基于LLC与交错并联结构的PFC电路研究

Research on PFC Circuit Based on LLC and Interleaved Parallel Structure

针对高频开关电源,设计一种基于Boost结构的功率因数校正(PFC)电路。前级采用交错并联的Boost结构,利用平均电流控制策略,实现输入侧的功率因数校正;后级采用半桥LLC谐振变换电路进行功率级变换,以实现电力电子器件软开关控制,从而降低系统开关损耗。通过电路系统建模仿真,表明输入电流能较好的跟随输入电压,半桥LLC谐振变换电路在原边实现了零电压开通(ZVS)、副边实现了零电流关断(ZCS),达到了优化电能质量及降低电能损耗的设计目标。

In this paper,a power factor correction circuit based on boost circuit is designed.The front stage adopts the interleaved boost structure,and designs the average current control strategy to realize the power factor correction of input side.The role of the second level is for power stage conversion,so as to realize the soft switching control of power electronic devices and reduce the switching loss of the system.Through circuit system modeling and simulation,it is shown that the phase of input current and input voltage is the same.When the half-bridge LLC resonant conversion circuit is turned on,the voltage of the original side is zero,and the voltage of the secondary side is zero when it is turned off,which achieves the design objectives of optimizing power quality and reducing power loss.