Electrical network protection device with automatic switch over between protection criteria
US3938007A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 1974 |
| Grant date | Feb 10, 1976 |
| Priority date | — |
| Expiry date | May 23, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/26
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A distance protection device and an overcurrent protection device are coupled to a circuit breaker means of the network being protected by means of a logic system which enables the circuit breaker means to be activated by one of the two protection devices as a function of at least one signal derived from the network being protected, the at least one signal being also used in determining faults in at least one of the two protection devices. The logic system is activated by, for example, the at least one signal falling below a set minimum value. The result is the automatic change of function between distance and overcurrent protection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.