Experience in measuring disconnector-generated interference currents in a high voltage substation using Rogowski coils

Rogowski coils have been indicated to be ideal in many applications, including measurement of transient currents in substations. Research presently conducted by Eskom and the University of the Witwatersrand, focuses on the generation of unwanted common mode currents by disconnector operations. The use of Rogowski coils to study these currents forms an integral part of this work. Complementary coil design, application details and initial measurements, to support a better scientific understanding of the source of interference, are discussed in this paper.