A Plug-Play Active Resonant Soft Switching for Current-Auto-Balance Interleaved High Step-Up DC/DC Converter

In high gain voltage conversion applications, the low-side switches usually suffer large current stress, resulting in dominate switching loss. In this paper, a general soft-switching method based on an advanced interleaved high-step-up converter, which features excellent performance but works in hard-switching, is presented to combat this issue by using a plug-play resonant circuit. Under this soft-switching method, the main switches reach zero-voltage switching (ZVS) turn-on and ZVS turn-off, and the soft-switching condition is derived. Meanwhile, the added auxiliary switches could be turned off under ZVS condition and turned on under zero-current switching condition as well. More importantly, due to its location out of the energy transferring path, the auxiliary circuit will never lead gain lost to the converter and maintain its other existing merits, such as current auto-balancing and diode inverse-recovery well. A 1-kW prototype is built and tested to verify the significant efficiency improvement and merits maintenance for the proposed converter considering active resonant soft switching.