Method and apparatus for monitoring the loss factor of capacitor bushings
US11125801B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 2018 |
| Grant date | Sep 21, 2021 |
| Priority date | — |
| Expiry date | Jul 26, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01G4/35
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method monitors capacitor bushings for an AC mains. The mains has first-third phases, associated with first-third mains lines, capacitor bushings, and mains voltages. Each capacitor bushing has a conductor, surrounded by foil, connecting its mains line. The method includes: at a first instant, for each phase: a first reference voltage phasor is determined; and a foil voltage present between the respective foil and ground potential is detected and a corresponding first foil voltage phasor is determined; at a second instant, for each of the phases: a second reference voltage phasor is determined; the foil voltage is detected and a second foil voltage phasor is determined; for each capacitor bushing: a loss factor change is calculated based on the respective reference voltages and foil phasors and those of the adjacent capacitive bushing; and a monitoring signal is generated based on a comparison of the loss factor and a tolerance value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.