Patent ID: 9684017
Date: 2017-06-20
CPC Classifications: G01R

Claim:
1. Current measurement device for measuring a current through a primary conductor, the current measurement device comprising: a current transducer, the current transducer comprising a conductor winding connected to a pair of transducer terminals and adapted to induce there between a measurement voltage indicative of a current through the primary conductor; a pair of calibration terminals adapted for providing a calibration current to a calibration current path, so that the calibration current induces a calibration response voltage component between the pair of transducer terminals, wherein the current transducer is of the Rogowski type, and the calibration current path is conforming to the primary conductor by running parallel, up to a tolerance of 20°, to the primary conductor and by being arranged sufficiently near to the primary conductor so that a current running along the calibration current path creates a flux in the current transducer that has a known relation, up to a tolerance of 20%, to the flux that the same current carried by the primary conductor would induce; and in that the current measurement device further comprises a control circuit comprising a calibration current generator for generating the calibration current and connected to the pair of calibration terminals for providing the calibration current via the pair of calibration terminals to the calibration current path, and a voltage analyzer connected to the pair of transducer terminals for receiving the calibration response voltage component induced between the pair of transducer terminals.