Study of turbine-generator shaft parameters from the viewpoint of subsynchronous resonance

Changes to the mechanical design have not received any consideration as a solution to the subsynchronous resonance (SSR) problem. This is mainly because the ordering and manufacture of the turbine-generator has often been done long before the SSR problem is diagnosed. It is observed that hydraulic turbines do not experience SSR problems and that the problem occurs with varying degrees of severity for different designs and sizes of thermal machines. The principal objective of this paper is to explore the sensitivity of shaft design parameters as a possible solution to the SSR problem. This assessment was performed using an eigenvalue analysis technique of the mechanical and electrical systems. A parametric investigation was also made to assess the sensitivity of the damping ratio for the different modes to the variation of generator-exciter shaft stiffness. (C) 1996 Elsevier Science Ltd.