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:
Jul. 10, 2007
Filed:
Apr. 15, 2004
Joel R. Cannon, Minneapolis, MN (US);
William R. Ockert, Cathay, ND (US);
Robert Cox, Carrington, ND (US);
Kevin Allmaras, Carrington, ND (US);
Joel R. Cannon, Minneapolis, MN (US);
William R. Ockert, Cathay, ND (US);
Robert Cox, Carrington, ND (US);
Kevin Allmaras, Carrington, ND (US);
Cannon Technologies, Inc., Golden Valley, MN (US);
Abstract
A method for detecting line under frequency (LUF) events and initializing load shedding of loads located near the electrical disturbance without customer and utility intervention is disclosed. In one example embodiment, the LUF detection system measures the time period of each power line cycle and then compares the measured time period to a utility-configurable trigger period. If the cycle length is greater than or equal to the trigger period, a counter is incremented. If the cycle is less than the trigger period, the counter is decremented. If the counter is incremented to a counter trigger, an under-frequency condition is detected and the LUF response either controls the load or temporarily disconnects it. A restore response is initialized after the frequency rises above a restore value and an under-frequency counter counts down to zero.