Evaluating the effect of SSSC stabilizer in different control channels on sub-synchronous resonance oscillations

To increase transmitted power, series capacitors may be used in the transmission lines. A compensated transmission line together with a turbine-generator may cause Sub-Synchronous Resonance (SSR) phenomena in a power system. In this paper, details of dynamic modeling of a single machine power system connected to the network through a transmission line, compensated with a series capacitor, have been presented. Static Synchronous Series Compensator (SSSC) as one of series FACTS devices has been used for the damping of the SSR oscillations. For this purpose, a linear damping SSSCbased stabilizer with lead-lag structure is incorporated into SSSC controller. To determine parameters of SSSC stabilizer, a new multi-objective function has been proposed. In this function, in addition to improving stability of critical modes, the gain of the stabilizer has been considered. To have a stabilizer with a minimum-phase structure, suitable constraints have been determined and added to the objective function. To optimize the objective function, a recently developed optimization technique known as Grey Wolf Optimization (GWO) algorithm has been applied. The eigenvalues analysis and nonlinear simulations of the IEEE First Benchmark Model (FBM) power system with a SSSC stabilizer illustrate the effectiveness of the proposed method in suppressing SSR oscillations in the studied system.