A Portable Current-Comparator-Based System for On-Site Calibrations of Low-Power-Factor Wattmeters

In this paper, a portable system for on-site calibration of low-power-factor wattmeters in high-voltage transformer/reactor loss-measuring systems under sinusoidal conditions using a current-comparator technique is described. Measurements can be made at any power factor between zero (lead/lag) and 0.1, at a voltage of 120 V, currents of 0.1 A, 1 A, and 5 A, and a frequency of 50 Hz or 60 Hz with an uncertainty of 20 $\mu\hbox{W/VA}$ $(k = 2)$ .