一种单相降压型PFC电路及其非线性控制

发布时间：2018-06-11 10:21

本文选题：单相功率因数校正 + 降压　；参考：《电机与控制学报》2017年11期

【摘要】：以Buck为基础的单相功率因数校正(power factor correction,PFC)电路,器件电压应力小,输入、输出电流控制能力强;但输入电流存在固有死区,造成输入电流畸变。提出一种双电路模式的单相降压型PFC电路,通过加入1个辅助开关和1个二极管,在传统Buck PFC变换器的输入电流死区时间段,使电路工作于Buck-Boost模式,消除电流死区。对于Buck与Buck-Boost之间的切换控制问题,基于单周期控制,推导出一种非线性控制策略,不同工作模式具有相同的电流控制律,消除了模式切换造成的电流畸变,从而实现单位功率因数。设计了1台开关频率为50 k Hz、输出为100 V/1 A的实验样机,在175~265 V输入电压范围内,输入电流保持较低的总谐波畸变率(total harmonic distortion,THD)。电路实现2个开关管共地,驱动电路设计简单;且不同电路模式采用相同的电流控制律,简化了控制,有利于实际的工程应用。
[Abstract]:The single-phase power factor correction circuit based on Buck has small voltage stress, strong input and output current control ability, but the input current has inherent dead zone, resulting in input current distortion. A single-phase step-down PFC circuit with two circuit modes is proposed. By adding an auxiliary switch and a diode, the circuit can work in Buck-Boost mode during the dead time of input current of the traditional Buck PFC converter, thus eliminating the dead-time of the current. For the switching control problem between Buck and Buck-Boost, a nonlinear control strategy is derived based on single-period control. Different working modes have the same current control law, which eliminates the current distortion caused by mode switching. Thus the unit power factor is realized. An experimental prototype with a switching frequency of 50 kHz and an output of 100V / 1 A is designed. In the range of 175V / 265V input voltage, the total harmonic distortion rate of the input current is lower than that of the total harmonic distortion THD. The circuit realizes two switches in common, and the drive circuit design is simple, and different circuit modes adopt the same current control law, which simplifies the control and is beneficial to practical engineering application.
【作者单位】：福州大学电气工程与自动化学院;
【基金】：福建省科技厅重大项目(2014H6012) 福建省自然科学基金(2015J01193)
【分类号】：TM46

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