Modeling and Analysis of a Novel Transformerless Voltage Quadrupler DC Converter

• Main Authors: Lee, Chao-Han, 李昭翰
• Other Authors: Pan, Ching-Tsai
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/79496616728732104978

碩士 === 國立清華大學 === 電機工程學系 === 99 === High voltage DC converters are widely used in various applications to provide a high output DC voltage. However, the existing voltage doubler is not sufficient for some much higher voltage applications. Although, one can cascade more stages to achieve the desired voltage level, however, the resulting complex topology will result in less efficiency and reliability. Hence, the major motivation of this thesis is to propose a high efficiency voltage quadrupler DC converter. In fact, the major contributions of this thesis may be summarized as follows. First, a single stage transformerless voltage quadrupler DC converter is proposed for achieving much higher voltage gain, less voltage stress of switches and higher efficiency. In addition, the proposed converter possesses automatic current sharing capability without adding any extra component. Second, mathematical model of the proposed converter is derived and fundamental characteristics of the new converter are analyzed. Third, a 400W rating prototype with 25V input and 400V output is constructed for verifying the feasibility of the prototype converter. It is seen that the voltage stress of the active switches and the diodes are equal to quarter and half of the output voltage respectively. The resulting efficiency can be maintained above 93% as the load is varied from 120W to 400W, and the highest efficiency of 95% is achieved at 120W. Both simulation and experimental results indeed verify the effectiveness of the proposed converter. Finally, the extended isolated version of proposed quadrupler converter is also presented in this thesis.