Boost PFC变换器快时标分岔分析及其双积分滑模控制

摘要

In order to analyze fast-scale nonlinear phenomenon in Boost PFC in peak-current control mode, a discrete iterative map for Boost PFC converter was derived, and the expression of the state transition matrix was obtained according to this map. In addition, the bifurcation boundary of the system was also derived. Then the simulation was presented to show the intermittent bifurcations and chaos phenomenon of the inductor current in one input voltage cycle. To avoid bifurcations, a double integral sliding mode control was adopted to make the system operate stably in single-period state. Compared with slope compensation, a conclusion can be drawn that double integral sliding mode control can achieve good robustness without imposing external disturbance, and avoid bifurcations caused by variation of the input voltage effectively, which can also attain high power factor (PF) with simple algorithm. The new method is easy to realize and can provide reference for bifurcation control in PFC converters.%为了分析峰值电流型Boost PFC(power factor correction)在快时标下的非线性现象,建立Boost PFC变换器的离散迭代映射,并基于此映射推导其状态转移矩阵的表达式,得到系统分岔的条件,通过仿真观察系统电感电流在输入电压周期内出现的间歇性分岔和混沌现象.为了避免分岔,使系统稳定工作在单周期态,采用双积分滑模的控制方法.仿真结果表明:与常规的斜坡补偿法相比,双积分滑模法不需要施加外部扰动,且具有良好的鲁棒性,在有效地避免因输入电压变化所产生的分岔现象的同时,让Boost PFC具有较高的功率因数(PF),且算法简单,易于实现,对PFC变换器的分岔控制提供了借鉴.