Grounding Resistance Measurement Research Articles

Accurate Measurement of Tower Grounding Resistance for Single-Tower and Multi-Tower Parallel Scenarios Based on the Clamp Meter Method: For the Sustainable Operation of Towers

Transmission tower grounding safety is a critical element that significantly impacts the reliability and sustainability of power grids. Tower grounding resistance is a significant grounding characteristic parameter. In order to accurately measure the grounding resistance of towers using the clamp meter method in both single-tower and multi-tower parallel scenarios, this paper establishes theoretical calculation models for measuring tower grounding resistance using the clamp meter method. Considering the interaction between the artificial grounding device and the tower foundation, this paper models and simulates transmission towers and lightning shield wires, analyzing the influencing factors on the grounding resistance measurement results using the clamp meter method in both single- and multi-tower parallel scenarios. The results show that for single towers, the clamp meter measurement results increase with decreasing foundation root spacing and increasing length of the artificial device’s extension lines, but the changes are relatively small. In multi-tower grounding scenarios, due to the shunting effect of the parallel branches formed by the towers and lightning shield wires, the value is smaller than in single-tower grounding scenarios. Changing the number of parallel towers and the type of lightning shield wire produces little effect on the measurement results. However, changes in soil resistivity have the most significant impact. Therefore, correction formulas for the impact of soil resistivity on clamp meter measurements are proposed and then verified by applying them to field tests.

Effect of high resistivity soil under high impulse currents

In this paper, experimental test results of several ground electrodes surrounded with gravelly soil medium subjected to high impulse currents were studied, to investigate the effect of confined soil surround electrodes. Ground resistance measurements were performed at low magnitude of voltage and current, where the results are compared to the impulse characteristics of ground electrodes. This paper shows a significant difference in the RDC values and impulse characteristics of ground electrodes when gravelly soil medium surrounded the ground electrode in comparison to the electrodes installed in natural soil. This indicates that the confined soil around the electrode has a major effect on the performance of ground electrodes, whether at steady state or under high impulse conditions. Equivalent circuit for each tested electrode was developed with personal simulation program with integrated circuit emphasis (PSPICE), where the effect of inductance was seen in the electrodes surrounded with gravelly soil.

Traditional and alternative grounding system's impedance and resistance measurements of a 138 kV transmission line tower

One of the main causes of outages in transmission lines is lightning. To mitigate this occurrence, grounding electrodes are used at the base of the towers that make up the transmission lines. Since lightning is a phenomenon with components of low and relatively high-frequency energy (approximately up to 2 MHz), there is a certain complexity in accurately characterizing grounding systems. The primary parameter used to model a grounding system is the grounding impedance, which can be obtained through measurement. This paper presents measurements conducted on a 138 kV transmission line's traditional and alternative grounding system. The measured traditional grounding system consists of two horizontally buried copper grounding conductors and the alternative system comprises an electrode with four conductors encapsulated in concrete and buried vertically. The measurements were carried out using a 25 kHz earth resistance meter and impulse generators with waveform shapes of 1.2/50 μs, 1/70 μs, and 8/70 μs. Different measurement configurations are employed. The obtained measurements are compared with similar systems found in the literature, and the contributions of the concrete electrode to the grounding system are discussed.

Feasibility Study of Grounding Systems in the Dean's Building, Faculty of Engineering, Universitas Negeri Padang

This research aims to see the level of feasibility of the existing grounding system in the Dean's Building, Faculty of Engineering, Padang State University. The quality of the grounding can be seen from the measurement results using an Earth Tester. This is intended to see how the grounding system is installed in the dean building. After that, a feasibility study will also be carried out on the value of grounding installed in all engineering faculty dean buildings. A good grounding value should be between 0 and 5 Ω. In this study, the grounding value was measured using the HIOKI FT6031 Earth Tester measuring instrument with a three-point measurement method. This measurement is used to see whether the grounding system installed in the engineering faculty dean building complies with PUIL or not. The results of the research carried out can show that based on ground resistance measurements carried out directly in the Dean's Building, Faculty of Engineering, Padang State University, the measured values ​​do not meet the PUIL 2011 requirements for network systems. Apart from that, there is also a difference in the voltage value between the grounding value on the panel box and the voltage value on the first to fourth floors of the engineering faculty dean's building which is caused by a poor installation system

