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:
Jun. 07, 2022
Filed:
Apr. 25, 2018
Mitsubishi Electric Corporation, Tokyo, JP;
Kazuma Murata, Tokyo, JP;
Shigetoo Oda, Tokyo, JP;
MITSUBISHI ELECTRIC CORPORATION, Tokyo, JP;
Abstract
A protection relay comprises a digital processing unit including: a first filter to eliminate a DC component in the time-series data, the first filter having a first window length; a second filter to eliminate a DC component in the time-series data, the second filter having a second window length shorter than the first window length; and a coefficient calculation unit to multiply an amplitude value of an output signal of the first filter and an amplitude value of an output signal of the second filter by first and second coefficients respectively, and integrate multiplication results. An operation determination is performed based on an output of the coefficient calculation unit. The first coefficient is decreased and the second coefficient is increased when a failure of the power system is detected, and thereafter, the first coefficient and the second coefficient are changed with a lapse of time.