Conversor buck chaveado-linear: estudo e desenvolvimento

Abstract

In this dissertation is presented a voltage source converter consisting of a Buck converter and a linear amplifier connected in parallel. This configuration is called as a Switched-Linear converter and the main feature of this converter is that when it is operating in permanent regime, the Buck converter, because it is a less dissipative converter, processes most of the energy, and the Linear amplifier, for having higher frequency band and fast response, regulates and eliminates the voltage oscillations at the output. The benefit of this configuration is that it combines the best features of both switched and linear converters. In addition, the circuit presented in this work can eliminate the need for an output capacitor, reducing filter and elevating the lifespan of the converter. Other features include: fast response to load disturbances (for load step of 100%: stabilization time less than 2.0 μs, risetime less than 100ns), null output voltage ripple, efficiency above 85% and high fidelity and output signal reliability. In this work, an analysis of this converter is also presented, which aims to show a project base form for future studies, presenting in the project methodology the equations of the converter in permanent regime, analysis of the circuits of the Linear amplifier and switched converter, principles that must be observed when connecting the two topologies in parallel and modeling the control to ensure the results. Finalizing with experimental tests and results.