Estudo das técnicas de controle de carga em conversores monofásicos para correção de fator de potência.

Abstract

In this dissertation, a simplified classification of active solutions for singlephase power factor (PF) correction circuits with sinusoidal line current is given first. Next, a review of general aspects of PF control strategies used with unidirectional boost converter is carried out. Then, a systematic study of the charge control technique is proposed for both discontinuous conduction mode (DCM) and continuous conduction mode (CCM) by considering either peak or average current control. The charge control has several advantages: it is independent of the pulsating or non-linear characteristic of the converter, does not need to template the line current thus eliminating multipliers, and allows making zero the current error in just one switching period. Also, a new technique here named Frequency Modulation Charge Control (FMCC) is introduced in order to improve the line current Total Harmonic Distortion (THD) of an interleaved boost with capacitance midpoint connection (IBC) converter already existent in the technical literature. Simulated and experimental results are reported showing that the application of the FMCC technique results in a satisfactory performance. In addition, two new integrated AC to AC converters are conceived from the IBC converter, which present high power factor, low THD, and fast response.