Measurement of switching transients in 735 kV substations and assessment of their severity for transformer insulation

Author

Malewski, Ryszard ; Douville, Jean ; Lavallée, Louis

Author_Institution

Res. Inst. of Hydro-Quebec, Varennes, Que., Canada

Volume

3

Issue

4

fYear

1988

fDate

10/1/1988 12:00:00 AM

Firstpage

1380

Lastpage

1390

Abstract

An automatic measuring system that digitally records transients generated by EHV-transmission-system switching operations and lightning strokes has been developed. The severity of these transients was assessed by comparing them with test voltages applied to the transformers during acceptance tests. In order to quantify in-service transients with respect to the impulse-test voltages, the frequency spectra of the time-domain records were calculated and expressed as a percentage of the test level. The presence of high-frequency winding oscillations was revealed by simultaneous measurements of the bushing voltage and neutral current. The results of these measurements are presented in the form of a transfer function, which can also be used to detect winding displacements in service

Keywords

automatic test equipment; power transformers; substations; transformer insulation; transients; 735 kV; EHV-transmission-system switching operations; impulse-test voltages; lightning strokes; substations; switching transient automatic measuring system; transformer insulation; winding displacements; Current measurement; Displacement measurement; Frequency; Impulse testing; Insulators; Lightning; Substations; Time domain analysis; Transfer functions; Transformers;

fLanguage

English

Journal_Title

Power Delivery, IEEE Transactions on

Publisher

ieee

ISSN

0885-8977

Type

jour

DOI

10.1109/61.193935

Filename

193935