Electrical protective device and method for selective disconnection of a subsystem in case of a second fault in an IT power supply system
US9929558B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 13, 2015 |
| Grant date | Mar 27, 2018 |
| Priority date | — |
| Expiry date | Jun 7, 2036 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY04S10/52
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electrical protective device (20) and method are for selective disconnection of a subsystem (6a, 6b) in the event of a second fault in an ungrounded power supply system (2) with a main system (4) and at least one subsystem (6a, 6b), the subsystem (6a, 6b) having a differential current measuring device (12a, 12b) and a switching device (14a, 14b) for separating the subsystem (6a, 6b). The invention is based on generating and applying a measuring signal voltage (Um) between one or more phase(s) of the main system (4) or from a neutral point of the main system (4) against ground (9) using a resonant coupling circuit (22) that has a measuring signal generator (24) and a series resonant circuit (26) connected in series to the measuring signal generator (24), a resonant frequency (f0AK) of the series resonant circuit (26) being set to correspond to the measuring signal frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.