Testing of current transformers
US7030602B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 2004 |
| Grant date | Apr 18, 2006 |
| Priority date | — |
| Expiry date | Jun 25, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/62
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for evaluating the accuracy of a current transformer is presented. The current transformer has a primary winding and a secondary winding. A current is not circulated through the primary winding. A load is disconnected from the current transformer. A load impedance is measured of an internal instrumentation associated with the current transformer. The resistance in the secondary winding of the current transformer is determined. The load impedance is compared to a standard burden. A standard burden value is selected. The secondary voltage for a rated current is determined. The injection voltage is adjusted to the value of the secondary voltage. The exciting current and power are measured. The ratio error or the phase angle are then calculated by using the exciting current and power.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.