Diagnosis of arcing in retaining rings of turbogenerators

Harmukh, Sajal Kumar

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https://hdl.handle.net/2142/90752 Copy

Description

Title

Diagnosis of arcing in retaining rings of turbogenerators

Author(s)

Harmukh, Sajal Kumar

Issue Date

2016-04-18

Director of Research (if dissertation) or Advisor (if thesis)

Haran, Kiruba Sivasubramaniam

Department of Study

Electrical & Computer Eng

Discipline

Electrical & Computer Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• retaining ring
• arcing
• diagnosis
• turbogenerator

Abstract

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.

Graduation Semester

2016-05

Type of Resource

text

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

Copyright and License Information

Copyright 2016 Sajal Harmukh

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