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:
Jun. 23, 1981
Filed:
Oct. 12, 1979
Larry L Church, Washington Twnp., Fayette County, PA (US);
Shan C Sun, Bell Twnp., Westmoreland County, PA (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
Pilot protective relay apparatus for high-voltage, three-phase alternating current transmission lines which provides the functions of an electromechanical pilot-wire protective relay, without the necessity of having a continuous, metallic conductor connected between the points to be compared. The protective relay apparatus is completely solid state, making trip decisions based upon three separate comparisons of the near and far line current conditions represented by line current derived single-phase voltage signals. The three comparisons indicate the magnitude of the phasor difference, the magnitude of the phase angle, and the relative average absolute magnitudes.