Systems for detecting faults in electric power systems
US4281386A · kind A · utility
24Cited by
2References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 1, 1979 |
| Grant date | Jul 28, 1981 |
| Priority date | — |
| Expiry date | Aug 1, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/58
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The method and the system are for detecting a current I and a voltage V of the electric power system and judging that there is fault if: EQU .vertline.V-I.epsilon..sup.j.phi. .vertline.V.vertline./.vertline.I.vertline..vertline.<k.sub.o is fulfilled, where k.sub.o represents a constant and I.epsilon..sup.j.phi. an electrical quantity obtained by shifting the current I by a predetermined angle .phi.. In a modified form, the expression EQU .vertline.V-I.epsilon..sup.j.phi. X.vertline.<k.sub.o is used, where X equals to .vertline.V.vertline./.vertline.I.vertline. or Z (a predetermined line impedance) whichever is smaller.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.