| With the continuous development of power technology, switching power supply is widely used in various forms of electrical products. However, in the conventional hard-switch mode:the active device is connected on the rigidity of the voltage and current sources, which will limit the improvement of the switching frequency and cause large switching loss. In order to reduce the switching losses, lossless passive power factor correction (PFC) technology has become one of the possible ways. By increasing passive lossless absorbing circuit, we can effectively reduce the switching losses, raise the switching frequency, etc.In this article, a passive lossless snubber circuit is introduced into the conventional boost power factor correction (PFC) circuit. By using lossless absorption technique, it does not introduce additional current and voltage stress on the main switch; and limits switch tube from output diode reverse recovery current. Firstly, the article detailed analysis the working principle of the proposed passive lossless buffer PFC circuit. Secondly, it researches passive lossless buffer circuit structure and performance compared with conventional Boost PFC. Finally, developed a250W prototype and experimental results verify that the proposed buffer structure in the operating range can effectively reduce the switching losses and improve efficiency.At last, the experimental results and waveforms show that proposed passive lossless snubber circuit can significantly improve the efficiency and performances. |
