Watthour meter accuracy under controlled unbalanced harmonic voltage and current conditions

This work presents the results of phase I of the project on the accuracy of watthour meters when subjected to closely-duplicated real-world unbalanced harmonic voltage and current conditions. Such real-world conditions involved differences in voltage and current magnitudes as well as differences in the voltage and current total harmonic distortion levels of each phase. Tests were performed on a selected sample of nine three-phase and three single-phase watthour meters. Some results showed that under a particular set of unbalanced waveforms with harmonic conditions of I/sub THD/>80% and V/sub THD/>2%, the percentage errors exhibited by these meters ranged from -10.09% to +0.52%.