Method and apparatus for monitoring faults by means of a polygonal trigger region
US4249124A · kind A · utility
7Cited by
4References
9Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 27, 1978 |
| Grant date | Feb 3, 1981 |
| Priority date | — |
| Expiry date | Mar 27, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/382
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of, and apparatus for, monitoring faults at electrical lines, wherein there are formed a multiplicity of detection signals, and threshold monitoring the phase angle between timewise successive detection signals. According to a first aspect of the invention none of the detection signals has a magnitude equal to the line voltage signal. As a further aspect one of the detection signals can comprise an external signal. A still further feature contemplates that one of the detection signals is a difference signal formed by the line voltage signal and an external signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.