scholarly journals Grounding Electrodes with Internal Resistance: Application to Feasibility Study of the Driven-Rod Method for Modeling the Soil Electrical Resistivity Profile

2021 ◽  
Vol 11 (11) ◽  
pp. 5032
Author(s):  
Gregorio Denche ◽  
Eduardo Faleiro ◽  
Gabriel Asensio ◽  
Jorge Moreno

The paper presents a model to include the internal resistance of the grounding electrodes in the calculation of its electrical features. The semi-analytical expressions for the calculation of the grounding resistance arising from the model are used to study the feasibility of the driven-rod method for the estimation of the soil resistivity profile since, unlike other methods, the internal resistance of the conductors can be of great influence for a correct estimate. From the grounding resistance profile an inverse problem based on the minimization of the quadratic differences between the resistance measured and that calculated from the model is posed. Several synthetic examples are used to assess the limitations of the method in conditions close to real situations. Finally, some real cases involving data measured in the field are analyzed. Whether in synthetic examples or in real soils it is found that the spatial frequency of the driven-rod resistance sampling is a determinant factor in order to study the feasibility of the driven–rod method.

Mathematics ◽  
2021 ◽  
Vol 9 (14) ◽  
pp. 1624
Author(s):  
Leonid Litinskii ◽  
Boris Kryzhanovsky

In the present paper, we examine Ising systems on d-dimensional hypercube lattices and solve an inverse problem where we have to determine interaction constants of an Ising connection matrix when we know a spectrum of its eigenvalues. In addition, we define restrictions allowing a random number sequence to be a connection matrix spectrum. We use the previously obtained analytical expressions for the eigenvalues of Ising connection matrices accounting for an arbitrary long-range interaction and supposing periodic boundary conditions.


2016 ◽  
Vol 680 ◽  
pp. 361-364 ◽  
Author(s):  
Jun Du ◽  
Cheng Tang ◽  
Bo Jia ◽  
De Zhang ◽  
Qiang Miao

The steel fiber/graphite conductive concrete is applied in power system grounding. In high soil resistivity regions, the common methods for reducing the grounding resistance are not practical. It is difficult for grounding resistance of substations to meet the requirements of working earthing and safety earthing. In order to solve this problem, a steel fiber/graphite conductive concrete is developed in this paper. Steel fiber and graphite are added as conductive fillers. The long-term stability of the steel fiber/graphite conductive concrete is studied. The experiment results show that steel fiber/graphite conductive concrete not only maintains excellent conductivity, but also has good mechanical strength and corrosion resistance in 300 days.


2009 ◽  
Vol 24 (10) ◽  
pp. 3013-3017 ◽  
Author(s):  
Yang-Tse Cheng ◽  
Fuqian Yang

Using Laplace transform, we solve the inverse problem of obtaining the shear relaxation modulus and creep compliance of linear viscoelastic solids from indentation by axisymmetric indenters of power-law profiles. We identify several simple, though nontrivial, loading paths for carrying out indentation measurements such that the inverse problem has analytical solutions. We show that the shear relaxation modulus and creep compliance may be readily obtained using the newly derived analytical expressions together with proposed indentation loading paths.


Author(s):  
Marina Kizhlo ◽  
Arvids Kanbergs ◽  
Mihails Kizhlo

Correlation Analysis between Grounding Resistance and Diurnal Variations of Upper Soil Resistivity during March 2010 in Balozhi, LatviaThe accurate measurement of soil resistivity and grounding system resistance is fundamental to electrical safety. However, geological and meteorological factors can have a considerable effect on the accuracy of conventional measurements and the validity of the measurement methods. This paper examines some aspects of grounding measurements and grounding system performance in the context of both geological and meteorological effects.We are reporting the results of grounding measurements using the 3-point method with ground resistivity tester type M416. The measurements were conducted during selected period from 2010 March 1 to March 31 in Balozhi, Latvia. We also noted that the resistivity of the upper layer significantly varied from a point to another, reflecting difference in water content in the upper soil layer due to local topography and other parameters.


