Substation and switchyard both are different and these two switchyard is the inter connector between generation and transmission, and same voltage is mentained in switchyard, substation is the inter connector between transmission and distribution. If the earth grid impedance is less than 10 ohm then the design will be ok. Distribution substation a distribution substation transfers power from the transmission system to the distribution system of an area. Syllabus of substation design course advance electrical. The first step in designing a power substation is to design an earthing and bonding system go to content earthing and bonding. Professional certificate of competency in substation design.
In order to address the subsequent need for clean power, there. Important formulas for designing a substation grid earthing system. Switchyard design a seminar report submitted in partial fulfilment of the requirements for the award of the degree bachelor of technology in electrical engineering by milind punj roll. If the live wire touches the grounded case then the circuit is effectively shorted. Anyone wishing to make further use of ed material, by itself and apart from this text, should seek necessary permission directly from the proprietors. Pmi revision 00 presentation outline understanding basics of switchyard switchyard equipments and schemes components of switchyard. I need a free software for earthmat design for 33kv to 400 kv substations in india. Before 1960s the design criterion of substation earthing system was low earth resistance.
Distribution voltages are typically medium voltage, between 2. Program is designed as per ansiieee 80 code, it calculates step potential of switchyard, touch potential of switchyard, total length of earthing mat conductor. New inverter design expected to have shortcircuit contribution limited by the inverter apparent power kva rating and similar to that of a type 4 full converter type wind turbine generator. Vuspec summary this new comprehensive collection represents the most complete resource available for professional engineers looking for best practices and techniques covering design, construction and operation of devices or assembled gear to establish.
The earthing conductors, composing the grid and connections to all equipment and structures, must possess sufficient thermal capacity to pass the highest fault current for the required time. The problem is formulated as a mixedinteger linear. 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. The earthing calculation aids in the proper design of the earthing system. The input for a distribution substation is typically at least two transmission or subtransmission lines. Selection of the location of a substation must consider many factors.
Earthing practices free download as powerpoint presentation. Ieee guide for safety in ac substation grounding ieee std. Earthing design of 11kv and 33kv rural substations in the uk. Substations involves many earthlings through individual electrodes, which will have fairly high resistance. Pdf this is a guideline to design the earthing system of ac substation based on ieee 80 standard. Pdf earthing is an important aspect of every substation construction. Substation earthing system grounding system earthing mat.
Trends in systems design there are many new factors to consider in the design of power distribution systems. Detailed syllabus for substation design course, our syllabus is comprehensive,structured and aim to build design career in epc companies,aedei syllabus bases on the epc industries, all the content and syllabus are realated to the industries, aedei is providing priactical projects on substration design. The development of the expressions for the calculation of the ground resistance, mesh and. The earthing systems for a substation must have a minimum design life of 50 years. This document is part of the construction virtual manual maintained by document. Design of a proper substation grounding system is very involved as many. The switchyard is located approximately 850 feet southwest of the right abutment of the dam, and approximately 170 feet higher than the top of the dam. Earthing guide for surge protection 1 earthing for surge protection of electronic equipment 1.
Ensure safety to personnel in substations against electrical shocks. Earthing mat design for a power substation ms excel. When all metallic parts in electrical equipments are grounded then if the insulation inside the equipments fails there are no dangerous voltages present in the equipment case. University format manual, and that this project is suitable for shelving in the library. Distribution substations michigan technological university. Standard equations are used in the design of earthing system to get desired parameters such as touch and step voltage criteria for safety, earth resistance, grid. 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. All rus borrowers rus electric staff effective date. Hence substations in general can be considered as heart of overall power system. Ei to design amethod to calculate the total groundresistance of a system of two substation grounding grids intertied by a bare conductor, as seen from the station where the fault occurs, and lie ground potential rise at both the substations. Meysp advanced electrical substation and switchyard design.
Behrouz has also gained good knowledge in substation design, hv cables sizing and installation, transmission system design, earthing system design and applications, and power system protection design and applications. Substation civil design and construction standard 1 general 1. Technical specification for design, supply, installation. Substations can be of various capacities, voltages, configurations and types depending on what is the application for which the substation is being designed. Major substation earthing design, construct and commissioning. Design of earthing grounding system in a substation grid.
Determine the minimum size of the earthing conductors required for the main earth grid ensure that the earthing design is appropriate to prevent dangerous step and touch potentials if this is necessary when to do the. Program is designed as per ansiieee 80 code, it calculates step potential of switchyard, touch potential of switchyard, total length of earthing mat conductor, size of earthing mat conductor and total number of earthing rods. Design guide for rural substations usda rural development. Design of earthing system for new substation project citeseerx. The main purpose of this work is the development of an optimization model for the design of the grounding grid in electrical substations. If the reprint or republication includes ed material, the credit should also state.
