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:
Aug. 10, 2010
Filed:
Jun. 22, 2009
Gabriel Olguin, Santiago, CL;
Gabriel Olguin, Santiago, CL;
ABB Research Ltd., , CH;
Abstract
A signal injection unit injects a test signal at a main frequency between a reference point of an electric circuit and ground, where the electric circuit is connected with the facility and injects another test signal at a second main frequency between a reference point of the electric circuit and ground. A signal conversion unit measures first and second response voltages and first and second response currents in the electric circuit, where the response voltages and the response currents result from the test signals. A processing device determines impedances to ground of the facility from the response voltages and the response currents, analyses impedances to ground of the facility, where this analysing includes comparing each determined impedance to ground with a predetermined value, and determines a safety state of the disconnected electrical facility based on the analysed impedances to ground.