2013 ◽  
Vol 353-356 ◽  
pp. 911-917 ◽  
Author(s):  
Mohd Hazreek Zainal Abidin ◽  
Fauziah Ahmad ◽  
Devapriya Chitral Wijeyesekera ◽  
Rosli Saad ◽  
Mohamad Faizal Tajul Baharuddin

In the past, most of the soil electrical resistivity charts were developed based on stand-alone geomaterial classification with minimal contribution to its relationship to some of geotechnical parameters. Furthermore, the values cited a very wide range of resistivity with sometimes overlapping values and having little significance to specific soil condition. As a result, it created some ambiguities during the interpretation of observations which were traditionally based on qualitative anomaly judgments of experts and experienced people. Hence, this study presents soil resistivity values based on laboratory experiment with a view to predict the soil moisture content and density in loose and dense soils. This study used a soil box and a resistivity meter to test a clayey silt soil, increasing its water usage from 1-3% based on 1500 gram of dry soil. All the moisture contents and density data were observed concurrently with 25 electrical soil resistance observations being made on the soil. All testing and formula used were in accordance with that specified in BS1377 (1990). It was apparent that the soil resistivity value was different under loose (L) and compact (C) condition with moisture content (w) and density (ρbulk) correlations being established as follows; ρbulk(C) = 2.5991ρ-0.037, ρbulk (L) = -0.111 ln (ρ) + 1.7605, w(L) = 109.98ρ-0.268, and w(C) = 121.88ρ-0.363 with determination coefficients, R2 that ranged between 0.69 0.89. This research therefore contributes a means of predicting these geotechnical parameters by related persons such as geophysicist, engineers and geologist who use these resistivity techniques in ground exploration.


This chapter contains the factors affecting the soil resistivity and grounding resistance such as the soil moisture content, soil mineral content and soil temperature. It discusses the methods of measuring of soil resistivity and grounding resistance using Wenner method. Method to obtain the required samples for obtaining accurate site resistivity is presented. Soil resistivity measurement procedure is given in this chapter. The chapter contains three electrode method or fall-of-Potential method, dead earth method, and ground resistance testing existing systems using ‘Selective' Clamp-on-Measuring of high voltage transmission towers feet resistance. Methods of calculating the apparent soil resistivity of Multi-Layers, apparent soil resistivity of two layers and apparent soil resistivity of three layers are presented in this chapter.


2019 ◽  
Vol 36 (3) ◽  
pp. 273-284
Author(s):  
X. Ma ◽  
B. Zhou ◽  
S. F. Xue

ABSTRACTIn this paper, a novel continuous fiber reinforced piezoelectric composite (CFRPC) actuator is proposed to improve the stability and reliability of piezoelectric actuators. A piezoelectric driving structure composed of a cantilever beam and the CFRPC actuator is utilized to research the actuation performance of the CFRPC actuator. The expression of the equivalent moment for the CFRPC actuator is obtained using the equivalent load method and electro-mechanical coupling theory. Based on Euler-Bernoulli beam theory, the analytical expression of the deflection for the cantilever beam is derived. The accuracy of the obtained analytical expressions is demonstrated by finite element simulation as well as published experimental results. The actuation performance of the CFRPC actuator is investigated through the analytical expressions of the equivalent moment and deflection. The results show that the key parameters such as driving voltage, fiber volume fraction, cantilever beam height, actuator height, actuator length and actuator position have great influence on the actuation performance of the CFRPC actuator. The CFRPC actuator has good mechanical and electrical properties, and has a wide application prospect in the field of structural shape control.


2013 ◽  
Vol 655-657 ◽  
pp. 1857-1863
Author(s):  
Zamri Chik ◽  
Taohidul Islam

This paper shows the performance of multi-layer soil electric resistivity model comparing with two-layer characterizations in geotechnical investigations. In conventional model, there are inter-relationships between soil apparent electrical resistivity (ρ) and several soil physical or chemical properties. These empirical relationships show limitations to obtain specific soil characterizations of different layers with. Multi-layer true resistivity model is the improvement of conventional two-layer earth model including the criteria of four points probe method. Multi-layer soil resistivity profile shows more accuracy to obtain near surface soil characteristics including the types of soil and rocks, and to detect anomalous materials in soil profile. Alternatively, apparent resistivity in two-layer model can be used to obtain deeper profile of soil characteristics. In this multi-layer soil model, the soil resistivity and resistivity ratio corresponding to the depth in soil medium are considered for geotechnical investigations. Two-layer model includes soil apparent resistivity according to probe distances in depth corresponding resistivity profile. This paper is important for including criteria and performance of multi-layer soil resistivity model and conventional two-layer model for geotechnical characterizations.


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