Effect of exciter gain on small signal stability of power system

Power system which is responsible for supplying electrical energy to the consumer consists of synchronous machine, its excitation system, loads, interconnection networks etc. Small signal stability is the ability of the power system to remain in synchronism after subjected to the small disturbances which are continuously acting on the system in the form of small load changes. Nowadays fast acting voltage regulators are used in the excitation system of the alternator which can increase the steady state limit of the system but they contributes negative damping to the system in the form of low frequency sustained oscillations. This paper discusses the effect of exciter gain on the small signal oscillations of the system. Single machine infinite bus (SMIB) system is taken as the test system. Simulation results are obtained for different values of the exciter gain.