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:
Apr. 26, 2016
Filed:
Sep. 30, 2009
Ryan M. Tumilty, Glasgow, GB;
Adam Dysko, Motherwell, GB;
Graeme Burt, Johnstone, GB;
Alstom Technology Ltd., Baden, CH;
Schneider Electric Energy UK Ltd., Leeds, GB;
Abstract
A phase angle drift method for loss of mains/grid protection is disclosed. According to one aspect, an accumulated electrical phase angle drift derived from the difference between the current measured local frequency and the estimated frequency using historical data is compared to an angle threshold. An estimated grid frequency may be calculated based on the historical delay, and the window, over which the estimated frequency is calculated. An addition/subtraction of a phase angle offset value is calculated for a half cycle is performed when the frequency difference between the estimated frequency fand the measured frequency fis greater or equal to a first determined value.