一种改进型双升压功率因数校正电路

摘要

针对双升压功率因数校正电路(dual boost power factor correction,DBPFC)输入电压采样和电感电流采样困难,控制电路复杂的问题,提出一种改进的DBPFC拓扑.该拓扑在MOS开关管的源极正串一个肖特基二极管以阻塞MOS开关管的体二极管,既可以采用电阻采样法来进行电感电流平均值取样,优化了控制电路设计.详细分析电路在一个开关周期内的工作模态和MOS开关管寄生电容对电路工作模态的影响,给出电路的重要仿真波形.对电路的功率损耗和效率进行了理论分析和对比.设计了基于该拓扑的实验样机,样机输出波形表明该电路抗扰动能力强,能够快速准确地实现功率因数校正.样机效率曲线验证了理论分析的正确性,表明电路在宽电压输入宽功率输出时均能取得良好的工作效率.%According to the voltage and current sensing difficulties and the complex control problems in dual boost power factor correction ( DBPFC) with two diodes, an improved DBPFC is proposed. Through connecting a schottky diode to the MOSFET' s source in series, the circuit can sense the boost inductor' s average current by using the sensing resistance, which optimized the control circuit. Operating modes of the improved DBPFC and the influence of the parasitic capacitances on MOSFET were discussed in detail and the key simulation waveforms were given. On the basis of it, the power dissipations and the efficiencies were theoretically analyzed and compared. The prototypes of the experimental circuit based on the improved DBPFC was built to provide waveforms which show that the circuit has better disturbance rejection ability, and achieves power factor correction quickly and accurately. The efficiency curves verify the correctness of theoretical analysis, and show that the circuit can achieve high efficiency in the wide input voltage range and wide power output.