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:
Feb. 27, 1996
Filed:
Nov. 22, 1994
David J Mrowiec, Rockford, IL (US);
Jef W Good, Beloit, WI (US);
Sundstrand Corporation, Rockford, IL (US);
Abstract
A system of protection for an electric power generating system having a poly-phase generator switchably coupled through a generator control breaker to a load distribution bus, wherein the generator output voltage is controlled by a generator control unit which utilizes isolated voltage and current sense signals having a magnitude proportional to the output voltage and current for each phase of the poly-phase generator, the isolated voltage and current sense signals being generated by isolated voltage and current sensors, comprises a first circuit for monitoring the magnitude of each of the isolated voltage sense signals and generating a first output control signal if the magnitude of any isolated voltage sense signal is below a first predetermined threshold. The system further comprises a second circuit for monitoring the magnitude of each of the isolated current sense signals and generating a second output control signal if the magnitude of any isolated current sense signal is below a second predetermined threshold. A logic circuit is included which is responsive to the first and the second control signals, and to the generator control breaker for generating a protective trip signal for de-exciting the generator and opening the generator control breaker. Preferably, this signal is delayed for a predetermined period of time which is set to a value based on maximum generator output voltage and applicable standards for abnormal voltage transients to ensure that the standards are not exceeded by the maximum generator output voltage.