Synchronization of Voltage Stability in AVR-PSS using Fuzzy Logic Controller

The operation and stability of modern power systems have been threatened by the tremendous increase in the electrical energy usage. To meet the rising power demand, a large number of generators operate synchronously. Often electromechanical oscillations called power swings are induced by faults occurring within the system. A suitable damping device is needed to combat the loss of synchronism and other stability problems caused by these power swings. High performance excitation systems (AVR) with damper are well suited to maintain the steady state and transient stability of the generators in power system. In case of relatively weaker tie line interconnections between the power systems, low frequency oscillations are observed. These oscillations ranging from 0.5 – 3 Hz are quite common in the system. An effective means of improving the system damping of the electric power system is by using power system stabilizers. Effort has been given to develop a robust co-ordinate AVR-PSS using a fuzzy logic controller for an effective improvement in power system stability of a single machine system. In this work, a fuzzy logic based power system stabilizer has been designed for a single machine infinite bus power system. Simulation results indicate that the proposed fuzzy logic based coordinate AVR-PSS achieves a robust performance for a wide range of system operation conditions and offers superior performance over AVR-PSS without fuzzy logic controller.