Protective relaying system
US4511981A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1982 |
| Grant date | Apr 16, 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 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 input conversion unit adapted for connecting the electric power system to receive a first and a second input signals corresponding to the current and the voltage and for converting the magnitude and/or the phase of the first and second input signals to produce a first, a second and a third electrical quantities. The protective relaying system also includes comparing unit connected to receive the first, second and third electrical quantities, for comparing the first and second electrical quantities to produce a first logical state signal, and comparing the third and a fourth electrical quantities to produce a second logical state signal cyclically, and for producing a logical state signal including the first and second logical state signals cyclically. The protective relaying system further includes digital data processing unit connected to receive cyclically the logical state signal, for producing a first and a second serial logical state signals and for judging whether a phase-…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.