由于开关非线性，功率因数校正(power factor correction，PFC)Boost变换器中会出现工频周期尺度上的分岔，即慢时标分岔。首先分析所有影响慢时标分岔的因素，并揭示其影响规律；然后引入负载电流前馈方法，使PFC变换器在远离饱和区工作，实现对慢时标分岔的控制；最后，实验验证了理论分析和仿真的结果。研究结果有助于更好地理解PFC变换器中的慢时标分岔，对PFC变换器的设计也有一定的参考价值。

Because of switching nonlinearity, the slow-scale bifurcation with the line period time-scale may occur in the power-factor-correction (PFC) Boost converter. Firstly, all factors that influence the slow-scale bifurcation were analyzed and the influencing results were also revealed. Secondly, the load current feedforward method was introduced to control the slow-scale bifurcation through keeping the PFC converter from saturating. Finally, the theoretical analysis and simulating results were verified by experiment. The research results are beneficial to understand the slow-scale bifurcation in PFC converters more clearly and is helpful to the design of PFC converters.

国家自然科学基金项目(50577047)；山西省自然科学基金(2009021021)。