Rogowski-Coil-Based Current Sensor with Zero-Current Detection for Optimized Lower Cut-Off Frequency

This work combines a rogowski coil with a Zero-Current Detector (ZCD) to significantly enhance the current sensing ability of rogowski coils. The proposed method allows the design of an integrated rogowski-coil-based sensor which is able to measure alternating currents with dc offsets. Thereby, rogowski-coil-based current measurement are made applicable to a wide grade of applications, e.g., for grid-connected applications or control of electrical machines. This paper presents the design and implementation of the sensor as well as the evaluation algorithm. Measurements are shown for a prototype sensor with a design frequency range of $f$ = 100Hz to 40000Hz and currents of up to $I$ = 50A. The measurements validate the ability of the sensor to measure alternating currents with dc offsets.