Projeto de um conversor meia ponte com saídas isoladas para alimentação de drivers

Abstract

This paper presents a project and the implementation of a converter using the half bridge topology, having seven isolated outputs. The aim is to study, project and make the implementation of the converter with a total output power equal to 100W, the controller and all converter’s auxiliary circuits. To the components selection is done firstly a bibliographic review of static converters culmanating at the half bridge converter circuit and its small signals model. The half bridge converter uses a capacitive divider and pair of MOSFETs to create an alternating square wave voltage, which supply the transformer primary. The transformer reflects the primary voltage in its secondaries, respecting the coil’s relation. The secondary voltage of the transformer can be used to supply derived circuits of the buck converter, making possible the use of several voltage levels at the outputs of the converter, all of them with ohmic isolation. During the development of this paper are presented all projected components used by the half bridge converter together with the auxiliary circuits components and the controller’s project. After the presentention of all projects, is realized the presentation some results obtained with simulation using the PLECS simulator, also are shown the experimentally obtained results, using the TMS320F28027 microcontroller. After the obtainment of the experiments results, it bacame possible to compare these with the simulation results, comproving the correct operation of the converter, which presented a good voltage regulation. It was also observed the presence of some noises and oscillations, which were caused by the intrinsic characteristics of components and circuit board.