Electronic front end for Rogowski coil current transducers with online accuracy self monitoring

In order to lower the overall amplitude error of the combination of a medium voltage Rogowski coil current transducer (RCCT) with its associated readout electronics, a specific electronic architecture is presented here. It implements online accuracy monitoring, i.e. an online self calibration, that enhances accuracy performances of the electronics. This new architecture also provides transducer connection diagnostic. As illustrated by the experimental results, this new accuracy drift monitoring function allows one to divide the amplitude error caused by the drifts of electronic components by a factor of 10. Besides, the electronic front end automatically detects the disconnection between the coil and the usually remote electronics. The new Rogowski coil read out electronic front end is implemented with standard low cost CMOS electronics supplied with 5V. However it is compatible with high primary current measurements which correspond to several tens of Volts at the RCCT output.