Buck变换器线性参数变化模型的增益调度控制

针对开关变换器的输出电压极易受到输入电压或者负载波动的影响,提出一种建立在Buck变换器线性参数变化(LPV)模型基础上的增益调度控制策略.首先,将Buck变换器的小信号模型转换成以负载电阻和输入电压作为变参数的LPV模型,基于LPV的凸分解方法,利用线性矩阵不等式(LMI)技术对凸多面体各顶点分别设计满足H∞和闭环极点配置的反馈控制器,再插值各顶点所设计的反馈控制器,综合得到具有多面体结构的LPV控制器.该方法在线计算量小,容易实现.最后,通过仿真验证了设计方法的有效性,与传统的鲁棒控制策略的控制器相比,所设计的LPV控制器受Buck变换器中输入电压和负载电阻波动影响较小,具有更好的控制性能.

Gainscheduling Control Based on Linear Parameter Varying Model of Buck Converters

The output of switching converters can be easily influenced by the load and the line voltage. In this paper, a gain scheduling control based on a linear parameter varying (LPV) model of Buck converters is proposed to avoid this situation. Firstly, based on the small signal model of Buck converters, the LPV model with the load and the line voltage used as varying parameters is established by convex decomposing technique. Then, an LPV controller is designed with a structure of convex polytope using linear matrix inequality (LMI) technique. A system with this controller can have H∞ performances and all the closed loop system poles are located in a specific area. Finally, the simulation results show that the system with LPV controller has better performances than those with robust state feedback controllers.