Tylavsky, chair john undrill raja ayyanar arizona state university december 20. Tylavsky, chair john undrill raja ayyanar arizona state university. To provide a safe condition for personnel within and around the substation area, the grounding system design limits the potential difference a person can come in contact with to safe levels. In this paper, effect of increasing in grounding grid resistance on transient overvoltage which is caused by short circuit, switching and lightning on the interior equipments and safety in a grounding grid at substation. Rahi1, 2abhas kumar singh, shashi kant gupta3, shilpa goyal4 electrical engineering department, national institute of technology, hamirpur, india1,2,3,4 abstract this paper presents the design of earthing system for 2 kv substations.
National grid substations technical specification ngts 2. Grounding is an important aspect of every substation. The enduser would use a test instrument and probes to first inject a current into the earth between a test electrode and a remote probe, measure the voltage drop caused by the soil to a designated point, and then use ohms law to. The woomera test range squadron is a subelement of the air force ranges directorate afrd, which is also part of the air warfare centre. Bachelor degree in electrical engineering contact hours. Solving static electricityrelated hazards by grounding and bonding role of grounding in protecting substation structures from lightning hazard role of grounding in surge protection of power distribution equipment and sensitive systems noise in electrical systems and the role of grounding in noise mitigation. It provides a means of dissipating electric current into the earth without exceeding the operating limits of the equipment 2. Optimal substation ground grid design based on genetic. Students will get practical knowledge about the grounding system of substation, transmission tower and induced voltage nearby object of the transmission. Originally presented at the 2015 purdue underground corrosion short course, this video covers the essentials of using gradient control mats to address overvoltage concerns from touch and step. The main purpose of this article is to study the optimum design of grounding system of high voltage substations by using artificial neural.
Substation grounding system a case study mohau mapane, jm van coller school of electrical and information engineering, university of the witwatersrand, south africa abstract the aim of this research is to investigate the effect of increased fault current on an existing substation grounding system. A neutral earthing system is a system in which the neutral is connected to earth, either solidly, or through a resistance or. Substation and transmission lines pse consulting engineers. Grounding a substation located on a bedrock jghrist electrical 15 jun 07 15. Grounding systems analysis and optimization by a thesis. Substation earthing system grounding system earthing. Read about design of substation earthing system here. Substation grounding a project presented to the faculty. It provides a means of dissipating electric current into the earth without exceeding the operating limits of the equipment. The grounding gives low resistance path to earth and reduces rise in ground potential which is dependent on magnitude of fault current and resistance of grounding system. The addition of new generation on the clients 46 kv system caused increased fault current availability at several substations. Grounding mats for step and touch voltage protection youtube. Substation grounding programs technical report osti. Testing and evaluating grounding systems for substations located in urban areas.
Preliminary design of grounding system for ac substations. As the measurement of touchstep voltages does not require long cables extending outside of a substation 16, it is very suitable for longterm online moni toring. Safety design planning of ground grid for outdoor substations in meas power distribution system 103 involved with hot line maintenance, may cause serious consequences, very little has been paid attention to issues of safety criteria in substations of electric power utilities in thailand. Utilization of sound engineering principles is required for acceptable substation grounding providing a safe and shockproof grid around the substation. Rahi1, 2abhas kumar singh, shashi kant gupta3, shilpa goyal4 electrical engineering department, national institute of technology, hamirpur, india1,2,3,4 abstract this paper presents the design of earthing system for 2 kv substations and simulation for. Both methods implement safety criteria according to ieee std 80 or cenelec en 50522. Safety design planning of ground grid for outdoor substations. 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. With weldment and bolted products up to 500kv, homacs wide product offering includes a full line of couplers, taps, bus supports, terminals and expansion connectors. Grounding system design of high voltage substations in uniform and nonuniform soil using equal and nonequal spacing grid gouda, ossama on.
