Conversor CC-CC de elevado ganho autogrampeado baseado na configuração boost empregando indutor acoplado

Abstract

This work presents a new topology of a DC-DC converter based on a boost configuration employing coupled inductor. The main features of the proposed circuit are high voltage gain, high efficiency and the absence of a clamping circuit to limit the voltage peaks in the semiconductor devices. The converter is also constituted of two stacked capacitors in the output. Therefore, besides the duty cycle and the turn ratio, the total gain is obtained by the sum of the voltage of the two capacitors, characterizing the high voltage gain. In regard to the efficiency, considered high in this work, this is due to the fact that, although the converter operates with pulsating current at its input source, it can be designed for intermediate duty cycle and presents switching similar to zero voltage switching. In addition to the high step-up and high efficiency, the system presents natural characteristics of active voltage clamping on the semiconductor devices, characterizing it as a self-clamped converter. As for the mathematical model, the steady state and dynamic analysis are also presented. Beyond the developed project methodology, the converter is implemented in closed-loop. Three control techniques are designed and applied in closed-loop. First, the traditional linear proportional-integral control (PI) and two other nonlinear techniques, the sliding mode control and the piecewise affine system control. Accordingly, a comparative analysis of the converter working with the three techniques is presented. One of the main applications of the proposed converter is for electrical energy processing systems that need to be integrated into AC grids, such as energy from photovoltaic systems. Finally, simulation results are presented for the converter operating with an input voltage of 48 V, output voltage of 400 V, switching frequency of 100 kHz and output power of 300 W.