Real time simulation based study of effect of exciter gain on control mode oscillations in power system

A power system consists of the generating machine and transmission network in which the generating machine includes turbine, alternator and excitation system. The ability of power system to remain stable despite of small frequency oscillations occurring in the system is called small signal stability. A generating system operating without voltage regulation may have the problem of steady increase in rotor angle due to lack of synchronizing torque. With voltage regulation the power system may have the sustained oscillations due to negative damping torque. In this paper the effect of exciter gain on small signal oscillations has been studied. A single machine infinite bus system (SMIB) is taken as test system and the simulation result is obtained for variation in electrical torque, rotor angle variation and rotor speed variation for different values of exciter gain.