A Novel Control Scheme for Power Factor Improvement in Modified Bridgeless Boost Converter

In Green Energy technologies like wind energy conversion systems and Domestic applications like SMPS and UPS systems, the input voltage amplitude and input frequency are time varying in nature. Fast-Escalating and extremely challenging high efficiency requirements for AC-DC power supplies for notebooks, desktop computers are to minimize the power losses (Conduction losses). In the conventional rectifiers power losses are more and power factor is poor resulting in loss of efficiency. Normally, the bridgeless topologies, also referred to as dual boost power factor correction (PFC) rectifiers, may reduce the conduction losses by reducing the number of semi-conductor components in the line current path. Power supply units have to make the load compatible with the source. The presence of non-linear load results in poor power factor operation and produces harmonic components in the line. So PFC techniques are necessary to meet harmonic regulations and standards such as IEC 61000-3-2 and IEEE 519. A modified bridgeless topology may be used for such applications. A novel switching controller is developed that regulates the input resistance to a desired value. Hence input power factor is unity and also the total harmonic distortion is controlled to a tolerable limit. In the proposed model, the modified bridgeless boost converter is activated in to a pure resistance mode. Finally the performance of the modified bridgeless boost converter is compared with the existing basic bridgeless boost converter.