Craig S Eid

US Patent:

20120019962, Jan 26, 2012

Filed:

Jul 19, 2011

Appl. No.:

13/185858

Inventors:

Frederick R. Faxvog - Long Lake MN, US
Wallace Jensen - Centerville MN, US
Terrance R. Noe - Sebastopol CA, US
Craig Eid - Santa Rosa CA, US
David Blake Jackson - Excelsior MN, US
Greg Fuchs - River Falls WI, US
Gale Nordling - Excelsior MN, US

International Classification:

H02H 1/00
H03K 5/00

US Classification:

361 1, 327551, 327557, 327558

Abstract:

Systems and method for detecting potentially harmful harmonic and direct current signals at a transformer are disclosed. One such system includes a plurality of detection components electrically connected to electrical signal lines leading from one or more connection points on a power grid, and a plurality of threshold detectors, each threshold detector configured to compare an incoming signal from a detection component to a predetermined signal having a threshold. The system also includes a controller receiving an output from each of the plurality of threshold detectors and configured to drive at least one external component in response to receiving an indication from at least one of the plurality of threshold detectors of a detected signal above a threshold.

US Patent:

20130308229, Nov 21, 2013

Filed:

May 21, 2013

Appl. No.:

13/899078

Inventors:

WALLACE JENSEN - Centerville MN, US
TERRANCE R. NOE - Sebastopol CA, US
CRAIG EID - Santa Rosa CA, US
DAVID BLAKE JACKSON - Excelsior MN, US
GREG FUCHS - River Falls WI, US
GALE NORDLING - Excelsior MN, US

International Classification:

H02H 7/04

US Classification:

361 35

Abstract:

Systems and method for detecting potentially harmful harmonic and direct current signals at a transformer are disclosed. One system includes a protection circuit electrically connected to a transformer neutral, the transformer electrically connected to a power grid, the protection circuit including a DC blocking component positioned between the transformer neutral and ground and one or more switches selectively actuated to form a path between the transformer neutral and ground in the event of unwanted DC current at the transformer neutral. The system also includes a control circuit electrically connected to the protection circuit and positioned to selectively actuate the switches based on observed conditions within the protection circuit. The system further includes a plurality of test connections disposed within the protection circuit and useable to test electrical properties of the protection circuit.

US Patent:

20150311697, Oct 29, 2015

Filed:

Jul 6, 2015

Appl. No.:

14/792211

Inventors:

- St. Louis Park MN, US
WALLACE JENSEN - Centerville MN, US
TERRANCE R. NOE - Sebastopol CA, US
CRAIG EID - Santa Rosa CA, US
DAVID BLAKE JACKSON - Excelsior MN, US
GREG FUCHS - River Falls WI, US
GALE NORDLING - Excelsior MN, US

International Classification:

H02H 3/52
H02H 3/16

Abstract:

Systems and methods for protecting an electrical component in an alternating current system that includes a transformer are disclosed. In one aspect, a circuit includes a switch assembly connected between a transformer neutral of a transformer and a ground and having an open position and a closed position. In normal operation, the switch remains in a closed position. The circuit further includes a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground, a voltage probe connected between the transformer neutral and ground and configured to monitor an instantaneous voltage level at the transformer neutral, and a control circuit configured to control the switch assembly, the control circuit including a sensor configured to actuate the switch assembly to an open position at least upon detection of a harmonic signal in at least one phase of the transformer or a predetermined threshold of DC or quasi DC current between the transformer neutral and the ground.