Using copper-coated round rod electrodes at various depths in freshwater marshes

Purpose: High-voltage electrical equipment requires a grounding installation in order to protect lives in freshwater swamps with a hydrogen potential of 6.75. To build a grounding structure, it is required to know the resistance value and grounding materials, namely copper-coated rod electrodes at different depths.
 Research methodology: The research was conducted in a freshwater swamp close to the shampooing substation using field observations and direct measurement of soil resistance values, followed by a literature review and comparisons using COMSOL simulation and FEM Analysis.
 Results: The results of direct research and simulations indicate that in order to accomplish a grounding resistance value < 5 ohms according to the PUIL 2011 standard for a single rod system made of copper, it is necessary to optimize the depth of the grounding electrode within a range of 10 meters, which differs from the simulation results of ground resistance measurement and the Comsol application. The percentage error is 1.05%.
 Limitations: This research analyzes the results of measurements and grounding analysis using Comsol Multiphysics at a depth of 1 meter for a particular type of copper-coated round rod electrode at depths of 1, 1.5, and 2 meters.
 Contributions: The results of the study offer information on the usefulness of grounding resistance in freshwater wetlands with a pH greater than 6, where several rod electrode types are utilized to compare future research.

Tower impulse grounding resistance measurement based on multiple frequency impedance

AbstractTower impulse grounding resistance is important for judging the lightning protection performance of transmission lines. Therefore, it is significant to accurately measure the tower impulse grounding resistance. Existing measurement methods mainly contain the real‐type test method and the impulse coefficient method. However, the real‐type test method requires heavy and complex excitation and measuring equipment, which is difficult to be used in a practical environment. The impulse coefficient method adopts the empirical equations, which could have large measurement errors in different environments. To solve the above problems, this paper studies a novel impulse grounding resistance measurement method (IGRMM) based on multiple frequency impedance. Spectrum characteristics of typical lightning currents and the calculation method of impulse grounding resistance of grounding electrodes are studied, the IGRMM is proposed. Finally, a case study and on‐site tests are carried out. The results show that the proposed IGRMM can accurately obtain the impulse grounding resistance by measuring grounding impedance at a few frequency points, which helps accurate and convenient evaluation of impulse grounding performance in practical environments and lightning protection performance of the power transmission systems.

Pengaruh Tahanan Jenis Tanah Terhadap Sistem Pentanahan Menggunakan Elektroda Batang Dilokasi Gedung Teknik Elektro Unimal

Providing a return line for short-circuit currents or fault currents to a low-resistance ground, grounding system is useful for achieving a uniform potential voltage over a given area of buildings and equipment. Because a large voltage difference can occur if a fault current is forced to ground against a high resistance. Placement of the electrode to be planted is one of the elements to obtain a low grounding resistance value. Grounding resistance measurements, which will serve as a guide for the grounding system design process, are required during the planning stage for certain types of grounding systems. The problem is how the grounding resistance is affected by the buried depth of the rod conductor and the soil type resistance. Therefore, it is very important to conduct research and testing to determine the extent to which these parameters influence. The experimental results of measuring resistance on dry and wet soils are on dry soil 30 cm obtained 98.48 Ω, 60 cm obtained 37.07 Ω, 90 cm obtained 20.52 Ω, 120 cm obtained 19.77 Ω, and for wet soil at a depth of 30 cm obtained 43.34 Ω, 60 cm obtained 22.21 Ω, 90 cm obtained 15.43 Ω, 120 cm obtained 11.66 Ω. So to get the 5Ω value we make an estimate by adding a depth of 56.603 cm for wet soil and 38.58 cm for dry soil, then the length of the electrode needed is 176.603 cm for wet soil and 158.58 cm for dry soil.

접지 전위 간섭의 특성을 반영한 접지저항 측정 방법

Domestic low-voltage electrical equipments have an environment prone to ground potential interference, due to the characteristics of grounding system. This ground potential interference affects electrical equipments and communication facilities, and amplify the error of ground resistance measurement. It is desirable to find and eliminate the root cause of ground potential interference, however it is difficult to remove that in an environment such as in a dense urban area or an area adjacent to the transmission line. In this paper, the pattern of the potential interference voltage and the effect on the conventional ground resistance measurement are analyzed based on the actual field measurement cases of the ground potential interference, and propose a ground resistance measurement method that reflects the characteristics of ground potential interference.

