Self calibration by signal injection
US11538628B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 2020 |
| Grant date | Dec 27, 2022 |
| Priority date | — |
| Expiry date | Mar 26, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/66
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A current transformer (CT) for the purpose of, for example, current measurement, that uses a power line as a first coil and a second coil for measurement purposes, is further equipped with a third coil. Circuitry connected to the third coil is adapted to inject a known reference signal to the third coil of the CT. The injected reference signal, i.e., current, generates signals in the first and second coils of the CT. The signal generated in the second coil is compared using circuitry attached thereto to the reference signal. Based on the results, and the difference between the expected results and the actual results, updated calibration parameters are determined. These provide improved accuracy when using the CT, for example for measurement of the like of current or phase of the primary coil when measurements are adjusted using the newly determined calibration parameters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.