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:
Nov. 24, 1981
Filed:
Jun. 15, 1979
Thomas H Putman, Penn Hills, PA (US);
Donald G Ramey, Churchill Borough, PA (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
This concerns a compensator for electrical lines fed by a turbine-generator. The mechanical properties of the turbine-generator are such that modulation of the terminal voltage is possible due to subsynchronous mechanical torsional oscillations. If the carrier frequency or synchronous frequency of the generator minus the torsional oscillation frequency is equal to the resonant frequency of the electrical line driven thereby, a relatively large side band current may flow in the electrical line at the resonant frequency. The effect of this current may feedback through the air gap of the generator to increase the torsional oscillation. A boot strapping effect between the electrical properties of the line and the torsional oscillation may thus result which could ultimately end in shaft breakage. The present apparatus utilizes the torsional oscillation signal to modulate compensating inductance connected in parallel between the lines of the electrical system to thus generate a small current at the appropriate electrical resonance frequency. This current leads to the production of a compensating line current at that frequency which in turn opposes the previously described undesirable effect.