The project was the subject of a public open tender in 2004. A highvoltage, direct current hvdc electric power transmission system also called a power superhighway or an electrical superhighway uses direct current for the bulk transmission of electrical power, in contrast with the more common alternating current ac systems. Therefore, the design of line arrester with an external. The purpose of the preliminary design is to advance the project definition from the current conceptual level to a. Easy access for maintenance if located along a roadside. The main supporting unit of overhead transmission line is transmission tower. The itaipu 60 hz 765 kv hvac transmission system is operating over two series compensated lines with the aid of a digital emergency control scheme ecs to match generation and transmission capability in case of disturbances in the electrical system. The hvdc itaipu is a highvoltage direct current overhead line transmission system in brazil from the itaipu hydroelectric power plant to the region of sao paulo. Ac transmission line impedance parameters ac transmission is done through 3phase systems. Large hvdc transmission schemes having power transmission capacities of.
For the 6,300 mw hvdc transmission, detailed studies, including firm bid prices for the converter. Transmission line design manual bureau of reclamation. This type of transmission is preferred over hvac transmission for very long distance when considering the cost, losses and many other. Hvac 3phase lower transmission loss because of no reactive loss lower insulationclearance of conductor dc voltage is about 71% of the ac peak voltage. In 1882, a 50kmlong 2kv dc transmission line was built between miesbach and munich in germany. Pdf design of the dc 500kv full scale transmission test line in. Download ehvac, hvdc transmission and distribution. Simulator insulation coordination ac and arresters thyristor valves computer simulation study design data for all equipment of the hvdcsystem acnetwork. Electrostatic field at ground level and biological effects ehvac and hvdc 39. Full detail design of hvac lines up to 765kv and hvdc up to 800kv providing support to over 31 000 km of transmission lines 220kv,275kv,400kv, 533kvhvdc, 765kv 340 000 km of distribution lines 11kv, 22kv,66kv, 88kv,2kv, busy with designs for over 8. Printed circuits handbook, seventh edition pdf clyde f.
There are various types of hvdc power supply designs available in the market, including voltage doubler or quadrupler, flyback converter and boost converter. The availability of transformers and the development and improvement of induction motors at the beginning of the 20th century, led to the use of ac transmission. Basic concept operation and control of hvdc transmission. A simplified 2d model of the transmission lines, and tower were considered in the electrostatic simulations. Therefore dc transmission system have improved transient stability. This is due to the many advantages associated with hvdc transmission as explained in chapter two of this project.
Circuits like geiger counters, insect zappers, nixie tubes and sensors require highvoltage directcurrent hvdc supplies. Hvdc transmission systems unit1 introduction electric power transmission was originally developed with direct current. In addition to that all towers have to sustain all kinds of natural calamities. The filter calculations must reflect detuning caused by ac network. The report will not deal however with short distance hvdc power cables that connect offshore wind farms or oil extraction platforms to the continent. The massive transmission of electricity in the form of dc over long distances by means of submarine cables or overhead transmission line is the high voltage direct current transmission. The variables effecting hvdc tower height and row width are very complex and interdependent as shown in fig. Thus the design of tangent tower provides the greatest opportunity for the structural engineer to minimise the total weight of steel required.
Towers for transmission line and substation structures. For longdistance transmission, hvdc systems may be less expensive and have lower electrical losses. Basic concept, operation and control of hvdc transmission system. Western alberta transmission line watl hvdc project. A new approach for compaction of hvdc transmission lines. For longdistance power transmission, hvdc lines are less expensive, and losses are less as compared to ac transmission. Conductor sag is the principle factor effecting tower height for a given. Igbt insulatedgate bipolar transistor ln2 liquid nitrogen lts lowtemperature superconductor ltt. Beginning with a brief historical perspective on the development of high voltage direct current hvdc transmission systems, this paper presents an overview of the status of hvdc systems in the world today. With the changes in demands due to evolving environmental needs, hvdc has become a common tool in the design of future global transmission grids. Ieee power transmission and distribution standards. Introduction the concept of high voltage direct current hvdc power transmission emerged in the mid1920s for reliable and economic transmission of bulk power to longer distances as well as for undersea applications. This project is currently moving from the conceptual stage to a preliminary design and estimate stage.
