A method for reducing grounding resistance by drilling deep grounding wells in substations

Abstract

The invention discloses a method for reducing grounding resistance in manner of digging a grounding deep well in a transformer station, comprising steps of calculating a station address soil layered model, calculating target parameters like a power frequency grounding resistance safety value of a horizontal grounding grid and safety values of a contact potential difference and a step potential difference, obtaining a power frequency grounding resistance calculation value of a horizontal grounding grid and calculation values of the contact potential difference and the step potential difference, determining the amount, the positions, the well depth, the perpendicular grounding electrode materials and equivalent radiuses of the grounding deep wells, regulating the parameters of the grounding deep well, providing a horizontal grounding grid material table, a perpendicular grounding body material table, rise of earth potential, the power frequency grounding resistance, the calculation values and the safety values of the contact potential difference and the step potential difference of the grounding grid of the station. The invention can dramatically reduce the grounding resistance of the transformer station, enables the contact potential difference and the step potential difference to be reduced to below the safety value, and enables the design of the high soil resistivity and transformer station grounding system having the ground water layer to be simple, accurate and effective.

Description

technical field [0001] The invention relates to the technical field of substation grounding systems, in particular to a method for reducing grounding resistance by drilling deep ground wells. Background technique [0002] A good grounding system is the basic guarantee for the safe, reliable, and stable operation of substations. However, the site selection of domestic substations is often located in areas with high land resistance such as fertile land, residential areas, and economic development zones. Areas with high power and poor address conditions bring great challenges to the design of the substation grounding system, so a reliable and high-performance grounding system is required. [0003] At present, the domestic grounding system design generally adopts the following steps: Calculate the grounding resistance value, the contact potential difference in the station and the minimum value of the step potential difference according to the measured value of soil resistivity, ...

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Problems solved by technology

[0002] A good grounding system is the basic guarantee for the safe, reliable, and stable operation of substations. However, the site selection of domestic substations is often located in areas with high land resistance such as fertile land, residential areas, and economic development zones. The area with high power rate and poor address conditions brings great challenges to the design of the substation grounding system, so a reliable and excellent grounding system is required

[0003] At present, the domestic grounding system design generally adopts the following steps: Calculate the grounding resistance value, the contact potential difference in the station and the minimum value of the step potential difference according to the measured value of soil resistivity, the maximum value of the ground current, and the area of ​​the substation to judge The effect of the grounding grid and the use of resistance-reducing measures in turn, such a design method requires relatively high experience for designers, especially in the face of complex geological conditions (such as high soil resistivity, the existence of groundwater layers), it is impossible to accurately adopt the grounding grid after the resistance-reducing measures It is even more difficult to evaluate the resistance reduction effect of the grounding grid in different regions. Therefore, for the sake of conservatism, the material consumption of horizontal grounding grid materials and resistance reduction measures is often fearlessly increased, resulting in a waste of financial and material resources.

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