Method and a system for analyzing the secondary current in a current transformer, the primary side of which is connected into a line of an electric energy supply network
US4511839A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 1983 |
| Grant date | Apr 16, 1985 |
| Priority date | — |
| Expiry date | Mar 22, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H1/046
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to a method and a system for analyzing the secondary current (J.sub.2) of a current transformer (20), the primary side of which is connected into a line (10) of an electric energy supply network. When the current transformer (20) is saturated as the result of a short-circuit on the line (10), a saturation signal (X) indicating this saturation and a polarity signal (P) indicating the polarity of the displacement of the short-circuit current (J.sub.1) are generated. The two signals (X, P) are used to select zero transitions of the secondary current (J.sub.2), corresponding to the polarity of the displacement of the short-circuit current (J.sub.1). After the selected zero-transitions, the secondary current (J.sub.2) is extrapolated by a current signal (C), in accordance with its saturation-free curve-shape. The current signal (C) is finally supplied to protective systems, instead of the secondary current (J.sub.2).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.