Analysis of voltages generated in auxiliary windings of large steam turbine-generators

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:7048790

Fogarty, J M

Factors that determine the fundamental frequency voltage induced in the potential windings of the excitation system of a large synchronous generator during a steady state armature short circuit were investigated by a magnetostatic finite element analysis. The windings, which consist of conductors (P-bars) placed at the top of the slate containing the armature winding, are subject to the following six voltages: (1) A voltage proportional to the armature slot leakage reactance which arises because the P-bar is linked by flux from the field winding that is equal to the armature slot leakage flux. (2) A voltage proportional to the armature and leakage reactance that is generated by magnetic flux in the stator yoke equivalent to the voltage behind that reactance. (3) A voltage increase for a P-bar located at the top of a slot where the armature bars beneath it are not in phase. This voltage is caused by a reduction in the net current in the slot available to cancel flux from the field. (4) A voltage reduction induced in the P-bar and arms by leakage flux in the ends of the machine. (5) A voltage reduction because the P-bar may be located within rather than at the top of the stator slot. (6) A voltage induced in the end connection ring by the armature currents flowing in adjacent connection rings. A 2-D magnetostatic finite element method was employed to investigate the voltages induced in the P-bar.

• Research Organization: Rensselaer Polytechnic Inst., Troy, NY (USA)
• OSTI ID: 7048790
• Country of Publication: United States
• Language: English

Related Subjects

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VOLTAGE DROP