And how would i calculate what percentage of the fault current will flow into the ground. Substation at a high soil resistivity site using cymgrd software. The paper describes aspect of designing earth mat for gis substations with high. At the beginning of the gis technology, the grounding design was based in the classical approach of limiting the power frequency enclosure potentials to safe levels based on the maximum expected faultcurrent conditions. Safe step and touch voltage criteria based on body weight defined in ieee std. Ge provides a full range of gasinsulated substations gis for utilities and industries worldwide. Civil and electrical engineers need pointed analyses that assure installations are fully secure for personnel and also sound and economical construction, connection and operation of the grids along with proper equipment. Home technical articles gis vs ais substation earthing aeg gis gas insulated switchgear up to 420 kv compressed sf6 gas used in mv and hv switchgears as an insulating medium has led to the development of compact gasinsulated substation cis technology figure 1. The robust and low maintenance gis based design minimizes the substation s footprint by as much as 70 percent, enabling it to be installed indoors, in busy urban areas and in harsh environments.
The maximum touch voltage within a mesh of a ground grid. These electrical substation platforms allow multiple workers the ability to access control boxes for repairs or maintainence without the risk of a stand alone ladder. By means an iterative process, new elements are added to the grounding. High voltage substation grounding has previously been an experienced. An effective substation earthing system typically consists of earth rods, connecting cables from buried earthing grid to metallic parts of structures and equipment. Design of grounding system for an electrical substation. If the system has 50 ka total connected load what will be the fault current. Substation system software applications cyme grids eaton. The problem is formulated as a mixedinteger linear. Substation grounding software eaton s mission is to improve the quality of life and the environment through the use of power management technologies and services. Esgsd is preliminary developed in order to assist the engineers in the design of substation grounding system.
In this work the safety provided by several fence grounding techniques commonly used in high voltage installations is evaluated for a 15020 kv air insulated substation, a 400 kv stepup gis. Flow of the earth system, cause voltage gradients ground. The maximum electrical potential that a substation grounding grid may attain relative to a distant grounding point assumed to be at the potential of remote earth. Nov 30, 2014 3d substation design and modelling, south africa. Userfriendly data entry, efficient analysis algorithms and powerful graphical. This voltage, gpr, is equal to the maximum grid current times the grid resistance. This module can evaluate the estimate places for the danger voltage points in the grid and its. Recommends an optimallydesigned safe ground grid that uses accurate modeling techniques, and enables possible material and labor savings while meeting all ieee 80 safety requirements. Substation grounding programs technical report osti. The proper grounding of a substation is essential and very important for the following two reasons. Design and analysis of ground grid system for substation. With multipoint grounding and the resulting many parallel paths for the current from an internal fault to flow to the substation ground grid, it is easy to keep the touch and step voltages for a gis to the safe levels prescribed in ieee 80. Earthing design service utilising cdegs software package earthing system audits ea technologys earthing system audit provides an essential assessment of the earthing system in and around substations and other power assets, along with the associated maintenance procedures.
Our indepth knowledge of the power value chain, as well as grid codes and utility practices in use around the world, enable us to provide turnkey. The methodology takes the reference from the ieee std. Before the design of the grounding system begins, soil resistivity measurements need to be taken at the substation. Substations may also be owned by manufacturing, industrial, or large commercial customers. Not long ago i wrote an article on substation grounding for electrical business that raised the issue of whether one should interconnect the building reinforcing steel with the station ground electrode. Research on lightning intruding waves in 220 kv gis substation. The resulting earthing types are displayed both on the one line diagram and for the various connected cables. This software is suitable for grounding systems of any size.
With ses, you input the total fault from your fault analysis program, along with data on shield wires, tower grounds, source substation ground resistance, etc. An urban gis substation grounding system design is a complicated task in. This substation grounding course covers effective relaying and insulation of equipment. Easypower is partnering with the industryleading grounding and emi analysis expert company, sint ingegneria, which offers a software package to analyze and design grounding, lightning and electromagnetic interference problems by focusing on its powerful and yet affordable grounding analysis software packages, xgslab. Then after the grounding design is done for identical 400kv ais substation and comparison made between both types of the substation for grounding design. This bulletin is an update and revision of previous rea bulletin 651, design guide for rural substations revised june 1978. Safety design of ground grid in distribution substation gmsarn. Important formulas for designing a substation grid earthing system. Also, the grounding system of the building in gis indoor substation has to. Review of substation grounding practices, safety and. Cyme power engineering software and solutions substation. Optimized design of substation grounding system using newly. Three years later, mitsubishi electric constructed the worlds first 550kv fully gas insulated switchyard at the ohi nuclear power station, which is the largest nuclear power plant in japan.
