【作者】 黄峰；

【导师】 孙苓生；

【作者基本信息】 上海交通大学 ， 电力系统及其自动化， 2008， 硕士

【摘要】 为了适应我国城市用电的增长,近年来我国电力工业快速发展,总装机量大幅增长,同时电网建设也进行的如火如荼。再加上各类城镇规模的不断扩大,超高压架空线路毗邻居民住宅区,甚至穿越城镇的情况屡屡出现,其产生的电磁场对生活环境以及人类健康的影响正在引起居住在输电线旁的广大人民群众的关心,同时受到社会各方面的关注。工频电场一直是人们关注的重点。为了获得架空线的地面电场分布,已有不少学者做了相关研究。文章对已有的模型进行分析。这些算法大多采用了方法简单、计算结果准确的模拟电荷法为基础,建立工频电场二维模型。有的是将架空线看作无限长线电荷;有的考虑到弧垂的影响,建立了悬链线模型;还有的在无限长导线下引入了建筑物。可见,模型越来越复杂,也越来越贴近实际情况。但这些模型在算法的设计过程中,始终脱离不了二维电场的特点,这点使得通过这些模型得到的仿真结果无法准确描述工频电场的三维分布。文章考虑到以上算法的缺点,提出悬链线下具有建筑物的模型,并在算法的设计过程中完全按照三维电场的特点进行,通过此模型得到架空线跨越建筑物时的三维工频电场分布。其中,建筑物对周围地面附近工频电场有屏蔽作用,但在建筑物的上方如天台、屋顶等居民仍会接触的地方,场强较地面附近大的多;在建筑物的尖角出,还会有场强的畸变点出现,这对正确评估和测量场强非常关键。MATLAB是数值计算和仿真的主要工具之一,其软件包提供了强大的数学和图形函数库。利用这些函数库,能够实现对各种商业算法的调用,同时得到效果理想的仿真图。基于上述算法,本文采用了调用MATLAB的C\C++函数库的技术进行工频电场仿真软件的编写;软件的用户界面则采用VC++定制。既保证了算法的准确、实现了仿真结果的三维可视,又缩短了软件开发的周期。利用上文中所开发的仿真软件对多个实际线路进行了仿真,总结出建筑物、导线离地高度、线路布置方式、运行方式、分裂导线数等不同因素对工频电场的影响。此外,还讨论了建筑物内外场强的变化、以及植物和屏蔽线对场强的屏蔽作用,总结了包括相序排列优化、升高杆塔高度、减少分裂数、改变导线间距和布置方法、采用混合线路和屏蔽措施等各种降低工频电场的措施。超高压架空线同时产生磁场。文章对工频磁场进行了计算和仿真,并与各国以及国际组织工频磁场标准中的限值比较,发现工频磁场与标准中的限值有一定的差距。同时将工频磁场与人类生活中的各种磁场源所产生的磁场比较,发现工频磁场相对生活电器和工业设备磁场而言要小很多。总结各国对工频磁场和人类健康之间关系的试验和研究后我们看到,工频磁场危害人类健康的观点并不准确。更多还原

【Abstract】 In order to meet the needs of power consumption, power industry has been growing fast these years. Total generator’s volume has been increased and what’s more, the building of power grid is enhanced greatly. With the growth of power industry and human cities’expanding, high voltage headlines have appeared near cities and towns. Some have already crossed towns. The influence of power-frequency electromagnetic field is being concerned by both the residents nearby and the whole society.Power-frequency electric field has always been the emphases. In order to know the distribution of power-frequency electric field, many academicians have done a lot of research. In this paper, old models have been analysed. Most of them used the method Charge Simulation Method (CSM) to build a 2-D models, which is easy to be understood and through it, a very good result can be obtained. Among these models, some considered headline as unlimited line charge, some considered headline as catenary for the reason of its arc, other introduced buildings into the models. The models are getting more and more complex and close to real situation, but all of them are calculated using 2-D arithmetic and the results can not describe 3-D electromagnetic field. For this reason, a model using 3-D electric field arithmetic is built with a building in.Through this model, 3-D distribution of power-frequency electric field has been obtained. As a result, buildings can shield the power-frequency electrical field near the ground, but on the top of buildings, such as roof and terrace where people can also appear, the power-frequency electric field is far stronger. Around the corners of buildings, there can be aberrance. These results are very important for correctly evaluating and meaturing power-frequency electrical field.MATLAB is one of the most useful calculating and simulation tools and it provides powerful maths and figure function libraries. Using these libraries, all kinds of commercial algorithmic functions can be utilized and very good simulation figures can be obtained. In this paper, the power-frequency electrical field simulation software has been designed by introducing MATLAB C\C++ function library. The interface of the software is programmed through VC++. Using these tools and methods, the algorithmic veracity can be guaranteed and 3-D view of simulation result can be realized, what’s more, the period of developing a softwore can be reduced.Using the simulation software above, the electric field of several real lines has been calculated and simulated. Then several facts such as the height, disposal, oprating patterns and numbers of divisived leads which influence the electric field have been analysed. Then, the power-frequency electrical field inside the buildings and the power-frequency electric field shielding by plant and shield lines have been discussed. Several measures to reduce power-frequency electrical field, such as optimizing operating patterns and disposal, increasing line height, reducing numbers of divisived leads and distance of lines, using mixed lines and shielding measures have been given.High voltage headlines also generate magnetic field. In this paper, a model has been established to calculate the magnetic field. Compared with the criterions of magnetic field in several countries and international organizations, power-frequency magnetic field is far smaller than the limits in these criterions. A lot of magnetic field generated around people has been given and compared with power-frequency magnetic field. The result shows that power-frequncy magnetic field is far smaller than other magnetic fields generated by electrical equipments and industrial equipments. Based on the experiments and research results of the power-frequency magnetic field influence on human health, the view that power-frequncy magnetic field endanger human health is not correct.更多还原