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雾霾影响下的直流输电线路离子流场分布及绝缘子污秽特性研究

Research on the Ionized Field and Instulator Pollution of HVDC Transmission Lines under Haze Weather

【作者】 刘泽辉

【导师】 何为;

【作者基本信息】 重庆大学 , 电气工程, 2014, 博士

【摘要】 我国雾霾多发地区同时也是输电走廊和用电负荷高密度地区,长期暴露在雾霾天气下的架空输电线路的安全运行会受到雾霾天气的影响。雾霾颗粒在直流输电线路周围离子流场的作用下会荷电,荷电后的雾霾颗粒将影响输电导线表面的电晕放电以及周围的空间电场分布,在电场作用下雾霾颗粒的运动轨迹会改变,将可能影响输电导线或绝缘子表面的污秽堆积程度。特高压直流输电线路将在全国范围内推广建设,因此对于空气污染指数超过300μg/m3(严重污染),甚至是500μg/m3(爆表污染)的地区,研究雾霾对特高压直流输电线路的离子流场影响规律以及在电场影响下雾霾颗粒对输电设备的污秽影响有着重要的工程价值。因此论文针对雾霾对直流输电线路离子流场以及污秽的影响开展了研究,首先提出了一种可以计算直流输电线路离子流场的改进无网格法,进而推导了雾霾颗粒的荷电模型以及考虑雾霾的离子流场计算模型,采用改进的无网格法对其进行了求解。在此基础上研究了温度对雾霾天气下离子流场的影响规律。最后研究了雾霾颗粒在离子流场作用下的运动特性,并通过试验研究了雾霾在离子流场作用下对绝缘子的污秽影响。论文的主要创新性工作包括:(1)提出了一种改进的MLPG (Meshless Local Petrov-Galerkin)无网格法,通过采用RPIMp (radial basis function with additional polynomial basis)形函数和自适应缩小局部子域s的方式,重点解决了MLPG无网格法计算不规则区域难的问题。采用改进的MLPG无网格法对直流输电线的离子流场进行了计算,并对其准确性进行了验证。(2)建立了雾霾颗粒的荷电模型以及考虑雾霾影响的离子流场控制方程,并采用改进的MLPG无网格法对其求解。研究了温度对雾霾天气下离子流场分布的影响规律。结果表明:雾霾会使直流线路下方的合成场强增大,且增大幅度随着雾霾污染程度的增加而增加;在温度较高情况下发生雾霾天气时的地面合成场强相对于温度较低时更大。(3)研究了雾霾颗粒在离子流场中的运动特性,通过试验研究了雾霾颗粒在离子流场中的荷电极性以及雾霾对直流输电线路绝缘子污秽的影响。根据雾霾颗粒在离子流场中的运动特性,得出了不同污染等级雾霾天气对绝缘子积污量的影响。

【Abstract】 The areas where haze activities are higher are also with limited transmission linecorridors and large power load. The performance of overhead transmission lines isunder threat of the haze. The haze particulates around the HVDC transmission lines willbe charged due to the ionized field and the charged haze particulates will affect thecorona and electric field of in the vicinity of HVDC transmission lines. In addition, themovements of the haze particulates will change because of the electric field and theinsulators’ pollution characteristics could be affected.The UHVDC transmission lines will be extended across China. The research of theinfluence of haze on the ionized field and the effect of charged haze particulates oncontamination of transmission equipment are very necessary, especially for those areawith air pollution index goes into300μg/m3(serious pollution) or500μg/m3(hazardous pollution). This paper focus on the influence of the haze on the ionized fieldand contamination of HVDC transmission lines. Firstly, an improved Meshless Methodwhich is more suitable for dealing with ionized field problems has been proposed.Secondly, the charging process of haze particulates and numerical model of ionizedfield in presence of haze has been studied. Based on the numerical model construct bythe improved MLPG method, the distributions of the ground level ionized field inpresence of haze with different temperature has been discussed. At last, the movementcharacteristics of the charged haze particulates in the ionized field has been studied, andthe influence of haze on the contamination of insulator has been studied by experiment.The main innovative points of this thesis are shown as follows:(1) An improved MLPG (Meshless Local Petrov-Galerkin) method is proposed inthis thesis. The improved method uses the RPIMp (radial basis function with additionalpolynomial basis) shape functions and self-adjusted local sub-domain sto overcomethe shortcoming of regular MLPG method. This makes the improved MLPG methodvery easy to deal with irregular or complex geometries. The improved MLPG methodhas been used to calculate the ionized of HVDC transmission lines, the results show thatthe improved MLPG can obtain accurate results in the ionized field problem.(2) Based on the charging process of haze particulates and influence mechanism ofhaze on ionized field, the governing equation of ionized in presence of haze are given inthis thesis. The improved MLPG method are used for the construction of the numerical model, the distribution of the ground level ionized field in presence of haze withdifferent temperature are discussed. The results show that, the haze will increase theground level total electric field, and the maximum value get higher with the pollutionlevel of haze increasing. The calculation results indicated that the ground level electricfield becomes stronger if the haze with higher temperature.(3) The movement characteristics of the charged haze particulates in the ionizedfield has been studied. The charge polarity of charged haze particulates and theinfluence of haze on the contamination of insulator has been studied by experiment.Based on the movement of the charged haze particulates in ionized field and thedynamic commination accumulating of the haze particulate on the HVDC insulator, theinfluence of haze weather on the insulator contamination are given in this thesis.

【关键词】 无网格法直流输电雾霾离子流场
【Key words】 Meshless MethodHVDCHazeIonized Field
  • 【网络出版投稿人】 重庆大学
  • 【网络出版年期】2014年 12期
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