使用有源功率因数校正技术可有效抑制电网电流谐波和提高开关电源功率因数。文中分析了临界导电模式Boost型功率因数校正电路的电路结构及其工作原理,应用反馈控制理论,研究了功率因数校正环节的控制特性,给出了其电路参数的设计方法,保证在电网电压和负载功率大范围变化时,功率因数维持在0.99 以上。

Active power factor correction technology can restrain humorous waves of input current, and improve the power factor of switch power efficiently. Prototype and working principle of current critical conduction mode Boost PFC circuit are introduced. The chracteristic of control for circuit regulation is studied and design method of circuit parameters is given based on feedback control system, so that good performance can be achieve at steady stage in fluctuation of input voltage and overload. This prototype power factor is greater than 0.99.