Committee Chair

Eltom, Ahmed H.

Committee Member

Sisworahardjo, Nurhidajat; Kobet, Gary L.

Department

Dept. of Electrical Engineering

College

College of Engineering and Computer Science

Publisher

University of Tennessee at Chattanooga

Place of Publication

Chattanooga (Tenn.)

Abstract

A large utility was experiencing a problem when switching a two-stage capacitor bank resulting in misoperations of the bank protection. When the bypass switch is opened a long duration dc offset occurs across all capacitors. This dc causes saturation of the tap point VT resulting in a false differential voltage and misoperation of the protection. The utility had to disable the voltage differential during switching until the phenomenon could be studied and a suitable solution found. The work is a comprehensive analysis of the transients affecting the protection and how the problem could be mitigated. An analytical approach was taken to understand the occurrence of the dc offset and an Electromagnetics Transients Program (EMTP) was used to study various mitigation techniques. A simple solution is presented for future installations that prevents the problem completely. A “next best” mitigation is presented for existing banks where reconfiguration would not be cost justified.

Degree

M. S.; A thesis submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Master of Science.

Date

8-2013

Subject

Electric power systems; Electric power distribution

Discipline

Electrical and Computer Engineering

Document Type

Masters theses

Extent

ix, 41 leaves

Language

English

Rights

Under copyright.

License

http://creativecommons.org/licenses/by-nc-nd/3.0/

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