斜坡补偿电流模式控制开关变换器的动力学建模与分析

降压型、升压型和升压-降压型DC-DC变换器是应用广泛的基本开关DC-DC变换器.电流模式控制开关DC-DC变换器在较宽的电路参数范围内具有两个边界,基于开关切换前后电感电流的上升和下降斜率,建立了斜坡补偿电流模式控制开关DC-DC变换器的统一模型.该模型进行无量纲归一化处理后只有三个参数,可有效展示开关DC-DC变换器在电感电流连续传导模式(CCM)和电感电流不连续传导模式(DCM)时的动力学特性.利用此模型,导出了轨道状态发生转移时的两个分界线方程,由此确定了开关DC-DC变换器的稳定周期1域、CCM鲁棒混沌域和DCM弱混沌强阵发域三个工作状态区域.开关DC-DC变换器二维参数映射图和电流模式控制降压型DC-DC变换器的电路实验观察验证了由两条分界线划分工作状态域的正确性.

Dynamical modeling and analysis of current mode controlled switching converter with ramp compensation

Buck, boost and buck-boost converters are three basic switching DC-DC converters. Current mode controlled switching DC-DC converters have two boundaries in a wide circuit parameters variation range. Based on the ramp up and ramp down slopes of the inductor current before and after the turn on of power switch for switching DC-DC converters, a unified model of the current mode controlled switching DC-DC converters with ramp compensation is established in this paper. Only three parameters appear in this model after dimensionless normalization, from which the dynamical behaviors of switching DC-DC converters in continuous conduction mode (CCM) and discontinuous conduction mode (DCM) can be effectively illustrated. By utilizing the proposed unified model, two orbit state shifting borderline equations are derived, from which three operation state regions namely the stable period-one region, CCM robust chaos region, and DCM weak chaos and strong intermittence region, of switching DC-DC converters can be determined. The two-dimensional parameter bifurcation diagrams of switching DC-DC converters and circuit experimental observations of current mode controlled buck converter verify the analysis results of the partitioning of operation state regions by two borderline equations.