Impact of Harmonics on Accuracy of Metering

Till 1950s, the harmonics were not regarded as a real problem. However after 1970, there was a growth of nonlinear loads and it was felt necessary to provide a metering system that records normal frequency and harmonic frequency consumptions separately. Therefore, efforts have been made from time to time to measure energy under non-sinusoidal conditions. Billing of harmonic energy has become the matter of concern. It is however, not yet clarified how the utility should treat the presence of harmonic distortion at metering point.Using appropriate instruments that follow the algorithms specified in the IEC 61000-4-30 standard can avoid unwanted disputes between the utility and end users of electrical energy owing to measurement variations arising between two meters.