【摘要】 输入电流在输入电压过零点附近会发生畸变是功率因数校正(PFC)变换器普遍存在的现象。当输入频率增大时,其畸变会变得非常严重。本文详细分析了PFC变换器的输入电流在输入电压过零附近产生畸变的原因,指出电感大小和电流环的相位差是影响高频输入下过零畸变严重的根本原因,Boost三电平变换器由于可以减小电感,提高等效开关频率,因此可以有效地减小过零畸变。仿真和实验结果证明了该变换器输入电流的各次谐波均有效地减小。该拓扑适合于高输入频率下的PFC应用场合,尤其对于即将采用360Hz-800Hz变频交流供电体制的航空电网。更多还原

【Abstract】 Input current distortion at the zero-crossing of the input voltage is a common problem in Power Factor Correction (PFC) converters. When the line frequency is increased, the distortion will become more serious. This paper analyzes the essential causes of the zero-crossing distortion and points out that the major causes are the value of inductor and the phase displacement of the current loop. Because the Boost Three-Level (TL) converter can decrease the inductor and increase the equivalent switching frequency, it is adopted to reduce the distortion. Simulation and experimental results are presented to show that all harmonics of the input current are attenuated efficiently. This topology is suitable for the high frequency PFC application, especially for the future airborne systems which will adopt variable frequency AC system ranged from 360Hz to 800Hz.更多还原