A harmonic analysis of the induction watthour meter´s registration error

A frequency-domain mathematical model developed to quantitatively analyze the effect of the different parameters on the registration error of the induction watthour meter in the presence of harmonic distortion is presented. These harmonics are included in the input voltage and current waveforms applied to the watthour meter. Measurements on the meter´s voltage and current coils were utilized to include the saturation effect in the model and to obtain the variation of the frequency dependence of the meter parameters. An expression for the torque that is actually developed within the induction watthour meter in the presence of harmonics is developed along with an expression for the torque that would be measured by an errorless or ideal induction watthour meter. The ideal induction watthour meter is based upon the assumptions necessary for errorless meter operation