改进型高增益耦合电感Boost-Sepic变换器

Improved high-gain coupled inductor Boost-Sepic converter

针对光伏电池输出电压等级低、稳定性差的问题,本文将Boost-Sepic变换器进行改进,并加入耦合电感与开关电容两种增益单元,提出一种高增益耦合电感组合Boost-Sepic变换器。首先将组合后的Boost-Sepic变换器中输入电感替换为耦合电感原边,保证输入侧电流连续并钳位开关管电压;同时将耦合电感倍压单元与开关电容进行串联以提高电压增益。采用无源钳位吸收回路回收耦合电感漏感的能量,抑制开关管两端产生的电压尖峰。详细分析了Boost-Sepic变换器的工作模态、电压增益、开关器件电压/电流应力及器件参数的选择,并与其他高增益变换器对比。最后,通过200 W实验样机验证了变换器的可行性与正确性。

Aiming at the problem of low output voltage level and poor stability of photovoltaic,a high-gain coupled inductor combination Boost-Sepic converter was presented by improving the Boost-Sepic converter and adding two gain units of coupling inductor and switched capacitor.First,the input inductor in the combined Boost-Sepic converter was replaced with a coupled inductor primary side to ensure continuous input side current and clamp the power switch voltage;meanwhile,the coupled inductor multiplier unit was connected in series with the switching capacitor to improve the voltage gain.In the converter,a passive clamp absorption loop was used to recycle the energy of the leakage inductance of the coupled inductor,suppresses voltage spikes generated on the power switch.The new Boost-Sepic converter was analyzed in detail,including the selection of operating modes,voltage gain,switching device voltage and current stress,and device parameters,and compared with other high-gain converters.Finally,the feasibility and correctness of the converter was verified by a 200 W experimental prototype.