基于混杂系统理论,建立了升压型开关变换器的混杂自动机模型,使得开关变换器的控制简化为混杂自动机模型的边界选择问题。与传统的状态空间平均法和电路平均法相比,该模型中没有任何假设和线性近似,建模精度高,可以对电力电子电路进行更好的分析与控制。根据开关变换器电感最小电流与输出电流的比较,将电感电流连续模式细分为完全电感供能模式和不完全电感供能模式两种子模式,提出一种新的混杂控制策略,应用电路理论方法给出了理想变换器和考虑输出电容寄生电阻的混杂控制边界的综合方法和计算公式。数值结果和分析表明了混杂建模和控制策略的有效性。
The boost switching converter is modeled as a hybrid automaton model with three modes of operation for the purpose of designing an appropriate control law to regulate its output voltage.The control problem is simplified to a boundary selection problem.Compared with the state space average method and the circuit average approach,the proposed model makes no assumptions and linear approximation,which is more suitable for analyzing and controlling of power electronic circuits.By comparing the minimum current through the inductor with the average output current,the CCM(continuous conduction mode) is divided into two types,i.e.,the Complete Inductor Supply Mode(CISM) and the Incomplete Inductor Supply Mode(IISM).A new hybrid control scheme is put forward to regulate the output voltage of the boost converter.Boundary conditions,governing the transition of the converter operation from one discrete state to the other in a hybrid automaton representation are derived for both the ideal and the practical boost converters from the basic circuit laws.The state trajectories have been shown to reach a hybrid limit cycle already proved to be super-stable from consideration of chaos.Numerical results clearly bring out the advantages of the proposed control scheme and the hybrid model.