Existing fault diagnosis methods for grounding grids are limited by the number and distribution of grounding leads, and some of them cannot be used for online detection. Today we are going to discuss the design of substation earthing system. In any substation, a well designed earthing plays an important role. The substation grounding system is an essential part of the every electrical system. The ergon energy design philosophy is to provide substations. Substation earth system injection testing swp page 5 of 14 standard work practice sp0510 ver 4 ergon energy corporation limited abn 50 087 646 062 b outside the substation in general, locations outside the substation fence should be analysed using guidelines as defined in the electrical safety code of practice 2010 works. It matches the output of the source unit to the input level of the powered enclosures ampli. D substation standards ground cable on tubular steel. In the high voltage substation damages or malfunctions of the electric and electronic equipment can be caused by lightning. Points to consider regarding the insulation coordination of. Ieee guide for measuring earth resistivity, ground impedance, and earth surface potentials of a grounding system ieee std 81 ieee standard for qualifying permanent connections used in substation grounding ieee std 837 ieee guide for direct lightning stroke shielding of substations ieee std 998.
As shown in figure 1, the human bodys resistance varies from as low as 500 ohms to as high as 600,000 ohms. As the need for reliable and stable power increases the inconvenience of unwanted downtime in processing, robotics and data service also become more critical and costly. These include distribution, transmission, and generating plant substations. Substation grounding is a critical part of the overall electric power system. Train users to perform their responsibilities to inspect and maintain lightning and grounding systems as identified in table 1 when requested. Vuspec page 3 ieee 12402000 r2012, ieee guide for the evaluation of the reliability of hvdc converter stations ieee 12462011, ieee guide for temporary protective grounding systems used in substations.
Between the generating station and consumer, electric power may flow through several substations at different voltage levels. Ieee industry applications society atlanta chapter january 19, 2010 meeting 2 purpose of grounding lightning and surge protection stabilize circuit potential and assist in proper operation of. Bond all ground points to eliminate ground loops and create an. Before 1960s the design criterion of substation earthing system was low earth resistance. Ic 8767 1978 guide for the construction of drivenrod ground beds. Next, slowly turn the gain on the powered enclosure up clockwise until you can hear audible distortion, then turn it down a little. The dc megger test shall be performed at 2,500 volts on coils rated over 600 volts, and at 1,000 volts on coils rated 600 volts and below. Slide gate operator installation guide linear pro access. Given extensive bedrock, achieving 15 ohm resistance was not deemed cost effective. Substation mechanic i at entergy find jobs and apply online.
Safe work practices on high voltage substation apparatus summary this document supports the power system safety rules and its requirements assembled under high voltage substation apparatus category 5. Capital projects group performance specifications for structures passing over electrified corridors mxelec strspec2017rev3. We have already given an introduction to substation earthing system in an article published earlier. As the skin becomes moist, the contact resistance drops. Those devices are very sensitive for any transient state. Results obtained here are found to be quite matching with those given by. Bsee and boem as to what additional standards may be applicable to offshore substation design as the agencies update their regulations. The document describes safe work practices for the control of hazardous situations. Unit substation construction checklist page 4 of 6 version 0206 verify mounting, location and clearances are per plans and specifications inspect for physical, electrical and mechanical condition of equipment and cabinet no damage evident inspect panels and doors for proper fit and alignment equipment labels permanently affixed. Power systems analysis and design br gupta power systems earthing. Calculationofimportantdesignparametersforgroundingsystemsi. Selecting directional elements for impedancegrounded.
This paper presents an overview of how the lightning strikes and their e ects on power distribu. Due to it is directly related to production safety, the grounding system has a key position in electric power system. Points to consider regarding the insulation coordination of gis substations with cable connections to overhead lines m. Improved grounding can be a costeffective method to improve power quality by reducing the number of lightning flashovers on shielded overhead transmission lines. Nov 14, 2019 in those cases, we can say that the grounding path is ok if on more than half of the grounding points of that apparatus down current is higher than the up current. Direction and methods for qualifying permanent connections used for substation grounding are provided in this standard. Ic 8835 1980 guide to substation grounding and bonding for mine power systems. Three phase, liquid filled primary and secondary unit.
Gas insulated switchgear gis when coupled with short cables complicates insulation coordination practice particularly regarding fast front transients. Unit substation transformer construction checklist page 4 of 6 version 0206 equipment installed agrees with shop drawings and specifications verify mounting, location and clearances are per plans and specifications inspect for physical, electrical and mechanical condition of equipment and cabinet no damage evident. 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. Principles of electrical grounding john pfeiffer, p. Changing footing resistance to 15 ohm had little effect on overall fault current, but opgw return current was reduced by 12%. Distribution substation a distribution substation transfers power from the transmission system to the distribution system of an area. First, it provides a means of dissipating electric current into the earth without exceeding the. Pdf investigation of potential grounding compound for. Find the listing on this page corresponding to the model, voltage and horsepower rating of your operator. Grounding connectors and accessories quick reference grounding figure 6 see page c55 figure 8 see page c55 figure 66 see page c56. Line to ground voltage monitoring on ungrounded and impedance grounded power systems december 2010at301 by reza tajali, p. 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. Design and analysis of substation grounding grid with and without considering seasonal factors using edsa software mithun mondal, dr r.
