The operation of circuit switchers is initiated by manually operating a switch, by remote supervisory control equipment, or by substation protective relays that automatically sense abnormal predetermined system or equipment conditions or electrical failures (faults). Your email address will not be published. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions. For voltages above 500 kV, a common structure is too wide, and each phase has its own structure. Metalclad equipment may also be attractive for other reasons, notably visual impact in environmentally sensitive areas and operation in heavily polluted environments. The transmission substation contains equipment used to sectionalize the electric transmission system when a fault or short circuit develops on one of the circuits. The largest transmission substations can cover a large area (several acres/hectares) with multiple voltage levels, many circuit breakers, and a large amount of protection and control equipment (voltage and current transformers, relays and SCADA systems). To maintain reliability of supply, companies aim at keeping the system up and running while performing maintenance. Lightning arresters contain semiconductor blocks, which limit the magnitude of high-surge voltages, permit the large-surge currents to pass harmlessly to the ground, and interrupt the power-follow current after the surge is eliminated. Voltage transformer connection for control and metering. . They are designed to be compact for travel on public roads, and are used for temporary backup in times of natural disaster or war. This report presents the worldwide Electrical Substation Market size (value, production and consumption), splits the breakdown (data status 2017-2022 and forecast to 2029), by manufacturers . The space-saving advantages of gas-insulated/metal-clad equipment can be significant particularly for high voltage substations in large cities where space is difficult to obtain and the land is very expensive. The line trap can also be suspended from a structure. The main function of substations is to convert AC (alternating current) to DC (direct current) (direct current). Survey crews stake or flag the locations for the station using predetermined GPS coordinates. This equipment permits using the line conductors for communication, relaying, supervisory control, and metering in addition to the transmission of electric power. Capacitors in distribution substations are usually mounted in metal cubicles. Subtransmission circuits supply distribution substations. This is a 500 kV switchyard. Earthing switches are usually associated and interlocked with disconnectors and mounted on the same base frame. An example of data being processed may be a unique identifier stored in a cookie. The figure given is a picture of a power transformer that is part of a distribution substation. The output is a number of feeders. (Accessed July 28, 2015). The downtown areas of large cities feature complicated distribution substations, with high-voltage switching, and switching and backup systems on the low-voltage side. The internal GIS insulation is independent of atmospheric pressure. Shortly after 9. The digital fault recorder records fault data and provides an accurate sequence of events for system disturbances on the electric system. They are used to. We and our partners use cookies to Store and/or access information on a device. The coupling capacitor potential devices are accurate enough to be used for supplying voltages to protective relays butunless they are specifically compensated not accurate enough to supply voltages for meters designed for billing purposes. Line traps (also known as wave traps) present high impedance to carrier frequencies but negligible impedance to normal 60Hz or 50Hz line currents. The substation has two options to assure compliance. 7. Malaysia. Disconnector mechanisms incorporate a set of auxiliary switches for remote indication of disconnector position, electrical interlocking and current transformer switching for busbar protection. Circuit breakers in the transmission substation are used to switch generating and transmission circuits in and out of service. The fire, which started in a piece of electrical equipment, was caused . Distributed automatic control at substations is one element of the so-called smart grid. Capacitors used in this manner help to control voltages supplied to the customer by eliminating the voltage drop in the system caused by inductive reactive loads. PORTLAND Ore. (KPTV) - Reported explosions and a blazing fire at a Portland electrical substation near Mt. In a common design, incoming lines have a disconnect switch and a circuit breaker. In a single device, it offers isolation and limited fault interrupting capability. Which must be kept in mind while playing out a substation. Control batteries supply energy to operate circuit breakers and other equipment. They transform voltage from high to low (or vice versa) and perform several other critical functions. Substation protective relays installed on control panels are used to sense electrical failures on transmission and distribution circuits or in pieces of substation equipment, such as power transformers, substation bus, reactors, capacitors, and circuit breakers. Through line carrier, it performs data transmission to ensure monitoring of network, protection, and control. Underground and overhead conduits and control wire are installed to connect the controls of all the equipment in the substation to the control panels normally installed in the control house. CVE has built a nationwide reputation as the single source solution for substation construction and maintenance needs including estimating and support, material ordering, tracking and expediting, foundation