Methodology for protection of current transformers from open circuit burden
US8542469B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 2010 |
| Grant date | Sep 24, 2013 |
| Priority date | — |
| Expiry date | Dec 28, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/28
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A protected electrical power system may comprise a feeder between a power source and an electrical load. A first current transformer may be positioned on the feeder in a first location. The first current transformer may have a shunt resistor electrically connected across its winding. A second current transformer may be positioned at a second location on the feeder. A control unit may be interposed between the first and second current transformers and may be interconnected with the first and second current transformers on current-monitoring loops independent from the feeder. The control unit may be responsive to a predetermined differential in feeder (DF) current between the first and second current transformers to disconnect the power source from the electrical load. The control unit may have a compensation network for reducing DF error resulting from presence of the shunt resistor in the first current transformer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.