高增益耦合电感组合Boost-Sepic变换器

High Gain Coupled Inductor Combination Boost-Sepic Converter

传统的DC/DC变换器由于其寄生损耗,在高占空比下提供的实际增益有限,对此,此处提出一种高增益耦合电感组合Boost-Sepic变换器。该变换器将耦合电感与开关电容相结合,构成耦合电感倍压单元实现变换器的高电压增益,同时开关电容中的二极管和电容作为无源电压箝位支路,回收耦合电感中漏感储存的能量,而且拓扑组合结构还保留了开关管的无源电压箝位支路,保证了开关管的低电压应力。此处详细分析了该新型Boost-Sepic变换器,包括工作模态、电压增益、开关器件电压应力及器件参数的选择,并与其他高增益变换器进行对比。最后,通过200 W实验样机验证了该变换器的可行性和优点。

Traditional DC/DC converters can only provide limited actual gain at high duty cycle due to their parasitic losses,so a high gain coupled inductor combination Boost-Sepic converter is proposed.The converter combines coupled inductor with switched capacitor to form a coupled inductor voltage doubling unit to realize the high voltage gain of the converter,while the diode and capacitor in the switched capacitor act as a passive voltage clamping branch to recover the energy stored in the leakage inductor in the coupled inductor.Moreover,the topology combination structure also retains the passive voltage clamping branch of the switching tubes,which ensures the low voltage stress of the switching tubes.The novel Boost-Sepic converter is analyzed detailedly,including its operation modes,voltage gain,voltage stress of switching devices and device parameter selection,and the comparison with other high gain converters.Finally,the feasibility and advantages of the converter are verified by a 200 W prototype.