Chapter 2 explains ground fault currents and chapter 3 covers grounding conductors. Pdf design of groundmat for 11kv substation using auto grid pro. Omega red group are the uk market leaders in the specialist design, supply, installation, testing and maintenance of electrical earthing and lightning protection systems. The electrical grid transmits power over wires to our houses, and our bryan cockfield has covered it very well in his electrical grid demystified series, but what part does the earth ground play. 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 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. The following sitedependent parameters have been found to have substantial impact on the grid design. Hence substations in general can be considered as heart of overall power system. Optimized design of substation grounding system using newly developed ieee compliant software issn. 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. Optimal substation ground grid design based on genetic algorithm and pattern search by qianzhi zhang a thesis presented in partial fulfillment of the requirements for the degree master of science approved november 2014 by the graduate supervisory committee. The following steps were established by the ieee standard 802000 for the design of the ground grid. Etap model for earth mat design etap model for earth.
But the generation plant is right beside the new substation. Design and analysis of ground grid system for substation. International journal of engineering trends and technology. Therefore, this number should be as close to the realworld. My question is how can i measure the resistivity of the area as there is an existing plant right there. The ergon energy design philosophy is to provide substations.
For comparison of the calculations done by both techniques, the obtained results are shown in table 3. Substation grounding grid design and analysis module is specially designed to help. Successful operation of entire power system depends to a considerable extent on efficient and satisfactory performance of substations. Covers the design of the ground grid for safety and proper operation. For calculation of this current grid resistance and fault resistance are assumed to be zero. Pdf three dimensional grounding grid design researchgate. Fence is outside of ground grid area and is connected to the substation ground grid. Kasirawat safety design of ground grid in distribution substation. In particular, protection relay data including characteristic curve, overcurrent setting, time multiplier setting, instantaneous. International journal of engineering trends and technology ijett volume 15 number 8 sep 2014.
The rod length is varied to determine the influence of rod length on gpr, furthermore, when the soil structure is. Over the years grounding design terms and definitionsprocedures have. Performance analysis of actual step and mesh voltage of. The following data given in the table is considered for the substation ground grid design table 1. In contrast, the topology of grounding grid is based on substation equipment layout and therefore it may not necessarily be equally spaced grid as. A vertical rod is more effective electrode than a horizontal rod. Grounding design calculations part sixteen electrical knowhow. The size of the soil model is calculated as a multiple of the grounding grid size and is closely dependent on the accuracy of calculations. Jul 12, 2010 the purpose of this paper is to report a new test method and make a recommendation to improve the procedures according to the findings.
Access above ground level shall be from mobile or fixed platforms though the latter may be accessed by. Some of them are already fully activated, while others still await their time. The test method involves measurement of high voltage substations earth grid impedance, by utilization of a variable frequency current source and frequency selective measurement techniques. This paper presents a safety design of ground grid for a practical 120 mva, 11524 kv substation grounding grid system in mea. We use skms stateoftheart groundmat software module and accurately determine the touch and step potentials. Connections used in substation grounding, new york.
Several parameters define the geometry of the grid, but the area of the grounding system, the conductor spacing, and the depth of the ground. Mortezaeei 2 1 electrical engineering department, seraj higher education institute, tabriz, iran, n. Moreover, this software also provides finite element modeling fem of the ground grid for detailed analysis. You can see this grid as a fine lattice of light pulsations. From the past, ground grid design without rods and with rods was carried out. In this video, i mentioned the basic steps for designing power substation grounding grid using custom codeprogram made under matlab environment. Oct 30, 2012 in this video, i mentioned the basic steps for designing power substation grounding grid using custom codeprogram made under matlab environment. Design and analysis of substation grounding grid with and without considering seasonal factors using edsa software. Effects of ground grid configuration of two neighbouring. Covers general issues related to site design, foundation design and control house design. Index terms conductor material saving, ground rods, optimization of substation grounding grid, sveraks method.