Earthing scheme design the present day earthing system in a substation takes the form of a grid or mat comprising a number of square or rectangular meshes of earthing conductor buried horizontally and connected to several electrodes driven at interval as shown in figure. Earth resistance earthing, grounding, methods of earthing, types of earthing, components of earthing and its specifications in respect to electrical earthing for electrical installations. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions. Provide the ground connection for connecting the neutrals. He has also worked as an engineering manager and senior project engineer on major copper mine projects overseas. We have already given an introduction to substation earthing system in an article published earlier. Substation design services 4002202kv gis substation. Breakers, isolators, earth switch, ct, cvt, wave trap etc brief description of modes of transmission conclusion. The function of an earthing and bonding system is to provide an earthing system connection to which transformer neutrals or earthing impedances may be connected in order to pass the maximum fault current. Ensure that the earthing design is appropriate to prevent dangerous step and touch potentials if this is necessary. Earthing switch also known as ground disconnect, which used to connects the equipment to a grid of electrical conductors buried in the earth on the station property. Earthing guide for surge protection mtl instruments. However, the pro tection provided depends crucially on the quality of the installation. The functions of grounding systems or earth mat in include.
The difference between the ground potential rise and the surface potential at the point where the person is standing while at the same time having a hand in contact with a grounded structure. The average resistivity thus obtained shall be used for the design of the earthmat. To connect the metallic conductive parts of an electric appliance or installations to. Earth mat is preferable to large substations because of space saving on the. Earthing mat design for a power substation ms excel spreadsheet. Design the main considerations taking into account during the design process are. The fill for embankment ranges up to 27 feet in depth and the cut for excavation ranges up to 24 feet in depth. The switchyard fence earthing practices are possibleand are used by different utilities. Nov 27, 2011 the main reason for doing earthing in electrical network is for the safety. The ergon energy design philosophy is to provide substations. Electrical substations and switchyard design technology training that works. 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. Pdf earth mat design for 233kv substation in rivers state.
Construction of main control room adjoining the 66kv switchyard is in bhel scope. It is a switching station which has the following credits. The grounding system in substation is very important. All substation earthing systems must be designed to ensure the following functional requirements are met. Army, usa, technical manual tm 58116, electric power plant design. Pdf earth protection system, also known as grounding system, is to protect the equipment in the substation by providing low impedance path. All intellectual property rights including without limitation any, patents, logos, designs, circuit layouts, trademarks, moral rights and know how in the. Power plant switching station switchyard electrical. Design of earthing system for 400 kv ac substation. Electrical earthing, grounding, methods of earthing, types of earthing, components of earthing and its specifications in respect to electrical earthing for electrical installations. Technical specification for design, supply, installation and. Federal and state legislation has been introduced to reduce the output of carbon emissions into the environment. The cross section of the buried cable should calculated in accordance with the value of the phasetoearth short.
Today we are going to discuss the design of substation earthing system. Oct 23, 2014 electrical substations form important nodal points in all power networks. Read about design of substation earthing system here. This electrical substation and switchyard design course focus on elementary safety standards and practices in substations and switchyard design. To connect the metallic conductive parts of an electric appliance or installations to the earth ground is called earthing or grounding. The substation earthing system comprises of a grid earth mat formed by a horizontal buried conductors. Design of earthing system for 400 kv ac substation a case study. Technical specification for secondary substation earthing. The substation design manual is not intended to replace asset management standards, but rather. Find, read and cite all the research you need on researchgate. Earthing practices electrical substation transformer.
It is intended to protect people working on the grounded equipment. If the live wire touches the grounded case then the circuit is effectively shorted and fuse. Pdf design of safety critical substation earthing system based. What is the difference between a substation and a switchyard. Design the required electrical interconnections to ensure correct functioning of the substation equipment draw up a list of design inputs for building and structural design engineers plan the support facilities required for the substation electrical substation and switchyard design. Successful operation of entire power system depends to a considerable extent on efficient and satisfactory performance of substations. The main reason for doing earthing in electrical network is for the safety. A substation is a part of an electrical generation, transmission, and distribution system. This bulletin is an update and revision of previous rea bulletin 651, design guide for rural substations revised june 1978.
Determine the minimum size of the earthing conductors required for the main earth grid. Design of earthing system for 400 kv ac substation a case. Calculationofimportantdesignparametersforgroundingsystemsi. Ni000401r121 substation design manual ni000401r122 substation construction manual mn000301r171 test and commissioning manual na000403r328 queensland electricity connection and metering manual reference 4.
Substation earthing design akshay patil electrical and electronics engineering, navrachana university, india abstract. Different types of neutral earthing practices in substations india and abroad cable selection and sizing requirements of clamps for interconnection and equipment connectors. Between the generating station and consumer, electric power may flow through several substations at different voltage levels. An electrical substation is the component of a power system with which voltages are transformed for the transmission, distribution, transformation and switching of power. Ieee guide for safety in ac substation grounding ieee std 802000.
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