Second, we formalize this process in the endtoend learnable neural architecture we call seqground. This equipment must only be installed and serviced by qualified electrical personnel. Substation earthing system design optimisation through the. D substation standards lighting fixture pole and bracket mounting 19. When a substation fence is expanded or a section is removed, fence sections shall be isolated, grounded, or bonded as necessary to protect employees from hazardous differences in electric potential. The input for a distribution substation is typically at least two transmission or subtransmission lines. All grounding points in the substation should be tested that way. K substation standards switch operating and equipment platforms electrical design and details 20. Systems with this type of grounding are referred to as resonantgrounded or compensated systems. Realview mimic panel lv swgr substation version show the entire substation neutral grounding system, transformer protection.
Material requirements grounding systemconductors making up the grounding mat and associated ground risers, andor for encasement in concrete shall. Ground resistivity influence on the lightning overvoltage level in high voltage power substation jaroslaw m. This document supports the power system safety rules and its requirements assembled under work in substations general. Matrix is designed to be fitted with a filler that best matches the level of security required. 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. Ieee guide for safety in ac substation grounding, contains. The standard is available through your institution electronic library or college. Resonantgrounded faults are only used in overhead line applications and not in cables. Distribution voltages are typically medium voltage, between 2. A single pdf document will be created that contains the passfail test summary from pro test and all the applicable forms from the list below. Cisco 1120 connected grid router hardware installation guide. Ieee guide for safety in ac substation grounding ieee std 802000. Substation lightning protection and earthing standard.
Design guide for rural substations usda rural development. Optimal design of grounding system for hv ehv substations in. View the article pdf and any associated supplements and figures for a period of 48 hours. The grounding grid is critical to the safety and stability of a power system. If the address matches an existing account you will receive an email with instructions to. Optimized design of earthing system for substations with. Under practical conditions the magnitude of the current diverted from a substation grounding grid by the counterpoise conductor is a very complex function of the self and mutual impedances of overhead and underground conductors, substation grounding impedance, transmission line towers resistance, proximity effect between the grounding grid and. There are software for this purpose which build on this standard. Find out more about this job and similar jobs on dreamhire. As a comprehensive treatment of the topic, methodology and technology for power system grounding is ideal for engineers and researchers in power system, lightning protection, and grounding. This voltage, gpr, is equal to the maximum grid current times the grid resistance. The purpose of the grounding grid is to serve the dual purpose of carrying currents into the earth without exceeding the operating tolerances of any protected equipment while. With access to products from multiple manufacturers, wesco high. Also, it is very important to measure the voltage drop during the test.
There is a close match in the values obtained from these. Sep 09, 2019 tighten the grounding screws to 10 to 12 footpounds of torque. When the coil reactance matches the system capacitive reactance, the system. The substation grounding grid is a system of horizontal, interconnected bare ground conductors, spaced a few meters apart, buried in the earth at a depth varying from 0.
Design of earthing grounding system in a substation grid. Efficient reduction of fault current through the grounding. Convey energy to ground conduct the energy to the ground via a purposedesigned downconductor. If necessary, strip the other end of the ground wire and connect it to a reliable earth ground, such as a grounding rod or an appropriate grounding point on substation equipment that is grounded. Index terms substation, grounding, grounding system. Scribd is the worlds largest social reading and publishing site. The design is based on the measured soil resistivity of the substation site and proposed methodology is found to be safe for operation. The proper grounding of a substation is essential and very important for the following two reasons. Each realview mimic panel has a drawing key reference with notes to add your key safety details like interlocks, maintenance grounding points, or system clarifications.
Ground check monitors for underground power systems. The job description, requirements, and apply online for substation mechanic i at entergy. Abb drytype transformers july 14, 2017 slide 17 occurs when sustained current ex. Grounding system is one of the most widely used electrical safety measures. The current revisions of the relay maintenance and installation procedures, forms and policies are primarily available in p8.
Each of the matrix fillers have unique characteristics that provide specific levels of delay and visual screening. Dissimilar metals are electrically isolated to avoid galvanic corrosion. A substation is a part of an electrical generation, transmission, and distribution system. Methodology and technology for power system grounding wiley. Hence substations in general can be considered as heart of overall power system.
