International Journal of Scientific and Research Publications
Title: A Monograph on Fuzzy Logic Control for Improving Transient and Dynamic Stability of Power Systems
Author/s: Sanjeev. S. Gokhale
Power systems are often subject to stability problems. Faults and load changes give rise to oscillations in power system networks that result in poor power quality. The transient stability of an electric power system can be improved by a switched series capacitance. Progress in the field of power electronics has led to the widespread use of thyristor switches that can be used to switch on and off series capacitors and reactances. If the reactance of a transmission line is controlled for a small duration immediately after the occurrence of a fault or a load change the electromechanical oscillations can be damped and the system stability improved.
Attempts have been made to use optimal control theory to damp these oscillations in minimum time. As per optimal control theory, Three to four switchings of the correct reactance for the correct time can restore the system to the prefault state in minimum time. However, optimal control theory has many practical drawbacks.
Fuzzy logic is the most successful and popular branch of Artificial Intelligence. Fuzzy logic controllers are used whenever the system models are not well defined and there are inbuilt uncertainties and approximations in the process. Attempts have been made to construct artificial intelligent controllers to improve power system stability. This monograph simulates, control of a simple power system with a fuzzy logic controller. A set of fuzzy control rules is constructed and inference is provided by fuzzy logic reasoning. This monograph, shows that the electromechanical oscillations arising after a fault can be successfully damped and the system stability enhanced by the use of a fuzzy controller.
I express my sincere thanks to all those who gave me guidance, suggestions and encouragement which helped me complete the monograph.