Hvdc transmission is preferred over hvac transmission for power transmission over long distances. Igbt insulatedgate bipolar transistor ln2 liquid nitrogen lts lowtemperature superconductor ltt lighttriggered thyristor. Pdf development of 660kv dc transmission line arrester. During the first 30 years, it was a niche technology, with a limited number of installations per year. Hvdc transmission system basics, block diagram, working. Pdf a hvdc test line that functions as a prototype variation was constructed in. The contract for commercial transmission in the island of gotland has been signed. What is hvdc high voltage direct current transmission. High voltage direct current hvdc power systems use d. Hvdc highvoltage direct current ieee institute of electrical and electronic engineers, inc. A transmission tower or power tower alternatively electricity pylon or variations is a tall structure, usually a steel lattice tower, used to support an overhead power line they are used in highvoltage ac and dc systems, and come in a wide variety of shapes and sizes. Sag and tension calculation form for example problem on sag template metric. Electrical transmission tower types and design electrical4u. Design considerations of ultra high voltage dc system.
Engineer level 8 technical analysis foreign power purchase agreement branch power purchase agreement division electricity generating authority of thailand. Green energy corridor and grid strengthening 320 kv. A test transmission using this principle was put in service in 1996. Hvdc transmission, transmission line design, compact transmission, right of. The support towers were also design taking into considerations the values of transmission voltage, sag obtained, insulation lengths and minimum clearance of the line conductors from the ground the designed transmission line required two converter stations. To minimize the adverse effects of high voltage electric power transmission lines, new. Since hvdc requires no charging current and the reactive power, it is. High voltage direct current hvdctransmission systems. Tower construction area is reduced by 25% for impact calculations because of overlap with. Both of these circuits are also called converter circuits. Design project for 500 kv hvdc transmission line from.
Typical height ranges from 15 to 55 m 49 to 180 ft, though the tallest are the 370 m 1,214 ft towers of a 2,700 m. The figure does not relate to design procedures but illustrates that virtually every design variable effects either tower height, row width, or both and. Design, control and application of modular multilevel. So protections, fault clearance can be implemented faster than hvac. Type here the title of your paper semantic scholar. Pdf in order to improve the lightning withstand level of 660 kv dc transmission line in china, the. Western alberta transmission line watl hvdc project client.
The design, construction, and operation of longdistance high. An overview article pdf available in ieee transactions on power electronics 243. Influence of high voltage dc power lines on metallic pipelines. Ieee std 10702006 r2012, design and testing of transmission modular restoration structure components ieee 11242003 r2010, ieee guide for analysis and definition of dc side harmonic performance of hvdc transmission systems ieee 11592009, ieee recommended practice for monitoring electric power quality. Cross border electricity transmission with high voltage direct current hvdc executive exchange dhaka basic design process s p e c i f i c a t i o n main transmission data p dc u dc i dc etc. Hvdc was an obvious choice for the transmission system, due to the asynchronous networks and the long distance under water. Transmission towers have to carry the heavy transmission conductor at a sufficient safe height from ground. In case of faults, power levels on hvdc system can be controlled electronically i. Teshmont consultants lp 2016 acec canada awards 9 by selecting hvdc to interconnect the two largest load centres in the province, watl will help to improve the overall reliability of electricity supply to consumers in these centres and in the province. One of the important power electronics field application is high voltage dc hvdc transmission system. Hvdc power transmission systems high voltage direct current hvdc power transmission systems. The use of this report or any information contained will be at the users sole risk, regardless of any fault or negligence of hvdc transmission line task group, capp or its cofunders. Transmission line design information in these notes, i would like to provide you with some background information on ac transmission lines. Hvdc transmission system advantages, disadvantages over hvac.
High voltage direct current transmission brown university. Markus pettersson, september 22, 2016 plnabb power. Lightning overvoltages in a hvdc transmission system. Hvdc converter station with ac filters in the foreground and valve hall in the background. This project thus involved the design of a hvdc transmission line to transmit power between ethiopia and kenya. So transmission tower designing is an important engineering job where all three basic engineering concepts, civil, mechanical. At that time, conversion between reasonable consumer voltages and higher dc transmission voltages. The general design criteria for ac and dc transmission lines can be divided into. The transmission will have a rating of 60 mva and 50 mw. New control approaches are proposed that significantly reduce the dc side overvoltage and consequently minimize the required air clearances for maximum compaction of the hvdc overhead. Terminal design the hvdc terminal is an integral part of the hvdc sys. Hvdc power supply design detailed electronics project. If the transmission line traverses relatively flat, featureless terrain, 90 percent of the line may be composed of this type of tower. Hvdc light design aspects it was decided to base the hvdc light design on a modular concept with a number of standardized sizes, 10100 mw.
932 1538 536 815 678 1376 967 381 444 1438 378 319 395 1160 610 1563 943 813 892 680 1287 388 254 1017 870 1393 1398 417 452 1559 1137 1298 930 1469 111 996 553 1228 1144 598 1236 1276 197 1260 562