Boost Converter Grafted with Full Bridge Isolated Converter

• Main Authors: Yue-Hua Wu, 吳岳樺
• Other Authors: Tsai-Fu Wu
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/85201666246561991259

碩士 === 國立中正大學 === 電機工程研究所 === 102 === This thesis presents design and implementation of an isolated dc/dc converter for renewable energy supply system. A boost converter grafted with full bridge isolated dc/dc converter is adopted. The graft method is used to integrate a boost converter with a full bridge isolated converter, which can save switching component and increase power density. Moreover, the front stage of the proposed converter can boost the voltage twice from the battery, which can reduce the turns ratio, size and power loss of the transformer. Moreover, the proposed converter can cover the voltage range from 31 V to 41 V. The active switches of the converter are operated with variable frequency and pulse-width modulation method to accommodate power variation. The front stage is operated in continuous conduction mode to reduce the current ripple. The rear stage is operated in discontinuous conduction mode to reduce inductor size and increase power density. A Renesas RX62T microprocessor realizes the functions of circuit protection, generation of PWM signals and A/D conversion, etc. If the load voltage drops below the nominal value, the converter is operated in discharging mode to regulate the load voltage. Finally, a 1kW converter has been implemented to verify the feasibility and its characteristics.