Fault current and differential current detection system capable of preventing spurious triggering of a protection system due to transient interference pulses
US6625551B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 2000 |
| Grant date | Sep 23, 2003 |
| Priority date | — |
| Expiry date | Feb 7, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H1/043
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A fault or differential current detection system is provided. The detection system detects a fault or differential current generated on a conductive path supplying power to an electric device and prevents the fault or differential current from being supplied to the electric device. The detection system comprises a detector, a switch, and a controller. The detector detects a detected current generated on the conductive path and outputs a corresponding detection signal. The controller inputs the detection signal and determines if the detected current is greater than or equal to a first predetermined current threshold based on the detection signal. Then, the controller refrains from outputting a control signal to the switch for a predetermined delay period after the detected current becomes greater than or equal to the first predetermined current threshold. Then, the controller determines if the detected current is greater than or equal to a second predetermined current threshold when the predetermined delay period is over. After the detected current becomes greater than or equal to the second predetermined current threshold, the controller determines if the detected current is a faul…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.