摘要如今,三相电动机在我们的生产生活中发挥着日益重要的作用,所对于电动机的保护和控制也日趋紧要。故本课题主要研究电动机综合保护与软起动控制。
首先,我们对电动机的保护进行了研究,通过对分析电动机故障,我们了解到其可有对称和不对称两种故障,并且其不对称故障又可分为接地性不对故障和非接地性不对称故障。紧接着,我们引入了对称分量法,并用具体事例,来计算出,当非接地性不对称性故障发生时,会出现显著的负序分量;而当接地性不对称故障发生时,会出现零序分量,这样我们就得到了各种故障的判断依据,并以此引入了过电流速断保护、堵转保护、过负荷保护、负序过电流保护、零序过电流保护,形成了电动机的综合保护,最后我们再结合一些算法,以及单片机CPU形成了智能保护。
其次,围绕电动机的软起动控制,我们首先介绍了直接起动的弊端,然后我们又详细说明了降压起动的几种常用方法及其优缺点,最后我们引入了三相晶闸管交流调压主电路,并结合单片机CPU实现了软起动的智能化。39708
最后,我们会运用单片机将电动机综合保护和软起动控制糅合在一起,实现了保护和控制的一体化、智能化。
毕业论文关键词:异步电动机 综合保护 软起动 控制
Abstract Today, the three-phase motor in our production plays an increasingly important role in life, as for motor protection and control are becoming increasingly critical. Therefore, the main focus of this paper to investigate the comprehensive protection and soft start motor control.
First, we protect the motor were studied by analysis of motor fault, we understand that the failure can be pided into symmetrical and asymmetrical fault fault, and it can be pided into a ground of asymmetric fault and not the fault of ungrounded unbalanced fault. Then, we introduce the symmetrical components, with specific examples, to calculate, when ungrounded asymmetric fault occurs, there will be a significant negative sequence component; and when a ground fault occurs asymmetry, there will be zero sequence component, so that we get a variety of fault judgment basis, and thus the introduction of over-current protection, stall protection, overload protection, negative sequence overcurrent protection, residual overcurrent protection, forming an integrated motor protection, and finally we combined some of the algorithms, as well as the formation of a single-chip CPU intelligent protection.
Secondly, the soft-start control around the motor, we first introduced the direct start of malpractice, then we have a detailed description of the step-down start of several common methods and their advantages and disadvantages, and finally we have introduced a three-phase AC voltage regulator thyristor main circuit, and single-chip combination to achieve a soft start CPU intelligent.
Finally, we will combine protection and soft start motor control blend together to achieve the protection and control of integration, intelligent.
Keywords: induction motor protection soft start control
目 录
摘 要 I
Abstract II
1 绪 论 1
1.1 课题研究背景 1
1.2 三相电动机保护与控制的发展及现状分析 1
1.2.1 三相电动机保护的发展及现状分析 1
1.2.2 异步电动机控制现状及前景 2
1.3 本文内容安排 3
2 三相电动机的综合保护 4
2.1 三相电动机综合保护的故障分析 4
2.2 三相电机综合保护的故障判据 5 单片机三相异步电动机的保护与控制+硬件图:http://www.751com.cn/zidonghua/lunwen_40114.html