特高压直流输电线路地面合成电场的数值计算方法研究

发布时间：2018-01-29 03:07

本文关键词： 交直流并行三维铁塔电场逆问题主元加权—修正Newton法　出处：《重庆大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着我国经济的发展，对电力的需求急剧增加，，但是经济发展和资源的分布极不均衡。建设特高压直流输电工程，可以更合理的对能源和资源进行分配，解决能源短缺和经济发展的矛盾。但是随着人们环保意识的逐步增强，要求我们在建设特高压直流输电工程的同时必须考虑输电线路产生的电磁场对环境的影响，尽可能的满足环保的要求。因此，准确计算特高压直流输电线路下方的合成电场强度，可以为线路的设计布局和环境评估提供参考，具有重要的实际意义。本文基于模拟电荷法对特高压直流输电线路的地面合成电场数值计算方法展开了研究，主要工作如下：（1）根据模拟电荷法的基本原理，基于Deutsch假设的计算方法，计算了特高压直流输电线路下方地面合成电场强度，与实测数据进行对比，验证了方法的正确性。（2）考虑到不可避免的交直流输电线路并行的情况，分析了交流输电线路对直流输电导线表面电场及其电力线轨迹的影响，对基于Deutsch假设的计算方法进行了改进，从而计算出在邻近交流输电线路时直流线路下的地面合成电场及混合电场强度，通过与文献中实例进行对比，验证了方法的有效性；分析了交直流并行线路的参数（邻近间距）对地面合成电场及混合电场的影响。（3）采用线单元模拟电荷法对直流输电线下地面合成电场进行了三维计算，与实测数据进行对比，验证了方法的正确性。对铁塔建立了数学模型，计算了铁塔附近的地面电场,并以此方法分析了铁塔对直流输电线路下方地面合成电场的影响。（4）研究了特高压直流输电线路下方地面合成电场的逆问题计算方法，提出了一种主元加权—修正Newton法，对合成电场的逆问题进行了计算。通过与主元加权法及阻尼最小二乘法进行对比，验证了本方法的有效性及更高的精确度。（5）采用本文提出的主元加权-修正Newton法对测点个数进行了对比分析。当测点个数在8个左右时，采用该方法可以很好的计算出所测输电线路下方其他点处的合成电场强度。这种方法使得在环境测评时可以大大减小测量工作，获得一个可信的地面合成电场详细分布。
[Abstract]:With the development of economy in our country, the demand for electric power increases sharply, but the economic development and the distribution of resources are very uneven. The construction of UHV HVDC transmission project can allocate energy and resources more reasonably. To solve the contradiction between energy shortage and economic development. But with the increasing of people's awareness of environmental protection. In order to meet the requirements of environmental protection, we must consider the impact of electromagnetic field on the environment while building UHVDC project. The accurate calculation of the composite electric field intensity under UHVDC transmission lines can provide a reference for the design layout and environmental assessment of UHVDC transmission lines, which is of great practical significance. Based on the simulation charge method, this paper studies the numerical calculation method of ground synthetic electric field of UHVDC transmission line. The main work is as follows: 1) according to the basic principle of simulated charge method and the calculation method of Deutsch hypothesis, the ground composite electric field intensity under UHVDC transmission line is calculated and compared with the measured data. The correctness of the method is verified. (2) considering the inevitable parallelism of AC / DC transmission lines, the influence of AC transmission lines on the surface electric field of HVDC conductors and their power line trajectories is analyzed. The calculation method based on Deutsch hypothesis is improved to calculate the ground composite electric field and the mixed electric field intensity under the direct current transmission line adjacent to AC transmission line. The validity of the method is verified by comparison with the examples in the literature. The influence of the parameters of AC / DC parallel circuit (proximity distance) on the ground composite electric field and mixed electric field is analyzed. 3) Three-dimensional calculation of the ground synthetic electric field under DC transmission line is carried out by using the line element simulation charge method, and the correctness of the method is verified by comparing with the measured data. The mathematical model of the tower is established. The ground electric field near the tower is calculated and the influence of the tower on the ground composite electric field under the DC transmission line is analyzed by using this method. In this paper, the inverse calculation method of ground composite electric field under UHVDC transmission line is studied, and a principal component weighted modified Newton method is proposed. The inverse problem of the synthetic electric field is calculated and compared with the principal component weighting method and the damped least square method to verify the effectiveness and higher accuracy of this method. 5) the number of measured points is compared and analyzed by using the principal component weighted modified Newton method proposed in this paper, when the number of measured points is about 8. By using this method, the synthetic electric field intensity at other points under the measured transmission line can be well calculated. This method can greatly reduce the measurement work in environmental assessment. A credible ground synthetic electric field detailed distribution is obtained.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM721.1

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