Eddy currents modelling in synchronous machines during starting accounting for the nature of damper end connections

A model is developed for calculating eddy current in electric machines, taking into account the end connections of the conducting materials. The method is based on the combination of classical finite elements, representing the saturated parts of the machine, with a special type of element (conductor macroelements) simulating the subdomains where eddy currents are developed. The end connections of the conductors are considered by incorporating the corresponding circuit equations into the field equations. This technique offers a good accuracy involving reduced meshes and is particularly suitable for thin skin effect problems. The method is used to model the effect of damper configuration on the startup of a 4.5 MVA synchronous machine