Method for building horizontal soil model by using magnetotelluric three-dimensional inversion data

Abstract

The invention relates to a method for building a horizontal layered soil electrical model, which comprises the steps of building a composite layered soil model according to magnetotelluric three-dimensional inversion soil resistivity data, selecting the earth surface potential to act as a fitting index, fitting the earth surface potential of a composite model acquired by using a finite element method and the earth surface potential of a horizontal model deduced by using a Green function method by adopting a least square method so as to acquire an objective function of the horizontal layered soil electrical model, carrying out optimization solving on the objective function by adopting a genetic algorithm, acquiring a soil resistivity parameter and the corresponding layer depth of each layer in the horizontal layered soil electrical model, and thus realizing conversion from composite layering to horizontal layering of the model. The method provided by the invention reduces the complexity of the model, improves the reliability of the model, and can provide more accurate soil resistivity model data for analysis of an earth electrode.

Description

technical field [0001] The invention relates to the field of ground electrode soil resistivity modeling in a high-voltage direct current transmission system, in particular to a method for establishing a horizontally layered soil electric property model using magnetotelluric three-dimensional inversion data. Background technique [0002] Soil resistivity is a commonly used parameter in the calculation of grounding engineering, which directly affects the size of the grounding resistance of the grounding device, the ground potential distribution of the ground grid, the contact voltage and the step voltage. The size of the soil resistivity ρ mainly depends on the concentration of conductive ions in the soil and the water content in the soil. It is a function of the reciprocal A1 of the conductive ion concentration A contained in the soil and the reciprocal B1 of the soil water content per unit volume B, that is In other words, the higher the concentration of conductive ions cont...

AI Technical Summary

Problems solved by technology

The soil level layered resistivity model used in the analysis of ground electrode environmental impact is as follows: figure 1 As shown in (b), it cannot be simply applied figure 1 (a) Data format

Therefore, how to transform the magnetotelluric inversion data model into a horizontally layered soil electrical model has become a key issue that limits the application of the magnetotelluric method and improves the accuracy of the analysis of the grounding pole's environmental impact.

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