Power engineering

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A steam turbine used to provide electric power Dampfturbine Montage01.jpg
A steam turbine used to provide electric power

Power engineering, also called power systems engineering, is a subfield of electrical engineering that deals with the generation, transmission, distribution, and utilization of electric power, and the electrical apparatus connected to such systems. Although much of the field is concerned with the problems of three-phase AC power – the standard for large-scale power transmission and distribution across the modern world – a significant fraction of the field is concerned with the conversion between AC and DC power and the development of specialized power systems such as those used in aircraft or for electric railway networks. Power engineering draws the majority of its theoretical base from electrical engineering and mechanical engineering.

Contents

History

A sketch of the Pearl Street Station, the first steam-powered electric power station in New York City PearlStreetStation.jpg
A sketch of the Pearl Street Station, the first steam-powered electric power station in New York City


Pioneering years

Electricity became a subject of scientific interest in the late 17th century. Over the next two centuries a number of important discoveries were made including the incandescent light bulb and the voltaic pile. [1] [2] Probably the greatest discovery with respect to power engineering came from Michael Faraday who in 1831 discovered that a change in magnetic flux induces an electromotive force in a loop of wire—a principle known as electromagnetic induction that helps explain how generators and transformers work. [3]

In 1881 two electricians built the world's first power station at Godalming in England. The station employed two waterwheels to produce an alternating current that was used to supply seven Siemens arc lamps at 250 volts and thirty-four incandescent lamps at 40 volts. [4] However supply was intermittent and in 1882 Thomas Edison and his company, The Edison Electric Light Company, developed the first steam-powered electric power station on Pearl Street in New York City. The Pearl Street Station consisted of several generators and initially powered around 3,000 lamps for 59 customers. [5] [6] The power station used direct current and operated at a single voltage. Since the direct current power could not be easily transformed to the higher voltages necessary to minimise power loss during transmission, the possible distance between the generators and load was limited to around half-a-mile (800 m). [7]

That same year in London Lucien Gaulard and John Dixon Gibbs demonstrated the first transformer suitable for use in a real power system. The practical value of Gaulard and Gibbs' transformer was demonstrated in 1884 at Turin where the transformer was used to light up forty kilometres (25 miles) of railway from a single alternating current generator. [8] Despite the success of the system, the pair made some fundamental mistakes. Perhaps the most serious was connecting the primaries of the transformers in series so that switching one lamp on or off would affect other lamps further down the line. Following the demonstration George Westinghouse, an American entrepreneur, imported a number of the transformers along with a Siemens generator and set his engineers to experimenting with them in the hopes of improving them for use in a commercial power system.

One of Westinghouse's engineers, William Stanley, recognised the problem with connecting transformers in series as opposed to parallel and also realised that making the iron core of a transformer a fully enclosed loop would improve the voltage regulation of the secondary winding. Using this knowledge he built the world's first practical transformer based alternating current power system at Great Barrington, Massachusetts in 1886. [9] [10] In 1885 the Italian physicist and electrical engineer Galileo Ferraris demonstrated an induction motor and in 1887 and 1888 the Serbian-American engineer Nikola Tesla filed a range of patents related to power systems including one for a practical two-phase induction motor [11] [12] which Westinghouse licensed for his AC system.

By 1890 the power industry had flourished and power companies had built thousands of power systems (both direct and alternating current) in the United States and Europe – these networks were effectively dedicated to providing electric lighting. During this time a fierce rivalry in the US known as the "war of the currents" emerged between Edison and Westinghouse over which form of transmission (direct or alternating current) was superior. In 1891, Westinghouse installed the first major power system that was designed to drive an electric motor and not just provide electric lighting. The installation powered a 100 horsepower (75 kW) synchronous motor at Telluride, Colorado with the motor being started by a Tesla induction motor. [13] On the other side of the Atlantic, Oskar von Miller built a 20 kV 176 km three-phase transmission line from Lauffen am Neckar to Frankfurt am Main for the Electrical Engineering Exhibition in Frankfurt. [14] In 1895, after a protracted decision-making process, the Adams No. 1 generating station at Niagara Falls began transmitting three-phase alternating current power to Buffalo at 11 kV. Following completion of the Niagara Falls project, new power systems increasingly chose alternating current as opposed to direct current for electrical transmission. [15]