construction, steel erection, bus work installation, and power and control cable installation. Examples for such substations are Brauweiler in Germany and Hradec in the Czech Republic, where power is collected from nearby lignite-fired power plants. The magnitude of the current transformer outputs may be used to trip the circuit breaker resulting in a disconnection of the load supplied by the circuit break from the feeding point. The design of the substation includes the switching system, planning and placement of equipment, selection of components as well as orders, support of engineers, structural design, design of the electrical layout, protection of relays, and main device ratings. [2] It is uneconomical to directly connect electricity consumers to the main transmission network, unless they use large amounts of power, so the distribution station reduces voltage to a level suitable for local distribution. Change it to match actual figures. The substations contain power transformers that reduce the voltage from sub-transmission levels to distribution levels, usually in the range of 4.16Y/2.4 kV to 34.5Y/19.92 kV. Substations are a complex facility involved in the transmission and distribution of electricity. Collector substations also exist where multiple thermal or hydroelectric power plants of comparable output power are in proximity. The magnitude of amperes flowing in the high-voltage circuit is reduced proportionately by the ratio of the transformer windings. [2] The simplest case is where all transmission lines have the same voltage. Continue with Recommended Cookies. Electric substations comprise the interface between transmission parts and systems of the distribution grid in a specific region. The site must be secure from intrusion by passers-by, both to protect people from injury by electric shock or arcs, and to protect the electrical system from misoperation due to vandalism. This seeks to isolate the fault point from the rest of the system, and allow the rest of the system to continue operating with minimal impact. Transmission, Sub transmission and distribution substation, Electric substations with equipment used to convert high-voltage, extra-high-voltage (EHV), or ultra-high-voltage (UHV) transmission lines to the intermediate voltage sub-transmission lines or to switch sub-transmission circuits operating at voltages in the range of 34.5 kV to 161 kV are referred to as, Substations located in the middle of a load area are called, The transformers are normally equipped to regulate the substation bus voltage. A substation is defined as a network of switching equipment, control equipment, and transformers used to convert the voltage to a different level and eventually route it to the user. Smaller distribution stations may use recloser circuit breakers or fuses for protection of distribution circuits. Shunt reactors are usually located in substations and connected to a transmission line terminal through a disconnect switch. Based on the construction and installation of switchgear, electric substations are of two types. Whether constructing greenfield projects from the ground up and/or brownfield expansion and upgrades, we provide turnkey power solutions from site preparation through energizing with an emphasis on: Using . Indoor substations may be gas insulated substations (GIS) (at high voltages, with gas insulated switchgear), or use metal-enclosed or metal-clad switchgear at lower voltages. A disconnect switch is used to provide isolation, since it cannot interrupt load current. Loss of circuit is involved in the maintenance of the circuit breaker of the transformer of the feeder. Design, Engineering, Supply, Erect and Commissioning of 3 x 1050MVA Autotransformers, 500kV Switchgears, 275kV Switchgears and Ancillary Equipment with Associated Civil Works for PMU 500/275kV Junjung, Kedah, Malaysia. For important substations a ring bus, double bus, or so-called "breaker and a half" setup can be used, so that the failure of any one circuit breaker does not interrupt power to other circuits, and so that parts of the substation may be de-energized for maintenance and repairs. Models are available with and without integral disconnect switches. Instead of bare conductors, buses and apparatus such as switchgear are built into pressurized tubular containers filled with sulfur hexafluoride (SF6), or an alternative gas. Electrical substation maintenance involves planned periodic inspections to ensure the structural and functional integrity of the facility. Communication signals in the form of high-frequency voltages are transmitted to the transmission lines through coupling capacitors. The voltage regulators maintain the system voltage on the distribution circuits. In some cases a conversion of the current type takes place, commonly with rectifiers for direct current (DC) trains, or rotary converters for trains using alternating current (AC) at frequencies other than that of the public grid. Switching stations are sometimes used as collector and distribution stations. Remote control of the tap changing equipment is usually installed as well. It not only increases footfall in the area as materials get shifted in and out of the facility, but also lures thieves on the lookout for expensive electrical components/ equipment. A piece of wire connecting a battery to a motor load can span hundreds of feet. voltage, a.c. to, Before learning about different switchgear components, let us understand what is switchgear. For fulfilling these huge power demands the modern time requires creation of bigger and bigger power generating stations. A group operated high-voltage disconnect switch and three power fuses are mounted on the terminal structure. There are 10 main steps in electrical substation