Study and analysis of the propagation of harmonics in electrical grid connected photovoltaic system

Renewable energy sources especially solar energy connected to an electrical grid system by using power electronic devices, known that devices degrade the power quality and especially generate harmonic currents. This article presents the study investigation and propagation of harmonics in the integration system of an electric grid connected to the photovoltaic system in the presence or not of a non-linear load (polluting load). In this study, the perturb and observe type MPPT controller for the boost converter and the PWM control for the three-phase inverter which provides the connection are used. We use a passive filtering technique (single and multiple filters) to mitigate the harmonic currents generated by the non-linear load. In the first case where the integration system is alone, the results obtained show that the values of the total harmonic distortion (THD) rates are within the standard used. But in the case of the presence of the non-linear load, the THD values are higher than the used norm. After using our proposed technique, the values of THD obtained are in the norm used for the application of a tuned filter at the fifth harmonic, and better results find with using of multiple filters (fifth and seventh).