节点文献
空腹式接地装置及其应用研究
Study of Hollow Grounding Device and Its Application
【作者】 赵爱华;
【导师】 陈先禄;
【作者基本信息】 重庆大学 , 电气工程, 2004, 硕士
【摘要】 近几年来,空腹式接地装置作为一种新型的接地装置,在高土壤电阻率地区和接地面积较小的工程中得到了应用,并取得了良好的效果。但是,如何计算空腹式接地装置的接地电阻,在变电站中使用的设计计算方法等理论和工程应用等问题,却迄今为止没有人进行相应的研究。这些问题对空腹式接地装置的进一步推广和合理应用有重要的意义。本文根据地电流场理论,结合空腹式接地体的结构特点,建立了空腹式接地装置运行时的物理模型。根据电场计算方法和物理模型建立了空腹式接地装置的计算等效模型。基于空腹式接地体自身的特点和对接地电阻的计算精度的要求,选用表面电荷法作为电场数值计算方法。在传统的表面电荷法的基础上,进行了一些改进,并编制了相应的计算软件。将软件的计算结果与标准半球接地体的接地电阻的理论公式计算值相比较,二者比较吻合,证明了计算模型和计算方法的正确性,程序的计算精度完全满足工程要求。本文通过大量的仿真计算,分析了空腹式接地装置的接地电阻与接地体的底面直径、高和埋深等影响因素的关系。同时分析了接地坑降低接地电阻的效果,接地坑回填土的电阻率,接地坑的截面直径,接地坑的深度对接地装置接地电阻的影响。得到的结果对空腹式接地装置的设计和运行有重要的参考价值。本文通过实验室模拟试验,进一步检验了所建立的物理模型、计算等效模型和程序的正确性。并通过模拟试验分析了接地坑、自然水对降低空腹式接地装置的接地电阻的作用。本文分析了工程应用中空腹式接地装置之间的屏蔽作用和空腹式装置与水平地网之间的屏蔽作用,并提出了空腹式装置的工程设计计算方法。结合论文的研究工作,完成了两个变电站的改造和设计,取得了理想的结果。
【Abstract】 As a new type grounding device, hollow grounding device has played an important role in high resistivity soil and less-area grounding engineering. But it is still blank in the theoretic aspect of grounding resistance calculation, design method for substation which is important to the design and application for that device. Based on the ground current field theory, this paper built an operation model of hollow grounding device according to the configuration. According to the characteristic and the precision demand, it improved the electric calculation method of surface charge. With the model and electric calculation method, it programmed for the calculation of hollow grounding device resistance. Comparison results of the standard hemisphere grounding device grounding resistance values by theoretical calculation to those by program validate the model and the electric calculation method. The results also indicate that the program could get enough precision for engineering demand. This paper also analyzed the effect to grounding resistance of the device’s shape, device’s section diameter, height and depth which was the base of engineering application through lots of simulate calculations. It also analyzed the effect of grounding hole to the resistance, the influence of backfill soil resistivity, the hole’s section diameter and the hole’s depth to the resistance. By lab simulate experiments, it verified the model, the calculation model and the program. It also proved the effect of grounding hole and affused water to the device’s grounding resistance. This paper analyzed the effect of shielding between hollow grounding devices and between hollow grounding device and ground grid. It also put forward the way to apply the hollow grounding device. Based on the research of this paper, two substations’ grounding system have been designed and rebuilt successfully.
【Key words】 hollow grounding device; shielding; ground voltaic field; grounding hole; grounding resistance;
- 【网络出版投稿人】 重庆大学 【网络出版年期】2005年 01期
- 【分类号】TM862
- 【被引频次】7
- 【下载频次】189