一种交错并联高升压DC/DC变换器

Interleaved high step-up DC/DC converter

针对燃料电池应用系统中电池输出电压低的问题,提出一种具备高增益升压能力的非隔离型DC/DC变换器,该变换器通过在传统Boost三端口网络中串入由二极管和电容构建的DCM(diode-capacitor multiplier,DCM)升压单元来提高其输入输出增益。理论分析和实验结果表明,该变换器在提高输入输出增益的同时还具备以下优点:(1)开关器件电压应力低,可以选择更低导通电阻的开关管提高变换器工作效率;(2)所有二极管的电流电压应力均相等,有利于散热器设计;(3)输入输出增益可以通过DCM单元数来调节,方便根据输入输出工况做出合适的调整;(4)交错并联的输入形式,更适合于大电流输入的应用场合;(5)两相输入电流可以实现自动均流,控制方便。

Aiming at the problem that the output voltages of fuel cells are relative low in the typical fuel cell application systems,a non-isolated high step-up DC / DC converter was proposed,which is based on traditional Boost three-terminal network connecting in series with DCM（ diode-capacitor multiplier,DCM） boost units composed of diodes and capacitors to improve its input and output gain. Theoretical analysis and experimental results show that the presented converter meets the requirement for high step-up and has the following advantages. The switches and diodes were operated under low voltage stress. It is feasible to choose the switches with lower conduction resistance to enhance the efficiency. All the diodes have equal current and voltage stress is good for heat sinks design. It is flexible to change the number of DCM units to meet the various requirement for high step-up of different applications. The interleaved input form of this converter is more suitable for heavy input current applications. And this converter achieves automatic current-sharing with two-phase input and easy control.