Grid Ground Engineering Applications

With the rapid development of national economy and the power grid, a higher demand of power supply reliability and power grid safe operation is put forward. Therefore, the lightning trip, the lightning over-voltage accidents that are worked by power system grounding network are gotten more and more attention, also the increasingly high requirements for the grounding. Due to a large number of old network, as well as some of the ground that were put into production a few years lines, substation grounding grid failure, power system had to invest a lot of money to carry out ground network overhaul and transformation. In order to correct application of technical grounding, to increase the capacity of power grids to prevent lightning strikes, to avoid short-circuit current causing harm, it is necessary to study ground power system technology in-depth. On the basis of grounding device running and transformation in the Qujing power grid in recent years, and integrating ground-to-date technology at home and abroad, this article study the ground power systems engineering applications.First of all, this paper made a brief introduction on the power system grounding device, analyzed the development of the grounding device and the use in the Qujing power grid, and discussed the function and classification of grounding device.Second, based on the use of mature regulations at home and abroad, it focused on transmission line, substation grounding device of technical requirements and the principle of selection.Third, this paper also introduced the concept of grounding resistance and soil receptivity, discussed the principle of grounding resistance on surveying, soil receptivity measurements and the three-straight-line method, the three-triangle law,as well as other commonly used methods.Fourth, this article given the precise algorithm of the grounding resistance, and the algorithm of grounding resistance of substation grounding device with square level network, any shape to the level of net, shape of any complex network, as well as the shielding factor algorithm of typical overhead line grounding equipment, and derived the shielding coefficients of ground device of Two lines. From the theoretical calculation to proceed, it analyzed decreasing resistance efficiency of the substations, transmission lines' grounding network.Fifth, this article also introduced the common question of ground installations and the new grounding technology at home and abroad, it study the water on an empty stomach-grounding device, the plasma electrolytic grounding device, deep well perfusion pressure grounding technology, blasting technology and other new ground technical grounding in-depth and meticulous.Finally, as 110kV DaSongshu substation and 110kV Luchang T network connection grounding network transformation an example, the paper systematically carried out the design and verification and given the design.This paper connected with the actual situation of grounding device of the Qujing Power Transmission and Transformation Facilities. It also researched the method of calculating relating to the grounding device and the new grounding device, which is applicable to environment of the mountainous, the complicated geological structure in Yunnan Province. This work has an important reference value to resolve the practical problems.