三相异步电动机软启动装置设计
考生姓名： XXXXXXX 准考证号： XXXXXXXXXX 专业层次： XXXXXXX 院 （系）：XXXXXXXXXXXX 指导教师： XXXXXXX 职 称： XXXXXXX
二O一二年七月二十日
三相异步电动机软启动装置设计
考生姓名： XXXXXXXX 准考证号： XXXXXXXXXXXXXX 专业层次： XXXXXXXXXXX 指导教师： XXXXXXXX 院 （系）：XXXXXXXXXXXXXXXXXXXXXX
二O一二年七月二十日
重庆科技学院高等教育自学考试本科毕业论文 中文摘要
摘 要
三相异步电动机因具有结构简单、制造方便、运行可靠、价格低廉等优点，而广泛应用在工业、农业、交通运输业、国防工业以及其他各行各业中。但它也有明显的缺点，那就是起动转矩小，起动电流过大。这种情况对电机本身及周围电网都有非常不利的影响。为了减小异步电动机起动过程中对电网的冲击、消除传统降压起动设备的有级触点控制对异步电动机的冲击、改善异步电动机的起动特性，本文对基于单片机控制的晶闸管调压软起动器进行讨论。
本文首先阐述了软起动器晶闸管调压电路(即主电路)的工作原理，主要是基于晶闸管的三相异步电动机软启动器主电路设计和触发电路设计。然后是对电动机软启动器模式的设计，但主要还是软起动器的硬件电路设计。
本文设计的软起动器操作方便简单，能够使电机顺利起动。使之能达到了改善三相异步电动机起动性能的要求。在满足异步电动机起动转矩要求及降低起动电流的前提下，使电机能够平稳可靠起动。
关键词：异步电动机，晶闸管，软启动
I
重庆科技学院高等教育自学考试本科毕业论文 英文摘要
Three phase asynchronous motor soft start device design
ABSTRACT
The three-phase asynchronous motor because of its simple structure, convenient manufacture, reliable operation, low price and the like, and is widely applied in industry, agriculture, transportation, defense industry and other industries. But it also has obvious shortcomings, the starting torque is small, large starting current. This situation on the motor itself and the surrounding network has very adverse effect. In order to reduce the asynchronous motor starting process of the impact of power grid, the elimination of the traditional step-down start equipment with level control for asynchronous motor to improve impact, induction motor, this paper based on single-chip microcomputer controlled thyristor voltage soft starter were discussed.
This article first elaborated the soft starter thyristor voltage regulating circuit (i.e., working principle, main circuit) is mainly based on thyristor three-phase asynchronous motor soft starter the design of main circuit and trigger circuit design. The electric motor soft starter in model design, but mainly the hardware circuit design of soft starter.
In this paper, the design of the soft starter of convenient and simple operation, can make the motor start smoothly. To achieve the improvement of three-phase asynchronous motor starting performance requirements. In order to meet the requirements of starting torque of asynchronous motor starting current is reduced under the premise, so that the motor can stably start.
Keywords：Asynchronous motor; Thyristor; Soft starting
II
重庆科技学院高等教育自学考试本科毕业论文 目录
目 录
中文摘要 .................................................................................................... I 英文摘要 ................................................................................................... II 1 绪论 ........................................................................................................ 1
1.1 三相异步电动机国内外研究现状 .................................................................................. 1 1.2 本课题研究内容 .............................................................................................................. 1
2 三相异步电动机的起动控制的研究 ................................................... 3
2.1 三相异步电动机的起动过程的分析 .............................................................................. 3 2.2 三相异步电机的启动方法 .............................................................................................. 5
2.2.1 直接起动 .................................................................................... 5 2.2.2 传统减压起动 .............................................................................. 6 2.2.3 软启动 ....................................................................................... 9 2.3 软起动的原理及分析 ...................................................................................................... 9
2.3.1 晶闸管调压原理 ......................................................................... 10 2.3.2 软起动的起动方式 ...................................................................... 12
3 软启动器的硬件电路设计................................................................... 14
3.1 主要器件的介绍 ............................................................................................................ 14
3.1.1 KJ004功能介绍.......................................................................... 14 3.1.2 KJ041功能介绍.......................................................................... 16 3.2 主电路的选择 ................................................................................................................ 17 3.3 主回路设计 .................................................................................................................... 18
3.3.1 主回路电路 ............................................................................... 18 3.3.2 晶闸管参数选择 ......................................................................... 19 3.3.3 晶闸管触发电路 ......................................................................... 19 3.3.4 晶闸管保护电路 ......................................................................... 21 3.4 电压检测回路 ................................................................................................................ 22
3.4.1 同步信号检测 ............................................................................ 22 3.4.2 电压反馈回路 ............................................................................ 24 3.5 电流检测回路 ................................................................................................................ 24
3.5.1 电流反馈回路 ............................................................................ 24 3.5.2 过电流保护电路 ......................................................................... 25
4 基于单片机的软起动器的设计 .......................................................... 26
III