Analysis of the Performance of the Norton Equivalent Model of a Photovoltaic System Under Different Operating Scenarios

Abstract

The massive integration of photovoltaic systems to distribution networks has affected their operation in terms of harmonic distortion in voltage and current signals. This is due to the non-linear characteristic of photovoltaic inverters. For this reason, it is necessary to characterize these systems in different operating scenarios in order to analyze in detail their impacts on electrical grids. However, only a few studies use frequency domain models in order to study their real behavior. Therefore, this work seeks to estimate the parameters of the Norton equivalent model of the coupled and decoupled admittance matrix of a photovoltaic system that injects active power into the low voltage network of a university building. It is proposed to analyze the performance of the model with three operating scenarios based on solar irradiance, active power generated and the THDi index. Measurements at the common coupling point between the photovoltaic system and the electrical network have been taken into account in order to obtain the models and validate them. The results obtained show the analysis of the performance of the models for the three proposed operating states, in terms of powers, power factor, estimation of the waveforms of the current signal and the THDi index.