Analyses of Rogowski coils for partial discharge measurement

This paper presents analyses of toroidal air core Rogowski coils (RCs) with self-integrator for partial discharge (PD) measurement. The RC is the electromagnetic transfer device for measuring fast current pulse. The RC has linear characteristic and no saturation due to the air core. There are four configurations of the RCs in the consideration in this paper. From each designed RC, inductance and turn of each RC was determined almost the same values but different configurations. To analyses of the developed RCs, those RCs were employed to measure partial discharge current with various artificial charge levels from 10 pC to 50 pC. Also, comparison of the PD signals measured by the developed RCs and low inductive shunt resistor was carried out. From the experimental results, the best developed RC has the highest sensitivity or lowest background noise. It composes of two copper winding wound in the different directions. The first winding is wound around the toroidal air core and the other winding is wound with the opposite direction of the first winding. The both winding are crossed at the inner of the toroidal core. This RC also has wind frequency bandwidth for PD detection. The developed RC is an attractive sensor in partial discharge measurement.