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.:
Date of Patent:
Aug. 30, 2005
Filed:
Jan. 21, 2003
Takahiro Kase, Tokyo, JP;
Hidenari Amo, Tokyo, JP;
Yasutaka Sonobe, Tokyo, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A directional comparison distance relay system for protecting a power transmission line. The relay system comprises a fault detection unit which includes a directional distance relay element for deciding whether a fault is in forward or reverse directions; a short-circuit distance relay element for deciding whether a fault is within a protection zone by distance calculation; and an evolving fault detecting unit for deciding an evolving fault when a forward earth fault directional relay in a single phase and a reverse directional relay in a phase are in operation. The relay system further comprises a block unit for blocking trip of a circuit breaker at a near end due to the short-circuit distance relay, and for blocking permissive trip signal to a circuit breaker at the far end, based on an operation of the evolving fault detecting unit.