Design of impulse grounding resistance measurement system for distribution network based on wavelet packet optimal algorithm

Design of impulse grounding resistance measurement system for distribution network based on wavelet packet optimal algorithm

Design of impulse grounding resistance measurement system for distribution network based on wavelet packet optimal algorithm

Design of impulse grounding resistance measurement system for distribution network based on wavelet packet optimal algorithm

Studi Kelayakan Sistem Pentanahan pada Gedung Teknik Elektro Universitas Andalas

The grounding system is one part of the electric power system that has an important role in flowing overcurrent from the electric power system to the ground due to electrical power system disturbances or lightning strikes that can endanger the building and its surroundings. This grounding system aims to protect humans, electrical equipment, and electrical installations from the danger of electrical short circuits. In compliance with official regulations, safety standards and according to general electrical installation regulatory standards (PUIL) to avoid the danger of lightning strikes in buildings, it is necessary to have grounding resistance value of less than five ohms and is made as small as possible. In this study, the measurement of grounding resistance seen from the depth of the grounding and the grounding resistance are arranged in parallel. The results of this study indicate that the parallel grounding resistance method produces a more significant reduction in the value of grounding resistance compared to the grounding resistance in a certain depth From the calculation results, the resistance value of the Electrical Engineering Building at Andalas University using a rod electrode with a diameter of 0.016 meters is 24.5 Ω with an electrode depth of 0.5 meters and at a depth of 1 meter a grounding value of 17.52 Ω is obtained. The deeper the depth of the electrode, the smaller the resulting resistance value, and installing a grounding system with the multirod method, namely arranging electrodes in parallel with a certain depth, obtains less resistance compared to not parallelizing the electrodes

Simulation and Experiment of Substation Grounding Resistance Measurement Based on Pseudorandom Signal.

The grounding resistance of a substation is an important parameter that should be designed within a reasonable range to prevent operational accidents from damaging electrical equipment due to overvoltage and ensure the safe operation of an electrical system. However, simply and accurately measuring the grounding resistance of a substation has been a difficult problem faced by engineers and technicians for a long time. This paper proposes a method of denoising by applying the m-sequence correlation identification technology to the measurement of substation resistance. We established a grounding resistance model of a grounding grid and used LabVIEW to simulate it. Based on system identification and correlation function theory, pseudorandom signals or sinusoidal signals were used as excitation signals. The output results of the system were compared when pseudorandom signals and sinusoidal signals were used as excitation signals. It was verified that the grounding resistance value measured by a pseudorandom signal was closer to the actual value, which met the design requirements. Laboratory test results verify that the method of calculating grounding resistance based on the correlation analysis method is feasible.

A new approach for ground resistance measurements in onshore wind farms based on clamp-on meters and artificial neural network

Monitoring the grounding resistance of wind turbine generators (WTG) over the lifespan of a wind farm is important to ensure the safety of the personnel and equipment on the facilities. Conventional methods used to measure grounding resistance are not feasible in periodic maintenance activities of onshore wind farms due to test setup complexity and associated high costs. The clamp-on meter is an alternative method proposed to measure ground resistance in multi-grounded electrical systems. However, a significant error occurs in clamp-on meters on large grounding systems, such as those found in wind farms. Hence, we propose a solution to minimize methodological errors resulting from applying the clamp-on method in wind farms based on a neural network. Besides presenting lower errors than compared methods for a real Brazilian wind farm complex, it offers even greater practicality and safety to the workers involved in the measurement, as well as less test execution time.

Measurement and calculation method of substation grounding system parameters based on CDEGS

Indoor substations are often located in areas with intensive power consumption, and its grounding design has become a very important task. In this paper, the whole process of grounding design is studied from the grounding resistance measurement obtained in the early geological exploration to the final grounding resistance, touch voltage and step voltage verification to ensure the accuracy of the design. According to the design parameters of grounding performance, the simulation calculation based on CDEGS software is adopted and optimized, which improves the design accuracy. Taking a 110kV actual substation as an example, the simulation results are accurate and reliable, which shows that the research method of grounding design based on CDEGS software can effectively improve the design quality.

Investigasi Kinerja Resistansi Pentahanan (Grounding) pada Lahan Rawa Timbun

Abstract: This study aimed to determine the grounding resistance (grounding) in swampland. The method used in this research is to use the driven rod method. The investigation results through measurements with the 3 point method as well as with variations in depth and comparison of grounding resistance using a grounding rod made of coated copper with a resistance of 14.5 while the iron grounding rod is 16.70 or 15% larger than the copper grounding rod. In conclusion, In the investigation of the measurement of grounding resistance in swampland, copper-coated rod electrodes are more efficient than iron rods. Iron with rainy weather conditions.
 
