A single switch boost-flyback DC-DC converter integrated with switched-capacitor cell

Abstract

Without extreme duty ratio or complexity of circuits, by employing coupled-inductor and switched-capacitor cell achieved high voltage conversion ratio with a single switch is proposed in this paper. Coupled-inductor transfer source energy to secondary side through entire switching period, the leakage energy of coupled inductor is efficiently recycled; the inrush current problem on switched capacitors was restrained by leakage inductor of coupled-inductor; all the above features account to the high efficiency performance. The operating principles and steady-state analyses of continuous-conduction mode and boundary-conduction mode are discussed in detail. To verify the performance of the proposed converter, a 200 W/400 V prototype sample is implemented, the maximum efficiency is up to 96.3%; and full load efficiency is 92.4%.