Induction Watthour Meter Accuracy with Non-Sinusoidal Currents

This paper is concerned with the accuracy of registration of induction watthour meters when metering non-sinusoidal currents. Expressions are given for the meter registration errors for three cases of nonsinusoidal current wave forms: (1) full wave, phase triggered sinusoid (2) full wave, phase delayed square wave (3) full wave, battery charger wave errots in registration are found to be a function of the harmonic distortion of the impressed current and the ratio of impressed rms current to rated or class current. A generalization of this study is made, relating error to these two variables. It is suggested that a bound on the product PH¿k will similarly bound registration error. PH is the per unit harmonic distortion of the current and k is the per unit rms current in the watthour meter.