并联DC/DC变换器的混杂系统建模与优化控制

Hybrid system modeling and optimization control for parallel DC/DC converter

DC/DC变换器是一类典型的混杂系统,使用传统的建模方法难以表征其混杂特性。文章引入v步建模法深入分析了并联DC/DC Buck变换器的动态过程,导出了其动态演化方程,建立了系统的混合逻辑动态模型。在此基础上,提出了将模型预测控制与交错PWM技术相结合的DC/DC变换器控制策略,实现了对并联DC/DC变换器的优化控制。为验证控制的有效性,对系统进行了仿真。结果表明:这种控制策略即使在输入电压或负载发生突变时也能使系统快速有效地跟踪参考信号,迅速恢复至稳态且变化幅度小,具有良好的动态性能。

A DC/DC converter is a typical kind of hybrid system. It is difficult to characterize its hybrid characteris- tics by traditional modeling methods. In this paper, a v-step modeling approach is introduced to deeply analyze the dy- namic process of parallel DC/DC converter and deduce its dynamic evolution equation, thus yielding the mixed logical dynamical （MLD） model. On the basis of it, a control strategy combining model predictive control and interleaving PWM technology is proposed to implement the optimal control of a DC/DC converter. In order to verify the effective- ness of the control, a system simulation experiment is made. And the obtained results show that the strategy enables the system to quickly and efficiently track the reference signals and quickly return to its steady state with small magni- tude change even in such a case where the input voltage or load resistance suddenly changes, and the system has a good dynamic performance.