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:
Sep. 25, 2018
Filed:
Nov. 09, 2016
Rolls-royce Plc, London, GB;
Vaiyapuri Viswanathan, Singapore, SG;
Sivakumar Nadarajan, Singapore, SG;
Amit K. Gupta, Singapore, SG;
ROLLS-ROYCE plc, London, GB;
Abstract
A rectifier diode failure detection apparatus for an electrical machine (), the electrical machine () comprising an exciter armature winding (-), a rotor main field winding () and first and second rectifiers () arranged in parallel, each rectifier () comprising at least first and second diodes (), each rectifier being configured to independently supply the rotor main field winding () with DC electrical current, the failure detection apparatus comprising: a controller () comprising at least two current sensors (), each current sensor () being configured to measure output current (I, I) of a respective one of the rectifiers (), and the controller () being configured to determine a harmonic of the measured rectifier output currents; the controller () being further configured to determine a ratio of the magnitude of the first rectifier () output current harmonic to the magnitude of the second rectifier () output current harmonic, wherein the controller () is configured to determine that a fault has occurred in one of the rectifier diodes () where the ratio exceeds a threshold value.