Comparison of finite element methods for turbine generator negative sequence performance prediction

Line-to-line short circuits impose a substantial thermal loading on a turbine generator rotor as a result of the eddy current heating arising from negative sequence and direct currents. The temperatures produced may be large enough to cause a reduction in the strength of the rotor wedges, and to induce high thermal stresses at the corners of inertia slits. The authors demonstrate that provided accurate equivalent circuit parameters are available, the full time-stepping transient finite-element method for calculating negative sequence heating effects shows no significant advantage over the simpler mixed finite-element/equivalent circuit pseudo-steady-state method