Recently, rectifiers with capacitive loads connected to the network in order to supply electronic devices have increased. Since these rectifiers are nonlinear loads, they inject unwanted harmonics into network system. These harmonics create sever problems for the network. Therefore different standards are established to reduce these undesirable effects. One method to reduce current harmonics is to place a PFC (Power Factor Correction) converter after the rectifier to improve power factor. Conventional PFC converters have higher conduction Losses than regular rectifiers. For reducing conduction losses, the PFC block must be combined with the DC-DC regulator or rectifier and the resulting converters are called single stage PFC and bridgeless PFC respectively. The most conventional PFC converter is the boost converter. Boost type PFC converters suffer from many drawbacks like inrush current, output high voltage and etc. To overcome these problems, other basic converters like SEPIC, Cuk, buck and buck boost are applied. In this dissertation four families of bridgeless PFC converters to reduce volume and weight while, increasing efficiency are proposed. Key Words Power factor correction, Soft switching, Buck and boost converter, Bridgeless PFC, Resonant converter, Universal Applications.
