A Norton Model of a Distribution Network for Harmonic Evaluation

Abstract

This paper presents a Norton model for modelling distribution networks where the system configuration is not fully known. Traditionally harmonic studies use complex distribution networks modelled by harmonic current sources for specific frequencies. Although this model has been proved to be adequate for some studies, this may not be adequate for other applications. When changing the operating conditions of the supply-side system, the harmonic currents injected by the distribution network might change and to investigate these harmonic currents, the Norton model is used. The change of operating condition is obtained by switching shunt capacitors. The estimated model can be used to analyze, for example, the effect of harmonic filters under different supply system configurations or operating conditions. The method of estimating the Norton models is illustrated on a test system, simulated on the well-known simulation program EMTP-ATPDraw. Key words : Norton model; Distribution network; Operating conditions; Harmonic currents and voltages