级联H桥Boost PFC电源建模及应用研究

针对电感电流断续导电模式(DCM)功率调节器固定占空比,输入电流纹波含量大导致功率因数降低的问题,提出了一种具有自动调节功能的级联H桥开关周期平均模型。给出了Boost PFC电路拓扑结构,并分析了该电路的工作原理。论证推导了在DCM模式下时均模型修正方程表达式。利用LTspice软件进行仿真分析并进行实验验证,其结果与传统固定占空比的DCM功率调节器相比,很大程度减少了低频输入电流纹波,有效降低了谐波含量。仿真结果和样机实验验证了所提出的模型和控制策略的有效性。

Modeling and application research of power based on cascaded H-bridge Boost PFC

Aiming at the problem that the duty cycle of the inductance current discontinuous conduction mode(DCM)power regulator is fixed and the large input current ripple leads to lower the power factor,a cascade Hbridge switching cycle average model with automatic regulation function was proposed.The topology of Boost PFC circuit was presented and its working principle was analyzed.The modified equation expression of time-averaged model in DCM model was deduced.The results of LTspice simulation and experimental verification show that compared with the traditional DCM power regulator with fixed duty cycle,the low-frequency input current ripple greatly reduces and the harmonic content effectively reduces.The simulation results and prototype experiments verify the effectiveness of the proposed model and control strategy.