一种耦合电感高增益开关DC/DC变换器

A Coupled Inductor High Gain Switching DC/DC Converter

针对光伏发电并网系统对前级DC/DC变换器的要求,提出一种基于耦合电感倍压单元Boost变换器和flyback变换器的高增益非隔离DC/DC变换器。该变换器采用输出侧串联结构,提高了变换器的电压增益,同时引入由二极管和电容组成的箝位电路,有效吸收了漏感能量,抑制了漏感引起的电压尖峰,降低了开关管的电压应力,提高了效率,同时耦合电感倍压单元进一步增加了变换器电压增益。详细分析了变换器的工作原理及工作特性,进行了理论公式的推导,并给出了关键器件的设计步骤。最后通过一台360 W的实验样机验证了理论分析的正确性。

Based on the requirements of the front stage DC/DC converter in photovoltaic grid-connected systems, ahigh gain non-isolated DC/DC converter is presented with coupled inductor voltage doubler cell and flyback convertercell which possesses a high voltage gain by introducing the serial structure of the output terminal.Due to employingthe clamp circuit which consists of diode and capacitor, the leakage inductance energy is absorbed effectively, and thevoltage spike caused by the leakage inductance is suppressed, the voltage stress of the switch is reduced and the effi-ciency is improved.The voltage gain of the converter is increased further by using the coupled inductor voltage dou-bler unit.The working principle and the performance of the converter are analyzed, and the relevant theory formulasare deduced, and the design process of the key device is given.Finally the theoretical analysis is validated throughthe 360 W experimental prototype.