Twentieth century

Power engineering and Bolshevism

1929 poster by Gustav Klutsis Klutsis (1929) Soviet Power plus electrification.png
1929 poster by Gustav Klutsis

The generation of electricity was regarded as particularly important following the Bolshevik seizure of power. Lenin stated "Communism is Soviet power plus the electrification of the whole country." [16] He was subsequently featured on many Soviet posters, stamps etc. presenting this view. The GOELRO plan was initiated in 1920 as the first Bolshevik experiment in industrial planning and in which Lenin became personally involved. Gleb Krzhizhanovsky was another key figure involved, having been involved in the construction of a power station in Moscow in 1910. He had also known Lenin since 1897 when they were both in the St. Petersburg chapter of the Union of Struggle for the Liberation of the Working Class.

Power engineering in the USA

In 1936 the first commercial high-voltage direct current (HVDC) line using mercury-arc valves was built between Schenectady and Mechanicville, New York. HVDC had previously been achieved by installing direct current generators in series (a system known as the Thury system) although this suffered from serious reliability issues. [17] In 1957 Siemens demonstrated the first solid-state rectifier (solid-state rectifiers are now the standard for HVDC systems) however it was not until the early 1970s that this technology was used in commercial power systems. [18] In 1959 Westinghouse demonstrated the first circuit breaker that used SF6 as the interrupting medium. [19] SF6 is a far superior dielectric to air and, in recent times, its use has been extended to produce far more compact switching equipment (known as switchgear) and transformers. [20] [21] Many important developments also came from extending innovations in the ICT field to the power engineering field. For example, the development of computers meant load flow studies could be run more efficiently allowing for much better planning of power systems. Advances in information technology and telecommunication also allowed for much better remote control of the power system's switchgear and generators.

Power

Transmission lines transmit power across the grid. Qatar, power lines (6).jpg
Transmission lines transmit power across the grid.

Power Engineering deals with the generation, transmission, distribution and utilization of electricity as well as the design of a range of related devices. These include transformers, electric generators, electric motors and power electronics.

Power engineers may also work on systems that do not connect to the grid. These systems are called off-grid power systems and may be used in preference to on-grid systems for a variety of reasons. For example, in remote locations it may be cheaper for a mine to generate its own power rather than pay for connection to the grid and in most mobile applications connection to the grid is simply not practical.

Fields

Electricity generation covers the selection, design and construction of facilities that convert energy from primary forms to electric power.

Electric power transmission requires the engineering of high voltage transmission lines and substation facilities to interface to generation and distribution systems. High voltage direct current systems are one of the elements of an electric power grid.

Electric power distribution engineering covers those elements of a power system from a substation to the end customer.

Power system protection is the study of the ways an electrical power system can fail, and the methods to detect and mitigate for such failures.

In most projects, a power engineer must coordinate with many other disciplines such as civil and mechanical engineers, environmental experts, and legal and financial personnel. Major power system projects such as a large generating station may require scores of design professionals in addition to the power system engineers. At most levels of professional power system engineering practice, the engineer will require as much in the way of administrative and organizational skills as electrical engineering knowledge.

Professional societies and international standards organizations

In both the UK and the US, professional societies had long existed for civil and mechanical engineers. The Institution of Electrical Engineers (IEE) was founded in the UK in 1871, and the AIEE in the United States in 1884. These societies contributed to the exchange of electrical knowledge and the development of electrical engineering education. On an international level, the International Electrotechnical Commission (IEC), which was founded in 1906, prepares standards for power engineering, with 20,000 electrotechnical experts from 172 countries developing global specifications based on consensus.

