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:
Jan. 08, 1980
Filed:
Dec. 23, 1977
Applicant:
Inventors:
Assignees:
Mitsubishi Denki Kabushiki Kaisha, both of, JP;
The Tokyo Electric Power Co., Inc., both of, JP;
Primary Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
361 68 ; 324 51 ; 361 79 ; 364480 ; 364482 ;
Abstract
A protective relaying system including a protected AC transmission line and detection means for detecting a change in propagation mode of a traveling wave propagating along the transmission line. The transmission line has a pair of line ends and a surge propagation time .tau., and the detection means is effective for comparing a value of the traveling wave as it passes one of the line ends at a time t-.tau. and a value of the traveling wave as it passes the other of the line ends at a time t after the surge propagation time has elapsed for detecting a change in wave value resulting from a change in wave propagation mode.