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:
Jan. 11, 2022
Filed:
Jun. 06, 2019
Hitachi Mitsubishi Hydro Corporation, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
HITACHI MITSUBISHI HYDRO CORPORATION, Tokyo, JP;
HITACHI, LTD., Tokyo, JP;
Abstract
In a variable speed generator/motor device including a variable frequency power converter, a direct current voltage device including a voltage type self-excited converter, an automatic voltage adjuster, and a converter current adjuster that controls unit converters, a first three-phase branch circuit is provided between the direct current voltage device and an alternating current system; a second three-phase branch circuit is provided between the variable frequency power converter and a three-phase alternating current synchronous machine; a first load switch is provided between the first three-phase branch circuit and the second three-phase branch circuit; a measurement current transformer is provided between the three-phase alternating current synchronous machine and the second three-phase branch circuit; when switching from a converter mode in which the variable frequency power converter drives the three-phase alternating current synchronous machine to generate power to a bypass mode, the first load switch is closed to stop a gate command to the unit converters; and when switching from the bypass mode to the converter mode, a current command value of the converter current adjuster is calculated from a current value of the measurement current transformer, the gate command to the unit converters is started, and the first load switch is opened.