Development of a calculable potential transformer with a wide ratio error of −10 % to +10 % and its application

A calculable potential transformer (PT) with a nominal ratio error of -10 % to +10 % has been developed on basis of theoretical calculation of ratio error by the number of primary windings. The developed wide ratio error PT (WRE PT) can be used to evaluate the linearity and accuracy of the PT comparator by comparing both the theoretical and experimental values of the WRE PT. The WRE PT has been applied for the on-site calibration and correction of the PT comparator up to wide ratio error range of -10%to+10%.