异步电机矢量控制变频调速系统.doc

摘要 现代电力电子技术及计算机控制技术的迅速发展，促进了电气传动的技术革命。交流调速取代直流调速，计算机数字控制取代模拟控制己成为发展趋势。交流电机调速是当今节约电能、改善生产工艺流程、提高产品质量，以及改善运行环境的一种主要手段。本文正是以三相异步电动机为研究对象，从电动机调速的实质出发，对异步电机的矢量控制策略进行了研究。 本文的主要工作可以分为以下三个部分： 首先，介绍了交流调速及其相关技术的发展现状和发展趋势，以及交流调速系统的主要控制策略，分析了异步电机的数学模型及其矢量控制原理，根据矢量控制原理给出了交流异步电机矢量控制系统总体设计方案及其控制策略，并进行了相关控制仿真。 其次，矢量控制通过坐标变换将异步电动机转化为直流电动机的模型，将励磁电流分量与转矩电流分量解耦，以更方便的控制异步电动机。 再次，PWM变频器采用了PWM控制方式。它是指输出波形的半个周期内发生多个脉冲，使各脉冲的等值电压为正弦波形，使输出的波形含各次谐波成分少。 关键词：异步电动机；矢量控制；交流调速；PWM变频调速 Abstract With the development of modem power electronics and control technology based on computer,the technical revolution of electrical drive is promoted．It is a trend that AC drive replaces DC drive and computer-aided digital control takes the place of traditional analog contro1．contro1．Speed-adjusting has become the major mean to improve energy efficiency,the production processes，quality of products and operational environment．Therefore，this paper researched on the asynchronous motor,and the vector control system of speed-adjusting was established．The strategy of vector control for asynchronous motor was researched and implemented in this paper． The main work of this paper can be divided into three parts： Firstly,this paper induced the current condition and future trend of AC speed—adjustment system and its main control strategies，analyzed the mathematical model of asynchronous motor and the principle of vector control，gave the general control scheme and strategy for asynchronous motor speed regulation according to the principle of vector contro1．Besides，simulation had been conducted in this paper . Secondly,vector control can get through coordinate change in order to change asynchronous motor to be the modle of DC motor,and decompose field curret ponderance and torque curret ponderance ,so as to control asynchronous motor easily. Thirdly,PWM inverter using PWM control mode. It refers to that the output waveform of the half cycle pulse occurred more than make the equivalent of the pulse voltage sin