Determination of harmonic load characteristics in distribution networks of cities

Harmonics are the most important issues among power quality problems for their significant and mostly unpleasant effects on the entire power system. In order to evaluate the effects of harmonics in the network, first it is necessary to refer to their sources and define the real characteristics of harmonics produced by different load types. In this paper, the loads (consumers) in the city are analyzed. These loads may be in different types, such as, residential, commercial and industrial or combination of them. Some data-loggers have been installed in some chosen MV substations considering the difference in load types approximately for 1 year in a city as a case study. By analyzing the data obtained from the data-loggers, The Daily Harmonic Load Curves (DHLC) have been extracted for the different load types in the city. These curves determine the real characteristics of harmonic loads for further analyses of the network.