提出了一种新的纹波电流脉宽调制策略,以电容电流为调制信号主体,实现了动态调节过程的非线性控制,变换器动态过程逼近时间最优控制(TOC)运行轨迹。结合Buck变换器实例,导出了基于电容电流调制的控制方程,构建了相应的模拟控制电路。理论上重点分析了变换器的动态特性,给出动态调节时间与输出电压跌落的近似解析值。仿真和实验结果证明变换器动态响应过程逼近TOC运行轨迹.验证了所提控制策略优越的动态响应,实现了系统的准最优快速调节控制。
A PWM modulation strategy based on ripple current is presented,which takes the capacitor current as the main modulation signal to realize the nonlinear control of converter dynamic regulation process approaching to the TOC(Time Optimal Control) operating locus. With Buck converter as an example, its control equation based on the capacitor current modulation is derived and its corresponding analog control circuit is built. The dynamic response of converter is theoretically analyzed and the approximate analytical values of output voltage drop corresponding to dynamic regulation time are given. Simulative and experimental results prove that,the dynamic response of converter is approaching to the TOC operating locus,which verifies that,the proposed Control strategy has excellent dynamic response to realize the quasi- optimal control of fast converter regulation.