Insulation coordination for delta connected transformers

Author

Keri, A.J.F. ; Musa, Y.I. ; Halladay, J.A.

Author_Institution

American Electr. Power Service Corp., Columbus, OH, USA

Volume

9

Issue

2

fYear

1994

fDate

4/1/1994 12:00:00 AM

Firstpage

772

Lastpage

780

Abstract

It is common practice to install only phase to ground surge arresters for transformer insulation protection against electrical stresses. However, this may not adequately protect the delta connected transformer phase to phase winding insulation. High phase to phase overvoltages at the transformer terminals, due to capacitor switching, have been reported. This paper describes the excessive phase to phase overvoltages that can also occur due to wave propagation and surge transfer through transformers. This paper points out the need for surge arrester arrangements that protect both phase to phase and phase to ground transformer insulations. Surge arrester arrangements, selection criteria, installation practices, and application considerations are discussed in this paper

Keywords

electric breakdown; insulation co-ordination; power system protection; power transformers; surge protection; transformer insulation; transformer protection; transformer windings; application; capacitor switching; delta connected power transformers; electrical stresses; installation practices; insulation coordination; phase to ground surge arresters; phase to phase overvoltages; phase to phase winding insulation; selection criteria; surge transfer; transformer insulation protection; wave propagation; Arresters; Capacitors; Lightning; Optical propagation; Power system transients; Power transformer insulation; Power transmission lines; Stress; Surge protection; Voltage;

fLanguage

English

Journal_Title

Power Delivery, IEEE Transactions on

Publisher

ieee

ISSN

0885-8977

Type

jour

DOI

10.1109/61.296256

Filename

296256