Tape-wound Rogowski coil for measuring large-magnitude pulsed currents

This paper presents design, calibration and testing of a new tape-wound Rogowski coil for measuring large-magnitude pulsed currents. The performance of the coil is tested by different impulse current waveforms up to 9 kA peak value. The coil is calibrated versus two commercial impulse-current transformers with different impulse current waveforms. The coil design is optimized to work in the differentiating mode and achieve useful bandwidth and sensitivity up to 1 MHz and 102 mV/kA, respectively. Waveform distortion of the coil output voltage is examined by using the lumped-element model to optimize the parameters of the external passive integrator. It is desired to optimize the integrator parameters and achieve the desired bandwidth without having droop and backswing. To do so, the coil frequency response is investigated by making fast Fourier transform (FFT) of the impulse current waveforms and PSPICE simulation of the lumped parameter equivalent circuit of Rogowski coil and the external integrator. Finally, it is found that the PSPICE calculated sensitivity for the optimized integrator parameters deviates from the corresponding measured one by a percentage relative error of–0.05%.