Wide-Area Based SVC-Fractional Order PID Controller For Damping Inter-Area Oscillations

Inter-area low frequency electromechanical oscillation (LFEO) is one of the main threats to the stability and secure operation of interconnected power systems. Poorly damped growth of theses oscillations can cause system instability and may even lead to blackouts. In such a context, Flexible Alternating Current Transmission System (FACTS) devices, particularly, Static Var Compensator (SVC), could be used to effectively damp inter-area LFEO by using a proper supplementary damping controller. In this paper, a Fractional Order Proportional Integral Derivative controller (FOPID) based wide-area measurements is presented as an auxiliary control for the SVC in order to enhance power system stability and to improve inter-area low frequency oscillations. Different input signals are tested and the effectiveness of the novel controller compared to the integer order PID is demonstrated using a two-area four-machine test system. Generators rotor speed deviation is chosen as input signal for the proposed FOPID. The controller's parameters are adjusted using Genetic Algorithm (GA) optimization. Simulation results conducted on a two-area power system show that the developed wide-area SVC-based FOPID controller is highly capable to damp inter-area low frequency oscillations.