Gas insulated switchgear is used in industrial areas to fulfil highenergy demands by space saving design with a. Development of 22kv distribution systems and switchgear. A gas tight barrier insulator in switchgear serve for the separation of gas compartments and prevents neighbouring switchgear parts from being affected during maintenance. Gis there are two terms presented in iec gas insulated switchgear and ieee gas insulated substations.
Pdf the sf6 gas insulated switchgear has increasingly been used for high. A major difference between conventional air insulated substations ais and the gas insulated substations gis is that the sf6 gas insulated electrical components are placed within an earthed, pressurized metallic container. Elk cn3 current transformer installation in a separate manual available upon request. Introduction to gas insulated substations switchgears gis.
Gas insulated substations are used where there is space for providing the substation is expensive in large cities and towns 21. Current transformers are designed to provide a scaled down replica of the current in the hv line and isolate the measuring instruments, meters, relays, etc. Ges f35 gis is a fieldproven solution with high availability that meets the challenges of networks up to 170 kv for power generation, transmission, distribution, tertiary and heavy industry applications. Jan 02, 2019 in this gis or gas insulated switchgear system than one functional element are encapsulate in a single metal enclosure. Primarily used in substations located in urban areas including inside buildings, underground due to safety benefits. Gas insulated metalenclosed switchgear for rated voltages above 52 kv 092011 orequired leakage rate gas compartment tt f th td i 01% t t. To prevent moisture, the ring types have epoxyfiberglass applied. Each distribution voltage the substation supplies must have its own bus. Pdf analysis and calculation of very fast transient over voltages. Mv ct are usually installed indoors, in mv switchgears figure 4. Often, building new substations or increasing capacity is difficult because land is either not available or is prohibitively expensive. The thermal currentcarrying capacities and the faultwithstanding capabilities are tailored to meet all the substation requirements. Here is a brief history of its development and pioneers.
Gis gas insulated switchgear power transformer, gis. Iec 62271203 highvoltage switchgear and controlgear part 203. The gas insulated substation gis represents a key element of high voltage electrical transmission networks thanks to its reliability, low maintenance requirements and compact dimensions. With layout flexibility, the zf8550 gis consists of a circuit breaker.
Since its introduction back in 1968, siemens has installed more than 28,000 indoor and outdoor switchgear bays worldwide, and well over 300,000 bayyears of operation have been recorded. Elk cn14 current transformer installation in a separate manual available upon request. Consult abb ags entire tg gasinsulated high voltage current transformers 72. Current transformer is an instrument transformer used in substation for measurement and protection purposes. The thermal current carrying capacities and the faultwithstanding capabilities are tailored to meet all the substation requirements. It is applicable to both openterminal air insulated ais and metalenclosed gas insulated gis substation constructions and covers equipment operated at lower voltages on the same substation site. The high voltage conductors, circuit breaker interrupters, switches, current transformers, and voltage transformers are in sf6 gas inside grounded metal enclosures. Gasinsulated switchgear up to 550 kv, 63 ka, 5000 a type. Current, voltage and combined transformers, oilpaper or gas insulated up to 800 kv. The clearance required for phase to phase and phase to ground for all equipment is much lower than that required in an air insulated substation. Pdf methods that have been used to evaluate the performance of uhf couplers for partial discharge monitoring of gas insulated substations are briefly.
The current transformers are of the singlephase inductive. The history of gasinsulated substations think grid. Ge provides a full range of gas insulated substations gis for utilities and industries worldwide. The report gas insulated transformer market by type instrument transformer, others, voltage medium voltage, high voltage, extra high voltage, installation outdoor, indoor, enduser utility, industrial, commercial, and region global forecast to 2023, the gas insulated transformer market is expected to grow from usd 2. They are applied to isolate different elements of the substation, such as circuit breakers, transmission lines, transformer banks, b uses, and voltage transformers. In a gis substation, the various equipment like circuit breakers, bus bars, isolators, load break switches, current transformers, voltage transformers, earthing switches, etc. This is a significant change in operating the switchgear with circuit breakers, disconnectors, and switches earth. Current transformer 500kv sf 6 current transformer for over a century, utilities around the world have relied on ge to deliver. Current transformer the current transformers are of the singlephase inductive type with one or more cores and preferably located on the outgoing side of the circuit breaker. Siemens provides a wide range of services including the supply of complete packages of highvoltage. Distribution substation a distribution substation transfers power from the transmission system to the distribution system of an area.
