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.

Date of Patent:
Dec. 24, 2002

Filed:

Jun. 27, 2001
Applicant:
Inventors:

Yasuhiro Kurosawa, Tokyo, JP;

Tetsuo Matsushima, Tokyo, JP;

Hidenari Amo, Tokyo, JP;

Hiroshi Saito, Saitama-ken, JP;

Assignee:

Kabushiki Kaisha Toshiba, Kawasaki, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02H 3/18 ;
U.S. Cl.
CPC ...
H02H 3/18 ;
Abstract

A digital distance relay for deciding whether a fault point is within a stipulated operation region by obtaining an impedance to the fault point. The relay comprises: means for deciding whether the impedance is within a specified region by applying a value proportional to the relative phase; and means for deciding the fault point is within the stipulated operation region if: (a) when the load current indicates a sending direction, the positive-phase resistance and reactance are within a stipulated region based on stipulated positive-phase resistance and reactance, and the impedance is decided within the specified region; or (b) when the load current indicates a receiving direction, the positive-phase resistance and reactance are within a stipulated region based on stipulated positive-phase resistance and reactance, or the impedance is decided within the specified region.


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