A digital instrument for the calibration of current-to-voltage transducers

Modern instrumentation for the monitoring of electrical power systems is based on digital signal processing (DSP) techniques. If suitable design choices are made, the overall accuracy of this kind of instrumentation basically depends on the signal conditioning circuits. They have outputs proportional to the input to drive the A/D converters and are very often based on instrument transformers to ensure the isolation between the instrumentation and the monitored power system. This paper presents a lab prototype of a digital instrument for the calibration of current-to-voltage transducers (CVT's) and discusses its performance. The results of calibration tests performed on some commercial active and passive CVT's are also reported.