Power Systems Frequency Response using Frequency Dependent Network Equivalent based on a Rational Function in the z-domain

This article deals with the problem of harmonic resonance in power systems, which causes harmonic amplification and can worsen existing harmonic problems in the system. Therefore, performing a frequency response analysis is essential to identify series and parallel resonances in the system within a frequency range of interest. To address this issue, it is proposed to use a Frequency-Dependent Network Equivalent (FDNE) based on a rational function in the z-domain. This approach is based on acquiring measurement data and implementing parameter identification techniques using the recursive least squares method to evaluate the frequency response. To validate the proposed method, its implementation is carried out in different case studies.