Protective device for a load connected to a power supply line of an electric power system
US4672523A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 22, 1986 |
| Grant date | Jun 9, 1987 |
| Priority date | — |
| Expiry date | Apr 22, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/44
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a protective device for a load connected to a power supply line of an electric power system, comprising an LC network having low-pass characteristics, connected into the power supply line on the system side preceding the load. So that disturbances with frequencies below the cut-off frequency of the LC network can also be kept away from the load, a switching element controlled by a monitoring device is arranged according to the invention in series with the LC network in the power supply line. The monitoring device is connected to the power supply line on the system side at a junction preceding the switching element and keeps the switching element closed only for as long as the instantaneous value of the time derivation of the voltage on the power supply line deviates from the instantaneous value of a nominal value which is predeterminable in its variation with time, by no more than an equally predeterminable amount.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.