Installation of power system stabilisers and the evaluation of settings

The justification for the installation of power system stabilisers at selected Scottish power stations is outlined. The selection process, specification and design criteria for these stabilisers are detailed and the eigenvalue analysis to achieve optimum gain settings and margins is explained. The paper proceeds to illustrate the theoretical improvement in interarea damping and to explore the errors which can be introduced by modelling a multiplicity of identical sets by a single equivalent machine. Finally, the studies where three generating sites have stabilisers in service indicate scope for further co-ordination to optimise the improvement.