Title: Monitoring system for high-voltage switch gears
Application Number: 200610140319 Application Date: 2006.11.27
Publication Number: 1976147 Publication Date: 2007.06.06
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H02B13/065
Applicant(s) Name: ABB Technology AG Address:
Inventor(s) Name: Hagel Marek;Fehlmann Patrick
Attorney & Agent: yangsheng beng yanggong mei
Abstract:
    The present invention relates to a method and an apparatus for measuring contact erosion in an electrical switching device by a dynamic resistance measurement DRM. Acording to the present invention, to determine an overlap time and a contact erosion in an exemplary switching device, a change in current across the switching device can be measured indirectly by a measurement current being passed across the switching device and a parallel conductor, the change in current in the parallel conductor being measured. Other exemplary embodiments relate to the following: detection of a differential current measurement signal in the parallel conductor with the aid of a Rogowski coil; and selection of a parallel conductor resistance on an order of the switch resistance. Its merits include: even in relatively low measurement current of several A, the small change of the switch resistance in mu Omegea, results in big current change in several mA. As a result, a portable handheld DRM measurement device is provided.
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