基于风速概率分布与风切变指数的直流输电线路离子流场数值模拟方法  

Numerical Simulation Method of Ion Flow Field in DC Transmission Line Based on Wind Speed Probability Distribution and Wind Shear Exponent

作　　者：岳国华 杜志叶[1] 蔡泓威 修连成 Yue Guohua;Du Zhiye;Cai Hongwei;Xiu Liancheng(School of Electrical Engineering and Automation Wuhan University,Wuhan 430072 China)

机构地区：[1]武汉大学电气与自动化学院,武汉430072

出　　处：《电工技术学报》2024年第9期2907-2915,共9页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(51977152)。

摘　　要：特高压直流(UHVDC)输电线路下方的离子流场是电磁环境的重要评估指标之一。风速作为常见也是影响较大的因素之一,有着明显的地域特点。为了避免资源浪费,在对地高度设计时,应考虑到不同地区的风速分布差异,而不是用过大裕度换取安全度。为此,该文提出一种基于风速概率分布与风切变指数的输电线路离子流场数值模拟方法。该方法通过待计算地区的风速数据构建Weibull风速概率分布函数模型,选择风速数据在95%以内的最大临界风速作为参考值,考虑风速传感器的安装高度,根据风切变指数计算场域不同高度处的风速分布,作为离子流场计算中不同高度节点的风速输入量。结果表明,引入风切变指数后的离子流密度与合成电场强度误差分别下降了16.2百分点和3.8百分点,明显优于传统固定风速模型。并以昆明地区某±800kV直流输电线路为例,采用该方法进行了计算。该方法能够有针对性地考虑输电线路所处区域的风速影响,特别是在高海拔高风速地区,可为输电线路在合成电场安全限值下的对地高度设计提供参考依据。The ion flow field under ultra high voltage direct current(UHVDC)transmission lines is one of the important evaluation indicators for electromagnetic environment.Wind speed,as one of the most common and influential factors,has obvious regional characteristics.At present,scholars often use constant wind speed to replace natural wind speed,which can easily lead to the following two problems.One is the waste of resources,as the local wind speed used in the calculation is not necessarily as high as possible.Every 1 m increase in the height of the line installation will significantly increase the total project cost.Secondly,it is inconsistent with the actual situation.Due to the relationship between wind speed and height,there is a gradient relationship on the near ground side.Therefore,the impact of wind speed changes in the vertical direction on the ion flow field should be considered.In view of this,this paper proposes a numerical simulation method of transmission line ion flow field based on wind speed probability distribution and wind shear exponent.The calculation method is divided into two parts:wind speed calculation and ion flow field calculation.This method builds a Weibull wind speed probability distribution function model based on the wind speed data of the region to be calculated,and selects the critical wind speed with the max wind speed data within 95%as the reference value.It considers the installation height of the wind speed sensor,and calculates the wind speed distribution at different heights according to the wind shear exponent,as the wind speed input at different height nodes in the calculation of the ion flow field.The accuracy of the calculation model after the introduction of wind shear exponent is verified through outdoor tests.The voltage level is±800 kV,the conductor is 6-split,the radius of the sub conductor is 1.68 cm,the cross-sectional area of the sub conductor is 630 mm2,the height of the conductor to the ground is 16.5 m,the pole spacing is 22 m,the altitude is about 2000 m,and the w

关 键 词：特高压直流 离子流场 WEIBULL分布 风切变指数 数值模拟 

分 类 号：TM723[电气工程—电力系统及自动化]