中文摘要：

功率因数校正（PFC）变换器普遍存在输入电流在输入电压过零点附近发生畸变的现象。现分析了PFC变换器输入电流在输入电压过零点附近产生畸变原因的基础上，针对PFC变换器的输入电流超前于输入电压，从而导功率因数不为1和输入电流过零畸变的问题，提出了一种在输入电压过零点，根据输入电流实测值对PFC变换器的给定电压信号初始相位进行实时调整的数字控制方法，从而达到改善变换器输入电流过零畸变和提高功率因素的目的。通过仿真分析验证，该控制方法有效，特别是在400Hz输入电压时该方法取得了特别好的效果。

英文摘要：

Operation in the continuous conduction mode in power-factor-correction （PFC） converters, the behavior of the current control loop determines how accurately the input current tracks the desired waveshape. Since the behavior of this loop is influenced by the impedance of the electromagnetic interference filter and the unknown time-dependent line impedance, guaranteeing stability of the converter under all circumstances is not obvious. To increase the robustness of the current-control loop against variations of the impedance at the input of the converter, the insertion of a low-pass filter in the measurement circuit of the input voltage is suggested here. However this manner may lead to more serious input current distortion when the input voltage is at the zero-crossing in converters, and this prob- lem may be worsen in the applications with a high line frequency （e. g. , 400 Hz power systems on commercial aircraft）. This paper analyzes the cause of zero-crossing distortion and indicates that input current leads the input voltage is the key reason for a non-unity fundamental displacement factor and zero-crossing distortion in boost PFC converter. A digital control method is proposed, according to the value of input current at the zero-crossing of input voltage, and the initial phase angle of reference input voltage is adjusted to improve the zero-crossing distorted phenomenon of the PFC converter. The simulation results indicate that the proposed method is good for AC power supply, especially under higher frequency of 400 Hz.