Análise da operação e controle de um conversor modular para sistemas fotovoltaicos a partir dos conversores boost e meia-ponte

Abstract

This work presents the analysis and design of a modular converter, consisting of two boost and a half-bridge inverter, for photovoltaic systems connected to the electrical grid. The topology sizing was performed to comply with an active power of 980 W and an output rms voltage of 127 V, considering that each boost converter raises the voltage of approximately 60 V of the photovoltaic array composed by 245 W series modules (Kyocera model KD245GH-4FB). Due to the distinctive shadowing that can affect the photovoltaic array, a control system was de-signed to maintain the voltage balance in the capacitors that compose the dc bus, as well as a method to track the maximum power point (MPPT) in order to extract all available power from it. Simulation results are presented for different active power, voltages and current levels, in order to demonstrate the conditions that the total harmonic distortion (THD) of the injected current was within the limits allowed in standards for connection of photovoltaic systems to the distribution networks.