Research On Three-level ZVS DC/DC Converter

DC/DC converter is a main part of power electronic converter. Soft-Switching technique is a hotspot of power electronic research. It's the key technique in high frequency and high density converter.As high EMI desire for power converter, power factor correction (PFC) become an important part , result in high voltage stress on main switches. Three-Level DC/DC converter was brought forward, its main switches voltage stress is only half of the input DC voltage, Three-Level converter becoming the main DC topology in the mind of power export in the world. Many topologies was put forward in recent years, include half bridge and full bridge. Three-Level consist of zero voltage switching (ZVS) and zero voltage and zero current switching (ZVZCS).In this paper, investigate basic half bridge Three-Level DC/DC converter, the operation and parameter design are disused ,second side commutate diode reverse furbish bring high pinnacle on the main switches. A zero voltage switching PWM Three-Level converter with two clamping diodes is given, and experimental results are also given, the operation and parameter design are disused. The famous software SABER is used to validating the rationality and correctness of the improved circuit.Two experimental installation are given, the main devices and parameters and all parts of the circuit main parts are designed. The experimental results are given. Presents a Three-Level soft switching LLC series resonant DC/DC converter. Zero voltage switching is achieved for each main switch without any auxiliary circuit. Voltage stress of each main switch if half of input voltage, zero current switching is achieved for rectifier diodes. Wide input and output range can be achieved under low frequency range because of two stage resonance. Only one magnetic component is required in this converter. Efficiency is high in high line input, so this converter is a preferable candidate for power products with the requirement of hold up time. Design consideration of four dead times is presented to assure that voltage stress for main switches is within half input voltage and zero voltage switching for each main switch is achieved. Finally, the principle of operation for each main switch is achieved of the presented LLC series converter is verified on an experimental prototype.In conclusion, basic half bridge Three-Level DC/DC converter, zero voltage switching PWM Three-Level converter with two clamping diodes and Three Level LLC series resonant DC/DC converter are proved by the theoretical analyses, simulation research and experimental validation.