A multimass model with non-linear modal damping for SSR analysis of turbine generators

In this paper, a new nonlinear multimass model has been developed for SSR (Subsynchronous Resonance) evaluation. This paper first gives a brief derivation of the shaft model, which is without damping, and then provides the new nonlinear modal damping model, which is the primary contribution of this paper. Following that, the integrated modal multimass model is shown and applied to the Shangdu power plant in China. Comparison between the linear multimass model and non-linear one is also presented. The details of this approach are presented, and the performance of the non-linear modal multimass model is verified with the Shangdu system through electromagnetic simulations.