| With the rapid development of science,nonlinear dynamics is applied to various fields,for complex systems,cryptography,signal processing,multimedia,communication system,research in the field of biology,economy system and provides a new means and methods,the traditional linear method is difficult to accurately grasp and understand the current area of cognition,especially questions about the evolutionary dynamics.Chaotic circuit is the core of chaos widely used in information science.The integrated design,theoretical analysis,numerical simulation and circuit realization of chaotic system is to design the spectrum of chaotic signal and optimize the characteristics of chaotic signal in order to meet the needs of various applications.Therefore,it is of great significance to study the nonlinear dynamic behavior of the switching converter and control the chaos in the switching converter.In thesis,the converter topology in power electronics is taken as the research object,and a mathematical model is established for it.The simulink simulation platform is built through the mathematical model,and the simulation circuit is built by using multisim simulation software.The accuracy of the mathematical model is verified through multisim simulation,so that the dynamic behavior of the multi-module parallel converter topology can be easily studied.In thesis,single-module converter topology and multi-module converter topology are taken as research objects,and their dynamic behaviors are studied respectively.The specific work is as follows:(1)There are abundant dynamic phenomena in discrete time system and continuous time system.Thesis studies the dynamic behavior and stability analysis of one-dimensional discrete system and two-dimensional discrete system.Continuous time system is divided into autonomous system and non-autonomous system.Based on the one-dimensional discrete system,a simulink simulation model of the continuous time system was established,and the nonlinear dynamics of the system was studied with parameter change.(2)There are three basic topologies in power electronics: Boost converter,Buck converter and Buck-Boost converter.These three converters can be controlled by different control modes,the more common control modes are dual loop control and single loop control(such as: voltage loop control,current loop control).Taking Buck-Boost converter as the research object,a mathematical simulation model was established for it,and a simulink simulation platform was built to study the nonlinear dynamic behavior of the converter by changing different parameters.At the same time,the discrete mapping is established to guarantee the stable operation of the analysis converter.(3)Multi-module PFC Boost converter has a more complex circuit model than single-module PFC Boost converter.Therefore,a mathematical model is established for multi-module PFC Boost converter,and the established mathematical model is not only suitable for synchronous switching mode but also for asynchronous switching mode.In the synchronous switching mode,the system presents no interleaving state.Multiple PFC Boost converters with parallel modules can be equivalent to a single-module converter system,so the single-module converter theory can be used to analyze the multi-module converter system.Unsynchronous switching mode,the system presents a interleaving state;the parallel structure Boost PFC converter also has fast–scale bifurcation phenomenon,on the slope compensation design,can eliminate the fast-scale bifurcation phenomenon,fast change of phase parallel Boost PFC converter,with the increase of phase difference value,the study found that the system needed to compensate the amplitude is reduced,the decrease of the amplitude compensation can maintain a higher power factor,in different switching mode for multiple modules in parallel fast the stability range of the converter are analyzed.The results show that the system can obtain wider stable range and higher power factor in asynchronous switching mode than in synchronous switching mode. |
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