Majority of electronic appliances used today is operated only through dc power supplies and this requires ac-dc conversion. For such ac-dc conversion, the research focuses on single stage multi-level topologies because of their low cost. This paper proposes a new single stage three level ac/dc PFC converters for low power applications such as SMPS, laptop adapters, smart TV power supply systems, etc., With this proposed converter, the input current shaping and output voltage regulation can be achieved with the help of microcontroller based soft switching technique and it does not require any additional switches. Through this soft switching technique, the inverter switches are turned on under zero current and zero voltage in discontinuous conduction mode operation. Due to the flexible dc-link voltage, high power factor can be achieved with regulated dc output. A 300W/110V prototype is designed and developed for the proof of concept, which shows the power factor is in the range of 0.96 to 0.99.
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