【摘要】 滞环电流控制Buck变换器在滞环比较器阈值发生变化的情况下,产生Neimark分岔、倍周期分岔等行为.通过建立变换器系统的离散模型,利用牛顿-拉夫逊方法求取了不动点状态变量的值,进而推导了系统的单值矩阵,得到了其特征乘子的变化趋势.分析表明,变换器产生分岔行为的机理在于,随着比较器阈值的逐渐减小,单值矩阵的特征乘子从单位圆内穿越到单位圆外,造成系统的不稳定.仿真结果证明了理论分析的正确性.更多还原

【Abstract】 The instability behaviors of the hysteretic current controlled Buck converter have been studied. Based on the analysis,the period-doubling bifurcation and Neimark bifurcation will occurr as the threshold of the hysteretic is varied. The exact discrete-time model of the closed loop system has been built,the bifurcation point and types of the topology were predicted by using the monodromy matrix theory. The mechanism of the bifurcation lies in that one of the eigenvalues of the monodromy matrix passes through the right half plane of the unit circle. Simulation results proved the theoretic analysis.更多还原