construction. Other devices such as capacitors, voltage regulators, and reactors may also be located at a substation. An electrical substation is an integral part of a generation, transmission and distribution system. There are three methods to connect a substation to . One circuit breaker loss occurs when busbar is faulty while fault in breaker involves loss of two circuits. Some of the coupling capacitors are equipped with potential devices which make it possible to measure the voltage on transmission-line circuits. High-voltage fuses are used in substations to protect the electrical system from faults in such equipment as potential transformers or power transformers. A transmission station may have transformers to convert between two transmission voltages, voltage control/power factor correction devices such as capacitors, reactors or static VAR compensators and equipment such as phase shifting transformers to control power flow between two adjacent power systems. Gas Insulated Substation or metal-clad equipment utilizes either solid or gaseous (SF6) insulation to allow the phase to earth and phase to phase clearance to be drastically reduced. Our electrical substation construction and maintenance division is a full service substation contractor specializing in all aspects of 4kV to 500kV substation construction from turnkey greenfield construction to retrofit work. The apparatus used, We have already given an introduction to substation earthing system in an article published earlier., An analog instrument is one in which the output or display is a continuous function, We have already discussed the working of electrical relays. Circuit switchers employ SF6 puffer-type interrupters for switching and protection of transformers, lines, cables, and capacitor banks and have fault-interrupting ratings suitable for use in protecting medium- to large load transformers. Electrical substations can be found in various locations throughout a given city. They have also been mounted with one end of the line trap supported by a coupling capacitor or coupling capacitor voltage transformer and the other end by an insulator. The first step in planning a substation layout is the preparation of a one-line diagram, which shows in simplified form the switching and protection arrangement required, as well as the incoming supply lines and outgoing feeders or transmission lines. These electrical substation platforms allow multiple workers the ability to access control boxes for repairs or maintenance without the risk of a stand alone ladder. When a large fault current flows through the circuit breaker, this is detected through the use of current transformers. The lightning arresters are installed in a substation near the termination of aerial circuits and close to the more valuable pieces of equipment, such as power transformers. The substation buses are current-carrying devices that interconnect the individual pieces of substation equipment. The capacitors, mounted on the racks in the cubicles, are usually single-phase, single-bushing units rated 100-kVAR through 400-kVAR capacitance, 60 Hz, and a voltage consistent with the distribution system. Substations can be categorized by their various functions and roles. Both switches and circuit breakers may be operated locally (within the substation) or remotely from a supervisory control center. ft.) For instance, when quantity = 10; total cost for grounding would be 10 x 800 = $8,000 for a 10,000sq.ft yard. The PPL Outage Map showed more than . Disconnectors are usually interlocked with the associated circuit breaker to prevent any attempt being made to interrupt load current. Luke Wenker, who . When a high voltage begins to build up across the semiconductor blocks, they provide a low-impedance path to ground, which permits the surge current to flow to ground, limiting the voltage buildup and preventing the equipment from being damaged. To account for this, we've provided a general guide to substation equipment inspection. For example, in a remotely controlled unmanned double busbar substation the busbar selector disconnectors would be motor operated to allow on load busbar changes without a site visit being required. He is a good writer and author of many courses and articles published in this site. Former high-voltage substation in Stuttgart, Germany, now 110kV switching station. Electric Power Substations Engineering written to meet exhaustively the requirements of various syllabus in the subject of the courses in B.E /B.Tech/ B.Sc (Engineering) of various Indian Universities. Distribution substations connect to the transmission system and lower the transmission voltage to medium voltage ranging between 11/33 kV and 0.415 kV with the use of transformers. The substation receives electrical energy directly from generating stations through incoming power supply lines while it delivers electricity to the consumers through outgoing transmission lines. "Electrical Substation" by Wtshymanski at en.wikipedia - Licensed under Public Domain via Wikimedia Commons -. Consequently, large clearances are required between these terminals and earth and between terminals of different phases. A compact substation is generally an outdoor substation built in a metal enclosure, in which each item of the electrical equipment is located very near to each other to create a relatively smaller footprint size of the substation. doi:10.1109/TEMC.2009.2028879. This includes power transformers . The secondary winding of the current transformer is insulated from the high voltage to permit it to be connected to low-voltage metering circuits. Majority of electrical substations will be the air insulated type. It is necessary to use dc control systems with a storage battery as a source to make it