改进的单级功率因数校正AC/DC变换器拓扑的研究

Study on Topologies of Improved Single-stage Power Factor Correction AC/DC Converters

单级功率因数校正(简称单级PFC)由于控制电路简单、成本低、功率密度高在中小功率场合得到了广泛的应用。但是单级PFC中存在一些问题,如储能电容电压随输入电压和负载的变化而变化,在输入高压或轻载时,电容电压可能达到上千伏,变换器的效率低,开关损耗大等缺点。介绍了几种改进的拓扑结构来解决这些问题。

The single-stage power factor correction （SZ-PFC） is used widely because of simple control circuit, low cost and high power-density in medium and small power application. But there are some problems in the S2-PFC, for example, energy storage capacitor voltage varies with the input voltage and load, capacitor voltage is likely to amount to 1 000 volt at the high input voltage or light load. Converters have low efficiency and high switching losses. Several improved topologies are introduced to solve these problems in this paper.