Siemens transmission products presentation digital asset. Transmission substations can range from simple to complex. Ideal for installation at metering points due to its very high. A gas insulated substation gis is a high voltage substation in which the major structures are contained in a sealed environment with sulfur hexafluoride gas as the insulating medium. Tg gasinsulated high voltage current transformers 72. Elk cn14560 current transformer for gas insulated switchgear.
What is the function of the current transformer in a substation. Gis gas insulated switchgear power transformer, gis, gcb. Technology gas insulated substations wiley online library. Xdge provides gas insulated switchgear gis solutions for high to ultra. Sub stationsair insulated substations linkedin slideshare. For example, in some design, a three phase circuit breaker, current transformer, earth switches, even other feeder elements are covered together in a single metal capsule. Utilizing both technical presentations and case studies from leading utilities, attendees will be provided with a sound understanding of gis capability as well as realworld. Gas insulated substations gis are different from air insulated substations as all the substation equipment such as bus bars, circuit breakers, current transformer, potential transformers and other substation equipment are placed inside the modules filled with sf6 gas. Electromagnetic disturbances of the secondary circuits in. Similar to ais substations gis installation includes voltage transformers to decrease the bus. The gas insulated substations gis technology is a continuous development process involving new materials, technical functionality, manufacturing processes, quality, and reliability improvements. Sf6 gas having high dielectric property acts as insulating medium between. Typically, they do not have big interrupting capability except for small quantities of charging current associated with short pieces of bus.
Current transformers are typically installed in the circuit breaker bushing turrets. Tg is a gas insulated high voltage current transformer based on a topcore design, able to withstand current up to 4,000 a and designed for voltages from 72. Gas insulated transformer use sf6 gas as the insulating and cooling medium instead of insulating oil. In order to enhance the protection of current transformers in high voltage gas insulated switchgears, the invention is, that the current transformer is formed andor embedded by vacuum. The design of a gis follows the rules of pressure vessel design with the exception of the repetitive pressure test after installation. Current transformer, voltage transformers, gis, tank. Major components you can spot while looking at hvehv gis.
Current transformers can be used to supply information for measuring power flows and the electrical inputs for the operation of protective relays associated with the transmission and distribution circuits or for power transformers. Gis technology originated in japan, where there was a substantial need to develop technology to make substations as compact as possible. A typical gas insulated substation is shown in fig. A gas insulated substation gis uses a superior dielectric gas, sf6, at moderate pressure for phasetophase and phasetoground insulation. These current transformers have the primary winding connected in series with the conductor carrying the current to be measured or controlled. Basic working operations of both the substations are same. Gis highvoltage gas insulated switchgear substations. Guidelines for usage of air insulated substation ais or gas. The high voltage conductors, circuit breaker interrupters, switches, current transformers, and voltage transformers are in sf6 gas.
The invention relates to a current transformer for high voltage gas insulated switchgear substation, wherein the current transformer is arranged in a enclosure of housing, according to the preamble of claim 1. Gas insulated instrument transformer for enhanced safety and reliability. Gas tight barrier insulators ensure that any effect on adjacent substation components is kept to a minimum. Other common types are oil or vacuum insulated switchgear. Ct used for the measurement of ac current by taking the samples of higher currents of the system. Gas insulated substations gis is a compact,multicomponent assembly enclosed in a ground metallic housing in which the primary insulating medium is compressed sulphur hexafluoride sf6 gas.
The ring type current transformer can be used with both threephase commonenclosure and isolated type gis. Since 1974 we have supplied gas insulated substations. Gasinsulated switchgear up to 245 kv, 50 ka, 4000 a type 8dn9. An electrical substation is an installation with electrical equipment capable of interrupting or establishing electrical circuits and changing the voltage, frequency, or other characteristics of the electrical energy flowing in the circuits. Tg gas insulated high voltage current transformers 72. A small switching station may be little more than a bus plus some circuit breakers. Major components you can spot while looking at mvhv gis gas insulated switchgear gis are available internationally, covering the complete voltage range from 11 kv to 800 kv. Request pdf experimental study of fast transient currents in gas insulated substation the increasing demand in transmitting electrical energy at very high voltages with low transmission losses.
