恒流源负载开关变换器在发光二极管照明领域具有广阔的应用前景,其研究具有理论意义和应用价值.为了研究电路参数对恒流源负载V2控制Buck变换器稳定性的影响,建立了该变换器的二阶离散迭代映射模型,得到了输出电容等效串联电阻、恒流源负载变化时的分岔图.分析结果表明,当输出电容等效串联电阻、恒流源负载变化时,恒流源负载V2控制Buck变换器具有复杂的动力学行为.利用特征值和最大李雅普诺夫指数对系统进行稳定性分析,验证了分岔分析的正确性.通过数值仿真得到了输出电容及其等效串联电阻之间的工作状态边界,揭示了输出电容时间常数稳定临界值与开关周期间的非线性关系.最后,基于PSIM电路仿真和电路试验,得到了输出电容等效串联电阻时的时域波形,验证了二阶离散迭代映射模型的有效性和理论分析的正确性.%Switching converter with constant current source load has a wide application prospect in the lighting field of emitting diode,and therefore the study of V2 controlled buck converter with constant current source load has theoretical significance and application value.In order to investigate the influence of circuit parameters on stability of V2 controlled buck converter with constant current source load,a second order discrete iterative mapping model is established,based on which the bifurcation diagrams with the variations of the equivalent series resistance of output capacitor and constant current source load are obtained.The results show that the converter has complex dynamic behavior when the equivalent series resistance of output capacitor and constant current source load change.Stability of the system is analyzed by using the eigenvalues and maximum Lyapunov exponent,which validates the correctness of bifurcation analysis.The operation state boundaries between the output capacitor and its equivalent series resistance are obtained by numerical simulations,and the nonlinear relationship between the stable critical value of output capacitor time constant and the switching cycle is revealed.Based on PSIM circuit simulations and circuit experiments,the time domain waveforms under different equivalent series resistance of output capacitor are received.Thus,the effectiveness of the second order discrete iterative mapping model and the correctness of theoretical analysis are verified.
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