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. 13, 1998
Filed:
Sep. 18, 1995
Eisaku Mizufune, Hitachi, JP;
Takashi Sato, Hitachi, JP;
Katsuichi Kashimura, Takahagi, JP;
Osamu Koyanagi, Hitachi, JP;
Yoshihito Asai, Hitachi, JP;
Yukio Korosawa, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The steep initial rate of rise of the transient recovery voltage across the poles of a circuit breaker just after a fault current break is decreased. The breaking performance in the case of a short-circuit fault to ground taking place in an electrical power transmission system at relatively as near a place as several kilometers apart from the circuit breaker, that is a short-line-fault is improved by a saturable reactor having a capacitor connected in parallel therewith to the circuit breaker in series. As a result, as the saturable reactor changes from the magnetically saturated state to the unsaturated state just before the zero point of the fault current, the self-inductance of the saturable reactor gradually increases and an LC resonance is produced between the self-inductance of the saturable reactor and the capacitor connected to the saturable reactor in parallel. Therefore, the peak value and the time period of the current flowing from the saturable reactor can be controlled to control the initial rate of rise of the transient recovery voltage.