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:
Aug. 04, 1998
Filed:
Oct. 17, 1995
Applicant:
Inventors:
Jeffrey B Roberts, Moscow, ID (US);
Daqing Hou, Pullman, WA (US);
Assignee:
Schweitzer Engineering Laboratories, Inc., Pullman, WA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
364492 ; 361 80 ; 361 65 ; 361 79 ;
Abstract
At least two different time constants are used to produce the polarizing memory reference voltage which in turn is used in a protective relay for power transmission lines. For most conditions, a relative short time constant of 1.75 cycles is used, while under other specific conditions, determined automatically, a longer time constant of 15.75 cycles is used.