Method of detecting ground faults in a network for distribution of electric power and a device for carrying out the method
First Claim
1. Device for detecting ground faults in networks for distribution of electric power from a power station from which a number of lines, included in the network, emanate and where the active ground fault current IJR of each line is measured, comprising means for selecting the line having the greatest active ground fault current IJR, means for comparing the measured active ground fault current in the selected line with at least one predetermined reference value, and means for producing a fault-indicating output signal with said measured active ground fault current exceeding the reference value.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and a device for detecting ground faults in a network for distribution of electric power from a power station from which a number of lines, included in the network, emanate and where the ground fault current IJ of each line is measured. According to this method, that line is selected (10) which shows the greatest active ground fault current IJR (8), alternatively the greatest ground fault current IJ, or the greatest change in the ground fault current ΔIJ. Thereafter, the measured ground fault current, or the change thereof, in the selected line is compared (12) with at least one predetermined reference value (11). A fault indication is obtained (13) at a level exceeding the reference value.
-
Citations
26 Claims
- 1. Device for detecting ground faults in networks for distribution of electric power from a power station from which a number of lines, included in the network, emanate and where the active ground fault current IJR of each line is measured, comprising means for selecting the line having the greatest active ground fault current IJR, means for comparing the measured active ground fault current in the selected line with at least one predetermined reference value, and means for producing a fault-indicating output signal with said measured active ground fault current exceeding the reference value.
-
5. Method of detecting ground faults in networks for distribution of electric power from a power station from which a number of lines, included in the network, emanate by measuring the ground fault current IJ for each line,
selecting the line having the greatest ground fault current IJ, comparing the measured ground fault current in the selected line with at least one predetermined reference value, and deriving a fault indication at a level exceeding the reference value.
-
9. Device for detecting ground faults in networks for distribution of electric power from a power station from which a number of lines, included in the network, emanate and where the ground fault current IJ of each line is measured, comprising means for selecting the line having the greatest change Δ
- IJ in ground fault current, means for comparing the change in ground fault current Δ
IJ in the selected line with at least one predetermined reference value, and means for producing a fault-indicating output signal with said measured change in the ground fault current exceeding said reference value. - View Dependent Claims (10, 11, 12)
- IJ in ground fault current, means for comparing the change in ground fault current Δ
- 13. Device for detecting ground faults in networks for distribution of electric power from a power station from which a number of lines, included in the network, emanate and where the ground fault current IJ of each line is measured, comprising means for selecting the line having the greatest ground fault current IJ, means for comparing the measured ground fault current in the selected line with at least one predetermined reference value, and means for producing a fault-indicating output signal with said measured ground fault current exceeding the reference value.
-
20. Method of detecting ground faults in networks for distribution of electric power from a power station from which a number of lines, included in the network, emanate by measuring the ground fault current IJ for each line,
selecting the line having the greatest change Δ - IJ in the ground fault current IJ,
comparing the change Δ
IJ in measured ground fault current in the selected line with at least one predetermined reference value, andderiving a fault indication at a level exceeding the reference value. - View Dependent Claims (21, 23, 24, 25)
- IJ in the ground fault current IJ,
-
22. Method of detecting ground faults in networks for distribution of electric power from a power station from which a number of lines, included in the network, emanate by measuring the active ground fault current IJR for each line,
selecting the line having the greatest active ground fault current IJR, comparing the measured active ground fault current in the selected line with at least one predetermined reference value, and deriving a fault indication at a level exceeding the reference value.
Specification