PORTABLE AND STABLE SOURCE OF AC VOLTAGE, CURRENT, AND POWER

This paper describes a portable and stable source of ac voltage, current, and power. It was developed for use with the National Research Council of Canada (NRC) watt-voltampere (W-VA) Transfer Standard to provide high-accuracy on-site calibrations of standards maintained by Canadian electrical utilities in order to establish traceability of these standards to the NRC. The stability of the source monitored over 100 s, a typical measurement cycle of the NRC W-VA Transfer Standard, is better than 10 ppm of full scale for the voltage and current outputs. The stability of its ac power output is better than 20 ppm of full scale at all possible power factor settings. The stable source is needed to minimize test uncertainties during on-site calibrations and to take full advantage of the accuracy of the NRC W-VA Transfer Standard.