Method and apparatus for monitoring capacitor bushings for a three-phase AC system
US9759761B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 11, 2014 |
| Grant date | Sep 12, 2017 |
| Priority date | — |
| Expiry date | Nov 11, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R15/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A three-phase alternating current mains has capacitor bushings that each have a conductor connected with one of the mains lines of the alternating current mains and an electrically conductive lining surrounding the conductor. These bushings are monitored by first determining an upper capacitance and a lower capacitance for each bushing and then detecting a measured voltage between the respective lining and a ground potential at each capacitor bushing. An actual capacitance for each capacitor bushing is calculated that depends on the respective measured voltage and the respective lower capacitance as well as on the measured voltage, the lower capacitance, and the upper capacitance of one of the other capacitor bushings. For each capacitor bushing the respective upper capacitance is compared with the respective actual capacitance and a monitoring signal is generated that is dependent on the results of the capacitance comparison.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.