The signal processing unit compares the readings from all three sensors,introduces correcting coefficients, searches for core saturation in the small currenttransformer, and in the event of such saturation being revealed, communicates theresults of measurement from other primary converters, not been subjected tosaturation. Following demagnetization in the course of operation, the signalsprocessing unit automatically resumes communicating signals from the smallcurrent transformer as the most accurate sensor for electric power metering. Theresults of measurement with a small current transformer may also be required forrelay protection purposes, for example, in the event of remote backup protection,when short circuit currents differ from nominal values and high accuracy is neededto take correct decisions.ConclusionOur work shows the results of experimental studies of primary current andvoltage converters as parts of digital transformers. The frequency characteristics ofprimary voltage converters show smooth dependencies without the evidentfrequency surges characterizing conventional electromagnetic and capacitivevoltage transformers.