基于单片机的三相异步电动机
节能控制方法的研究
学生： 指导教师： 所在院系： 所学专业： 研究方向：
摘要
三相交流异步电动机是一种将电能转化为机械能的电力拖动装置。它主要由定子、 转子和它们之间的气隙构成。对定子绕组通上三相电源后，产生旋转磁场并切割转子,获得转矩。三相交流异步电动机具有结构简单、运行可靠、价格便宜、过载能力强及使用、安装、维护方便等优点，被广泛应用于各个领域。但在很多行业中电动机的使用并不合理，电机常常工作在轻载甚至空载状态下，这使得电动机的功率因数和效率很低， 不仅浪费了大量电能，而且降低了电网的供电质量。
本论文重点研究：电机轻载时降低定子电压提高功率因数的电机节能方式。 调压节能的主回路一般都采用晶闸管调压电路由六只两两反并联的晶闸管组成，串接于电动机的三相供电线路上。用单片机控制晶闸管触发角α的大小，调节交流电动机定子电压以减少电机的铁损及励磁电流，从而提高功率因数及运行效率。
关键词：三相异步电动机 调压节能 单片机 晶闸管
Abstract
Three-phase ac induction motor is a kind of energy into mechanical energy of electric drive device. It mainly consists of stator and rotor and between them the air-gap constitutes. General of the stator winding, after three phase power of rotating magnetic field generated and cutting rotor, obtain torque. Three-phase ac asynchronous motor has simple structure, reliable operation, price cheap, overload ability and use, installation, maintenance convenience etc, are widely used in every field. But in many industries motor use did not reasonable, motors often work in light load even under no-load condition, which makes motor power factor and efficiency is very low, not only wastes a lot of energy, and reduces the grid power supply quality.
This paper focuses on the research: motor stator voltage decrease when light load of motor improving power factor. Energy way
The surge of main loop energy commonly pressure regulating circuit using thyristor by six two LiangFan parallel thyristor composition, strung meet in the three-phase power supply lines motor. Using single-chip microcomputer control thyristor trigger Angle alpha size, adjust ac motor stator voltage to reduce the iron loss and motor excitation current, so as to improve the power factor and operation efficiency.
Key words: Three-phase asynchronous motor Microcontroller
Pressure regulating energy-saving Thyristor
目录
摘要 ...................................................................... II Abstract ................................................................. III 1.前言 ..................................................................... 1
1.1节能的必要性 ....................................................... 1 1.2电动机节能控制的基本方法 ........................................... 2 2.异步电机损耗分析及调压节能基本原理 ...................................... 5
2.1 交流异步电机的能耗与效率的分析 ................................... 5
2.1.1能耗分析 ..................................................... 5 2.1.2电机的功率关系 ............................................... 6 2.1.3效率与功率因数关系 ........................................... 8 2.2降压节能原理 ....................................................... 9
2.2.1降压节能概述 ................................................. 9 2.2.2不同负载情况下的降压节能分析 ................................ 10 2.2.3异步电动机降压节能估算 ...................................... 13 2.2.4降压节电实用场合 ............................................ 14
3.节能控制系统的硬件设计 .................................................. 15
3.1节能控制系统总体方案设计 .......................................... 15
3.1.1开关元件的选择 .............................................. 16 3.1.2主控芯片的选择 .............................................. 16 3.1.3片机最小系统 ................................................ 18 3.1.4供电电源的设计 .............................................. 19 3.2系统主要功能模块电路设计 .......................................... 19
3.2.1复位电路设计 ................................................ 19 3.2.2 功率因数检测电路设计........................................ 20 3.2.3 电压电流检测电路设计........................................ 22 3.2.4触发电路设计 ................................................ 23 3.2.5三相不平衡保护电路设计 ...................................... 24 3.2.6键盘及显示电路设计 .......................................... 25 3.3系统的硬件抗干扰技术 .............................................. 26 4.系统举例与分析 .......................................................... 28
4.1检测目的 .......................................................... 28 4.2 接线图 ........................................................... 28 4.3空载时降压对电机功率因数的影晌 .................................... 29
4.4不同负载率下电效果 ................................................ 30 5.总结 .................................................................... 31 参考文献 .................................................................. 32 致 ...................................................................... 33
基于单片机的三相异步电动机节能控制方法的研究
