The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Patent No.:

US 6731481 B1

PDF
Full Text
Expired
Date of Patent:
May. 04, 2004

Filed:

Oct. 23, 2001
Applicant:
Inventors:

Yong Cheol Kang, Jeollabuk-do, KR;

Sang Hee Kang, Seoul, KR;

Byung Eun Lee, Jeollabuk-do, KR;

Jae Sung Yun, Jeollabuk-do, KR;

Seung Hun Ok, Jeollabuk-do, KR;

Assignee:

Other;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H 7/04 ;
U.S. Cl.
CPC ...
H02H 7/04 ;
Abstract

The present invention relates to a relaying method using the ratio of induced voltages or the ratio of flux linkage increments. The protective relaying method for power transformers with one or more phases includes the first step of obtaining primary and secondary voltages and currents of the transformer; the second step of calculating induced voltages, induced voltage differences, ratio of primary and secondary induced voltages, or ratio of primary and secondary induced voltage differences from the currents and the voltages; the third step of calculating at least one predetermined decision parameter derived from at least one predetermined equation; the fourth step of deciding whether an internal winding fault occurs by comparing the decision parameter to the induced voltages, the induced voltage differences, the ratio of primary and secondary induced voltages, or the ratio of primary and secondary induced voltage differences.


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