Analysis of two-stage shunt capacitor bank protection deficiencies with mitigation suggested

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.

Grantor dc:publisher

University of Tennessee at Chattanooga

Author dc:creator

• Patterson, Russell William

Contributors dc:contributor

• Eltom, Ahmed H.
• Sisworahardjo, Nurhidajat; Kobet, Gary L.
• College of Engineering and Computer Science

• Electric power systems
• Electric power distribution

Licence

• https://rightsstatements.org/page/InC/1.0/?language=en

Language dc:language

English, eng

Repository record dc:identifier

https://scholar.utc.edu/theses/360

OAI identifier oai:identifier

oai:scholar.utc.edu:theses-1500