Methods for determining utility and customer harmonic contributions at the point of common coupling

Harmonic contributions at the point of common coupling have become a significant issue in power quality due to the increasing use of power electronic devices. One method to limit the amount of harmonic contribution in a distribution system is by establishing limits such as the IEEE Std. 519 and the IEC 1000-3. Another method is an incentive-based scheme whereby harmonic generators are to be charged an amount commensurate with their harmonic pollution level when the limits are exceeded. This paper presents a study for comparing a new method based on reactive power gradient with other methods from the literature based on real power direction and network theorem in determining the utility and customer harmonic contributions at the point of common coupling. In this study, a 10-bus distribution system is simulated using the electromagnetic transient EMTDC/PSCAD software. Index for each method is calculated using data obtained from the simulations. From the analysis, the reactive power gradient method and the network theorem give reliable results. The reactive power gradient method however is faster and has a good potential to be used for on-line determination of harmonic contributor.