US 12,355,230 B2
Residual current monitoring for a DC voltage switching device
Tobias Grote, Lüdge (DE); and Lutz Heuer, Blomberg (DE)
Assigned to Phoenix Contact GmbH & Co. KG, Blomberg (DE)
Appl. No. 18/576,685
Filed by Phoenix Contact GmbH & Co. KG, Blomberg (DE)
PCT Filed Jul. 3, 2022, PCT No. PCT/EP2022/068359
§ 371(c)(1), (2) Date Jan. 4, 2024,
PCT Pub. No. WO2023/280730, PCT Pub. Date Jan. 12, 2023.
Claims priority of application No. 2021/5520 (BE), filed on Jul. 5, 2021.
Prior Publication US 2024/0266819 A1, Aug. 8, 2024
Int. Cl. H02H 3/10 (2006.01); G01R 15/20 (2006.01); G01R 19/10 (2006.01)
CPC H02H 3/10 (2013.01) [G01R 15/202 (2013.01); G01R 19/10 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method for fault current monitoring when electrically coupling a direct voltage load via a direct voltage branch that comprises a positive conductor and negative conductor to a direct voltage source, the method comprising:
using only a single sensor for a detection of a fault current in the direct voltage branch by:
detecting a magnetic field by the single sensor, wherein the magnetic field is formed overall around the positive conductor and negative conductor for detecting a differential current across positive and negative conductors and in terms of amount, wherein a magnetic field of substantially zero value is detected when there is no fault current and a non-zero magnetic field is detected when there is a fault current,
comparing the detected magnetic field with respect to a threshold value; and
as soon as the fault current to be monitored leaves a permissible range in such a way that the differential current in terms of amount in positive conductor and negative conductor passes a predetermined value and the detected magnetic field accordingly passes the threshold value, activating a switching element for disconnecting the direct voltage load.