DC-DC变换器的通用大信号自适应控制策略构建

摘要

A general large-signal adaptive control strategy for a DC-DC converter is proposed to deal with its wide-range operations.The global operation space of the DC-DC converter is divided into several local subspaces, then small-signal modeling and linear compensation design are performed respectively. With convex combination, a global control structure is constructed by linear compensators in each subspace via weighted functions that automatically determine the weighted coefficients of every local linear compensator, which makes the controller possesses a region-adaptive functionality. According to the proposed large-signal controller, the nonlinear control problem of the DC-DC converter can be resolved indirectly through linear compensation approaches, by which, the advantages of clear physical meaning and easy design of the classical frequency-domain methods are preserved. Finally, with the basic DC-DC converter and cascaded DC-DC converter as study objects, the design process of the large-signal control strategy was illustrated, and the effectiveness of this strategy was verified by experimental and simulation results.%针对DC-DC 变换器工作点大信号范围变化的情况,提出了一种DC-DC开关变换器的通用大信号自适应控制策略.将开关变换器全局工作区域分割成若干子区域并分别进行小信号建模与线性补偿设计,依据权函数将各个子区域的线性补偿器通过凸组合构建出全局控制器结构,权函数依据外部扰动自助确定各局部线性补偿器的作用权重系数,从而具备"区域自适应功能".根据所提大信号控制结构,DC-DC变换器的非线性控制问题可以间接通过线性补偿解决,从而保留经典频域法具备物理意义明确和易于设计的优点.最后,分别以基本Buck变换器和级联DC-DC变换器为研究对象,说明了大信号控制策略的设计过程并通过仿真和实验验证了控制策略的有效性.