Non-linear Power Electronic Devices Chaos Control Study

A variety of nonlinear behaviors in DC / DC converter, for example: Loss of stability when the system is running, the uncertain electromagnetic noise and system crash, for a long time, was because of the chaos in nonlinear systems. Currently the attention of the majority of scholars has been attracted to this area and it became a hot research topic, then a variety of control methods have been one after another. However, due to the strong non-linear and complexity of modeling of switching circuit, research is still in the initial stage. In this paper, DC / DC converter (Buck converter and Boost converter) as an example for discrete modeling, theoretical analysis, design control method and computer simulation, etc.Specific content is given as follows:First of all, the history and characteristics of chaos theory has been introduced. Then, Several chaos detection methods have been introduced. The application of chaos theory in nonlinear power electronics converters and the overview of research on chaos control in recent years have been elaborated.Secondly, nonlinear circuit theory, some important theorems and terminology have been introduced. Then, the classification and characteristics of balance point have been described in detail. Next in this section, bifurcation theory as an important concept in chaos theory has been introduced.Thirdly, state space averaging method was briefly introduced. Then, based on the state space averaging method computer simulation was conducted. In this section, accurate discrete model of DC / DC converter is described in detailed. And according to the characteristics were different, modeling methods were classified. Based on accurate discrete modeling method, the discrete model of Buck converter was set up, at the same time improvements have been made based on the previous.Fourthly, in this section, the main discussion is on the control for the chaos of DC / DC converter. Some commonly used control methods were introduced, and the advantages and disadvantages of each method was analyzed. Then, adaptive synchronization control method was applied to control the chaos of DC / DC converter, and a detailed study and discussion were carried out.Finally, using accurate modeling method, the accurate discrete model of DC/DC converter working in discontinuous conduction mode is set up. Then, we choose feedback parameter K as the bifurcation parameter, the stability of the system was analyzed. In order to verify the validity of the mode, experiment, bifurcation diagram simulation and Lyapunov exponent simulation were conducted. At last, the adaptive synchronization method was adapted to control the chaos of DC/DC converter, we investigate the Synchronization results and the convergence curve under variation of a range of circuit parameters. Then, the simulation experiment is conducted.