A system to measure current transducer performance

Abstract

A special purpose ac current transducer measurement system capable of intercomparing transducers with ac output voltage ratios from 1:1 to 50:1 has been developed to extend the range and accuracy of current transformer, current shunt, and mutual inductor calibrations at power frequencies of 50 Hz and 60 Hz. The system consists of a two-stage binary inductive voltage divider, an amplifier-aided two-stage current transformer, a precision shunt, a wideband buffer, and a commercial, sampling digital multimeter (DMM). When comparing current transducers with ac output voltage ratios of 1:1 to 50:1, the system attains an overall relative standard uncertainty of the ratio of 10/sup -5/ to 10/sup -4/, respectively. The basic system can be used to calibrate transducers with input currents of 0.1 A to 200 A (RMS) and can be extended to measure devices handling input currents up to 15 kA.