Lightning stock flushing density number of thunderstorm. The earthing calculation aids in the proper design of the earthing system. Hand calculations design it is important to use the hand calculations method in the. Earth potential rise earth potential rise epr is caused by electrical faults that occur at electrical substations, power plants, or highvoltage transmission lines. Design of earthing grounding system in a substation grid. In many practical situations, a homogenous ground structure will be assumed with an average value of. Part 2 will cover the tolerable step and touch voltage.
Earth mat is preferable to large substations because of space saving on the. Quantity calculation made simple quantity calculation made simple generate volume calculation and section drawings from point data available. Here, the design uses etap electrical transient analyzer program software. Use of emix, a conductive earthing compound, with earth mats, will always improve the earth resistance. Etap model for earth mat design etap model for earth mat. Design safe buried earthing and grounding systems for applications including substations, power plants, transmission lines, transformers, mining, commercial and. The procedures for performing the grounding system design calculations can differ slightly according to the type of the building as follows. Design and analysis of substation grounding grid with and.
Etap model for earth mat design proceedings of international academic conference on electrical, electronics and computer engineering, 8th sept. Earth mat is preferable to large substations because of space saving on the ground level due to substantial reduction of earth pits which leads to ease of coordination. Cant do the earth mat design separately for each step and finally connect each steps together. Calculation of maximum permissible touch and step voltages.
The goal of this paper is to design earth mat earth grid, conductor size, vertical electrode size, permissible potential difference, grid resistance, maximum grid current, ground potential rise by a computer modeling. It is the ideal material to use in areas of poor conductivity, such as rocky ground, mountain tops and sandy soil. Earth mat design for 233kv substation in rivers state. Enter your steel or wood mat configuration and the ground bearing pressure below the mats and the amount of stress being applied to the mats will be calculated to. Safegrid earthing electrotechnik pty ltdelectrical calculations. Earthing mat design for a power substation ms excel spreadsheet.
Earth mat design can be done by manual calculations as well as with the help of computer software. Grounding system design calculations 1 course description. Earthing resistance and calculations electric power. We use skms stateoftheart groundmat software module and accurately determine the touch and step potentials. A ground grid mat study will determine if your substation grounding grid design is safe and will limit the touch and step potential to values below the ieee 80 standard ieee guide for safety in ac substation grounding limits. The earth filling calculation program should allow the estimator to measure trench plans and profiles, as well as determine slope, widths and heights. High efficient multicore parallel calculation allows fast analysis of irregular largescale renewable applications. Earthing mat design for a power substation ms excel. What is the tolarable value of gprepr for earthing grid calculation.
Safety analysis including surface materials, based on body weight and exposure time. Over time, corrosive soils with high moisture and salt content and high temperatures can degrade ground rods and their connections. The earthing calculation aids in the proper design of. Ensure that the earthing design is appropriate to prevent dangerous step and touch potentials if this is necessary. Optimal design of substation grounding grid based on. Braze to earth tape going direct to switch handle or mech box always make the connection visible for inspection if. Calculate no of down conductor for lightning protection area of building structure. Protection of earthing system and additional devices used in the earthing grounding system. Knowledge of the local soil conditions is mandatory and is the first step in the design process. Overview on etap capabilities in ground grid system design and analysis using ieee 80 standard and finite element method fem. The autogrounddesign software package is the only fully automated software tool that can analyze and design grounding systems without the intervention of the.
The earthing system is designed so that the allowable touch and step voltages do not be exceeded. The autogrounddesign package performs automated analyses of grounding earthing systems of any arbitrary perimeter and identifies an economical grid configuration complying with userdefined safety criteria that can be used as the design for grounding grids that are electrically small enough to be considered equipotential. In this paper design of the grounding grid for square and rectangular configuration is done and analysis is done by edsa software. How do you calculate voltage variations across a ground grid. Pdf earth mat design for 233kv substation in rivers state. The ground grid systems module enables engineers to quickly and accurately design and analyze ground protection. What are the next steps required for designing earth mat for 70 x 33 meter area of switch yard.
