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. 25, 2016
Filed:
Feb. 06, 2015
Kabushiki Kaisha Toshiba, Tokyo, JP;
Yutaro Kitamori, Tokyo, JP;
Takahisa Kageyama, Chiba, JP;
Teruyuki Ishizuki, Tokyo, JP;
Takashi Fujita, Tokyo, JP;
KABUSHIKI KAISHA TOSHIBA, Tokyo, JP;
Abstract
According to one embodiment, an over-voltage prevention device is provided between a secondary-winding side of a wound-rotor induction machine and a frequency converter configured to excite the secondary-winding side of the wound-rotor induction machine through a three-phase excitation power supply line. The over-voltage prevention device includes a first short-circuit device having a function of short-circuiting between phases of the excitation power supply line, and a second short-circuit device having a function of short-circuiting between phases of the excitation power supply line with a short-circuit impedance greater than a short-circuit impedance of the first short-circuit device.