Three-level zero-voltage-switching PWM DC-DC converters-a comparison

This paper states a comparative study of six three-level zero-voltage-switching TL-ZVS-PWM DC-DC converters. All converters operate at fixed frequency and offer zero-voltage-switching for all active devices. The studied TL-ZVS-PWM converters are namely: TL-ZVS-PWM, TL-ZVS-PWM with one commutation auxiliary circuit (CAC), TL-ZVS-PWM with two CAC, TL-ZVS-PWM parallel-resonant, TL-ZVS-PWM series-resonant and TL-ZVS-PWM series-nonresonant. The main features of the TL-ZVS-PWM converters are discussed and mentioned, some of these are: number of power devices, current through components, load range under ZVS operation, output characteristics, output rectifier commutation, command circuit and efficiency. The TL-ZVS-PWM DC-DC converters have been implemented. From the obtained experimental results the main sources of losses was evaluated, and analysis and comparison of the converter features was carried out. The TL-ZVS-PWM DC-DC converters´ greatest attribute is that the maximum voltage across the active switches is half of the input voltage. Tables, abacus and experimental results are presented