The substation grounding system is an essential part of the every electrical system. Abstract the main purpose of this paper is to acquaint the reader with various types of grounding systems prevalent in an electrical substation and their importance. The grounding grid was installed upon the construction. Ground potential rise gpr the substation earth grid is used as an electrical connection to earth at zero potential reference. This paper presents performance analysis of actual step and mesh voltages of a substation grounding system under the variance of length and number of ground rods. Identifying and implementing costsaving design practices 3 fault magnitude the magnitude of the fault current into the earth via the substation ground grid is directly proportional to the ground potential rise gpr at the substation. Grounding grid integrity energiforskrapport 2017405. These substation grounding design can be designed to regulate the system, to switch or changing the voltage of electricity in and out of a system. The problem is, when i do this it seems that the soil resistivity. Design and analysis of substation grounding grid with and without considering seasonal. Cost effective grounding grid design for substation.
Abdelhadi ragab introduction objectives of a grounding system may be summarized as follows. Subsequent chapters cover the types of voltages that must be addressed and how to design a ground grid. Tylavsky, chair john undrill raja ayyanar arizona state university. Covers the design of bus support structures and connectors. Clearing times for single line to ground and double line to ground faults. Design of groundmat for 11kv substation using auto grid pro. Jul 25, 2017 the electrical grid transmits power over wires to our houses, and our bryan cockfield has covered it very well in his electrical grid demystified series, but what part does the earth ground play. Chapter 1 is a general discussion of grounding issues. The comparison between theoretical values and experimental values for various types of grounding grid performance at fixed depth is carried out. In this paper a procedure of transformer grounding system design and spatial distribution of touch and step voltage on the ground surface level is analysed by using the cdegs current distribution electromagnetic interference grounding and soil structure analysis software. Design and analysis of substation grounding grid with and without considering seasonal factors using edsa software mithun mondal, dr r. Optimal substation ground grid design based on genetic.
Fence is outside of ground grid area, but is not connected to the substation ground grid. Electrical 20142018 sardar vallabhbhai institute of technology, vasad vadodara, india abstractthe paper depicts about design of ground grid system for 6611kv rectangular substation. The proper grounding of a substation is essential and very important for the following two reasons. Computer aided design of transformer stations grounding. Substation grounding design challenges and lessons learned. Flexible design methodologies allow for quick autodesigned layouts or very detailed schemes. Calculationofimportantdesignparametersforgroundingsystemsi. Ieee guide for safety in ac substation grounding ieee std. In high and medium voltage air insulated substations ais the electromagnetic field, which causes are the static charges of bare cable and conductors and by the atmospheric conditions surges, induce voltages at nolive parts of the installation that create potential differences between metallic parts and ground and also between different points of. Pdf design and analysis of substation grounding grid. High voltage substation earth grid impedance testing. Power station grounding grid design using field methods.
Optimal substation ground grid design based on genetic algorithm. Ground potential rise also mainly depends on the length and numbers of ground rods and grid spacing. Earthing design of 11kv and 33kv rural substations in the uk. Cold sites do not require any special design principles and the touch and step voltages are deemed to be safe by inference. Soil testing and soil data is typically provided by others. Fault current computations may be obtained from the owner or calculated by ees consulting. The substation design manual is not intended to replace asset management standards, but rather to act as a reference document that crossreferences existing standards and process documentation and plugs any gaps where asset management documentation does not exist. First, it provides a means of dissipating electric current into the earth without exceeding the operating limits of the equipment. Whitepaper substation grounding identifying and implementing. This voltage, gpr, is equal to the maximum grid current times the grid resistance. Grounding design calculations part sixteen electrical. Abstract substation grounding is a critical part of the overall electric power system. Design of grounding grid according to ieee standards. Student 2,3assistant professor 1,2,3 department of electrical engineering 1, 2, 3 g.
