适用于大功率DC/DC的新型无源无损缓冲电路
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摘要
无源软开关技术因其控制简单且易于实现,得到了广泛工程应用。但无源无损缓冲电路应用于大功率场合时,流过缓冲电路二极管和电感的电流较大,造成器件体积大和散热困难等问题。为了解决上述难题,提出一种适用于大功率场合的新型无源无损缓冲电路的拓扑结构以及该缓冲电路谐振元件参数的设计方法。通过使谐振回路尽量避免参与主电路续流过程,降低流过二极管与缓冲电感的电流。采用该拓扑设计的缓冲电路,在能够实现开关管零电流开通、零电压关断的前提下,具有更小的体积和发热量,提升了效率。通过设计一台15 kW的Buck变换器样机,验证了这种缓冲电路理论分析和设计的正确性。
Passive soft switching has been widely used in engineering because of its simple control and easy implementation. However, in high-power situations, the large current flowing through the diode and inductor result in a series problems such as device size and heat dissipation.In order to solve the above problems,a new passive lossless snubber which is suitable for high power situations and the design method of resonant elements is proposed.By making the resonant circuit avoid to participating in the main circuit's freewheeling process,the current flowing through the inductor and diode can be reduced.The snubber designed by this topology achieves zero current turn-on and zero voltage turn-off with smaller size,better heat dissipation performance and a higher efficiency.A 15 kW Buck converter prototype based on the passive lossless snubber has been designed to verify the correctness of the analysis and design methodology.
Passive soft switching has been widely used in engineering because of its simple control and easy implementation. However, in high-power situations, the large current flowing through the diode and inductor result in a series problems such as device size and heat dissipation.In order to solve the above problems,a new passive lossless snubber which is suitable for high power situations and the design method of resonant elements is proposed.By making the resonant circuit avoid to participating in the main circuit's freewheeling process,the current flowing through the inductor and diode can be reduced.The snubber designed by this topology achieves zero current turn-on and zero voltage turn-off with smaller size,better heat dissipation performance and a higher efficiency.A 15 kW Buck converter prototype based on the passive lossless snubber has been designed to verify the correctness of the analysis and design methodology.
引文
[1]阮新波,严仰光.直流开关电源的软开关技术[M].北京:科学出版社,2000.
[2] Smith Jr K M,Smedley K M.Engineering Design of Lossless Passive Soft Switching Methods for PWM Converters-part I:With Minimum Voltage Stress Circuit Cells[J].IEEE Trans. on Power Electronics,2001,16(3):336-344.
[3]杜宇,梁志刚,吴燮华.一种无源无损缓冲电路的工程设计方法[J].电力电子技术,2005,30(1):66-69.
[2] Smith Jr K M,Smedley K M.Engineering Design of Lossless Passive Soft Switching Methods for PWM Converters-part I:With Minimum Voltage Stress Circuit Cells[J].IEEE Trans. on Power Electronics,2001,16(3):336-344.
[3]杜宇,梁志刚,吴燮华.一种无源无损缓冲电路的工程设计方法[J].电力电子技术,2005,30(1):66-69.