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:
May. 10, 1994
Filed:
Jul. 01, 1993
Mitsuhiro Kawamura, Nagasaki, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An apparatus for measuring the electrical time constant of the quadrature-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 maintains a constant value. A current induced on a quadrature-axis damper diminishes at a rate determined by the quadrature-axis damper time constant, and this decreasing current and the constant armature current flow inside the synchronous machine to produce a constant resistance drop by resistance of the armature windings and the armature current. In this time, the length of time length until the voltage waveform falls to a prescribed level is measured as the time constant of the quadrature-axis damper with such a measuring device as an electromagnetic oscilloscope.