CCM和DCM模式Buck变换器建模与混沌现象仿真

Modeling and Chaotic Phenomena Simulation of Buck Converter in CCM and DCM

利用Matlab/Simulink分别建立了电流连续和断续模式的电压控制型Buck变换器的两种模型,通过仿真观察到了混沌现象。该模型成功地模拟了可控功率开关的开关状态及其PWM驱动信号,非常贴近于开关的实际工作状态。对两种模式的模型进行仿真,在电流连续模型中,得出输入电压变化时的V-I相图和系统主要电量的时域波形图,观察到了系统由稳定到混沌的演化过程;在电流断续模型中,得到了负载电阻和电感变化时系统动力学行为变化的相图,从而验证了电流断续模式下混沌现象的存在性。仿真结果均符合理论分析。

Two models of Buck converter controlled by voltage operating in CCM and DCM were respectively established with Matlab/Simulink, and their chaotic phenomena was observed through simulation. The models successfully simulated the ＂on＂ and ＂off＂ state of the controlled switch and the PWM driving signal, they＇re very similar to the practical operative state. Using the two kinds of models, simulations were done, so with the CCM model, the phase space diagrams and the waveforms of system main parameters were drawn out by varying input voltage, thus the transforming of system behavior from steady state to chaotic was observed; with the DCM model, a series of phase diagrams were obtained by varying the load resistance and inductor, which showed the change of system dynamic behaviors and proved the existence of chaotic phenomena. All the results are corresponded with the theory.