NEW INDEX PARAMETER FOR RAPID EVALUATION OF TURBOGENERATOR SUBSYNCHRONOUS RESONANCE SUSCEPTIBILITY

This paper proposes the use of a new index parameter which provides in itial insight into the expected subsynchronous resonance (SSR) suscept ibility of a turbo-generator without the need for detailed numerical c alculations. This index parameter, derived from the modal representati on of a turbo-generator shaft, is called the 'torsional interaction su sceptibility' (TIS) and it indicates the propensity of a mode to becom e unstable due to torsional interaction. Calculated results are presen ted to show that this index parameter can be used to provide initial i nformation about the expected SSR behaviour of a turbo-generator and t o enable comparisons between the SSR behaviour of modes from different turbo-generators.