Field-oriented approach to turboalternator modelling. Dynamic description and frequency responses

A linear model of a turbogenerator is proposed, suitable both for furnishing an accurate description of external performance, and for matching the physical processes of the actual machine. The effects of eddy currents flowing inside the solid conducting materials are brought out particularly clearly by developing an exact analytical investigation of the electromagnetic-field configuration inside the model. The dynamic functions which connect the external variables in the frequency domain are theoretically determined as functions of both the construction specification and the operating constraints. Comparison is made with experimental results from two different 370 MVA generators; test data have been provided by ENEL and specify the frequency responses of both open-circuited and short-circuited machines.