 Keywords: Swamp Landfill, Measurement, Grounding Resistance

Novel Method for Measuring the Grounding Resistance of Towers With Short Electrode Wire

The three-electrode method is the most commonly used grounding resistance measurement method. But the electrode wire of the three-electrode method is too long to be used in mountainous areas or densely built areas. Therefore, it is of great application value to effectively shorten the electrode wire under the condition of ensuring measurement accuracy. In this article, a novel method for measuring the grounding resistance of towers with short electrode wire is proposed. Based on the connectivity of soil inside and outside the tower foundation, the limited space inside the tower foundation is fully used to arrange the electrodes. The principle of arranging electrodes inside the tower foundation to measure the grounding resistance is deduced in detail. The calculation method of the compensation point position and measurement error is studied. The best way of arranging electrodes is proposed. Through simulation experiments and field tests, we confirmed that the measurement accuracy of this novel method is similar to that of the three-electrode method. Its electrode wire length is shorter than the three-electrode method and other improved methods. Only the length of electrode wire needs to be the same as the length of the grounding conductor, and the measurement error can be controlled at about 3%. The novel grounding resistance measurement method has a wider application range and higher measurement efficiency.

Current pole inner distribution method for measuring tower grounding resistance

Three electrode method is a common method in measuring tower grounding resistance. However, its wiring distance is too long to complete accurate measurement in some terrain narrow areas, which is also an application problem to be solved urgently in the field of tower grounding resistance measurement. The traditional three electrode method is to find the compensation point between the grounding pole and the current pole. After calculation, there are also compensation points near the current pole besides the grounding pole and the current pole by using the traditional three electrode method. Based on this principle, the current pole is arranged between the grounding pole and the voltage pole by the current pole inner distribution method, which can greatly shorten the distance of the distribution pole. Through simulation analysis and test verification, the pole inner distribution method can control the pole distribution distance around 50m on the basis of ensuring the accuracy of the measurement results. Compared with the three-pole method, the pole distribution distance is shortened to 60%.

Estimation of an Upper Bound to the Value of the Step Potentials in Two-Layered Soils from Grounding Resistance Measurements.

Due to the constant updating of regulatory standards on safety issues in electrical installations, limits are established for the maximum step potential that an installation can hold in a ground fault situation. In this paper, an upper bound to the maximum value of the step potentials arising in the soil surface when a fault takes place in a grounded electrical installation is estimated by means of a simple procedure. The direct measurement of the grounding electrode resistance together with some information about the soil resistivity and the knowledge of characteristic parameters of the electrode are used for the calculation of that upper bound. The procedure is tested at numerical simulation level by using different electrodes in several different scenarios corresponding to two-layered soils with different resistivity ratios. The dependency of the calculated upper bound with the electrode burial depth is also studied. Finally, a real case study is presented, and the results of the field measurements are shown as an example of the validity of the procedure.

Research on Earth Resistivity Measuring and Modeling of HVDC Deep-Well Grounding Electrode Sites

HVDC Deep-well grounding electrode covers a small area, which effectively alleviates the problem of difficulty in selecting the site of grounding electrode. Due to the small number of electrodes, each sub-electrode has to bear tens of times the current of conventional electrodes. In order to reduce the current density on the electrode, it is usually necessary to use long vertical electrodes to extend into low resistivity layers’ hundreds of meters underground. Because it involves a wide range of underground depths, it is particularly important to accurately evaluate the distribution of resistivity at the electrode site for calculating the electrical parameters of deep-well grounding electrodes. In this paper, four-point method (FP), controllable source audio magnetotelluric method (CSAMT) and magnetotelluric method (MT) are proposed to analyze the conductivity structure of the shallow layer, deep layer and the vicinity of the electrode, and the earth resistivity model of deep-well grounding electrode is obtained. By comparing the on-site grounding resistance measurements of practical engineering application, it is found that the absolute error of the earth resistivity model obtained in this paper is $0.064\Omega $ when calculating the grounding resistance of the deep-well grounding electrode. Engineering examples show that the exploration method in this paper has strong adaptability to the site, and the earth resistivity modeling method has good reliability.

A New Method for Grounding Resistance Measurement Based on the Drained Net Charge

This paper presents a new method for measuring grounding resistances, which is based on the measured net charge drained by the grounding system when excited by an impulse generator. The circuit property used by the method is briefly described, alongside with the method itself. An advantage of this method with respect to the traditional ones is that it is not affected by the self and mutual reactances present in the grounding system and in the measuring wires. Moreover, the proposed method does not require the measurement of surface potentials, which are prone to interference due to soil non-homogeneities, buried conductive bodies, and stray currents. This paper presents experimental results from the method using lumped components and using actual grounding systems. The results show that the method provides consistent and accurate values of grounding resistances.