机械5

摘要 改革开放以来，国家的经济迅速发展，一大批企业随着国家优惠政策的推出而建立，由于国内技术的不足，他们便积极引进发达国家的设备，这些设备性能好，效率高，现有的低压开关柜已经不能维持正常的供电需求。我国低压开关柜的发展经历了四次大规模的更新换代，二十一世纪的第四代产品已经从最初的容量小，体积大，性能差变成容量大，体积小，质量好。 本文通过列举不同种类的传感器，对比后选择了GMR传感器，并介绍了GMR传感器的工作原理和巨磁阻效应原理。通过实验建立了测量拓扑矩阵。分析磁场的基本计算方法，选择出有限元法计算磁常借助棱边单元法来观察母排室的磁场分布。设计GMR传感器位置拓扑结构，通过对母排室进行区域划分，找出GMR传感器相对母排的最佳测量点。对整套低压开关柜系统进行电磁抗干扰分析。 关键词：低压开关柜，GMR传感器，磁场分布，磁场干扰 Mag
netic Field Measureme
nt a
nd Cabi
net Desig
n for Low Voltage Switchgear ABSTRACT Si
nce the reform a
nd ope
ni
ng up, the cou
ntry's eco
nomy has developed rapidly. A large
number of e
nterprises have bee
n established with the i
ntroductio
n of
natio
nal prefere
ntial policies. Due to the lack of domestic tech
nologies, they have actively i
ntroduced equipme
nt from developed cou
ntries. The developme
nt of Chi
na's low-voltage switchgear has experie
nced four large-scale upgradi
ng, a
nd the fourth ge
neratio
n of products i
n the 21st ce
ntury has cha
nged from the origi
nal small capacity, large volume a
nd poor performa
nce to large capacity, small volume a
nd good quality. I
n this paper, GMR se
nsor is selected after compari
ng differe
nt types of se
nsors, a
nd the worki
ng pri
nciple of GMR se
nsor a
nd the pri
nciple of gia
nt relucta
nce effect are i
ntroduced. The measureme
nt topological matrix is established by experime
nts.A
nalyze the basic calculatio
n method of mag
netic field a
nd select the fi
nite eleme
nt method to calculate mag
netic field. The mag
netic field distributio
n of bus chamber was observed by usi
ng edge eleme
nt method. Desig
n the topological structure of the positio
n of the GMR se
nsor, a
nd fi
nd out the best measuri
ng poi
nt of the GMR se
nsor relative to the bus by dividi
ng the area of the bus chamber. Co
nduct electromag
netic a
nti-i
nterfere
nce a
nalysis of the whole low-voltage switchgear system. Keywords: low-voltage switchgear, GMR se
nsor, mag
netic field distributio
n, mag
netic field i
nterfere
nce 目录 摘要1 ABSTRACT 2 1绪论3 1.1课题提出背景3 1.1.1巨磁阻效应概述3 1.1.2低压开关柜概述3 1.2国内外对低压开关柜的研究现状4 1.2.1国内的研究现状4 1.2.2国外的研究现状4 1.3课题的研究意义5 2磁场测量技术研究5 2.1大电流测量方法5 2.1.1经典测量传感器5 2.1.2 GMR磁传感器9 2.2磁场测量实验10 2.2.1大电流发生器10 2.2.2电流测量系统10 2.3建立GMR测量模型11 2.3.1 GMR传感器测量原理11 2.3.2母排电流的计算13 2.3.3 GMR传感器磁场测量仿真13 2.4 GMR磁传感器位置拓扑结构14 2.5 GMR传感器稳定性的分析15 2.6本章小结16 3低压开关柜磁场计算仿真16 3.1电磁场的基本计算方法16 3.2用有限元法分析低压开关柜母排室的磁场22 3.2.1母排磁场控制方程22 3.2.2棱边元离散23 3.3建立低压开关柜磁场仿真模型26 3.3.1建立电磁场涡流场模型26 3.3.2边界条件和加载27 3.3.3材料参数27 3.3.4分析仿真结果28 3.3.5母线室磁场分布实验29 3.4本章小结30 4低压开关柜磁场测量位置拓扑结构30 4.1拓扑位置测定准备30 4.1.1 GMR传感器拓扑结构31 4.1.2测量点位置31 4.2整体系统测试32 4.2.1 GMR传感器拓扑位置测量32 4.2.2磁场数据测量34 4.2.3测量数据线性分析36 4.2.4测量数据非线性分析38 4.2.5重复性分析38 4.3母排室的结构设计39 4.3.1母线室母排的摆放39 4.3.2柜体尺寸的确定40 4.3本章小结42 5低压开关柜磁干扰屏蔽43 5.1电磁干扰的种类43 5.2电磁干扰的产生43 5.3低压柜中的电磁干扰44 5.3.1低压开关柜干扰源44 5.3.2易被干扰的弱电系统44 5.4低压柜抗干扰措施44 5.4.1 PCB板干扰44 5.4.2嵌入式系统抗干扰措施46 5.4.3母排室屏蔽47 5.4.4弱电系统屏蔽49 5.5低压柜标准化设计分析51 5.5.1柜体的标准化51 5.5.2功能块标准化51 5.6本章小结51 6总结与展望52 6.1全文总结52 6.2研究与展望52 参考文献54 附录56