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:
Aug. 27, 1985
Filed:
Feb. 22, 1984
Walter A Elmore, Coral Springs, FL (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
A current differential pilot protective relay apparatus for multi-terminal high-voltage, three-phase alternating current transmission lines. The pilot protective relay system provides comparison, at each terminal of the transmission line, of the currents flowing on each phase of the three-phase transmission line at each terminal thereof. A novel scheme of summing the current-derived signals at one terminal reduces the number of receivers and transmitters necessary to send the local signal from each terminal to all of the other terminals. Instead, the current-derived signals are summed at one of the terminals and the sum signal is then transmitted to each of the other terminals.