See also

Related Research Articles

<span class="mw-page-title-main">Electric power transmission</span> Bulk movement of electrical energy

Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a transmission network. This is distinct from the local wiring between high-voltage substations and customers, which is typically referred to as electric power distribution. The combined transmission and distribution network is part of electricity delivery, known as the electrical grid.

<span class="mw-page-title-main">Alternating current</span> Electric current that periodically reverses direction

Alternating current (AC) is an electric current that periodically reverses direction and changes its magnitude continuously with time, in contrast to direct current (DC), which flows only in one direction. Alternating current is the form in which electric power is delivered to businesses and residences, and it is the form of electrical energy that consumers typically use when they plug kitchen appliances, televisions, fans and electric lamps into a wall socket. The abbreviations AC and DC are often used to mean simply alternating and direct, respectively, as when they modify current or voltage.

<span class="mw-page-title-main">George Westinghouse</span> American engineer and businessman (1846–1912)

George Westinghouse Jr. was a prolific American inventor, engineer, and entrepreneurial industrialist based in Pittsburgh, Pennsylvania who is best known for his creation of the railway air brake and for being a pioneer in the development and use of alternating current (AC) electrical power distribution. During his career, he received 362 patents for his inventions and established 61 companies, many still in existence today.

<span class="mw-page-title-main">Electric generator</span> Device that converts other energy to electrical energy

In electricity generation, a generator is a device that converts motion-based power or fuel-based power into electric power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even hand cranks. The first electromagnetic generator, the Faraday disk, was invented in 1831 by British scientist Michael Faraday. Generators provide nearly all the power for electrical grids.

<span class="mw-page-title-main">Mains electricity</span> Type of lower-voltage electricity most commonly provided by utilities

Mains electricity or utility power, grid power, domestic power, and wall power, or, in some parts of Canada, hydro, is a general-purpose alternating-current (AC) electric power supply. It is the form of electrical power that is delivered to homes and businesses through the electrical grid in many parts of the world. People use this electricity to power everyday items by plugging them into a wall outlet.

<span class="mw-page-title-main">Electric power distribution</span> Final stage of electricity delivery to individual consumers in a power grid

Electric power distribution is the final stage in the delivery of electricity. Electricity is carried from the transmission system to individual consumers. Distribution substations connect to the transmission system and lower the transmission voltage to medium voltage ranging between 2 kV and 33 kV with the use of transformers. Primary distribution lines carry this medium voltage power to distribution transformers located near the customer's premises. Distribution transformers again lower the voltage to the utilization voltage used by lighting, industrial equipment and household appliances. Often several customers are supplied from one transformer through secondary distribution lines. Commercial and residential customers are connected to the secondary distribution lines through service drops. Customers demanding a much larger amount of power may be connected directly to the primary distribution level or the subtransmission level.

<span class="mw-page-title-main">Electric power industry</span> Industry that provides the production and delivery of electric energy

The electric power industry covers the generation, transmission, distribution and sale of electric power to the general public and industry. The commercial distribution of electric power started in 1882 when electricity was produced for electric lighting. In the 1880s and 1890s, growing economic and safety concerns lead to the regulation of the industry. What was once an expensive novelty limited to the most densely populated areas, reliable and economical electric power has become an essential aspect for normal operation of all elements of developed economies.

<span class="mw-page-title-main">William Stanley Jr.</span> American physicist (1858 - 1916)

William Stanley Jr. was an American physicist born in Brooklyn, New York. During his career, he obtained 129 patents covering a variety of electric devices. In 1913, he also patented an all-steel vacuum bottle, and formed the Stanley Bottle Company.

