Micro inversor de estágio único conectado à rede elétrica baseado no conversor flyback

Abstract

The present work introduces the study and the implementation of a single stage flyback converter (DC-AC) with six switches, based on topological variations: flyback circuit, flyback with two switches and with four switches. The study had the intention to certify that this topological variation could regenerate the energy of the dispersion inductance during the commutation, this supposition has proven to be true. Besides that, another goal was to connect the converter to the electrical network and inject the active power to the grid of the photovoltaic panels. The studied converter works using four high frequency (50 kHz) switches and two low frequency (60 Hz) switches, and being able to deliver effective 127 V on its output. The study also presents a qualitative analysis of the four stages of the operation and math analysis, it also presents theoretical and simulated waveforms. It also presents a dynamic analysis of small signal, where it is presented the transfer function with a resistive load and when it is coupled to an electrical network. Efficiency results of the converter are also presented, the best result was 94,3 %. The wave forms of the close loop operation with a resistive load, coupled to an electrical network and coupled to a sinusoidal source are also presented at the prototype test. Besides that it presented a little analysis of the total harmonic distortion for the injected current into the network. Finally, it concluded that effectiveness of the converter in realizing the connection with the electric network generates a sinusoidal current in its output with low harmonic distortion and the injection of an active power in the network.