【摘要】 针对低压大电流DC-DC变换器负载经常变化的特点,以动态过程输出电压超调量最小和调节时间最短为目的,提出了一种改善DC-DC变换器动态性能的数字控制方式。将变换器在负载变化时的暂态过程分为两个阶段,在每个阶段内对占空比进行直接设置,使开关处于一直导通或一直关断的状态,通过计算两个阶段转折点的输出电压并与采样电压比较以决定开关的状态。该控制方式在负载突变时和计算开关状态时间的最优控制方式有同样的性能,而算法的实时计算量却大幅降低。实验结果表明分段控制可以有效改善DC-DC变换器的动态性能。更多还原

【Abstract】 According to the characteristics of frequent load changes of low-voltage high-current DC-DC converter,a digital control method objective to least output voltage overshoot and shortest setting time for DC-DC converter was proposed to improve the dynamic performance under load changes.The transient procedure under load change was divided into two stages,in either of which the switch was set directly to be on or off.The output voltage on turning point was deduced and compared with the sample voltage to decide the state of switch.The proposed control method is of the same performance with the optimal method which calculates the time of each interval while the computation complexity declines significantly.The experiment results show that the subsection control method proposed in this paper can effectively improve the dynamic performance of DC-DC converter.更多还原