All-digital Dual Closed-loop Reversible Dc Pwm Speed Control System

Today,autocontrol systems have been widely used and deleloped in every Walk of life,while DC speed regulation as the artery in the area of electric drive systems acts the main effect in modernization production.DC speed regulation is mainly made up of control unite,power unite and DC motor.For a long time ,DC motor has possessed the main role in the area of electric drive field because of its neatly adjust,easy method and smooth timing in wide rage,also,its control performance is very good. With the rapid development of microcomputer,it is widely used in the control field. This paper reserches reversible DC-PWM timing system with a dual-converter and dual-closed-loop.Beginning with the theory of the DC timing system,this article has build up the maths model of the reversible DC-PWM timing system with a dual-converter and dual-closed-loop , discussing a new control method that combines microcomputer with DC-drive.Based on the overall review of control object,the emphasis is put on the part of control system,which includes the discussion of hardware and software,control policy and algorithm,etc.In the hardware,it fully utilizes the advantage of microcomputer that are abundant interface and fast speed so as to realize the control of the system. This paper analyzes the working principles of the system and some key technical issues of the application based on the IGBT apparatus,which include drive circuit,snubber circuit,protection and controlling the quantity of heat,and so on.In the aspect of microcomputer control,it has discussed the principle of number touch off,number velocity testing,current/velocity controller ,number PWM modulator and presents the hardware/software scheme to achieve it.This scheme is based on the core of 89C52 single chip,using the chips of 8255/8253/8279/ADC0809/74191 and some peripheral circuits.By real time testing dand adjusting the motor's velocity/current,this timing system can get quick and exact timing result.