Performance Improvement of Power System Stability by Using Multiple Damping Controllers Based on PSS and the UPFC

Enhancement of stability of the power system has been achieved by the application of Unified power flow controller (UPFC) device with an additional supplementary controller. This supplementary damping controller can be installed on any control channel of the UPFC inputs to implement the task of power oscillation damping (POD) controller. We have presented a comprehensive assessment and performed analytical study through simulation of the damping function of the multiple damping controllers. Dual and triple-coordinated design among power system stabilizer (PSS) and different UPFC-POD controllers were considered in order to identify the design that provided the most robust damping performance in a single machine infinite bus (SMIB). The parameters of the damping controller were tuned in the individual and coordinated design by using a chaotic particle swarm optimization (CPSO) algorithm that optimized the given eigenvalue-based objective function. The simulation results demonstrate that the proposed dual and triple-coordinated designs provide higher damping of Low-frequency oscillations and improve the system damping over their individual control responses. Keyword-Power system stability, Transmission lines, Flexible ac transmission systems, Power system stabilizer, Coordinated design