Both current and voltage transformers are used for measuring and protection purposes. What is the function of the current transformer in a. A study of air insulated substation ais and gas insulated. Gas insulated substation gis also called sf6 gas insulated metalclad switchgear is preferred for 12kv, 36kv, 72. The possibility of a subtransmission circuit fault is much higher than a transformer fault. A switchgear may be a simple openair isolator switch or it may be insulated by some other substance. Sep 17, 2012 gas insulated substation 10sep12 10 11. Gas insulated substations use sulphur hexa fluoridesf6 gas which has superior dielectric properties. Gas insulated substation ppt pdf presentation gas insulated substations gis is a compact,multicomponent assembly enclosed in a ground metallic housing in which the primary insulating medium is compressed sulphur hexafluoride sf6 gas. An effective although more costly form of switchgear is the gas insulated switchgear gis, where the conductors and contacts are insulated by pressurized sulfur hexafluoride gas sf 6. Siemens transmission products offers all products of highvoltage substations including bundling and their electrical integration to systems up to 1. Over the last 30 years, gas insulated switchgear gis has been used for a wide range f application. Gas insulated substation is employed where a where there is less space available b for high altitude substations c in terrain region d all the above.
Wo2017102983a1 current transformer for high voltage gas. Secocue 36v gas insulated medium voltage switchgear secocube is an indoor, factoryassembled, metalenclosed, cubicle type gas insulated switchgear for single busbar applications. Distribution voltages are typically medium voltage, between 2. Major components you can spot while looking at mvhv gis gasinsulated switchgear gis are available internationally, covering the complete voltage range from 11 kv to 800 kv. The siemens gas insulated switchgear gis is an extremely successful product concept. Distribution substations michigan technological university. The input for a distribution substation is typically at least two transmission or subtransmission lines. Gas insulated substation electrical substation transformer. Elk cn31080 current transformer for gasinsulated switchgear. The largest transmission substations can cover a large area several acreshectares with multiple voltage levels, many circuit breakers, and a large amount of protection and control equipment voltage and current transformers, relays and scada systems. Experimental study of fast transient currents in gas. Guide for application of gasinsulated substations gis 1 kv up to 52 kv. The transformer may have differential relaying that trips all of the feeder breakers in the event of a fault.
Voltage transformers f gas insulated bus duct section between gis and xlpe cableoverhead conductor. Siemens is a leading supplier of engineering, equipment, solutions, and services for highvoltage substations, such as air insulated substations, gasinsulated substations, and gasinsulated lines. National grid substations technical specification ngts 2. Factors such as higho immunity against adverse atmospheric conditions, less maintenance, higher reliability or space savings compared with open air substations are main reasons today for a preferable choice of gis installations worldwide. They can, however, be located at any point within the bay or substation. Operation and maintenance of a gas insulated substation. Tranformers, gas insulated switchgears, circuit breakers, surge arresters, disconnectors, instrument transformers, and bushings. Hv ct are commonly installed outdoors, in ais substations air insulated substation figure 2 or indoors, in gis substations gas insulated substation figure 3. Though, both have some properties which differs each other. Extreme low emissions protect the environment stateo eart design gas compartment axial direction. Which is the first equipment seen in the substation while coming from transmission system a circuit breaker b lightning arrester c current transformer d transformer. Gasinsulated metalenclosed switchgear for rated voltages above 52 kv 092011 orequired leakage rate nov 04, 2017 gas insulated substations gis differ from air insulated substations substations we usually see such that all the substation equipment such as busbars, circuit breakers, current transformer, potential transformers and other substation equipment are placed inside sf6 modules filled with sf6 gas.
Development of 22 kv distribution systems and switchgear 160 conductor for connecting to the cable head at the bottom of the molded case, a current transformer for metering that is built into the epoxy molded insulated housing, a condenser for voltage detection, and three for three phases fourposition vacuum switches. Siemens is a leading supplier of engineering, equipment, solutions, and services for highvoltage substations, such as air insulated substations, gas insulated substations, and gas insulated lines. With gis experience spanning 50 years across a wide range of industries and applications, ge is a leader in the. As a result, gas insulated transformers, gas insulated shunt reactor, gis and control panels can be installed in the same room, and such installation realizes the fully sf6 gas. The portfolio includes gis solutions from 60 to 800 kv, along with secondary products to maximize switchgear and network operation. Gasinsulated switchgear up to 550 kv, 63 ka, 5000 a type 8dq1. Electromagnetic disturbances of the secondary circuits in gas insulated substation due to disconnector switching ivo uglesic1, sandra hutter1, viktor milardic1.