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:
Jun. 11, 2013
Filed:
Jun. 14, 2011
Chikashi Komatsu, Hitachi, JP;
Mitsuyasu Kido, Hitachinaka, JP;
Hideyuki Yoshioka, Hitachi, JP;
Tokushiro Uno, Hitachi, JP;
Chikashi Komatsu, Hitachi, JP;
Mitsuyasu Kido, Hitachinaka, JP;
Hideyuki Yoshioka, Hitachi, JP;
Tokushiro Uno, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A multi-terminal power line protective relay system is provided, which divides a power transmission line having four or more terminals into two or more power line sections composed of three adjacent terminals and portions of the power transmission line lying among the three adjacent terminals and one of the three adjacent terminals being shared by two adjacent power line sections, and includes protective relays at the respective terminals including a current-driven differential protective relay element for detecting a fault occurring in a power line section through current-differential calculation by using measured currents, inter-terminal communication channels linking two protective relays at two different terminals; and intra-terminal communication channels linking two protective relays at each shared terminal. Each protective relay that detected the fault transfers a trip instruction to the other protective relays via the inter-terminal and intra-terminal communication channels and causes the other protective relays to trip circuit breakers.