Turbine generator

Abstract

The rotor 2 of a rotating field type turbine generator is provided with slots 3 for accommodating the field windings, wedges 4 positioned at the portions of the magnetic poles on the rotor 2 for holding the field windings and wedges 5 positioned between the magnetic poles on the rotor. These wedges 4 and 5 are constituted by metal bars without joints to enhance damper effect thereby. Magnetomotive forces due to higher harmonics, which causes temperature rise of the rotor 2 and torque ripple during starting with thyristors, induces an elliptic rotating magnetic field having the longer diameter on d axis extending in the direction of magnetomotive force induced by the field windings and the shorter diameter on q axis perpendicular to d axis, and thus a larger eddy current is induced flowing along q axis on the rotor 2 than that flowing along d axis. Therefore the thickness d' in radial direction of the wedges 5 positioned between the magnetic poles on the rotor 2 is determined larger than the thickness d in radial direction of the wedges 4 positioned at the portions of the magnetic poles on the rotor 2 to reduce the resistance of the wedges 5 and to easily lead the eddy current flowing in the axial direction of the rotor 2, thereby a good thermal balance over the entire portions on the rotor 2 is achieved. Drawings to Be Selected FIG. 1