AC current measurements via digital processing of Rogowski coils signal

The main advantages of Rogowski coils are the high degree of galvanic insulation and low cost compared to shunts and current transformer measuring systems. Its typical application is in the field of high-amplitude and/or high frequency currents. The integration of the EMF induced at the end conductors of the coil is classically obtained by an analog integrator. We propose an original integration process, based on a simple digital signal processing, allowing for better accuracy in the integration procedure and higher stability of the output signal. In addition, the use of digital integration extends the use of Rogowski coils also to low-amplitude and low-frequency current measurements.