The fence is connected to a separate grounding conductor. The comparison between theoretical values and experimental values for various types of grounding grid performance at fixed depth is carried out 5,6. Design and analysis of substation grounding grid with and without considering seasonal factors using edsa software article pdf available april 20 with 3,151 reads how we measure reads. Design guide for rural substations usda rural development. Optimal design of grounding system for a substation is complex due to the involvement of numerous parameters. Ground grid, ground potential rise, step voltage, touch voltage 1 introduction metropolitan electricity authority mea is an electric. Earth grid commissioning for new electrical systems routine earth testing for preexisting systems high voltage safety compliance audits accreditations asnzs2067 asnzs3007 1016 0 267 373 earth grid design and testing. Grounding grid design using matlab for power substations. I am trying to design a ground grid, but i need to add a ground well a ground rod that is driven deep enough till it is in water, e. Underlying the b grid is another grid system called the a grid or master grid. Etap model for earth mat design etap model for earth mat design. Bs 7354 code of practice for design of highvoltage openterminal substations. Ground grid systems software ground grid design ieee 80.
Integrated grounding, equipotential bonding and lightning. Ground grid design ground grid design poutchi electrical op 9 apr 08 10. High voltage electronic system area is to bereferred as substation. These revisions may include smaller conductor spacing, additional ground rods, and use of closer. Cost effective grounding grid design for substation soni m, dr. Pdf this study presents an advanced methodology and a computer model for analysis of. The ground grid systems module enables engineers to quickly and accurately design and analyze ground protection.
The uniform and two layer soil structure for substation ground grid design is mostly used in india 4,5. The epr is caused only by the current injected into the ground by the earthing grid. Design of earthing grounding system in a substation grid. Determination of maximum grid current a single line to ground fault is more common and causes more fault current as compared to a double line to ground fault. Two other important design parameters, which depend upon the value of the ground. Design and analysis of substation grounding grid with and. This bulletin provides a basic design guide and a reference tool for designing rural substations. National grid substations technical specification ngts 2. Over the years grounding design terms and definitionsprocedures have been developed. Part 3 c ode of practice for the design of industrial type stairs, permanent ladders and walkways. Substation grounding grid design and analysis module is specially designed to help engineers optimize the design of new grids and reinforce existing grids, of any. Similar designs are used in substations in the grid. Wherever two of these threads of light intersect, a vortex is formed.
Ground network design algorithm block diagram in figure 1 is the sort earthing studies. I am working on a ground grid for a new substation. Optimized design of substation grounding system using newly. Safety design of ground grid in distribution substation. Therefore, the design is based on single line to ground fault current. This bulletin is an update and revision of previous rea bulletin 651, design guide for rural substations revised june 1978. Below is the sequence of procedure to design the ground. Design of grounding system for an electrical substation.
High efficient multicore parallel calculation allows fast analysis of irregular largescale renewable applications. It would be conservative to assume no existing power plant ground grid, as far as the design of the new substation grounding is. Optimized design of substation grounding system using. Ground grid systems software ground grid design ieee. The maximum touch voltage within a mesh of a ground grid. The simulation results show the effects of the changes on the design and analysis of power. I am trying to design a ground grid, but i need to add a ground well a ground. This connection, however, is not ideal due to the resistivity of the soil within which the earth grid is buried.
Conductors a substation earthing grid will consist of a earthing system of bonded cross conductors. Etap facilitates an engineer to carry out ground grid design as well as analysis with considerations specified in various standards such as ieee801986, ieee802000 and ieee6651995. Welldesigned grounding system is very much essential as far as the safety of the crew and the substation equipments are concerned. Integrated grounding, equipotential bonding and lightning protection in smart grids and smart buildings a multifaced approach. This rise in voltage of the grounding grid is referred to as the ground potential rise gpr, and is proportional to the magnitude of the fault current, and the ground resistance of the grounding grid. Design and analysis of ground grid system for substation using etap software and fdm code in matlab deep b. Calculationofimportantdesignparametersforgroundingsystemsinsu. Connections from equipment and structures to ground grid.
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