Distance protection apparatus for electrical lines
US4268886A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 20, 1978 |
| Grant date | May 19, 1981 |
| Priority date | — |
| Expiry date | Sep 20, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
By switching-in a trip boundary, which excludes the load range in the complex impedance plane, of a directed or non-directed end or final stage of a measuring system of a distance protection apparatus, it is possible to eliminate faulty or spurious triggering of the protection apparatus, notwithstanding a possible improper excitation. The functional reliability of the protection apparatus is thus improved and there is possible monitoring of fault functions where, in each case, there is logically coupled a "yes" or "no"-type output response of the measuring system with a "no" or "yes"-type excitation output by means of appropriate and comparison logic circuitry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.