Standard crowfoot earth 25mm x 3mm copper tape x 5m long joined to. The calculation of the earthing resistance requires a good knowledge of the soil properties, particularly of its resistivity thus, the large variation in the value of. Poor grounding contributes to downtime but a lack of good grounding is also dangerous and increases the risk of equipment failure. Xgslab is one of the most powerful software of discover more. We recommend the cdegs grounding software package for design, however it is quite expensive and is rarely worth your time to purchase the software and then learn how to use it. Cymgrd, substation grounding program the cymgrd software is a substation grounding grid design and analysis program specially developed to help engineers optimize the design of new grids and reinforce existing grids, of any shape, by virtue of easy to use, builtin danger point evaluation facilities. International journal of engineering trends and technology. Earth mat minimizes the danger of high step or touch voltages in critical operating areas or places that are frequently used by people. Learn how to measure ground resistance and test large ground systems. Earthing calculator lightning protection services lpi. Mat computer printout study setup and data touch voltage calculations. Its cdegs suite of software packages is the state of the art in this field of expertise and an industry reference worldwide.
Ability to analyze the potential rise for each grounding system including neighboring passive grids or rods. We would be glad to help you with the design for only a fraction of the cost. Our lpi earthing calculator is used to give preliminary estimations for earthing installations in power system and lightning applications. Design of earth grid for a 3311kv gis substation at a. Flexible design methodologies allow for quick autodesigned layouts or very detailed schemes. Design of earth grid for a 3311kv gis substation at a high. A ground grid mat study will determine if your substation grounding grid design is safe. Domestic, commercial and industrial premises, high and medium voltage electricity substations.
Determine the minimum size of the earthing conductors required for the main earth grid. I have used skm ground mat software to calculate the touch and step voltages for two earthing configurations of the transformer kiosk assuming. We use skms stateoftheart groundmat software module and accurately. Or is it must to do the design for all the steps together. Xgslab, a complete software tool for the simulation of power, earthing, grounding and lightning systems. Video 1 earthing of ac substation basic part 1 youtube. Grounding system design calculations according to type of the building. The cross section of the buried cable should calculated in accordance with the value of the phasetoearth short circuit current, but it is common to use the three phase shortcircuit current for this purpose. Calculations that take into account the resistivity of the soil and any surface treatment in the protected area it is customary to put a layer of crushed stone over the. Greymatters earthing arrangements hv earthing design to. Designing for a low resistance earth interface grounding. Etap model for earth mat design etap model for earth.
Important formulas for designing a substation grid earthing system. Calculate whether lightning protection is required or not for following building. Sophisticated cut and fill software should allow the estimator to select any grid from grid staking reports and view the cut and fill measurements associated with that area. Principles and testing methods of earth ground resistance. Since their is huge civil work in step 144m and 147m it may take some time, so we can start lower 3 level works if we can lay the earth mat. Skm groundmat is a program for substation ground grid design and analysis. It sounds like your substation is in real need of a properly designed ground safety grid. Earth pressures is an intuitive program used to calculate earth pressures active, passive, at rest acting upon an arbitrary structure. Calculate lightning protection for building structure. Though manual calculation is a good, software tools ensure.
Application guide for equipotential earth mat installation on substation structure mounted switches version. Steel bar grid mat welded wire geosynthetics geotextile sheets or geogrids. Ground grid systems software ground grid design ieee 80. The earth must be treated as a semiconductor, while the grounding electrode itself is a pure conductor. High efficient multicore parallel calculation allows fast analysis of irregular large scale renewable applications. These factors make the design of an earthing system complex, not derived from a simple calculation or the random driving of a few rods into the soil. Awareness of step and touch potential, caused by earth potential rise, is important for anyone working on highvoltage power transmission and distribution systems above 1 kv. Copper plate earthing the conventional system of gi pipe earthing. Spreadsheet design of mechanically stabilized earth walls. Design safe buried earthing and grounding systems for applications including substations, power plants, transmission lines, transformers, mining, commercial and industrial sites.
How to determine correct number of earthing electrodes. Substation absd equipotential earth mat application guide. The cymgrd software is a substation grounding grid design and analysis. Build custom earthing systems, using finiteelements determine a safe design overview features videos screenshots faq testimonials training overview determine earthing system performance, touch and step voltage safety compliance. Though manual calculation is a good, software tools ensure a detailed design so that the earth mat is neither underdesigned hence safe nor this paper presents the complete design of earth mat for a 3311kv indoor gis gas insulated switchgear. Elek safegrid earthing and grounding design software. How do you calculate the step and touch voltages in the. With over 126 years experience, furse provide a renowned total solution for earthing, lightning risk and electronic systems protection.
This course is intended to prepare the target persons with the ability to perform all electrical grounding system design for domestic, commercial and industrial facilities and ac substations. So, although the ground system had low earth ground resistance values when initially installed. International journal of engineering trends and technology ijett volume 15 number 8 sep 2014. Ground grid systems software ground grid design ieee. However, it is acceptable to include the facing dimensions and.
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