Identify Resonant Frequencies in AC Distribution Networks – A Numerical Example Part I – Harmonic Nodal Admittance Matrix Method☆

Abstract The subject of the paper is part of the general issue, particularly complex, establishing the means and methods of intervention for maintaining an appropriate quality of power supplied to consumers connected to existing distribution networks, which are subject to more pronounced harmonic pollution. In this context, the analysis in the frequency domain of the normal operating regimes of electrical distribution networks is a mandatory operation, the main instrument being the harmonic impedance seen in the network buses nodes. A typical application of this tool of analysis refers to reactive power compensation in distribution network harmonic polluted, operation that may lead to increased non-sinusoidal regime and consequently to increased negative effects on the operating of installations belonging to the supplier or consumers. Avoidance of harmonic resonances is possible only by knowing the frequency response of the network, more exactly the change of harmonic impedance seen in the network buses. This paper presents, in two parts, the numerical examples carried out on the same area of a real distribution network, two analytical methods: harmonic nodal admittance matrix method, respectively state matrix method. The results are analyzed and compared with the values obtained by the two methods.