Calibration of Rogowski coils at high currents

This paper describes the calibration of a Rogowski coil (RC) with an integrator assigned for current measurement in the range up to 25 kA at 50 Hz mains frequency. A current loop with 10 turns with a current of 2.5 kA is used for calibration. The magnetic field generated in such a way differs from the field of one turn placed in the centre and passed with a current of 25 kA. The influence of non-homogeneities of winding and the cross-section of the RC may cause a calibration error when using a current loop. The difference in the results between using a current loop and one turn and the measurement uncertainties are given below.