Optimising high frequency integrator operation of Rogowski current transducers

The high frequency (hf) behaviour of Rogowski current transducers is dictated by both the Rogowski coil and electronic integrator. Normally the Rogowski coil determines the hf response but when measuring small currents with a Rogowski coil of small cross section or low winding density the integrator behaviour can dominate. This paper describes this effect and subsequently presents a model and experimental verification of the high frequency behaviour of an optimised electronic integrator, including the effects of parasitic impedance, op-amp open loop transfer function and output impedance.