This paper is to provide information pertinent to safe earthing practices in ac substation design and to establish the safe limits of potential difference under normal and. Method of calculating plate and shell reinforcement area. International journal of electrical, electronics and data. Wire resistance should be considered in parallel with the rods. This calculation is based primarily on the guidelines provided by ieee std 80 2000, guide for safety in ac substation grounding. Simplified analysis and design of ships subjected to. The calculation method of grounding system using analytical approaches 2, 3 in which the soil. Pier b online a mathematical model for the transient. This calculation method does not consider the interconnecting cable between rods because the effect produced by the rod on the earth resistance is more important than the one produced by 7 m of bare cable. Method of determination of step, touch and transfer potentials. Photovoltaic system grounding florida solar energy center. This is the conductive part of equipment which can be touched and which is not a live part, but which may become live under fault conditions. Grounding system modeling, grounding grid representation, earth conductivity and connected power system determining easy procedures to determine ground potential rise for particular fault type and location.
Ieee guide for safety in ac substation grounding ieee std. Current distribution in extended grounding systems. Energex limited manual manual 00758 v5 10 aug 2017 energex limited 2017 uncontrolled when printed page 4 of 65 1. Circuit private home ground is performedusing rods, as which can act steel corner fittings with smooth structure, pipe, double tee. Grounding of electrical substations for safety and neutral point by ground rods provides the lowest. Usually all exposed conductive parts are connected to the earth electrode by protective conductors with the object of providing a. Metallic elements, particularly those in flammable zones, should be bonded together and adequately grounded using a single point ground. The following are methods of determining reinforcement of plates and shells. A mathematical model for accurately computing, when combined with the fast fourier transform fft, the lightning currents flowing along a high voltage a.
The fact that a solidlygrounded system will support a large ground fault current is an important characteristic of this type of system grounding and does affect the system design. Ieee guide for safety in ac substation grounding ieee std 802000. Design of earthing system for 400 kv ac substation a case study. Analytical methods for earth surface potential calculation. The problem of whether a system neutral should be grounded, and how it should be grounded. Designing for a low resistance earth interface grounding roy b. If the equipment grounding system and the system bonding jumper have sufficiently low impedance i. They were thought to be the most stable grounded type of systems because only when.
Method of determination of step, touch and transfer. Substation grounding system resistance calculations using a. The second project is designed with optimum conductors land based network optimization single variable, total conductors earth. First project is designed with the earth system network is presented with the same intervals. Pdf substation grounding system resistance calculations using a. This will permit a calculation of the range in grounding resistance achievable in that soil with the final system design.
Sample data for test system this test system is carried from b3 rectangular grid with ground rod in ieee std80. The design of grounding system for rocky areas requires special measures to obtain safe step and touch potentials for grounding system. Fallofpotential or threepole method, clampon or probless method, measurement of step and touch potentials transmission and distribution tower grounding. For example, microinverters and ac pv modules have different grounding requirements than other pv systems. Measurement of lowimpedance grounding systems by power system staged faults 10.
System grounding has been used since electrical power systems began. A single point grounding system is achieved when all equipment within the structures are connected to a master bus bar which in turn is bonded to the external grounding system at one point only. Shoush 1suez university, suez, egypt, 2alazhar university, cairo, egypt. Calculationofimportantdesignparametersforgroundingsystemsinsu. Design of charts for ground resistance calculations of driven. Use of vertical grounding rods a grounding system at a power station often requires the form of a horizontal grid supplemented by. 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.
Lightning protection and grounding system evaluation for. The process is a combination of science and art as opposed to pure science, because it is necessary to test the. Successful operation of entire power system depends to a considerable extent on efficient and satisfactory performance of substations. Calculation of earthing and screening effects of compensation conductor laid alongside underground multicable power lines i. With the development of technology mnogomoschnye electrical appliances. This paper presents the design of earthing system for 400 kv substation and calculation of its parameters. A system neutral found in areas of mid to high load density, where it is grounded connected to earth at frequent intervals. The us military handbook for lightning protection milhdbk10046 and iec 62305 std. When calculating the fault current you need information about the zero sequence impedance of the wire and transformer, and youre good.
Abstractutilities and industrial plants use many types of grounding methods in mediumvoltage distribution systems. To ensure that a person who is in the vicinity of earthed facilities during a fault is not exposed to the possibility of a fatal electric shock. This paper presents the design of earthing system for 2 kv substation and simulation for calculation of required parameters. Current flow through circuits seeking the path of least resistance. The voltage and current on the other two phases are not affected. The webinar on safety through proper system grounding and ground fault protection is intended for the practicing electric power engineer whether a recent graduate or a seasoned. New equipment grounding conductor conductor area of original egc ratio 26240 1. Pdf grounding systems are very important for the safe construction of a substation or a simple building. Sarajcev1 1faculty of electrical engineering, mechanical engineering and naval architecture, university of split, croatia. Calculation of the preliminary grid resistance, rg, of the grounding system in uniform soil. Common multiple earth neutral system cmen is a system where the combined high voltage and low voltage distribution earthing system is connected to a zone or transmission substation earthing system.
Grounding design calculations part four electrical knowhow. Safety through proper system grounding and ground fault. Design of earthing system for 400 kv ac substation a case. The handbook contains a wide array of topics and each topic is written by an authority on the subject.
