Invention Grant
- Patent Title: Method and arrangement for monitoring the bearing currents in an electrical machine
- Patent Title (中): 用于监测电机轴承电流的方法和装置
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Application No.: US13055818Application Date: 2009-07-21
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Publication No.: US08610591B2Publication Date: 2013-12-17
- Inventor: Hans-Richard Kretschmer , Arno Steckenborn , Oliver Theile
- Applicant: Hans-Richard Kretschmer , Arno Steckenborn , Oliver Theile
- Applicant Address: GE München
- Assignee: Siemens Aktiengesellschaft
- Current Assignee: Siemens Aktiengesellschaft
- Current Assignee Address: GE München
- Agency: Henry M. Feiereisen LLC
- Priority: DE102008035613 20080725
- International Application: PCT/EP2009/059341 WO 20090721
- International Announcement: WO2010/010081 WO 20100128
- Main IPC: G01R27/26
- IPC: G01R27/26

Abstract:
The invention inter alia relates to a method for monitoring the bearing current of an electrical machine (10). An electrode (100) arranged at a distance (d) to a shaft and the shaft—due to the gap (S) between the electrode and the shaft—produce a measurement capacitance (C) and an electric shift current (i) which flows through the measurement capacitance when there is a temporal change of the voltage (Ug) applied between the shaft and the housing is measured. A measurement signal (Ms) indicating a bearing current flow is generated when the shift current or a measurement variable produced by the shift current meets a predetermined trigger criterion. Preferably, the electrode has a circular inner contour so that the gap is annular. The annular inner contour results in an error compensation in the case of a balance error of the shaft because the factor dC/dt remains at least substantially constant. Due to the contactless measurement of the shift current, no contact brushes for contacting the shaft are required. The method can be used irrespective of whether the bearings are insulated from the machine housing or not.
Public/Granted literature
- US20110175631A1 METHOD AND ARRANGEMENT FOR MONITORING THE BEARING CURRENTS IN AN ELECTRICAL MACHINE Public/Granted day:2011-07-21
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