The low resistance of substation ground can not be obtained in deserts and rocky areas. Homac is ready with worldclass product configurations to meet your specific needs for transformers, hand holes andor pedestal applications. The additional fault current raised concerns for the adequacy of the grounding systems at certain substations. Cost effective grounding grid design for substation. Optimal design of grounding system for a substation is complex due to the involvement of numerous parameters. A substation grounding system is an underground, regular mesh conductor network that serves the purpose of providing the path of least resistance to the traversing current so that, in the case of a fault, it is distributed in all directions in the underlying earth. The mesh may be covered with a layer of earth or crushed stone depending on the application. Cyril and methodius university, macedonia introduction the ground potential rise gpr in high voltage substations in case of ground faults 1 may cause dangerous voltages between telecommunication installations and local ground. Ground potential rise influence near hv substations in urban.
Headquarters awc, air force ranges directorate and the test range squadron are all currently based at raaf base edinburgh, in adelaide, located approximately 450 kilometres 280 mi southwest of the complex. Ground potential rise influence near hv substations in urban areas l grcev, v filiposki, v arnautovski st. To illustrate the governing equations presented above, a 115 kv substation grounding grid system, whose input data given in, is investigated. From the transmission network side, the ararat spitskop 275kv lines are thermally constrained and the 27588kv 3x315mva transformers at. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Electric substation design implementations through cymgrd this book is to discuss developmental procedure of an effective substation earthing system model to ensure that step and touch potentials. The comparison between theoretical values and experimental values for various types of grounding grid performance at fixed depth is carried out 5,6.
This substation training course give an overview of substations, primary breaking device, transformer, secondary switching devices. 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. Design of grounding system for an electrical substation. Ground grids provide a fundamental safety feature in substations and should be tested periodically. The project involved tapping into existing overland power transmission lines, designing new overland transmission lines to the substation site, and providing power distribution from the new substation to the facility. Substation grounding training the electricity forum.
This paper proposes an online substation touch and step voltage monitoring scheme, which can continuously inject. Practical grounding of utility and industrial distribution. Electrical grounding and earthing systems presented by. This 2day substation grounding training course will discuss how to maintain, test, and inspect a proper grounding system for the electrical power substation. The five volume report comprises the user manual, installation, and validation manual and an applications guide for the sga substation grounding analysis software package. Safety remains a primary concern for substation owners, specifically in terms of protecting human life, and ensuring reliable network. Principles of electrical grounding john pfeiffer, p. The most important factor in the substation is the grounding. The system neutral is connected to the ground through grounding. Marked with the proper number and location of crimps. Model and evaluate the existing grounding system at the site. Grounding design calculations part sixteen electrical. This substation training course give an overview of substations, primary breaking device, transformer, secondary switching devices, switchgear lineup, instrument transformers, relays.
Our 2day substation training course will cover the major elements that build electrical substations and switchyards. Transformer substation of 122b uit unit total area 61 m2. We use your linkedin profile and activity data to personalize ads and to show you more relevant ads. 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. Optimum design of grounding system of high voltage. Computing the potential distribution on the earth surface when a fault condition occurs is essential to assure the security of the grounding systems in electrical. Presented to the faculty of the department of electrical and electronic engineering. The relative infrequency of accidents is due largely to the low probability of coincidence of the above unfavorable conditions. Testing should include a fallofpotential test, 3 or 4point grounding tests and stakeless earthground tests for testing connections to the grid.
Safety performance evaluation of typical grounding. This includes things to look for that might indicate problems in the stations grounding system. Effect of increasing the grounding grid resistance of a. The two primary distribution feeders of the substation illustrated in figure 1 are protected by either power circuit breakers or automatic circuit reclosers. 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. Safety in ac substation grounding systems under transient. There is need to ensure that the ground potential rise, and touch and step voltages are within permissible limit, an accurate soil model is required to design grounding system of the substation that ensures. Substation grounding system a case study research project by mohau mapane 689839 submitted for the partial fulfilment of the requirements for the degree master in science in electrical engineering in the school of electrical and information engineering at the university of the witwatersrand supervisor.