This document assumes a proper ground reference is being created by either a separate grounding transformer or a wye. The earth system for different conditions, the study is performed in three cases. However, many companies and industrial plants have used system grounding methods differently. Principles of electrical grounding john pfeiffer, p. Ground resistance is a measurement of the conducting connection between a grounding system and earth. If the distance between rods is bigger then 7 m should be considered. Lay out the tester, the wire spools, and the electrodes. High medium voltage transmission grids distribution grids are usually equipped with a ground wire that will carry the fault current back to a grounded transformer in case of a lineground fault. Etap model for earth mat design etap model for earth mat design.
How to calculate the size of a grounding conductor. The matrix method was used in this work since it is the. To calculate a realistic distribution of the earthfault cur rent, all the lines. The system ground connection, made by a system bonding jumper, is the path that allows fault currents to return to the source.
Etap model for earth mat design etap model for earth. Here the focus is on classification of grounding systems with respect to the operating voltage of the system. Download limit exceeded you have exceeded your daily download allowance. In case of impact excitations characteristic for lightning currents, the potential distributions around the analyzed grounding system are shown for the selected multilayer soil, and then, the obtained simulation results were compared with the case of the corresponding uniform soil. The earthing system, sometimes simply called earthing, is the total set of measures used to. The fundamental part of calculation of the earth potential rise is the calculation of the phase to earth fault current magnitude in a given network. Ship collision and grounding represent significant potential incidents which may result in very unfavorable consequences to both human life and environment. The required design data has now been defined, and the design process can start from a solid foundation, i. The earthing circuit the device, calculation and installation of grounding system for a country house. That what must be provided is ground resistance r 5 ohms minimum. How to calculate the size of a grounding conductor sciencing.
Lanzoni october 2007 introduction grounding or earthing is the art of making an electrical connection to the earth. Design of charts for ground resistance calculations of. Important in this worksheet, you will find multi choice check boxes for each item, sometimes you need to check all of them, sometimes not while some items must have one checked box only one selection only, in this case two or more checked boxes will contradicted with other selections. Pdf calculation models for grounding systems based on hybrid. Measurement of lowimpedance grounding systems by testcurrent injection 8. This paper is to provide information pertinent to safe earthing practices in ac substation design and to establish the safe limits of potential difference under normal and fault conditions.
I am trying to calculate this, but i do not have here any grounding software or any book with a calculation. Figure 1 explains the grounding system with grounded electrical equipment and shows the very important parameters in grounding system design. Andreoni, twolayer soil model for power station grounding system calculation considering multilayer soil stratification, electric power systems research, pp. If you are using an aemc ground resistance tester for the first time, attach a spade lug to the end of the green wire lead and on one end of the short red and blue wire leads. For the purpose of mitigating or preventing the collision or grounding event from developing into consequences disproportional to the original cause, continuous effort is being made by the. Design and analysis of substation grounding grid with and.
Performance analysis of actual step and mesh voltage of. Grounding electrode calculations using the matrix method. If ground resistance is r 5 ohms, i have to provide extra ground wires and extra ground rods. Quick calculation of the grounding resistance of a typical. Common terms used in earthinggrounding of installations. The earthing system provides a reference potential for electronic circuits and helps reduce electrical noise for electronic, instrumentation and communication systems. If grounding is inadequate, current doesnt flow as intended, which. Classification of grounding systems fig 6 could be evasive. Eduardo obtained a bsee with power system emphasis from. Every family and young person deserves the opportunity to make calm, confident and informed choices each step of the way. Yes, it is possible to be immune to college hype and engage every strategy when preparing for college applications. Grounding system theory and practice ced engineering. Design of charts for ground resistance calculations of driven rods system in uniform and nonuniform soils o.
This ensures the neutral has strong reference to ground and is at a potential voltage which is at, or very near, ground potential. Ground resistance depends on grounding electrode selection, soil resistivity, soil contact, and other factors. Designing for a low resistance earth interface grounding. Sullivan, alternativ earthing calculatons for grids and rods, iee proceedings. To provide a low impedance path to earth for currents occurring under normal and fault conditions.
Remarks on methods of calculating plate and shell reinforcement. This is a discussion of the basic principles behind grounding systems and how grounding is related to safety and the effective operation of circuit protection devices such as fuses and circuit breakers. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Calculationofimportantdesignparametersforgroundingsystemsi. Hence substations in general can be considered as heart of overall power system. Pdf substation grounding system resistance calculations. Preface the handbook of electric power calculationsprovides detailed stepbystep calculation procedures commonly encountered in electrical engineering. Function, objectives, design procedure, calculation of ground resistance, ground resistance measurement. Under normal circumstances, it is the current constitutes the main threat to personal an effective earthing system has the following objectives.
Functions of an earthing system the two primary functions of a safe earthing system are. Calculation of current flow in grounding systems of substations and. This requires network impedance calculations, fault current analysis and then design of the earthing system to assess and control the hazardous epr. Proper grounding is essential for the proper operation of electrical circuits. Analytical methods for earth surface potential calculation for grounding grids sherif s. Calculation of the footing resistance 33 development of the finite expression 33 model i. Trifunovic and others published quick calculation of the grounding resistance of a typical 110 kv transmission line tower grounding system find, read and cite. Pdf abstract this paper analyzes the calculation models employed by two commercial grounding system analysis modules, gsa and. Non multigrounded system neutral a system neutral usually found in rural areas of low. Analysis of system of intertted grids 41 basic considerations 41 ladder circuit solution 42 an approximate solution to the problem 44 voltage decay along a very long buried conductor 46 7. This paper presents the design of earthing system for 2 kv substations and simulation for calculation of required parameters. Statistically, 9095% of all system shortcircuits are ground faults so this is an important topic.
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