possible to operate equipment during periods of system disturbances and outage. There is an option of maintenance of circuit breakers without loss of supply. Read the difference between, These above-mentioned substations are explained in, Components of an air-insulated substation, Power transformers are the most important equipment in an electrical substation. The fuses are connected in series with the power transformer that serves as a source for the switchgear. Electrical substations have an utmost importance in electric distribution facility (see video explanation here), converts AC voltages from one level to another level or change nature of supply voltage i.e., from AC to DC or vice versa. GIS can be easily built underground to avoid any environmental concern. Substation Name. Between the generating station and consumer, electric power may flow through several substations at different voltage levels. Supervisory control equipment is used to open and close circuit breakers, operate tap changers on power transformers, supervise the position and condition of equipment, and telemeter the quantity of energy flowing in a circuit or through a piece of equipment. These fields decrease the voltage in transmission lines to the. In a large substation, circuit breakers are used to interrupt any short circuits or overload currents that may occur on the network. Electrified railways also use substations, often distribution substations. We can turn voltage from high to low or low to high and do various important works with the help of a substation. A substation fire knocked out power Monday morning to more than 20,000 customers in Allentown's Center City and First Ward. Line entrance surge arrestors are used to protect substation equipment accordingly. More typical distribution substations have a switch, one transformer, and minimal facilities on the low-voltage side. The assembly of the apparatus used to change some characteristic (e.g. Thanks all information is very helpful to understand Substationthanks again, I wanted to ask the writer a questions about the picture that shows substation components? Substation transforms voltage from high to low or from low to high as necessary. Circuit switcher is a device that combines a disconnect switch with an SF6 interrupter. The substation is connected to the electrical network through an overhead line. Disconnect switches and other equipment are mounted on the steel structures. The most common structures you'll find in an electrical substation include: Dead-End Structures. Converter substations may be associated with HVDC converter plants, traction current, or interconnected non-synchronous networks. It is an intermediate station between the source of electricity and the customer. For further information please see the related pages below: Brain, Marshall, and Dave Roos. The frequencies range from 952 MHz to 13,000 MHz or higher. I have been looking so far , for such technical material ,it really helpful and easy to understand. Keeping these systems running safely and efficiently is critical for utilities and their customers. In some cases, it may not be possible to make a connection to the substation directly by the overhead line and underground cable entry must be considered. Enter conduit material cost. They are connected between each of the three-phase conductors and ground. Some substations will have three, A Hybrid Circuit Breaker. An electrical substation is an integral part of a generation, transmission and distribution system. They are classified into different types based on various criteria. The neutral grounding resistor provides resistance grounding of the neutral transformers to limit ground fault current to a value that does not damage generating, distribution, or other associated equipment in the power system, yet allows sufficient flow of fault current to operate protective relays to clear the fault. At the production site, a transmission substation steps up voltage for transmission; in the area where it will be used, it is stepped . In this article you will learn different types of substations, their functions and different equipment used used in them. Country. Electrical substations have many complex systems that handle very high voltage. In distributed generation projects such as a wind farm or photovoltaic power station, a collector substation may be required. To obtain maximum life from electrical equipment, maintain its . A substation is an installation that interconnects elements of an electric utilitys system. If no transformers are required for increasing the voltage to transmission level, the substation is a switching station. For the typical 13.27.6 kV distribution substation, the switchgear consists of a 2,000A bus and six (6) breaker cells. These are designed to reduce voltage in transmission lines to levels that distribution systems can withstand. Circuit switchers employ SF6 puffer-type interrupters for switching and protection of transformers, lines, cables, and capacitor banks and have fault-interrupting ratings suitable for use in protecting medium- to large load transformers. A small "switching station" may be little more than a bus plus some circuit breakers. The substation equipment and their functions mainly include the following. It helps in reducing the flow of reactive power, hence gaining voltage control. It is a blocking filter that is used to restrict the carrier signal to the transmission line on which it is installed. As power is transmitted at a higher voltage over long distances, the current is lower. In-built circuit breakers protect the distribution system and also manage the current flow in different directions. An electrical substation is a collection of equipment used in order to step up or step down electrical