Analysis of Passive Filters for Pv Inverters Under Variable Irradiances

Abstract

In this study, passive filters used for photovoltaic (PV) inverters producing different values of power under variable irradiation were analyzed. The use of passive filters is essential to obtain a sinusoidal output voltage with a low harmonic content at the output of PV inverters. For this reason, L-type, L-C and L-C-L type passive filters were designed for PV inverters operating with Maximum Power Point Tracking (MPPT) and Total Harmonic Distortion (THD) analyzes were performed under the same conditions. In addition, the behavior of these filters in PV inverters operating at different irradiations and therefore at different power ratings was observed and compared. In the study, Perturb and Observation (P&O) MPPT technique is used for PV inverter and classical PI controller is used for output voltage control. After the related design studies, the whole circuit with a rated power of 1kW was simulated in the Matlab/Simulink program and the results were compared.