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.

Date of Patent:
Jul. 28, 2015

Filed:

Feb. 20, 2012
Applicants:

Lixiang Wei, Whitefish Bay, WI (US);

Zhijun Liu, Menomonee Falls, WI (US);

Inventors:

Lixiang Wei, Whitefish Bay, WI (US);

Zhijun Liu, Menomonee Falls, WI (US);

Assignee:

Rockwell Automation Technologies, Inc., Mayfield Heights, OH (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01R 31/00 (2006.01); G01R 31/42 (2006.01); G01R 31/02 (2006.01);
U.S. Cl.
CPC ...
G01R 31/42 (2013.01); G01R 31/025 (2013.01);
Abstract

The present techniques include methods and systems for detecting a high resistive ground fault condition in an HRG system. Embodiments include systems and methods of measuring drive voltages and detecting voltage changes in the drive once the drive is in operation, particularly for drives operating at relatively low voltages and frequencies. In some embodiments, an integrator is utilized to detect peaks in the measured voltage changes. Relatively small ground currents are also measured to determine HRG faults. Moreover, in some embodiments, the detection of an HRG fault for one of several motor drives provide indication for the particular motor drive in fault.


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