Substation grounding earthing has an example at the end of ieee std 80. University format manual, and that this project is suitable for shelving in the. Stations with uniform resistivity throughout the entire area are rarely found. Pdf this paper describes a design method for upgrading the existing grounding system. The reactor is tuned so that it matches the phasetoground capacitance of the power system. Design of lightning arresters for electrical power systems. Guidelines to properly designed substation grounding. The fence is connected to a separate grounding conductor.
Add iec 61850 rtu functionality for status indication from other relays or communications. Also connect the new substation to building steel, the associated incoming duct bank when a new duct bank entrance is installed, and to all water services. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions. Design and analysis of substation grounding grid with and. It details the electrical hazards which must be managed to ensure the safety of personnel when working in switchyards, substations, high voltage areas including cable tunnels, general. Pdf grounding systems are very important for the safe construction of a substation or a simple building. Line to ground voltage monitoring on ungrounded and. The following current and former members of the substation subcommittee of the nreca. Design of earthing system for 400 kv ac substation international. No attempt is made to cover the grounding problems peculiar to dc. Ieee guide for safety in ac substation grounding ieee std. Pdf upgrading existing grounding system for substation.
Dissipate energy into the grounding system dissipate energy into a low impedance grounding system using gem and nvent erico ground rods. This bulletin is an update and revision of previous rea bulletin 651, design guide for rural substations revised june 1978. This illustration identifies the components and introduces the basic rules for an. Electrical acceptance tests architecture engineering and. This standard particularly addresses the connection used within the grid system, the connection used to join ground leads to the grid system, and the connection used to join the ground leads to equipment and structures.
Wiater bialystok technical university, poland summary. Electrical engineering fundamentals related to grounding and bonding applications. The goal of this course is to learn how to design lightning protection systems. Building your pathway to success with lean construction. Substation transformers a dc megger test and a turns ratio test shall be performed on unit substation transformers.
Instead and perhaps counterintuitively, the more electrodes in the loop the more closely the reading matches the individual resistance of the electrode under test. This example demonstrates the design steps in the earthing matgrid in the substation. Methods of analyzing soil include curve matching and analytical procedures to identify. Turn the source unit up to about 34 volume if the source unit goes to 30, turn it to 25. Turn off all power supplying this e quipment before working on or inside equipment. Corrosive cracking of the grounding conductor is the main cause of deterioration of grounding grid performance. Thus, measurements should be made at multiple locations within the site.
It may seem logical that the presence of these additional rods in the loop would affect measurement accuracy. Before the design of the grounding system begins, soil resistivity measurements need to be taken at the substation. Add annunciator functions for transformers, fan, temperature, sudden pressure, etc. Pdf ieee guide for safety in ac substation grounding.
It is also known as an arcsuppression coil or groundfault neutralizer. Offshore substation design development of standards. The fence is not connected to a separate grounding conductor fence grounding. A quantitative analysis of the effects of lightning surges is also beyond the scope of this guide. Distribution substations michigan technological university. Nov 28, 2012 touches on lightning impulse characteristics of grounding devices for towers and buildings. Scope this document states the functional requirements with regard to substation earthing and bonding, and integration into a substation, as well as items that. Efficient reduction of fault current through the grounding grid of a substation supplied by an overhead line. Customer substation manual 6272019 table of contents page 2 of 82 section description 0 preface 010. When the electrical contact is such that the circuit path through the body is across the heart, you have the greatest potential for death. Conductive fences around substations shall be grounded.
Always use a properly rated voltage sensing device to confirm power is off. Ensure that user organizations identified in table 1 are aware of their maintenance responsibilities. Substation earthing and bonding and their integration into a substation and the potential impacts on third party owned assets in the immediate vicinity of the substation. Resonant grounding provides selfextinction of ground faults. First, it provides a means of dissipating electric current into the earth without exceeding the operating limits of the equipment. With proper caution, the methods described herein are also applicable to indoor portions of such substations, or to substations that are wholly indoors. Pdf grounding of overhead transmission lines for improved. A qualified contractor must provide all the necessary material and installation of the gas andor electric facilities for the project. The grounding system in substation or power generation plants is an important part of electric installation. Modeling of camosun substation existing ground grid. Sensors free fulltext a nondestructive testing method. The book will also better equip postgraduates, senior. Grounding connectors and accessories quick reference.
In addition, isolation from the power frequency voltage and transient overvoltage protection is provided. Wesco high voltage brings together the substation and transmission application expertise of hamby young, and the distribution application expertise of kva supply and modern wholesale electric, to offer the electric utility industry a complete suite of products and services. No attempt is made to cover the grounding problems peculiar to dc substations. Confirm metallic pv module frame grounding uses a dedicated grounding conductor or the rackmodule system is ul listed for grounding proper grounding of all other metallic surfaces that might possibly become energized conduit, combiner boxes, disconnect enclosures, etc. Hslg slide gate operator installation guide 2 p1220 revision x10 11042016 wiring specifications refer to the following steps for details on power and accessory wiring for the operator.