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. 13, 1993
Filed:
Oct. 15, 1991
Mitsuhiro Kawamura, Nagasaki, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An apparatus for measuring the time constant of the direct-axis damper of a synchronous machine is designed such that a voltage from a d.c. power source is applied by switching to armature windings of two phases, so that an armature current rises and thereafter it keeps a constant value. A current induced on a direct-axis damper diminishes at a moderate rate of the direct-axis damper time constant, and this decreasing current and the constant armature current flow inside the synchronous machine. In response to a change in the induction current on the direct-axis damper caused by the transition of the armature current to the steady state, a voltage induced on the field winding rises sharply and then falls gradually. The time length until the field winding voltage falls to a prescribed level is measured as the time constant of the direct-axis damper with such a measuring device as an electromagnetic oscilloscope.