End winding deformations in different turbo generators during 3-phase short circuit and full load operation

Influence of End Structure on Electromagnetic Forces on End Winding of a 1550 MW Nuclear Generator

“…Simplifying the end coil as straight line inductors, Richard et al [16,17] calculated the electromagnetic force on the end winding of a 600 MW turbogenerator using the 3D electromagnetic model of the stator end region. Senske et al [18], Drubel et al [19], and Grüning and Kulig [20] calculated the electromagnetic force on end winding based on the Biot-Savart law to line circuit segments. Albanese et al [21] proposed a numerical approach based on an integral formulation to calculate the magnetic field and forces on the end winding of a large generator.…”

Electromagnetic Forces and Mechanical Oscillations of the Stator End Winding of Turbo Generators

“…As a likewise practicable method to obtain discrete time functions of currents, also a two-dimensional finite-difference time-stepping method as described in [6] was applied. Using the finitedifference method more accurate results with differences to measurements of less than 5% can be obtained, but at the price of an extensively longer computation time [1].…”

“…With the constant fraction decreasing the time functions are increasingly dominated by a fraction of twice the system frequency [1]. …”

“…In both figures the force distribution enables the classification of the winding coils corresponding to the respective phase. Indeed the force distribution is nonsinusoidal [1].…”

“…Primarily the capability of the stator end winding to perform oscillations owing to the operant electromagnetic forces and the resultant eventuality of damages like fatigue or even cracks of the insulation gives reason to accomplish improvements [1].…”