A nonlinear model for the analysis of the turbine generator vibrations including the design of a flywheel damper

This paper proposes a nonlinear model to simulate the turbine-generator mechanical system, This system structure is considered to be one where the blades are pegged into the discs fitting into the shafts. In this nonlinear model it is considered that the shaft and blade stiffness are changed by the effect of the rotary centrifugal force and the viscous damping is varied at different velocities. Simulation results of an operating turbine-generator set with actual parameters are presented to validate the accuracy and reliability of the proposed analytical method. Conventionally turbine-generator vibrations caused by power system disturbances are clamped by using the damper windings in which no power energy is dissipated under normal operation. According to the above theory, this paper describes the equivalent models and designs for the flywheel dampers installed in the couplings of the shaft mechanical system. Such a mechanical method is adopted due to its ability to effectively depress torsional vibrations because of the high reliability of these added mechanical elements. (C) 1997 Elsevier Science Ltd.