Design and Implementation of A Novel Isolation Topology for High Step-Down Power Conversions

• Main Authors: LI, I-CHIEN, 李易謙
• Other Authors: TSENG, KUO-CHING
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/rr7w66

碩士 === 國立高雄第一科技大學 === 電子工程系碩士班 === 105 === This thesis proposes a novel isolated high step-down conversion circuit, (Integrated Buck and Isolated-Buck, IBIB), which is able to lower the voltage on the primary side of the ideal transformer, adopt a lower turns ratio, higher the coupling rate, decrease the leakage inductance, and avoiding duty cycle operating in extremely conditions. Furthermore, the proposed IBIB adopts active clamp techniques to recycle leakage energy and voltage spike suppressing, so that the conversion efficiency can be effectively improved. The advantages of IBIB with simple topology, easy control mechanism, which required only two signal with 180 degree phase shift, high converision ratio, low component counts of power switches, part of the switches on the high voltage side endure lower voltage stresses. The operation principle, steady-state analysis, design considerations, and experimental results of the proposed IBIB are presented in detail. Finally, the feasibility of IBIB is verified by hardware implementation. The full load efficiency with 250W is 84.76%, as the input and output voltage are 380V and 5V respectively.