基于开关–电容网络的单相三电平PFC电路研究

Research on Three-level PFC Circuit Topology Based on Switch-diode-capacitor Network

三电平及多电平技术的应用可以降低开关管电压应力,并且在一定的程度上可以降低滤波器的体积。为减少传统三电平整流器的可控器件数量,降低开关损耗和提高装置自身运行可靠性,首先,该文提出一类基于开关–电容网络的新型三电平功率因数校正电路,该电路在每个工作模态中至多存在一只开关管工作,一定程度上降低了拓扑结构损耗及控制复杂程度,在模态切换过程中存在有互补性脉宽调制信号,使控制方式较为简单。然后,该电路在开关管故障的情况下,由于该拓扑结构集成体二极管为H桥提供电流流通路径,以保证电路短时间对外输出功率。最后,搭建输入交流为220V、输出直流为400V、额定功率为0.8kW及输出效率为97.8%的一台实验样机,验证理论分析的正确性。

To a certain extent, the application of three-level and multi-level technology can reduce the voltage stress of the switch, and can reduce the volume of the filter. To reduce the number of controllable components for the traditional three-level rectifier, which was reduced switching losses and improved the operation reliability of the device itself. Firstly, a novel three-level power factor correction circuit based on switch capacitor network was proposed. In this circuit, there were at most one switch in each working mode, which reduces the topology loss and control complexity to a certain extent, There were complementary pulse width modulation signals in the process of mode switching, which makes the control mode simpler. Then, in the case of switch failure, the integrated diode provided a current flow path for the H-bridge to ensure the short-term output power of the circuit. Finally, an experimental prototype was built with input AC of 220 V, output DC 400 V, rated power 0.8 kW, and output efficiency 97.8% to verify the correctness of the theoretical analysis.