Digital Compensation of Rogowski Coil's Output Voltage

Due to inherent characteristics of Rogowski coils, measured signals by these transducers are distorted, and hence, it is a need to compensate their output voltages in order to reconstruct their input current. Using analog circuits for the reconstruction of the input current of a Rogowski coil is a very common technique, but this technique has no appropriate performance upon partial discharge signals. In this paper, digital techniques for the reconstruction of the input current of Rogowski coils have been presented and examined, and the best practical one that can be used for either unshielded or shielded coils has been proposed. The proposed method is a model-free compensation method; in other words, there is no need to extract any of the parameters of a given coil as long as its frequency response is measured and processed according to the proposed method.