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. 03, 1989
Filed:
Dec. 11, 1987
Eddy So, Gloucester, CA;
Canadian Patents and Development Limited, Ottawa, CA;
Abstract
A current-comparator technique for obtaining a load loss standard with adjustable loss tangent (or power factor) for in-situ calibration of transformer loss measuring system is described. The load loss standard, driven by the test voltage through a low-loss high-voltage compressed-gas-dielectric reference capacitor, simulates an inductive load which can be operated with load currents of up to 1000 A. For a 500 kV reference capacitor and a load current of 1000 A, the load loss standard simulates an equivalent inductive load with a rating of 500 MVA. Adjustment of the loss tangent (or power factor) is achieved by comparing the load current, using the current comparator, with in-phase and quadrature reference currents derived from the test voltage.