基于Sepic的单开关高增益DC/DC变换器

High step up DC/DC converter based on Sepic with a single switch

为解决传统耦合电感型升压变换器电压增益低、输入电流纹波大等缺点。将传统的Sepic变换器与耦合电感、开关电容两种电压增益提升单元组合,提出了一种新型的高增益变换器。该变换器在提高电压增益的基础上削弱了MOS管漏、源极间于振荡所产生的电压尖峰,并且保留了Sepic变换器输入电流连续的优点,适合应用在可再生能源系统中。首先利用耦合电感替换Sepic变换器中的输出电感,随后引入开关电容单元与无源箝位电路,增加电压增益的同时还解决了漏感问题,漏感能量得到了循环利用,从而进一步提高了变换器效率。详细分析了该新型高增益变换器的工作原理,并且在实验室构建了一台额定功率为200 W的实验样机,实验结果成功验证了所提变换器原理分析的正确性与可行性。

In order to solve the shortcomings of traditional coupled inductance boost converters such as low voltage gain and large input current ripple.Combining the traditional Sepic converter with coupled inductor and switched capacitor voltage gain boosting units,a new type of high gain converter is proposed.On the basis of improving the voltage gain,the converter weakens the voltage spikes caused by the oscillation between the drain and source of the MOS tube,and retains the advantage of continuous input current of the Sepic converter,which is suitable for application in renewable energy systems.Firstly,the output inductor in the Sepic converter is replaced by a coupled inductor,and then a switched capacitor unit and a passive clamp circuit are introduced to increase the voltage gain and solve the leakage inductance problem.The leakage inductance energy is recycled,thereby further improving the converter effectiveness.The working principle of the new high-gain converter was analyzed in detail,and an experimental prototype with a rated power of 200 W was constructed in the laboratory.The experimental results successfully verified the correctness and feasibility of the principle analysis of the proposed converter.