Projeto e análise de um conversor CC-CC Buck não-isolado baseado na célula de comutação de quatro estados com ampla taxa de conversão.

Abstract

In off-grid systems, battery energy storage systems, or off-board electric vehicle chargers, a conversion stage with a DC-DC converter is required to adjust voltage and current levels appropriately for battery charging. In this context, this work presents a qualitative and quantitative analysis of a Wide Conversion Range (WCR) Buck DC-DC converter based on the Four-State Switching Cell (4SSC). The employed modulation drives 12 switches, and all six operating stages are described, including the design equations for the converter components. Finally, the results include a comparison of the DC voltage gain obtained through simulation and analytical values, and an analysis of the inductor current ripple behavior as a function of the duty cycle and the transformer turns ratio. Furthermore, the voltage and current stress on the switches is determined. The converter features advantages such as reduced voltage and current efforts on the switches and a reduction of

the LC filter, resulting from operation at three times the switching frequency. As disadvantages, the high number of switches and the need for auxiliary power supplies for switch biasing are highlighted. To verify the operating principle, a design example is developed with simulation and experimental results for the following nominal values: output power Po = 5 kW, input voltage Vi = 800 V, output voltage Vo = 108 V, and switching frequency fs = 30 kHz. The converter operates in region R2 (1/3 < D < 2/3 ), and the three- phase transformer has a turns ratio of 1.8 (n = 1.8)