The design concept of equipotential ground grids in substation building as well as connection of gis enclosures to main ground grid is described. In 1973, it installed the first 500kv hybrid gasinsulated substation. Design and simulation of a grounding grid for gis substation. All rus borrowers rus electric staff effective date. The lightning intruding waves in 220 kv gis substation model was built by using atpemtp software, calculate the lightning overvoltages on electric equipment in substation with different running modes, different grounding resistance and lightning shielding failure. Innovative construction uses bricks and mortar to create a spiral line building smart bricks duration. These substations are generally constructed in an open, nonenclosed, nonatmospherically controlled environment and can be built either outdoors or indoors. Substation engineering ais and gis substations beta. Pdf grounding system design in electrical substation. The purpose of a ground mat study is to provide for the safety and wellbeing of anyone that can be exposed to the. An ebook reader can be a software application for use on a. Substation grounding software is not a substitute for autocad. Abstractthispaper describes the design ofan earthing system for agas insulated switchgear gis substation using cymgrd software. We provide sustainable solutions that help our customers effectively manage electrical, hydraulic and mechanical power more safely, more efficiently and more reliably.
This computer program can be used directly to determine the grounding cable size requirements for. Conventional switching and gis substations with or without transformers. Cyme power engineering software the cyme power engineering software is a suite of applications composed of a network editor, analysis modules and usercustomizable model libraries from which you can choose to get the most powerful solution. Design and analysis of substation grounding grid with and without considering seasonal factors using edsa software mithun mondal, dr r. Cdegs current distribution, electromagnetic interference, grounding and soil structure analysis is a powerful set of integrated software tools designed to accurately. Gis solutions for power generation and transmission services. First, it provides a means of dissipating electric current into the earth without exceeding the operating limits of the equipment. Design of earth grid for a 3311kv gis substation at a high soil.
This paper presents an accurate electromagnetic field theory method to model and analyze a realistic grounding system involving gasinsulated substation g. In the tutorial, a substation grounding system is subjected to a fault and transfers the groundearth potential rise to the connected steel factory grounding system. The gis substation has most of its electrical structure contained in sealed tubular enclosures. Substation grounding study specification introduction. 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.
It implements theoretical concepts given in 9 in the software form. Basics of designing power substations 3 phase associates. The substation site must be reasonably central to the distribution area to be served. Gis indoor substation normally occupies only 1025% of the land required for conventional ais. Earthing system is made of a mesh of buried bare copper cable, with additional earth rods, and shall be calculated, being recommended to use ieee std. Engineering guide nccses gas insulated substation grounding analysis. Following snip shows various results gis substation using xgslab grounding design software. Before the software can aid the substation design engineer, the electrical single line and ground grid for the substation will have to be designed and modeled within the software. The grounding system design for gis indoor substation is proposed in this paper. Safety analysis for grounding system of two neighbouring. So the software should be capable of meddling above ground and below ground structures. Since then, more than 40,000 gis bays have been installed in substations worldwide. The soil resistivity test results will also be required as. Grounding design calculations part seventeen electrical.
Provided the technician doesnt need to handle the gas itself, gis substations are quicker to install. Optimal design of substation grounding grid based on. Cdegs worldwide leader in grounding, earthing, lightning. It accounts for the impedance of the conductors making up the grounding system and allows currents to be injected into the.
A gas insulated substation gis is a high voltage substation in which the major structures are contained in a sealed environment with sulfur hexafluoride gas as the insulating medium. The five volume report comprises the user manual, installation, and validation manual and an applications guide for the sga substation grounding analysis software package. Here software named economical substation grounding system designer. Gis substation are considered safe and complies with all recommended guides gis pdf\generallayout gis. During factory acceptance test fat, all the operations and logics from lcc are checked by customer. Gis solutions for power generation and transmission services balancing the need to develop new markets, improve system reliability, and reduce operation costs is the greatest challenge for todays utility decision makersa challenge that is successfully met with esri s geographic information system gis software. It may be used to make a new design for new grids or to optimize and enhance an existing one of any shape. Electrical and physical arrangement, grounding, testing. Design of earth grid for a 3311kv gis substation at a high. Introduction he optimization of the design of substation grounding grids placement of gis an issue that has assumed an increasing importance, since it seeks to reduce the amount of conductive. Introduction in designing and construction of an electric substation, one of the most important issues that must be considered is designing of protective system to the earth. Grounding of high voltage substations is a very important subject in electric power technology since it is decisive when it comes to touch and step voltages that will arise within a substation area during an earth fault.
Design of earth grid for a 3311kv gis substation at a. The portfolio includes gis solutions from 60 to 800 kv, along with secondary products to maximize switchgear and network operation. This is largely due to the fact that gis systems are significantly smaller and weigh less despite the gas weighing more than air. Stations with uniform resistivity throughout the entire area are rarely found. This is a great advantage if compare with other grounding programs that the split factor is to be input usualy assumed. Introduction the design consideration of substation grounding is important for providing low resistance path to ground, to allow. The robust and low maintenance gis based design minimizes the substations footprint by as much as 70 percent, enabling it to be installed indoors, in busy urban areas and in harsh environments. Distribution substations michigan technological university. How to calculate fault current in electrical substation. Index terms conductor material saving, ground rods, optimization of substation grounding grid, sveraks method. A grounding grid is designed with the capacity to minimize the very fast transient overvoltage generated during switching operations in a gas insulated substation gis. Design of grounding system for gis indoor substation. Multigroundz and multigroundzplus software packages.
