DC/DC变换器中的斜坡补偿法扩展及其理论分析

针对峰值电流模式控制Boost变换器的动力学模型,详细分析了斜坡补偿法控制混沌的原理,并针对占空比D>50%时发生分叉的现象,将传统的锯齿波补偿控制混沌改为三角波扰动,通过仿真发现可以很好地控制混沌且控制结果可以得到原混沌吸引子中的不稳定周期1,而且可以找到最优扰动相位和最小扰动幅度。对此进行理论分析可以给出三角波有效控制的最优相移和幅度的预计,从而为变换器的稳定设计提供了理论指导,有一定的实用价值。

Expansion of Ramp Compensation in Boost Converter and its Theoretical Research

Based on the technique of ramp compensation which has been widely used for the control of DC/DC converters,the dynamical model of current-mode controlled Boost converter has been established.Based on this model a chaos control method of ramp compensation is analyzed from bifurcation theory,and then with respect to the phenomenon of bifurcation when the duty cycle D exceeds 0.5,changes the conventional saw-tooth wave to the triangular wave to control chaos.Through the simulation,the chaos can be controlled and the number of one unstable periodic orbit of the original chaotic attractor can be found.Furthermore,the parameters of triangular wave,such as optimal phase shift and amplitude,can be forecasted for compensation from theoretical calculation,and has some practical value.