<span class="mw-page-title-main">War of the currents</span> Introduction of competing electric power transmission systems in the late 1880s and early 1890s

The war of the currents was a series of events surrounding the introduction of competing electric power transmission systems in the late 1880s and early 1890s. It grew out of two lighting systems developed in the late 1870s and early 1880s; arc lamp street lighting running on high-voltage alternating current (AC), and large-scale low-voltage direct current (DC) indoor incandescent lighting being marketed by Thomas Edison's company. In 1886, the Edison system was faced with new competition: an alternating current system initially introduced by George Westinghouse's company that used transformers to step down from a high voltage so AC could be used for indoor lighting. Using high voltage allowed an AC system to transmit power over longer distances from more efficient large central generating stations. As the use of AC spread rapidly with other companies deploying their own systems, the Edison Electric Light Company claimed in early 1888 that high voltages used in an alternating current system were hazardous, and that the design was inferior to, and infringed on the patents behind, their direct current system.

<span class="mw-page-title-main">Utility frequency</span> Frequency used on standard electricity grid in a given area

The utility frequency, (power) line frequency or mains frequency is the nominal frequency of the oscillations of alternating current (AC) in a wide area synchronous grid transmitted from a power station to the end-user. In large parts of the world this is 50 Hz, although in the Americas and parts of Asia it is typically 60 Hz. Current usage by country or region is given in the list of mains electricity by country.

Electrification is the process of powering by electricity and, in many contexts, the introduction of such power by changing over from an earlier power source. In the context of history of technology and economic development, electrification refers to the build-out of the electricity generation and electric power distribution systems. In the context of sustainable energy, electrification refers to the build-out of super grids with energy storage to accommodate the energy transition to renewable energy and the switch of end-uses to electricity.

<span class="mw-page-title-main">Switchgear</span> Control gear of an electric power system

In an electric power system, a switchgear is composed of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to be done and to clear faults downstream. This type of equipment is directly linked to the reliability of the electricity supply.

This is an alphabetical list of articles pertaining specifically to electrical and electronics engineering. For a thematic list, please see List of electrical engineering topics. For a broad overview of engineering, see List of engineering topics. For biographies, see List of engineers.

<span class="mw-page-title-main">Folsom Powerhouse State Historic Park</span> United States historic place

Folsom Powerhouse State Historic Park is a historical site preserving an 1895 alternating current (AC) hydroelectric power station—one of the first in the United States.

<span class="mw-page-title-main">Ames Hydroelectric Generating Plant</span>

The Ames Hydroelectric Generating Plant, constructed in 1890 near Ophir, Colorado, was one of the first commercial system to produce and transmit alternating current (AC) electricity for industrial use and one of the first AC hydro-electric plants ever constructed. It became operational in 1891 and was built by Westinghouse Electric around two of their large alternators. One was set up in the valley as a generator and driven by water. It was connected by a 2.6-mile (4.2 km) transmission line to the second alternator used as a motor up at the Gold King Mine to drive the mining operation. The facility has been changed and upgraded over the years but is still in operation. It is now on the List of IEEE Milestones.

<span class="mw-page-title-main">Electric power system</span> Network of electrical component deployed to generate, transmit & distribute electricity

An electric power system is a network of electrical components deployed to supply, transfer, and use electric power. An example of a power system is the electrical grid that provides power to homes and industries within an extended area. The electrical grid can be broadly divided into the generators that supply the power, the transmission system that carries the power from the generating centers to the load centers, and the distribution system that feeds the power to nearby homes and industries.

Electric power transmission, the tools and means of moving electricity far from where it is generated, date back to the late 19th century. They include the movement of electricity in bulk and the delivery of electricity to individual customers ("distribution"). In the beginning, the two terms were used interchangeably.

<span class="mw-page-title-main">Electrical grid</span> Interconnected network for delivering electricity to consumers

An electrical grid is an interconnected network for electricity delivery from producers to consumers. Electrical grids consist of power stations, electrical substations to step voltage up or down, electric power transmission to carry power over long distances, and finally electric power distribution to customers. In that last step, voltage is stepped down again to the required service voltage. Power stations are typically built close to energy sources and far from densely populated areas. Electrical grids vary in size and can cover whole countries or continents. From small to large there are microgrids, wide area synchronous grids, and super grids. The combined transmission and distribution network is part of electricity delivery, known as the power grid.

