all the techniques reveal that the performance of Robust Controller and Fuzzy Logic Controller is superior to the controller based on Lead-Lag compensation technique.