Protective relaying system
US4507700A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1982 |
| Grant date | Mar 26, 1985 |
| Priority date | — |
| Expiry date | Sep 29, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/40
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A protective relaying system is disclosed which detects a fault in an electric power system having a circuit breaker by using a current and a voltage of the electric power system. The protective relaying system includes an input conversion/unit adapted to receive a first and a second input signals corresponding to said current and voltage, for converting the magnitude and/or the phase of the first and second input signals to produce least two electrical quantities a first electrical quantity and a third electrical quantity, and for outputting the second input signal without conversion as a second electrical quantity. The protective relaying system also includes a comparing unit connected to receive first, second and third electrical quantities from the input conversion unit for comparing the first and second electrical quantities to produce a first logical state and comparing the third and fourth electrical quantities to produce a second logical state signal cyclically. The protective relaying system further includes a digital data processing unit for judging whether a specified logical condition between the first and second logical state signals holds for a predetermined number of…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.