<span class="mw-page-title-main">René Thury</span> Swiss pioneer in electrical engineering

René Thury was a Swiss pioneer in electrical engineering. He was known for his work with high voltage direct current electricity transmission and was known in the professional world as the "King of DC."

This glossary of electrical and electronics engineering is a list of definitions of terms and concepts related specifically to electrical engineering and electronics engineering. For terms related to engineering in general, see Glossary of engineering.

References

  1. ↑ "The History Of The Light Bulb". Net Guides Publishing, Inc. 2004. Retrieved 2007-05-02.
  2. ↑ Greenslade, Thomas. "The Voltaic Pile". Kenyon College . Retrieved 2008-03-31.
  3. ↑ "Faraday Page". The Royal Institute. Archived from the original on 2008-03-29. Retrieved 2008-03-31.
  4. ↑ "Godalming Power Station". Engineering Timelines. Retrieved 2009-05-03.
  5. ↑ Williams, Jasmin (2007-11-30). "Edison Lights The City". New York Post . Retrieved 2008-03-31.
  6. ↑ Grant, Casey. "The Birth of NFPA". National Fire Protection Association. Archived from the original on 2007-12-28. Retrieved 2008-03-31.
  7. ↑ "Bulk Electricity Grid Beginnings" (PDF) (Press release). New York Independent System Operator. Archived from the original (PDF) on 2009-02-26. Retrieved 2008-05-25.
  8. ↑ Katz, Evgeny (2007-04-08). "Lucien Gaulard". Archived from the original on 2008-04-22. Retrieved 2008-05-25.
  9. ↑ Great Barrington 1886 - Inspiring an industry toward AC power
  10. ↑ Blalock, Thomas (2004-10-02). "Alternating Current Electrification, 1886". IEEE. Archived from the original on January 5, 2008. Retrieved 2008-05-25.
  11. ↑ Froehlich, Fritz E.; Kent, Allen (December 1998). Fritz E. Froehlich, Allen Kent, The Froehlich/Kent Encyclopedia of Telecommunications: Volume 17, page 36. CRC Press. ISBN   9780824729158 . Retrieved 2012-09-10.
  12. ↑ Petar Miljanic, Tesla's Polyphase System and Induction Motor, Serbian Journal of Electrical Engineering, pp. 121–130, Vol. 3, No. 2, November 2006.
  13. ↑ Foran, Jack. "The Day They Turned The Falls On". Archived from the original on 2008-05-11. Retrieved 2008-05-25.
  14. ↑ Voith Siemens (company) (2007-02-01). HyPower (PDF). p. 7. Archived from the original (PDF) on 2012-07-25. Retrieved 2008-05-25.
  15. ↑ "Adams Hydroelectric Generating Plant, 1895". IEEE. Archived from the original on January 5, 2008. Retrieved 2008-05-25.
  16. ↑ Vladimir, Lenin (1920). Our Foreign and Domestic Position and Party Tasks. Moscow. Communism is Soviet power plus the electrification of the whole country, since industry cannot be developed without electrification.{{cite book}}: CS1 maint: location missing publisher (link)
  17. ↑ "A Novel but Short-Lived Power Distribution System". IEEE. 2005-05-01. Archived from the original on 2011-05-24. Retrieved 2008-05-25.
  18. ↑ Gene Wolf (2000-12-01). "Electricity Through the Ages". Transmission & Distribution World.
  19. ↑ John Tyner, Rick Bush and Mike Eby (1999-11-01). "A Fifty-Year Retrospective". Transmission & Distribution World.
  20. ↑ "Gas Insulated Switchgear". ABB. Retrieved 2008-05-25.
  21. ↑ Amin, Sayed. "SF6 Transformer". Archived from the original on 2008-06-16. Retrieved 2008-05-25.
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