Current transducer of the rogowski type and arrangement for measuring a current

摘要

The invention is about a current transducer of the Rogowski type, with a primary conductor winding having a first number of loops (N1) for carrying the rated current (IR) to be measured, with a secondary conductor winding having a pair of second terminals and a helical shape and a second number of loops (N2), said secondary conductor winding encircling the primary conductor in a toroidal manner, whereby a rated current voltage signal VS is induced between the pair of second terminals of the secondary winding, said rated current voltage signal being characteristic for the derivative of the rated current (dlR/dt), with a transducer electronics (IED) configured to receive the rated current voltage signal (VS ), characterized in that the current transducer comprises a third conductor winding having a pair of third terminals with a third number of loops (N3), whereby the transducer electronics (IED) is configured to feed a calibration current signal (ICal ) into the third conductor winding, whereby in response to the derivative of the calibration current signal (dl-Cal/dt) an additional calibration signal (Vcal ) is created between the pair of second terminals of the second winding and whereby the transducer electronics (IED) is configured to process the rated current voltage signal (VS ) and the calibration signal (Vcal ) to derive a corrected voltage signal (VS,corrected) with a calibrated sensitivity Scal.