The Development Of Three-phase AC Asynchronous Motor Control System

With the development of our national production capacity and production requirement,because of the high performance of AC speed regulation technology,the limitations of the DC motor speed control system is more and more obvious. The three-phase AC asynchronous motor has the advantage of simple structure,convenient manufacture,small repair workload, high reliable,low price and other characteristics. So it has been widely used in industrial production and daily life. It has become an indisputable fact that the AC speed regulation system will gradually replace the DC motor speed control system.It has the important significance to design a control system of three-phase AC asynchronous motor with man-machine interface system,so that it can be read in various states of the system and realize some complicated control.This paper introduced the principle of AC speed regulation in detail,fully considered the cost and reliability of the control system under the condition that used the three-phase AC asynchronous motor as an object. Through the comparison of various frequency conversion speed control mode,the design utilized direct torque control mode and SVPWM control technology to design an reliable digital three-phase AC asynchronous motor control system with low cost.The system is composed of upper machine and lower machine. The lower machine used the 80C196 MC chip made by Intel company as the control core,chose the intelligent power module as inverter,designed the main circuit,the inverting circuit,the current and voltage detection circuit and the speed detection circuit.The upper machine used the SH79F1611 chip as the core designed the keyboard circuit and display module. Finally,I completed the software programming,tested the performance of the system,verified its stability and reliability.