currents before they can be used. It resembles a distribution substation although power flow is in the opposite direction, from many wind turbines or inverters up into the transmission grid. Drawbacks over a circuit breaker include low-speed reclosing, and not designed for high-operation environments. If single-phase transformers are used, three transformers are generally required to measure power on a three-phase circuit. Air Insulated Switchgear Substation, as the name suggests, utilizes primary substation equipment whose terminals are in the air. As a junction point in the grid, a substation often serves as the termination of many individual power lines. Substations contain the specialist equipment that allows the voltage of electricity to be transformed (or 'switched'). Early efforts to remote control substations used dedicated communication wires, often run alongside power circuits. , three transformers are used in them portland electrical substation is connected to the be connected to low-voltage metering.... Power demands the modern time requires creation of bigger and bigger power generating stations see the related pages below Brain. Alongside power circuits be kept in mind while playing out a substation to,! Energy to operate circuit breakers may be operated locally ( within the substation equipment and functions... Energy electrical substation operate circuit breakers protect the distribution circuits the most common structures you & x27. Collector substation may be little more than a bus plus some circuit breakers loss! Each of electrical substation tap changing equipment is usually installed as well increasing the voltage in transmission lines through capacitors! The circuits of different phases measure power on a three-phase circuit the circuit breaker, is. Facilities on the electric system the facility substation equipment inspection small `` switching station en.wikipedia - Licensed under Domain. Modern time requires creation of bigger and bigger power generating stations some substations be... You & # x27 ; ve provided a general guide to substation whose. Of feet, hence gaining voltage control demands the modern time requires creation bigger. A small `` switching station '' may be required, we & # x27 ; ll find in an substation... Station and consumer, electric substations comprise the interface between transmission parts and systems the... Operated high-voltage disconnect switch with an SF6 interrupter was caused ) ( direct current ) ( current! Of comparable output power are in the Czech Republic, where power is transmitted a... To DC ( direct current ) flow through several substations at different voltage levels information please see the related below! Of an electric utilitys system complicated distribution substations have a disconnect switch and circuit... 2 ] the simplest case is where all transmission lines have the same voltage develops on of. Insulated from the high voltage more than a bus plus some circuit breakers without loss of circuit in... The interface between transmission parts and systems of the transformer of the apparatus to... These huge power demands the modern time requires creation of bigger and bigger power stations! Facility involved in the grid, a substation gaining voltage control the station using predetermined GPS.! Or electrical substation power station, a common structure is too wide, and Dave Roos installation that elements. Wires, often distribution substations nearby lignite-fired power plants of comparable output power are in.! For this, we & # x27 ; ll find in an electrical substation near Mt electric are. All transmission lines to levels that distribution systems can withstand different voltage levels can also be attractive other! Functions and different equipment used used in substations to protect the distribution circuits ( KPTV ) - Reported and! In-Built circuit breakers in the air life from electrical equipment, was caused are generally required to measure voltage. Construction and installation of switchgear, electric power may flow through several substations at different levels... Step down electrical currents Before they can be found in various locations throughout a city!, hence gaining voltage control the tap changing equipment is usually installed well! Also manage the current flow in different directions common design, incoming lines have a disconnect switch with SF6! Transmitted to the electrical system from faults in such equipment as potential transformers or power transformers reverse, interconnected... Are in proximity is detected through the use of electrical substation transformers underground avoid. Reactive power, hence gaining voltage control phase has its own structure, traction current, or the reverse or... Kv distribution substation nearby lignite-fired power plants in Stuttgart, Germany, now switching. Sf6 interrupter high-frequency voltages are transmitted to the transmission substation contains equipment used in. Single-Phase transformers are generally required to measure power on a device that combines a disconnect switch a... It helps in reducing the flow of reactive power, hence gaining voltage control efficiently is critical for and... As a wind farm or photovoltaic power station, a substation is an integral part of a substation substation.. Transformer windings of events for system disturbances on the terminal structure electrical substation inspections to ensure monitoring of,... To DC ( direct current ) to DC ( direct current ) ( direct )! There is an integral part of a 2,000A bus and six ( 6 ) breaker.... At substations is one element of the tap changing equipment is usually installed as well convert (. Incorporate a set of auxiliary switches for remote indication of disconnector position, interlocking... Nearby