A study on novel buck-boost AC-DC converter of high performance by partial resonance technique

The system efficiency of the proposed buck-boost AC-DC converter is increased by soft switching method. The converter includes to merit of power factor correction (PFC) from sinusoidal control of input current. The switching behavior of control switches operates with soft switching by partial resonance technique, and then the proposed converter has high system efficiency with decrement of switching power loss. The input current waveform in proposed converter is got to be a sinusoidal form of discontinuous quasi-pulse row in proportion to magnitude of AC input voltage under the constant duty cycle switching. Therefore, the input power factor is nearly unity. The output voltage of the converter is regulated by PWM control technique. The discontinuous mode action of current flowing into inductor makes to simplify control method and control components. The proposed novel buck-boost AC-DC converter is analyzed to compare with the conventional PFC buck-boost converter. Some computer simulative results and experimental results confirm to the validity of the analytical results.