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:
Oct. 28, 1986
Filed:
Jul. 20, 1984
Yoshihiro Sano, Katsuta, JP;
Fumio Iwatani, Hitachi, JP;
Takao Kubo, Hitachi, JP;
Yoshiteru Miki, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a carrier relay system in which protective relay apparatus are disposed in terminal stations respectively and interchange information between the terminal stations via a signal transmission line for detecting a trouble occurred in power transmission lines on the basis of the exchanged information, specific information K is inserted in a predetermined position of a signal transmitted from the first terminal station to the second terminal station, and the specific information K is inserted intact in another predetermined position of a signal returned from the terminal station to the terminal station. In the terminal station, the specific information K inserted in the signal transmitted therefrom is compared with the specific information K inserted in the signal returned from the terminal station for deciding the presence or absence of a trouble occurred in the power transmission lines. The signal transmission line extending between the terminal stations includes two transmission channels, and circuit breakers are tripped when a fault has occurred in one or both of the signal transmission channels and a trouble detection relay has operated.