适用于光伏发电系统的新型高增益DC/DC变换器

New high voltage gain DC/DC converter suitable for photovoltaic power generation system

基于耦合电感、开关管与输入电压源组成的基本功率单元,提出了一种适用于光伏发电系统的新型高增益DC/DC变换器。变换器中耦合电感和二极管-电容结构组成的倍压单元提升了电路的升压比,无源箝位电路对漏感能量进行了二次利用,削弱了开关管漏、源极间的电压震荡,且箝位电容的位置进一步提升了输出电压。另外,漏感的存在缓解了二极管的反向恢复问题,优化了开关管和二极管的选择。详细解释了变换器在不同模式的工作原理,并计算出了电压增益及各元件的电压、电流应力。设计了额定功率为500 W的实验样机来评估所提变换器的可行性与优越性,样机最高效率达到了94.5%。

Based on the basic power unit composed of coupled inductor,switch tube and input voltage source,a new type of high-gain DC/DC converter suitable for photovoltaic power generation system was proposed.The voltage doubler unit composed of the coupled inductor and the diode-capacitor structure in the converter improved the boost ratio of the circuit,and the passive clamp circuit used the energy of the leakage inductance twice to weaken the voltage between the drain and source of the switch tube spikes,and the location of the clamping capacitor further increased the output voltage.At the same time,the existence of leakage inductance alleviated the reverse recovery problem of the diode,and optimized the selection of the switch tube and the diode.The working principle of the converter in different modes was explained in detail,and the voltage gain and the voltage and current stress of each component were calculated.An experimental prototype with a rated power of 500 W was made to evaluate the feasibility and superiority of the proposed converter.The maximum efficiency of the prototype reached 94.5%.