The Analysis And Design Of Grounding Network In 500kV Ningzhou Substation

Lightning protection and grounding technology is closely linked with our life today, so it has become a hot topic. With the increase of the national economy, the development of electric power system and the expansion of the power supply network, the lightning strike accident is increasing. In addition, with the diminishing supply of land resources, power supply equipment is more intelligent, and the substation electrical layout is required more and more concentrated. Therefore, the ground connection demand is higher and higher.Grounding resistance is a important parameter of the substation ground network. If the value is too large, it may cause the insulation of the electric power system secondary equipment suffered severe damage, high pressure into the control room, leading to unreliability of motion control testing equipment, which may cause expansion of the accident. Therefore, the design of substation grounding system is directly related to the safe and reliable operation of power system, to ensure the safety of operators and electrical equipment. Around this situation, this paper discussed the project of 500 kV Ningzhou Substation, trying to analyze the substation ground network problems.In the first part, this paper introduces the concept, classification and significance of the grounding, and docking technology are described briefly the present situation. What's more, problems of the structure, function and existence of the substation ground network are described in this paper. In the second chapter, it focuses on the main factors affecting the resistivity and the methods of measuring soil resistivity, as well as the establishment of soil resistivity model. In Chapter 3 and Chapter 4, substation ground network design model is put forward to introduce the calculation method of earth resistance and the resistance reduction methods. Finally, according to the southern power grid company rules, the substation ground network project of Ningzhou Substation is analyzed and designed combined with the actual situation such as on-site engineering survey and geological survey. It showed that the effective resistance reduction method can meet the requirements of the substation grounding resistance.