基于单片机控制的开关电源的研究与设计

Microcontroller-based control of switching power research and design

基于单片机控制技术设计了一种数控开关电源。以89C51单片机作为控制核心,对开关变换电路进行脉宽调制,构成一个智能闭环控制系统。设计的开关电源具备更加完善的功能,更人性化、智能化,便于实时监控。可以实现对开关电源输出电压进行检测,并显示实时电压值;通过按键进行编程预置期望输出的电压。通过A/D转换器采样输出电压,根据PID算法计算控制量修改占空比,以得到期望的输出电压,并稳定在设定的电压值。过流保护功能以及辅助电源给单片机提供工作电压与电源输入,并通过键盘修订PID参数,进行实时调整。

A new kind of digital control switching mode power supply has been designed based on single-chip microcomputer in this paper. The microcomputer 89C51 was used as the core device to modulate pulse width in switching transformation circuit, constituting a closed loop intelligent control system. The designed switching power supply has many advantages such as perfect functions, humanization, intelligence and convenience for the real-time monitoring. The output voltage that may be preset to an expected value can be tested and displayed in real-time. The expected output voltage was obtained and kept constant by sampling through A/D converter and by modifying duty ratio of control using PID algorithm. The over-current protection function and an auxiliary power supply provide working voltage for single chip microcomputer, and were used as input voltage of system that can be modified by changing PID parameter.