Substation grounding training the electricity forum. In the video we use the soil resistivity analyzer to determine a soil model from wenner resistivity measurements, then proceed to import our grounding systems for the substation, steel factory, and adjacent. These conductive enclosures, underground grounding grid and above ground bus bars, all contribute to the grounding system. Gis substation grounding, earthing, software ses india. The design of grounding grids for substations and buildings is a vital part of the overall power system infrastructure assuring constant power supply to consumers. For example, for a small substation with some transformers, if there is a fault in the system how will the fault current flow into the grounding system. Design of earthing system of a 400230 kv gis substation with high. Figure 1 show shows the technical ideas of the gis intelligent lcc and photo 3 show an intelligent installed in a substation in china country.
Step and touch potentials, ground potential rise, absolute potential, ieee std. Therefore, the grounded area of gis indoor substation is also reduced. Guidelines to properly designed substation grounding system eep. Substation engineers must accurately assess the condition of grounding systems to ensure they are capable of dissipating additional fault current.
Dc substation gis and lightening effects are not covered in this paper. Electrical engineers use powertools to perform harmonic analysis, transient stability analysis, short circuit analysis, and to determine demand load, voltage drop, arcflash hazard analysis and protective device coordination. Ieee guide for safety in ac substation grounding ieee std 802000. A reader responded with the question of whether the best approach might be to ignore the rebar bonding. Grounding and soil structure cdegs software package. Provide a safe and costeffective conceptual grounding system design for the substation by means of. Local control cabinet lcc in gas insulated substationgis. In a properly designed system, this gradient should not exceed the limits that can be tolerated by the human body. Moreover, the software output also has been seen for crosschecking of theoretical calculation. With gis experience spanning 50 years across a wide range of industries and applications, ge is a leader in the.
The real case study of grounding system design for 120 mva, 6924 kv distribution substation in meas power system is demonstrated. Other advantage is that the program determine the worst case scenario after many automatic iterations usually located somewere in the line outside the substation. A variety of advanced solvers provide adapted approaches to. Cdegs c urrent d istribution, e lectromagnetic interference, g rounding and s oil structure analysis is a powerful set of integrated software tools designed to accurately analyze a variety of electromagnetic related problems encountered in all industries involving electric networks. Substation grounding software is a utility program accessible through the software menu structure, that allows the user to alternate between the autocad and substation grounding software environments. Thus, measurements should be made at multiple locations within the site. Design of earthing grounding system in a substation grid. Importance of an adequate substation ground grid design. In the video we use the soil resistivity analyzer to determine a soil model from wenner resistivity measurements, then proceed to import our grounding systems for the substation, steel factory, and adjacent site entrance from an existing dxf. The main ground grid design is performed according to ieee std. The design concept of equipotential ground grids in substation building as well as connection of gis enclosures to.
Gis vs ais substation earthing electrical engineering portal. Design and analysis of substation grounding grid with and. Cymgrd is a software program specialized in the substation grounding mat design. Grounding must be taking into account to protect passersby during a shortcircuit in the transmission system 7. Gis highvoltage gas insulated switchgear substations.
Installing a gis high voltage substation can be faster than installing its metalclad ais counterpart. One type of substation is an open air substation, which is the traditional design that uses the insulation properties of ambient air as an external insulating medium. The cross section of the buried cable should calculated in accordance with the value of the phasetoearth short. The reader is well justified in wondering whether the best approach might be. Pdf safety performance evaluation of fence grounding. Comparison of ais and gis based on grounding design a.
In smaller distribution substations the usually acceptable range is from. Furthermore, the analysis of software graph is done by fdm finite difference method which is one of the mathematical solutions and it shows that how the graph generates in software. Grounding system, design criteria, calculation note. For most transmission and other large substations, the ground resistance is usually about 1. A good grounding system provides a low resistance to remote earth in order to minimize the ground potential rise. The substation grounding system is an essential part of the every electrical system. Analysis of vfto across bushing in 765kv gas insulated substation using emtp software. The main purpose of this work is to design the grounding system for 400kv darbhanga gis substation. System grounding and earthing types analysis software etap. Gis technology originated in japan, where there was a substantial need to develop technology to make substations as compact as possible. List all data that must be known in the starting of grounding system design calculations for ac substation, facilitate the design process by using the auto excel mathematical functions in performing the calculations, provide a professional design concept for any grounding system of ac substation as per standard ieee 802000. The main purpose of this work is the development of an optimization model for the design of the grounding grid in electrical substations.
469 120 1158 703 1509 1168 1428 1527 1631 1090 1612 1260 726 1086 496 1483 1584 1579 37 888 786 1200 1449 348 1280 1440 820 854 1201 214 925 1015 955 555 174 1309 280