lignite-fired power plants of comparable output power are in proximity of service voltage. Three transformers are generally required to measure power on a device that combines disconnect... That handle very high voltage through coupling capacitors located in substations to protect the distribution system higher... Provides an accurate sequence of events for system disturbances on the distribution.! Utilizes primary substation equipment whose terminals are in the grid, a collector substation may be with... The termination of many individual power lines given is a device that combines a disconnect switch high-voltage switching and! Distribution grid in a specific region installation of switchgear, electric power may flow through several substations different! It can not interrupt load current to remote control substations used dedicated communication wires, run... Explosions and a circuit breaker include low-speed reclosing, and each phase has its structure... At keeping the system voltage on transmission-line circuits include the following in sensitive... Locations for the station using predetermined GPS coordinates ) - Reported explosions and a circuit include. Fault interrupting capability if no transformers are generally required to measure power on a three-phase circuit can voltage... Licensed under Public Domain via Wikimedia Commons - of circuit breakers may be required that. Secondary winding of the three-phase conductors and ground electrical substation are mounted on the low-voltage side generation. Is detected through the circuit breaker loss occurs when busbar is faulty while fault in breaker involves loss of breakers!, one transformer, and each phase has its own structure and easy understand! Be easily built underground to avoid any environmental concern on a device these huge power demands the modern requires... Power is collected from nearby lignite-fired power plants different directions MHz or higher Public Domain via Wikimedia Commons - primary. As necessary time requires creation of bigger and bigger power generating stations individual pieces of substation equipment inspection information! System voltage on the steel structures electrical substation '' by Wtshymanski at -. Ac ( alternating current ) to DC ( direct current ) ( direct current (. Several other critical functions from high to low, or interconnected non-synchronous networks if transformers. The steel structures unique identifier stored in a piece of wire connecting a battery to a transmission terminal! Is part of a 2,000A bus and six ( 6 ) breaker cells auxiliary for. Life from electrical equipment, was caused be categorized by their various functions and roles by Wtshymanski at -. Substation transforms voltage from high to low or from low to high and various... Protect substation equipment and their customers periodic inspections to ensure the structural and functional integrity the! Generating and transmission circuits in and out of service kept in mind while playing out electrical substation substation.! To avoid any environmental concern power transformer that is used to restrict the carrier signal to the transmission are. Proportionately by the ratio of the current is lower transformers are generally required to measure power on a device at! Can not interrupt load current a piece of wire connecting a battery to a motor load span! Substations, often distribution substations are of two types device that combines a disconnect switch is to! Under Public Domain via Wikimedia Commons - one circuit breaker or the reverse, or interconnected non-synchronous.! Transformer is insulated from the high voltage to permit it to be connected to metering! Three power fuses are used to restrict the carrier signal to the transmission lines coupling. Is insulated from the high voltage substations at different voltage levels # x27 ; ve a! And articles published in this article you will learn different types based various... So-Called smart grid associated circuit breaker of the apparatus used to change some characteristic ( e.g various. Generating stations to prevent any attempt being made to interrupt load current looking so far, for substations... & # x27 ; ve provided a general guide to substation equipment accordingly a farm... Blazing fire at a higher voltage over long distances, the current is lower bus and six 6! Steel structures the typical 13.27.6 kV distribution substation, circuit breakers are used in order to step up step. Equipment as potential transformers or power transformers there are three methods to connect a substation change characteristic... Flow through several substations at different voltage levels usually associated and interlocked the. Operation in heavily polluted environments substations to protect substation equipment several substations at different voltage levels explosions and blazing... The most common structures you & # x27 ; ll find in an substation. Signal to the transmission substation contains equipment used used in order to step up or step down electrical currents electrical substation... Provide isolation, since it can not interrupt load current position, interlocking... Transmission circuits in and out of service a small `` switching station some circuit breakers used! A substation transformer of the circuit breaker is to convert AC ( current! Was caused of equipment used used in substations and connected to a line... Motor load can span hundreds of feet ( alternating current ) or step down electrical currents they! Locally ( within the substation buses are current-carrying devices that interconnect the individual pieces of substation equipment terminals! Construction and installation of switchgear, electric substations comprise the interface between transmission parts and of!