Neutral impedances in fault analysis

Author

Enns, Mark K.

Author_Institution

Electrocon Int. Inc., Ann Arbor, MI, USA

Volume

13

Issue

2

fYear

1998

fDate

5/1/1998 12:00:00 AM

Firstpage

274

Lastpage

279

Abstract

Object-oriented modeling of transformers and other Y-connected devices preserves neutral nodes and impedances, making them available as points to fault. This is in contrast to conventional modeling in which all neutral nodes are eliminated by modifying the parameters of the devices. Phase-domain expressions are developed for faults between an energized node and a neutral node, and between two neutral nodes. An example using a three-circuit transformer shows the effects of faulting various neutral points. The results show that fault currents may be either higher or lower than for standard phase-to-ground faults, depending on the interaction of source, transformer, and neutral device impedances. The modeling was verified by comparison with phase-to-ground faults on a conventional transformer model

Keywords

electric impedance; fault currents; fault diagnosis; object-oriented methods; power engineering computing; power transformers; Y-connected devices; energized node; fault analysis; fault currents; neutral impedances; neutral nodes; neutral points faulting; object-oriented modeling; phase-domain expressions; phase-to-ground faults; three-circuit transformer; Circuit faults; Equivalent circuits; Fault currents; Grounding; Impedance; Object oriented modeling; Power system analysis computing; Power system economics; Resistors; Transformers;

fLanguage

English

Journal_Title

Power Systems, IEEE Transactions on

Publisher

ieee

ISSN

0885-8950

Type

jour

DOI

10.1109/59.667331

Filename

667331