一种高增益交错耦合电感DC/DC变换器

High-gain Interleaved Coupled-inductor DC/DC Converter

提出了一种高增益交错耦合电感DC-DC变换器,采用二极管、电容和电感构建无源吸收网络,回收再利用漏感能量,开关管的开关电压尖峰得到抑制,进而减小了开关管的电压应力;选用导通阻抗低的MOSFET,降低开关损耗,改善变换器效率。将2个电容和2个耦合电感副边相结合,1个导通周期内,当电容并联导通时,储存在耦合电感中的能量给电容充电;当电容串联导通时,将能量释放给输出端,从而获得高增益。此外,二极管的反向恢复问题得到有效抑制;交错并联控制抑制了输入电流纹波,变换器性能得到改善。对电路的操作原理和模态变化作了详细分析,最后搭建了1台300 W、20 V/240 V的实验样机,验证了理论分析的正确性。

A novel high-gain interleaved coupled-inductor DC/DC converter is presented.By utilizing a passive snubber circuit composed of diode,capacitor and inductor,the leakage inductance energy is recycled,and the voltage spike stress in the power switch is suppressed,thus reducing the voltage stress in the power switch.Therefore,a low switch-on-resistance MOSFET can be used to reduce the conduction loss and improve the converter efficiency.Two capacitors are connected to the secondary side of two coupled inductors.During one switch-on cycle,the two capacitors are charged in parallel by the energy stored in the coupled inductor,and they are discharged in series to release the energy to the output terminal.In this way,a high voltage gain can be obtained.In addition,the reverse-recovery problem of diodes is effectively alleviated,and the input current ripple is reduced by the interleaved control,thus improving the performance of the converter.The operating principle for the circuit,as well as changes in mode,is discussed in detail.Finally,a prototype circuit with 20 V input voltage,240 V output voltage,and 300 W output power was implemented in a laboratory,and experimental results verified the theoretical analysis.