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:
Apr. 06, 1999
Filed:
Jul. 29, 1997
Yoshiyasu Watanabe, Hitachi, JP;
Toru Tanimizu, Hitachi, JP;
Kazuo Kano, Hitachi, JP;
Yasunobu Kanou, Mito, JP;
Toshio Horikoshi, Fujioka, JP;
Koji Kondou, Narita, JP;
Ryutaro Yamamoto, Tokyo, JP;
Nobuhiro Kuroda, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
The Tokyo Electric Power Co., Inc., Tokyo, JP;
Abstract
A protection apparatus for a spot network substation has a plurality of receiving lines connected between a network bus and a plurality of power sources. Each receiving line is connected to a primary switching device, a network transformer and a protector CB. A detector for detecting a phase of each receiving line voltage and a judging unit for judging the detected phase are provided on the primary side of each network transformer. A previously stored basic phase is compared with the detected phase of the receiving line voltage. If there is a lag in the detected phase of the receiving line voltage, it is judged to be a power-stop of the corresponding power source and the protector CB is tripped.