【作者】 邹艳丽；

【导师】 罗晓曙；

【作者基本信息】 广西师范大学 ， 电路与系统， 2003， 硕士

【摘要】 本文以几种非线性电路为主要研究对象，针对这些系统的特点，对其混沌产生机理和混沌控制方法进行了探索和研究，获得了较好的结果。首先，提出了基于变量的比例微分反馈进行混沌控制的方法，并将其应用到两个经典的自治混沌系统Lorenz系统和Chen氏系统以及两个经典的非自治系统Rossler系统和Buluser振子系统的混沌控制中，抑制了这些系统的混沌。其次，研究了混沌Chua电路和超混沌Chua电路的混沌控制问题。首先针对混沌Chua电路提出了应用变量的微分反馈控制混沌的方法，并设计了基于该方法的两种电路实现方案，即连续微分反馈控制电路实现和脉冲微分控制电路实现，电路仿真的结果与理论分析和数值模拟具有很好的一致性。接着研究了超混沌Chua电路的混沌控制，研究发现单变量的比例微分控制对超混沌的控制是不充分的，既至少需要应用两个变量的比例微分反馈才能实现超混沌Chua电路的控制。第三，研究了多涡卷Chua电路中不动点处Jacobian矩阵特征根的性质，并据此将不动点分成两类，应用变量的比例微分反馈法分别对这两类不动点的可控性进行了研究，研究发现该法只能实现第一类不动点及其相应子空间的混沌控制，而不能完成第二类不动点的混沌控制，并给出了数值模拟结果, 理论分析和数值模拟证实了该方法的有效性。第四，研究了DC/DC功率变换器中降压Buck变换器的控制问题。首先研究了脉宽调制式的buck变换器中混沌产生的原因，研究发现开关S导通时，电容充电过快是这类电路中混沌产生的主要原因，在此基础上提出了应用脉冲微分反馈控制Buck变换器的混沌，并设计了控制电路，数值模拟和电路仿真的结果证实了该混沌控制方法的有效性。然后提出了降压buck变换器的滑动模实现方案，并设计了滑动模控制的buck变换器的电路实现方案。电路仿真表明，滑动模控制的buck变换器的许多动态性能和静态性能都优于PWM控制的buck变换器。更多还原

【Abstract】 In this paper, we study the mechanisms of generating chaos and methods of chaos control with respect to several nonlinear circuits based on the characteristics of these systems. Better results are obtained.At first, a feedback chaos control method based on variables’ proportional and differential is presented. and then it is applied to two autonomous classical physical systems Lorenz system and Chen system as well as two non-autonomous classical physical systems Rossler system and Buluser vibrator. Chaos in these systems are suppressed.In the next place, chaos control on chaotic and hyper-chaotic Chua’s circuits are studied. First of all, a chaos control method based on variable’s differential feedback is presented and applied to control chaos on chaotic chua’s circuit. And then based on this chaos control method, two schematic circuits are designed, i.e. continuous differential feedback realization and impulse differential feedback realization. The circuit simulations are consistent with the theoretical analysis and numerical simulations. Then, chaos control on hyper-chaotic Chua’s circuit is studied using feedback method of variables’ proportional and differential. It is demonstrated that instead of feeding back one system variable to control chaos it needs at least two system variables to control hyper-chaos. Third, controlling chaos in the chaotic n-scroll Chua’s circuit is studied. The approach taken is to use feedback of a single state variable in a simple PD (proportional and differential) format. First, the unstable fixed points in the n-scroll Chua’s circuit are classified into two different types according to the characteristics of the eigenvalues of the linearized system matrix at the fixed points. Then, the controllability of these two-types of fixed points is studied. Theoretical analysis shows that the first type of unstable fixed points can be stabilized, at which Hopf bifurcation can also be generated. Control results of the n-scroll Chua’s circuit are then demonstrated. Both theoretical analysis and numerical simulation results show that the proposed chaos control method is indeed effective. Forth, chaos control on buck converter in DC/DC converter is studied. At first, the mechanism of generating chaos on PWM buck converter is analyzed. It is found that when the switch S is on, the capacity charges too fast is the main reason why generating chaos in the circuit. Then based on above analysis, we present the method of using output voltage pulse differential feedback to control chaos in the buck converter. theoretical analysis, numerical calculation and circuit simulation demonstrate the validity of this chaos control method. Then, we present a schematic of buck converter by using sliding mode control and then design a circuit based on it. Circuit simulation demonstrated that the dynamic and static performances of buck converter controlling by sliding mode are better than that of PWM converter.更多还原