Method and apparatus for fault detection in a three-phase electric network
US3958153A · kind A · utility
8Cited by
5References
14Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 14, 1974 |
| Grant date | May 18, 1976 |
| Priority date | — |
| Expiry date | May 14, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/353
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The voltage-to-ground or neutral of one phase conductor of a three-phase line is compared with the mesh or interphase voltage of the other two phases on an amplitude basis and the comparison result is used to trigger a threshold switch if the former is much smaller than the latter. The threshold switch may be connected to the selector of an excitation system of a network protection assembly or a nonselective excitation system may utilize the outputs of the threshold switches for each of the three comparisons, in order to produce selective triggering of a network protection assembly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.