一种降低Buck PFC电流谐波的SVPWM方法

An SVPWM Method to Reduce Current Harmonics of Buck PFC

对于三相六开关Buck功率因数校正(PFC)整流器,采用3个驱动信号的空间矢量脉宽调制(SVPWM)方法,能够保证最小的开关损耗和节约硬件成本,然而在相电压交点附近,输入滤波电容电压纹波会导致输入电流畸变。对此,研究3个驱动信号的SVPWM方法产生电流畸变的原因,提出一种改进的6个驱动信号的SVPWM方法。在调制方法中加入叠流时间,比较所提出的4种叠流方式,保证所有开关管先开通后关断的同时减少开关损耗。最后,实验验证所提的SVPWM方法的可行性,能够有效降低输入电流总谐波畸变率(THD)。

For the three-phase six-switch Buck power factor correction(PFC)rectifier,the space vector pulse width modulation(SVPWM)method using three driving signals can ensure the minimum switching loss and save the hardware cost,however,near the intersection of phase voltages,the input filter capacitor voltage ripple will cause distortion of the input current.In this regard,the reason for the current distortion caused by the three driving signals SVPWM method is studied,and an improved SVPWM method with six driving signals is proposed.In the modulation method,the overlap time is added,and the four proposed overlap methods are compared to ensure that all switches are turned on first and then turned off while reducing the switching loss.Finally,experiments verify the feasibility of the proposed SVPWM method,which can effectively reduce the total harmonic distortion(THD)of the input current.