Verification of on-site oil reclamation process by means of polarisation/ depolarisation current analysis

Author

Bhumiwat, Supatra A. ; Phillips, Paul

Author_Institution

KEA Consultant, Auckland, New Zealand

fYear

2004

fDate

19-22 Sept. 2004

Firstpage

105

Lastpage

108

Abstract

This work starts with the reasons why on-site oil reclamation processing was required for two 250 MVA 3-φ banks of single-phase transformers. It reviews the results of routine diagnostics and describes the application of a new off-line diagnostic tools, polarisation/ depolarisation current (PDC) analysis in the verification of the effectiveness of the oil reclamation process. The moisture in insulating paper of each unit as assessed by the new tool is reported, in addition to various insulation properties such as oil conductivity, insulation resistance, polarisation index and recovery voltage. Finally, the comparison of PDC analysis result before and after oil reclamation indicates the degree of improvement in the insulation system and the final condition of the transformers.

Keywords

electrical conductivity; impregnated insulation; paper; polarisation; power transformer insulation; power transformer testing; transformer oil; 250 MVA; depolarisation current analysis; insulation resistance; moisture; off-line diagnostic tool; oil conductivity; oil reclamation process; paper insulation; polarisation current analysis; polarisation index; recovery voltage; single-phase transformers; Aging; Circuit testing; Conductivity; Dissolved gas analysis; Electrical resistance measurement; Moisture; Oil insulation; Petroleum; Polarization; Power transformer insulation;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrical Insulation, 2004. Conference Record of the 2004 IEEE International Symposium on

ISSN

1089-084X

Print_ISBN

0-7803-8447-4

Type

conf

DOI

10.1109/ELINSL.2004.1380473

Filename

1380473