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. 01, 2009
Filed:
Oct. 08, 2004
Ralph W Folkers, Pullman, WA (US);
Jeffrey B Roberts, Viola, ID (US);
Edmund O Schweitzer, Iii, Pullman, WA (US);
Armando Guzman-casillas, Pullman, WA (US);
Gabriel Benmouyal, Longueuil, CA;
Ralph W Folkers, Pullman, WA (US);
Jeffrey B Roberts, Viola, ID (US);
Edmund O Schweitzer, III, Pullman, WA (US);
Armando Guzman-Casillas, Pullman, WA (US);
Gabriel Benmouyal, Longueuil, CA;
Schweitzer Engineering Laboratories, Inc., Pullman, WA (US);
Abstract
Provided is a compensated inverse-time undervoltage load shedding system and method for use in an electrical power system. The compensated inverse-time undervoltage load shedding system includes a compensation element for determining a compensated value and an inverse-time undervoltage element operatively coupled to the compensation element and enabled based on the compensated value. When enabled, the inverse-time undervoltage element calculates a load shedding time delay value based on the compensated value, and determines a load shedding signal based on the load shedding time delay value. An associated load of the electrical power system is shed based on the load shedding signal. The compensation element may determine the compensated value using a voltage magnitude, a rate-of-change of power system voltage over time, a weighted rate-of-change of power system voltage over time, a current magnitude, a weighted current magnitude, and an impedance phasor value, to name a few.