基于改进积分分离PID的LED电源控制系统设计与仿真

Design and Simulation of Improved Integral Separate PID Algorithm Used on LED Source Control System

以电压反馈脉宽调制(PWM)控制模式的数字控制双管正激型LED开关电源为控制对象,设计合理的补偿算法。首先建立开关电源的功率部分模型并对该系统设计了数字PID补偿算法,通过闭环系统仿真分析传统PID算法存在的不足;然后针对数字PID算法存在的超调量过大的问题,以积分分离PID算法为基础,通过建立比例、微分两个增益系数与输入误差之间的函数,设计一种改进的积分分离PID算法;最后在Simulink中进行系统级别的仿真,对分别采用两种补偿算法的系统输出特性进行比较。结果表明:采用改进型积分分离PID算法可以在不改变稳定性以及调节时间的基础上减小超调量,取得更好的控制性能。

In this paper,a reasonable digital PID algorithm is designed for the dual switch forward LED which is in voltage feedback PWM（ pulse width modulation） control mode. At first,part of the model is established for the switching mode power supply and digital PID algorithm is designed for the system. The close loop system simulation analysis is used to analyze the shortcomings of the traditional PID algorithm.Aiming at the high overshoot of digital PID algorithm,an improved integral separate PID algorithm is designed by establishing the function with input error and gain coefficients of proportion and differential.System level simulation is conducted in Simulink to compare the output characteristics of the two compensation algorithms. The result show that improved integral PID algorithm can decrease overshoot of the system without changing stabilization and regulating time and get better control performance.