A new self-calibrating instrument for voltage transformer calibration

摘要

A new current comparator and digital ratio-meter based self-calibrating instrument for voltage transformer calibration has been developed at the Technical University of Budapest. The instrument measures the in-phase and quadrature components of the complex error by means of a digital ratio-meter. The built-in programmable analog signal processor facilitates comparison and direct calibration of voltage transformers of different ratios. Advanced hardware and software technology ensure complete on-site self-calibration of the instrument. The basic accuracy of the instrument is /spl plusmn/2 ppm with 1 ppm resolution.