Analysis And Research Of Non-Linear Phenomena In PWM DC-DC Converter

Chaos is a kind of seemingly random, chance or irregular movement, which appears in a definiteness system. The cognition of chaos phenomena is a very important effort of non-linear system. Chaos will be widely applied to engineering. A DC-DC converter exhibits abundant non-linear phenomena when it contents certain condition. Along with the increasing requirement to control performance of DC-DC converters, in order to improve the control performance of DC-DC converters, it is significant and helpful to further analyze non-linear phenomena in the DC-DC converters under the guidance of nonlinear dynamics theory.First, the article introduces the research status of nonlinear dynamics and the development of non-linear phenomena, discusses the development of nonlinear research in power electronics circuit both at home and abroad, and presents the content of this dissertation.Second, it introduces in detail the basic conception of nonlinear dynamics theories which are most critical and most closely related to the content of this dissertation. These theories include basic notions of chaos and bifurcation theory and summarize some familiar bifurcations in PWM DC-DC converters.Third, combine with the work principle of PWM DC-DC converters, it presents several main modeling methods: frequency mapping method, sampled-data method and subsection numerical value method and adopts sampled-data method to analyze the stability of DC-DC converter.At last, it adopts subsection numerical value method to analyze the period-doubling bifurcation phenomena and uses Matlab to emulate bifurcation phenomena when the parameters of input voltage, capacitance, inductance and period are varied. Then through circuit experiment, the author proves the period-doubling bifurcation phenomena when circuit parameters change.