The uniform and two layer soil structure for substation ground grid design is mostly used in india 4,5. Ground potential rise influence near hv substations in. Assessment of uncertainties in substation grounding system. Grounding a substation located on a bedrock electric. 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. The size and type of the substation can be vary, but those design aspects are similar. The ground system has three purposes, all of equal importance. A method is proposed for estimating the critical distance between mvlv substation and lv neutral grounding systems. This paper presents a safety design of ground grid. Substation grounding and step over native concerns power. This analysis covers the evaluation of a substation for. A method is proposed for assessing safety of typical mvlv substation grounding systems. Substation grounding a project presented to the faculty of. Safety in ac substation grounding systems under transient conditions.
Design principles of substation grounding system your. Successful operation of entire power system depends to a considerable extent on efficient and satisfactory performance of substations. Determine if the step and touch voltages are above the ieee 8020 thresholds for personnel safety. Sr3 was retained to perform a grounding study for two sites. Substations are designed with grounding systems with one function. Continue readingsubstation earthing system grounding system earthing mat. There are two components to the station s grounding system made up of the main grounding buss and the grounded mat. Substations shall be provided with a full interlocking scheme as specified in ngts 3. Therefore, substation reliability must be as builtin as possible because of the high available fault current levels present and unlikely occurrence of followup grounding inspections. Mortezaeei 2 1 electrical engineering department, seraj higher education institute, tabriz, iran, n.
Substation grounding naval facilities engineering command. The first three programs provide a comprehensive analysis tool for the design of substation grounding systems to meet safety standards. Plan of the grounding grid of the electrical substation buried to a. Optimum design of grounding system of high voltage substations. Prior to about 15 years ago, the basic methodology for ground testing remained fundamentally unchanged since it was originally devised in the early 20th century. The substation grounding system is an essential part of the overall electrical system. Calculation of the preliminary grid resistance, rg, of the grounding. The proper grounding of a substation is important for the following two reasons.
For testing tower grounding systems, special clamp on cts are an option that may be used with the fluke 1625 tester. Grounding systems analysis and optimization by xuan wu a thesis presented in partial fulfillment of the requirements for the degree master of science approved november 20 by the graduate supervisory committee. Access above ground level shall be from mobile or fixed platforms though the latter may be accessed by. The following are the primary efforts included in this analysis. 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. What you need to know about substations incident prevention. May 2, 2019 the substation earthing system comprises of a grid earth mat formed by a horizontal buried conductors. Apr 09, 20 high voltage electronic system area is to bereferred as substation.
Distribution systems are earthed to create a reference point for the system voltage, to facilitate the detection and discriminative isolation of faults involving contact to earth, and to limit overvoltages under transient conditions. The effect on ground resistance, mesh voltage and gpr is tabulated in table 5 and 6. In this paper, effect of increasing in grounding grid resistance on transient overvoltage which is caused by short circuit, switching and lightning on the interior equipments and safety in a grounding grid at substation is investigated. Brief discussions about different parameters which affect the designing of an. Cyril and methodius university, macedonia the ground potential rise gpr in high voltage substations in case of ground faults may cause dangerous voltages between telecommunication installations and local ground. Pse engineered the overland transmission line, 8 kv. White papers substation grounding and step over native concerns. Unfortunately, some are approaching 100 years old and havent been tested in many years. Welldesigned grounding system is very much essential as far as the safety of the crew and the substation equipments are concerned. Choosing grid spacing d 7 m, for a rectangular 63 m. Tosolvetheseproblems,themethodsthatcan monitor the grounding condition on a continuous, i. Java project tutorial make login and register form step by step using netbeans and mysql database duration. Chrome, edge, explorer, firefox, nokia mobilepcload internet care.
Over the years grounding design terms and definitionsprocedures have been developed as well as appropriate standards, most notable. Development of design software conference paper pdf available december 20 with 196 reads how we measure reads. Ansiieee std 802000, ieee guide for safety in ac substation grounding. Ieee std 80 is most often used to determine compliance for step and touch voltages and clearly applies within a substation fence. With these things in mind, i am going to share to you, some of important free ebooks, tutorials, links and pdf related to substation grounding.
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