Diagnosis of arcing in retaining rings of turbogenerators

Retaining rings are an important and most highly stressed component of the entire turbogenerator system. Arcing in retaining rings is a very serious problem and could easily escalate to a full-blown failure. In this project we diagnose arcing in the retaining rings. We determine the most likely mechanism by which arcing occurs and the category of events which lead to it. Specifically, we try to test two different mechanisms which could have led to the arc marks. The first one is sparking due to high field efects (or high voltage gradient across the contact junction) and the other is a make-and-break contact arcing owing to the presence of inductance in the system. Experiments performed to measure the contact resistance between the retaining ring and mild iron piece indicate that even very high fault currents cannot produce the voltage required to cause sparking. Transient 3-D finite element simulations show that a make-and-break contact can generate localized voltage spikes, on account of small contact break, which are high enough to lead to arcing. Interestingly this can happen at relatively low currents.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2016

Author dc:creator

• Harmukh, Sajal Kumar

Contributors dc:contributor

• Haran, Kiruba Sivasubramaniam

• retaining ring
• arcing
• diagnosis
• turbogenerator

Statement dc:rights

• Copyright 2016 Sajal Harmukh

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/90752

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/90752