Apparatus for sensing current transformer primary current as a function of differential core inductance
US4276510A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 1979 |
| Grant date | Jun 30, 1981 |
| Priority date | — |
| Expiry date | May 16, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/33
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The secondary winding of a current transformer is driven by a high frequency AC source to excite the core to alternating, uniformly equal positive and negative peaks of current excitation. An inductance sensor alternately senses the secondary winding inductances at corresponding points adjacent the positive and negative peaks of the flux wave generated in the core. Any difference in these inductances is a function of low frequency primary current and is utilized to develop a current flowing through a tertiary core winding to equalize these inductances. This tertiary winding current thus becomes a precise measure of the primary current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.