Testing the performance of three-phase induction watthour meters in the presence of harmonic distortion

Computer-based testing of a three-phase induction watthour meter in the presence of harmonic distortion is reported. Two three-phase harmonic generators produce the distorted current and voltage waveforms. Each waveform consists of prespecified harmonic magnitude and phase. Therefore, balanced or unbalanced conditions can be simulated in the testing. A fiber optic sensor is designed to convert the rotation of the disk of the meter into digital signals to be stored in an IBM PC/AT. A data acquisition system transfers the samples of current and voltage waveforms to compute the power and energy for comparison. Presented are: the computer-based harmonic generator facilities for testing, the testing procedure, and the impact of the different harmonics magnitude and phase angle on the meter´s registration error