针对传统线性控制Boost变换器存在的截止频率低、动态响应不理想的问题,提出一种非线性数字控制算法——电容电荷平衡控制。运用电容电荷平衡原理,当遇到负载电流跃变后,该算法将根据理论推导的理想动态响应曲线,计算出最优动态响应控制时间点以及占空比序列。利用Matlab软件对算法进行了仿真验证,与传统电压模式控制相比,电容电荷平衡控制算法可以明显减小Boost电路的输出电压超调量/欠调量,并缩短动态响应的恢复时间,使其动态响应特性得到极大提高。
A digital nonlinear control based on capacitor charge balance is proposed for Boost DC/DC converter to improve the bandwidth limitation and dynamic performance of conventional linear control,which,when load current changes suddenly,calculates the optimal control time points and duty cycle series according to the theoretical ideal dynamic response curve deduced based on capacitor charge balance.Simulation with Matlab shows that,the proposed control,compared with the conventional voltage-mode control,has smaller output voltage overshoot/undershoot,shorter recovery time and better dynamic response performance.