A Lossless Soft-Switching Boost Converter with Passive Auxiliary Circuit

Based on boost topology, a lossless soft-switching passive circuit with a single switch is proposed in this paper. The proposed circuit's power switch achieves approximately zero voltage switching (ZVS) and zero current switching (ZCS) without increasing the number of switches. Due to an auxiliary inductor, the reverse recovery loss of the rectifier diode is significantly reduced. Besides, all auxiliary circuit energy is returned to the power supply without additional energy consumption. Therefore, by using a traditional control method, simple design, and appropriate auxiliary circuit parameters, soft-switching can be realized in a wide voltage and full load range. Moreover, the number of components used in the auxiliary circuit is minimal. This method makes circuit design more manageable and achieves 95.39% high efficiency since the increase of voltage stress is relatively small.