| Power electronic circuits can show rich nonlinear phenomena, such as bifurcations, chaos, etc. Therefore, chaotic dynamics is needed to analyze the phenomena. Modeling power electronic circuits with chaotic dynamics can help us to learn more about dynamic behaviors of power electronic circuits, which is beneficial to engineering design. On the other hand, power circuits will supply instances for the study of nonlinear science, which, as a result, can also contribute to the development of nonlinear science. Base on the nonlinear phenomena of switch converter, this thesis do some researchs. The main results as follow:1 , The thesis mainly discusses how to use the time discrete mapping method to get the model of DC/DC Buck converter. Then a discrete model of the DC/DC switch converter is derived. The dynamic evolutionary process of DC/DC Buck converter bifurcation and the chaos phenomenon are analyzed. The stability of converter is discussed. Finally, the accuracy of the system bifurcation and the chaos phenomenon are verified through simulation test. The results show that bifurcation and the chaos phenomenon of DC-DC Buck converter can be prevented by adjusting the voltage feedback parameter, so that the DC-DC Buck converter can work in a steady state.2, OGY method is used to control chaos in DC/DC converter. But the periodic orbit of the system must be found, before OGY method can work. Sometimes it is difficult to predict and calculate the periodic orbit, so the chaotic control technology based on Washout filter is used to control chaotic phenomena of DC/DC converter. The simulation results show the validity of the method.3, In this thesis a novel inverter topology (Buck inverter) is designed. It consists of two symmetrical DC-DC converters. These converters produce a sine wave output with same dc bias.The modulation of each converter is 180 out of phase with the other. The load is connected differentially across the converters. Thus, whereas a dc bias appears at each end of the load, with respect to ground, the differential dc voltage across the load is zero. The output voltage is sine wave.4, This thesis studys the Buck inverter based on sliding mode control. Operation and sliding mode control strategy of each are analyzed in detail. The simulation results prove the Buck inverter based on sliding mode control has good dynamics and steady-state response and its output voltage is a ideal sine wave. |
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