Research And Application Of Induction Motor Drives System Based On Digital Control

With the rapid development of power electronics and power electronic devices and microprocessor,as well as various motor models and advanced control technology,which greatly promoted the development of motor speed control,making high precision,wide speed range,control the good performance of the motor controller is possible to achieve.This paper mainly introduces a vector control system of AC motor based on DSP.Controlled object to the asynchronous motor,the analysis of the vector control principle,the establishment of the motor model of asynchronous motor in different coordinate system,the nature of the vector control theory and its decoupling.Transform the asynchronous motor three-phase stationary coordinate system of each variable to the two-phase rotating coordinate system,and then the rotor magnetic field orientation,making the stator winding current magnetic field component and torque component decoupling,which will speed performance of the induction motor greatly increased.In this article,there are the following aspects for the main work:1.Preliminarily investigate the general development situation of AC variable-frequency adjusting-speed,discuss the principle of speed regulation control theory and merits and demerits of various control strategies,and elaborate the mathematical model establishment of asynchronous motor and FOC theory in depth.2.Systematically elaborate the hardware circuit design of digital control system,mainly including the design of rectifier circuit,current and voltage detection design,and the design of speed testing and over current and over voltage protection.3.For software implementation,elaborate the programming thoughts and framework of the whole system in detail.System program comprises of master control program and SVPWM underflow interrupt program.Specifically,the master control program is to implement the function configuration and the initial value setting for system clock of all peripherals,event manager unit,ADC and communication module.Besides,the design of SVPWM underflow interrupt program includes current and voltage sampling design,DSP implementation of motor speed detection,and SVPWM algorithm and corresponding DSP implementation.Then,the slave computer software is developed with Lab VIEW for theinduction motor drives system,which enables to communicate with DSP in real time,complete initial value and speed setting,and display real-time working condition of motor.4.Simulate and analyze the vector control system with MATLAB/Simulink,develop a digital vector control system of induction motor and build a experimental platform for Induction Motor Drives System.Further,according to the hardware circuit debugging,the experimental waveforms are recorded and analyzed,thereby achieve the expected effect.