A comparison among three-level ZVS-PWM isolated DC-to-DC converters

Considering that the designer of high-frequency high-input voltage power supplies does not always find semiconductors capable of sustaining the desired voltage, several topologies have been proposed based on multilevel converters in which only a fraction of the voltage is applied to each switch. This paper compares five different three-level ZVS PWM isolated DC-to-DC converter topologies. Basics concepts of each topology are shown along with their advantages and drawbacks. A comparison involving the size of reactive elements employed, stress of the semiconductors devices, number of semiconductors devices employed, simplicity and efficiency is made and summarised. Experimental results are included, in order to verify the theoretical analysis