文档介绍：内蒙古科技大学硕士学位论文
摘要
随着电力电子技术和微机控制技术的发展,为了减小三相异步电动机起动时产
生的大电流对电网电压的冲击等负面影响,本文针对目前国内电动机软起动器现状
和未来的发展趋势,开展了三相交流异步电动机斩波式软起动器的研究,包括主电
路、控制电路、驱动电路、系统软件设计等。其主要思想是通过 DSP 产生 PWM 脉
冲控制电力电子开关器件 IGBT 的开通与关断,调节占空比,使电机起动时定子端的
电压按预先设定好的曲线变化,从而降低起动电流,实现异步电动机的软起动。
主要工作如下:
首先对电机的起动特性进行研究;对三相交流斩波调压电路,以及基于三相交
流斩波调压的三相异步电动机的软起动方法进行分析。
其次,用 MATLAB 工具箱进行仿真,比较优缺点,并对分级变频法及节能进行
仿真,仿真结果证明 PWM 斩波式软起动的诸多优点和可行性。
然后介绍了斩波式软起动器的组成结构和控制原理,并就主电路、控制电路、
保护电路、检测电路的设计做了详细的说明。
最后介绍了基于 DSP 的软件设计方案,重点说明由 DSP 产生 PWM 的方法和基
本思路以及具体的步骤。

关键词:软起动,斩波,DSP,PWM,IGBT,离散频率法

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内蒙古科技大学硕士学位论文
Abstract
Along with the development of power electronic technology and puter
control technology,to reduce the big electric current produces the work voltage
impact and so on negative influence when the three-phase asynchronous motor starts,the
article in view of the present situation of domestic electric motor soft start at present and
future trend of development,it expands the realizing method of three-phase exchange
asynchronous electric motor chopped wave proceeds many studies including main
circuit、controlling circuit、driving circuit and the design of system’s software,whose main
thought is that pulse controls electronic power ponent IGBT to be on and be off
by the fact that DSP produces PWM,it adjusts the empty space ratio and makes the voltage
that the stator holds when the electric motor start electric current according to in advance
setting up good curve change,so it reduces the starting electric current and realizes the
asynchronous electric motor starts.
The main task is said as follow:
In the first place, the character and harmonious wave of three-phase asynchronous
motors is studied. the paper analyses the AC electrocircuit chopper of voltage modulated and
the soft starting method.
In the second place , three-phase asynchronous motors system is analyzed and
simulated with MATLAB, the simulatin