The design of turbine-generator optimal controllers including the effect of torsional modes of oscillation

Optimal linear control has been suggested for designing supplementary signal controllers for turbine-generators. It is shown that the design of the controller should include consideration of the torsional modes of oscillation of the rotor to obtain the best performance. The exciter voltage ceiling is shown to limit the sum of the synchronizing and damping torques. Practical designs normally require that tradeoffs be made. It is shown how advantage would be gained by using the supplementary signal. Normally fed to the speed governor controlling the main steam valve, for a second governor that would merely act on a fast interceptor valve