A Current-Doubler Rectifier ZVS Asymmetrical Half-Bridge DC/DC Converter with Synchronous Rectification: Analysis and Synthesis

• Main Authors: Tsung-I Yeh, 葉淙益
• Other Authors: Jong-Lick Lin
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/28740557452818180657

碩士 === 國立成功大學 === 工程科學系碩博士班 === 93 === Abstract In this thesis, based on the asymmetrical half-bridge (AHB) converter, a current-doubler rectifier ZVS AHB DC/DC converter is designed for the application of high current operation. The full-wave rectification with a central-taped transformer is replaced by the current-doubler rectification. Additionally, in order to improve the efficiency of the converter operating in heavy loads, the technique of synchronous rectification is used to reduced the conduction losses of output rectifier. The presented converter possesses the properties of high efficiency. The current-doubler rectification is envoled from the full-wave rectification. The advantages of this topology are not only easy implementation of the transformer, but also the rms current of secondary wilding of the transformer is much less than that of full-wave rectification topology. It follows from the facts that the magnitude of rms current is proportional to the copper losses. The copper losses of the current-doubler rectification is thereby less than that of the full-wave rectification under high current operation. The efficiency of the converter operating in is 85.5% by the experiment. Additionally, in order to improve the efficiency of the converter, the technique of synchronous rectification is applied in the output rectifier to reduce the high conduction losses due to the forward-voltage of the output diodes. The converter still has high efficiency when operating in low voltage and high current conditions. The detailed circuit analysis for the proposed current-doubler rectifier ZVS AHB converter is also presented in this thesis. The small-signal model is then derived by the averaging method. According to the small-signal mathematical model, a phase leading and phase lag compensator and a minor-loop controller are both designed to achieve output voltage regulation. The experimental responses show that the controllers has a good regulation capacity under the variations of load and line voltage.