Electronic circuit breaker using digital circuitry having instantaneous trip capability
US4943888A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 1989 |
| Grant date | Jul 24, 1990 |
| Priority date | — |
| Expiry date | Jul 10, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/0935
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Instantaneous trip capability is provided to an electronic circuit breaker, which is of the type that generates trip signals by accumulating squares of power line current samples and thresholds the accumulation results. Samples of power line current are taken directly from the current transformer and analog-to-digital converter cascade generating them. The analog-to-digital converter is of an oversampling type, using a delta-sigma modulator. The samples are threshold detected against a prescribed threshold value without previous squaring, integration and detection. The threshold detector result is checked for two consecutive overcurrent indications before an instantaneous trip signal is generated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.