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. 17, 1980
Filed:
Nov. 08, 1978
Shan C Sun, Bell Township, Westmoreland County, PA (US);
Larry L Church, Washington Township, Fayette County, PA (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
Protective relay apparatus which includes monitoring and detecting functions related to subsynchronous currents in a three-phase electrical power system. The monitoring function provides signals related to the positive sequence component of any subsynchronous current flowing at a monitored subsynchronous frequency. The detecting function is responsive to the signals provided by the monitoring function, distinguishing between subsynchronous currents due to self-excited oscillations, and those due to transient oscillations, to provide a timely trip signal for a circuit breaker in either instance.