Current summing arrangement for ground fault detection

DETAILED DESCRIPTION The present invention provides an arrangement for producing a signal representative of the sum of signals representative of electrical currents in an electrical power system of the type including at least a first electrical conductor and a second electrical conductor.
The arrangement includes first means, linkable by magnetic flux to the first electrical conductor, for producing a first magnetic field representative of a first current in the first electrical conductor, and second means, linkable by magnetic flux to the second electrical conductor, for producing a second magnetic field representative of a second current in the second electrical conductor.
A signal means produces a signal representative of the sum of the first and second magnetic fields, where the first and second magnetic fields induce a signal current in the signal means representative of the sum of the first and second magnetic fields.
The present invention further provides an arrangement for producing a signal representative of the signals representative of the currents in an electrical power system of the type including at least a first electrical conductor and a second electrical conductor.
The arrangement includes a first winding disposed about the first electrical conductor to produce a first current in the first winding, and a second winding disposed about the second electrical conductor to produce a second current in the second winding.
The first current is representative of a current in the first electrical conductor and the second current is representative of a current in the second electrical conductor.
A third winding is disposed about one conductor of each of the first and second windings to produce a third current in the third winding representative of the sum of the currents in the first and second electrical conductors.
The present invention further provides an arrangement for summing signals representative of the currents in first, second, third and neutral phase conductors.
The arrangement includes first, second, third and neutral windings disposed about the first, second, third and neutral phase conductors respectively, to produce first, second, third and neutral currents in the first, second, third and neutral windings respectively