Three Level Single Stage PFC Converter

DC power supplies are extensively used for most of the electronic and electrical power appliances such as in laptops, battery charges, computers, audio set and others. The presence of non liner loads results into low power factor for the operation of power system. A three level isolated single stage power factor correction AC/DC converter is proposed to achieve high power factor with less number of switches and diodes operates at constant duty ratio. With the proposed converter and switching scheme, input current shaping is achieved. In this, the middle two switches are turned on under zero current in discontinues conduction mode of operation and upper and bottom switches are turned on under zero voltage. Due to flexible DC-link voltage is obtained and high power factor is achieved.