数字式直流调速控制系统设计 毕业设计论文.doc

毕 业 设 计 说 明 书 题目：数字式直流调速控制系统设计 二级学院： 学院 专 业：电气工程及其自动化 班级： 学生姓名： 学号： 指导教师： 职称： 教授 评阅教师： 职称： 2013年 6 月 摘 要 现在，自动控制系统在很多领域得到了广泛的应用，而直流调速控制系统作为电气传动的重要部分在现代生产中起到了很多作用。直流调速调速范围宽平滑性好、启动转矩大的优点，因而在工业传动系统中得到了广泛的应用，微机数字控制系统的控制软件能进行逻辑判断与复杂的运算。 该系统主要由三部分组成，包括控制部分、驱动部分和直流电动机。控制部分采用STC90C516RD单片机，通过单片机和D/A转换电路产生适合频率的正弦波，把正弦波和三角波发生器产生的三角波输入比较器，产生PWM波，驱动部分PWM波通过L9110芯片将电压加在直流电动机上，使其旋转，通过单片机输出不同频率的正弦波来调节电动机的转速。直流电机采用130型玩具电机，该系统主电路线路简单，电流较连续，谐波少，电机损耗及发热都较小，低速性能好，调速范围广，系统频带宽，系统动态响应快。 关键词：数字控制系统，单片机，三角波，D/A转换。 Abstract Nowadays,the automatic control system has been widely used in many fields,however,as an important part of the electrical drive,DC speed control system has had a lot of effect in the modern production. It has a wide range of speed regulation ,a gliding property and a big start torque.Thus,it is widely used in Industrial transmission system.The control software of computer numerical control system can perform logical judgment and complicated operation. The control system is mostly made up of three parts,including the control part ,the drive part and the motor.The control system use STC90C516 MCU and D/Aconverter to produce sine wave.We put sine wave and triangular wave which produced from triangle generator into comparator to produce suitable PWM wave.PWM wave is exerted on the DC motor by the L9110 chip so that the motor can rotate.The MCU produce diferent kinds of sine wave so that it can control the speed of motor.We select 130 motor as the DC motor.The system has a simple main circuit , constant current and little harmonic wave.The cost and heat which comes from the motor are both little.It has a good feature of low speed and a wide range of controlling speed.The system has a wide area of frequency and it responses rapidly. Keywords:numerical control system,microcontroller,triangular wave, D/A c