Synchronous-machine model including eddy currents

A simple dynamic model is developed for smooth-rotor solid-pole synchronous machines which takes account of rotor eddy currents. The model (in the same form as that of Park, but with an increased number of damper windings) is developed from the field solution for a machine of simplified geometry, by using Green´s functions. The final field is expressed in terms of a series of modal eddy currents; by truncating the series, only the dominant eddy-current modes are retained; each retained mode is represented in the model by a damper winding. The method is applied to the Goldington generator, and the results computed from eddy-current models are compared with those computed from Shackshaft´s model and with the test result.