Characteristic Frequencies and Mode Shapes for TurboGenerator Shaft Torsional Vibrations

Fundamental to the study of turbogenerator shaft torsional vibrations, as occur in subsynchronous resonance and high speed reclosing, is the calculation of the characteristic frequencies and associated mode shapes of the vibrations. A calculation procedure is discussed which is based on distributed ed system concepts and does not require matrix eigenvalue-eigenvector routines as does the conventional method based on lumped inertia and compliance. The procedure is of value in the analysis and simulation of torsional vibrations.