【摘要】 介绍了一种新型三相单级全桥功率因数校正(PFC)变换器,该变换器能同时实现功率因数校正、输入输出侧电气隔离以及输出电压调节。详细分析了桥臂开关对臂导通期间,变压器一次侧振荡电压的产生机理及其抑制方法,并提出一种可抑制该振荡电压的无源缓冲电路。该电路由电容、电感和二极管组成,通过在变压器一次侧并联电容来达到抑制振荡电压的目的,利用电感与电容的谐振工作实现能量传递,将电容上的能量在一个开关周期内转移给负载。实验结果证明,该无源缓冲电路的采用有效地抑制了变压器一次侧以及各开关管的振荡电压。更多还原

【Abstract】 A novel three-phase single-stage full-bridge power factor correction(PFC)converter is presented,which can realize the functions such as power factor correction,electrical isolation between input and output sides and output voltage regulation.The mechanism and suppression method of oscillatory voltage across the primary side of transformer is analyzed in detail when the bridge diagonal-leg switches turn on,and a passive snubber circuit is proposed to suppress this oscillatory voltage.The snubber circuit is composed of capacitor,inductors and diodes.The capacitor is connected in parallel with the primary side of transformer to suppress the oscillatory voltage.The energy of capacitor can be transferred to the load during one switching cycle by the resonance of the inductor and capacitor.The oscillatory voltage across the primary side of transformer and the switches is suppressed efficiently through the passive snubber circuit,which has been verified by the experimental results.更多还原