具有高增益、低输入电流纹波的Boost变换器研究

Research of High-gain Low-input Current Ripples Boost Converter

针对光伏、燃料电池等低压可再生能源发电系统,在传统Boost变换器基础上,利用耦合电感的原边替代基本Boost变换器中的独立电感,同时引入一个较小的辅助电感,提出一种单开关高增益、低输入电流纹波Boost变换器。耦合电感的使用,既增加了变换器的控制维度,又能在合适占空比条件下实现较高的电压增益;较小的输入电流纹波可以改善变换器对前端低压输入电源的电磁干扰;另外,该变换器中开关管的电压应力可以得到有效降低,有利于选取低电压等级、低导通电阻的高性能开关器件,以提高变换器的性能;详细分析了该变换器的工作原理及其稳态工作特性,并通过实验验证了理论分析的正确性与有效性。结果表明,所提变换器可以实现较高的电压增益和较小的输入电流纹波,具有实用价值。

According to the renewable energy source system such as photovoltaic and fuel cells, a single switch high step-up Boost converter based on the conventional Boost converter with low-input current ripple is proposed in this paper. The application of coupled inductor makes the converter to achieve high voltage gain without utilizing extreme values of duty cycle by adjusting the turns ratio of coupled inductor. Also, the control dimension of the converter can be increased. The low-input current ripple can improve the electromagnetic interference of the converter to low-voltage power supply. Besides, the voltage stresses of the semiconductor devices are reduced efficiently, and the high-performance active switch and diodes with low voltage-rated and low resistance can be selected, which is helpful to improve the efficiency of the converter. The operating principle and steady-state characteristics of the converter are analyzed in detail. Finally, the ex- perimental results are given to verify the correctness and effectiveness of theoretical analysis, which prove that the proposed converter is practical in application with good performances.