Damping multimodal power system oscillation using a hybrid fuzzy controller for series connected FACTS devices

The paper presents a simple hybrid fuzzy logic proportional plus conventional integral controller for FACTS devices in a multi-machine power system. This controller is designed by using an incremental fuzzy logic controller in place of a proportional term in a conventional PI controller and provides a wide variation of controller gains in a nonlinear manner. This controller is well suited to series connected FACTS devices like UPFC, TCSC and TCPST, etc., in damping multi-modal oscillations in a multi-machine environment. Digital simulations of a multi-machine power system subjected to a wide variety of disturbances validate the efficiency of the new approach