Circuit breaker failure relay system for power transmission line systems
US5157575A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 1991 |
| Grant date | Oct 20, 1992 |
| Priority date | — |
| Expiry date | May 13, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A breaker failure relay circuit is responsive to either a trip signal from a protective relay or a manual trip signal, as well as the current through a circuit breaker protecting a transmission line. The trip signal is applied to an edge triggered timer (28) having selected pickup and dropout times, and is also applied as one input to one OR gate (24). The circuit breaker current is applied to an overcurrent element (34), the output of which is applied to a reset input of the edge triggered timer (28) to reset and disable the timer and also as one input to another OR gate (30). The other input to OR gate (30) is the output of the edge triggered timer (28). The outputs of OR gates (24, 30) are applied to an AND gate (26), the output of which is applied to a second timer (32) and as another input to the one OR gate (24). The output of the timer (32), if and when it occurs, is used as a trip signal for a backup circuit breaker.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.