EP 0809808 A1 19971203 - METHOD OF DETERMINING AN EARTH-FAULT CURRENT
Title (en)
METHOD OF DETERMINING AN EARTH-FAULT CURRENT
Title (de)
VERFAHREN ZUR ERFASSUNG EINES ERDSCHLUSSSTROMES
Title (fr)
PROCEDE DE DETERMINATION D'UN COURANT DE DEFAUT A LA TERRE
Publication
Application
Priority
- DE 9600255 W 19960209
- DE 19506860 A 19950215
Abstract (en)
[origin: DE19506860C1] A method of determining the earth-fault current (Ig) flowing in a multi-phase circuit (L1, L2, L3, N) is based on the use of standard current transformers with iron cores (W1, W2, W3, WN) for the phase conductors (L1, L2, L3) and neutral conductor (N). Allowance is made for the current-dependent linearity error (F(I)) of the current transformers (W1, W2, W3, WN) by subtraction of the product of the highest phase-current and associated error (F*Imax) from the vectorial sum ( SIGMA I) of the currents. This results in a one-sided position of the tolerance band of the measured earth-fault current and prevents spurious tripping.
IPC 1-7
IPC 8 full level
G01R 31/02 (2006.01); G01R 19/00 (2006.01); H02H 1/04 (2006.01); H02H 3/347 (2006.01)
CPC (source: EP US)
G01R 19/0092 (2013.01 - EP US); H02H 1/046 (2013.01 - EP US); H02H 3/347 (2013.01 - EP US)
Citation (search report)
See references of WO 9625671A1
Designated contracting state (EPC)
DE FR IT
DOCDB simple family (publication)
DE 19506860 C1 19960808; EP 0809808 A1 19971203; JP H10513567 A 19981222; US 6005393 A 19991221; WO 9625671 A1 19960822
DOCDB simple family (application)
DE 19506860 A 19950215; DE 9600255 W 19960209; EP 96902869 A 19960209; JP 52458196 A 19960209; US 89419297 A 19971218