Conversor CC-CC PWM bidirecional trifásico com três portas e isolado em alta frequência para aplicação em sistemas fotovoltaicos

Abstract

This work proposes the study and design of a single-stage three-phase bidirectional dc-dc converter, with high-frequency isolation, current-fed based on the dual active bridge converter (DAB). The mathematical analysis based on the fundamental component model is presented, it is validated through the study of the behavior of the phase shift angle in relation to the power transferred. The control strategy has as objectives to control the bus voltage of the High voltage side, the currents in the interleaved inductors and the tracking of the maximum power point of the set of photovoltaic panels. A design example is developed with component specifications, magnetic design, and controller designs, which is implemented through discrete controllers programmed through a 32-bit digital signal processor (DSP) manufactured by Texas Instruments. Simulation results are properly discussed, validating the operation of the proposed converter, both on a permanent basis, by analyzing the main waveforms, the transient response through load steps. A prototype of 3.5 kW was developed in the laboratory with the objective of validating the theoretical analysis and simulation results. The port I of the converter is current-fed through the insertion of interleaved inductors connected to a batteries bank of nominal voltage 48 V. The nominal voltage of Port II is 96 V powered by a voltage source programmed to emulate a photovoltaic system. In Port III of the converter, a DC bus with voltage level compatible with a medium power LVDC distribution system of 380 V. Due to the fact that it is multi-port, the converter provides seven modes of operation, which have been carried out to verify dynamic and steady state behavior, as well as performance verification for three modes of operation.