Stability Enhancement of Single Machine Infinite Bus System with UPFC using Bat Algorithm

Abstract

A major challenge in highly interconnected power systems is ensuring the stability of their networks. Even though low-frequency oscillations may not appear to be too harmful at first glance, the failure to dampen out the oscillatory signals can result in the system losing synchronization. Flexible AC Transmission Systems (FACTS) devices are effective in suppressing oscillations as well as enhancing power transfer rates. Among many devices within FACTS, the Unified Power Flow Controller (UPFC) is one of the most sophisticated and effective power flow controllers available. UPFC parameter optimization concerns real-time power systems problem with multiple objectives. In this paper, the optimization of UPFC parameters is carried out using a novel optimization approach named Bat Algorithm (BA) to dampen out the small signal oscillations, and thereby enhancing the stability of the system. The time domain simulation results of the proposed BA-tuned UPFC are compared with the results of a Tunicate Swarm Algorithm (TSA) tuned UPFC and also with a conventional fixed gain UPFC to measure the efficacy of the proposed algorithm. Also, a comparison is made between the eigenvalues of both the optimized and conventional UPFCs. Both the eigenvalue analysis as well as the time domain representation of system parameters ensures the superiority of the suggested controller over the traditional controller in all aspect.