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, 1990
Filed:
Sep. 02, 1988
Mirza A Beg, Lima, OH (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
A method of selectively isolating faulty channels in a parallel electric power system having at least two controllable AC power sources includes the steps of producing a DC content signal representative of the magnitude of DC voltage in an AC output of one of the power sources and producing a differential current signal representative of differential DC current flowing in connected phases of the power sources. The DC content and differential current signals are combined to produce an error signal which is used to control the operation of the first power source, thereby reducing the magnitude of DC voltage in its output. When the error signal exceeds a predetermined threshold level, a trip signal can be produced and used to selectively isolate a failed channel in the power system. Following isolation of the channels, the differential current signal is disabled such that the error signal is only representative of the DC content signal for split channel operation.