Dc leakage current detector and method of operation thereof for leakage current detection in dc power circuits

Abstract

The DC leakage current detector for detecting leakage current in a DC bus includes a pair of transformers each comprising a magnetic core and excitation and detection windings would about the magnetic core, with the magnetic core positionable about a pair of conductors that create a magnetic field that is a sum of currents in the conductors. An excitation and biasing circuit is connected to the excitation winding in each transformer to inject a current signal thereto that creates a changing magnetic flux in the core of each transformer and a detector output connected to the detection winding in each transformer to receive a voltage therefrom generated responsive to the magnetic flux in the core of each transformer, wherein the voltage on the detection windings provides a net voltage at the detector output whose value is indicative of a presence of a leakage current on the DC bus.