对单周期控制三电平Boost功率因数校正(PFC)变换器中存在的慢尺度分岔现象进行了研究,基于Floquet乘子法分析了主要电路参数对系统稳定性的影响.首先,分析了该电路的工作原理,并由输入输出功率平衡推导出电路的简化模型.然后,采用谐波平衡法求解出电路的周期解,根据Floquet理论分析周期解的稳定性.通过计算Floquet乘子,分析了电路中电压反馈电阻Rvf对系统慢尺度分岔行为的影响.搭建电路仿真模型,验证了简化模型及Floquet理论分析的正确性.最后,计算了电路中其他参数组成的稳定边界.研究结果表明,正确选择三电平Boost PFC变换器的电路参数对于其稳定运行,提高输入侧功率因数具有重要意义.
In this paper, the slow-scale bifurcation phenomenon of the one-cycle-controlled three-level Boost power factor correction (PFC) converter is studied in depth, aiming at analyzing the influence of main circuit parameters on the stability of the system based on Floquet multiplier method. Firstly, the working principle of the circuit is analyzed, and a simplified model is derived according to the power balance principle. The periodic solutions are investigated using the harmonic balance method, and its stability is studied by the Floquet theory. By calculating the Floquet multiplier, the influence of the voltage compensator resistor Rvf on the slow-scale behavior of the system is analyzed. The simulation result verifies the correctness of the simplified model and theoratical analysis. Finally, the stability boundary composed of filter capacitor C and load resistor R as well as feedback resistor Rvf and capacitor Cvf is calculated and simulated under certain conditions. The circuit simulation result is consistent with the theoretical calculation. The results show that the correct choice of circuit parameters of three-level Boost PFC converter is very important for achieving its stable operation and improving the power factor.