Synchronous generator excitation control via hierarchical fuzzy method

In interconnected power systems, non-stable trend of power consumption significantly affectsthe stabilization and synchronization of the generators. Various disturbances in power systemsresult in rotor angle and speed oscillations. Since the frequency of these oscillations is lowerthan power network frequency they are termed as low frequency oscillations. The protectionand control performance improvement in power generation systems is of vital importance inorder to produce high electric power quality with low cost.To increase the performance of the energy production controllers, various methods andcontrol theories have been developed for the last 50 years. In most of these studies, theperformance of the proposed methods has been tested via comparing with classical controlmethods and/or previously studied systems.In this study, dynamic performance of excitation control system that is an importantcomponent for power generation is improved. For this reason, hierarchical fuzzy controlmethod which has not been previously applied in excitation control systems is preferred as anovel control method. This control method is thought to applied power system stabilizer thatis component of excitation control system.The performance of the proposed method is tested for single machine infinite bus system andcompared to conventional power system stabilizer, PID controller and standard fuzzycontroller. For simulation purposes Matlab/SIMULINK software has been used.In proposed method positive impact of additional third input variable to controllerperformance is shown in simulation. Noticeable advantage of this method is to avoid ruleexplosion phenomena in fuzzy control applications which has more than two input. As aresult, the total number of rule increases linearly (not exponancialy) in spite of using the thirdinput variable.Keywords: Excitation control, Hierarchical fuzzy control, Power system stabilizer,Synchronous generator, Single machine infinite bus systemJURY:1. Doç. Dr. Nurettin UMURKAN (Supervisor) Date : 18.09.20062. Prof. Dr. Celal KOCATEPE Page : 1553. Prof. Dr. Burhanettin CAN4. Prof. Dr. Fahrettin ARSLAN5. Doç. Dr. İbrahim ŞENOL