History of electric power transmission

Last updated

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 (formally called "transmission") and the delivery of electricity to individual customers ("distribution"). In the beginning, the two terms were used interchangeably.

Contents

Early transmission

Berlin, 1884. With double the brilliance of gaslight, arc lamps were in high demand for stores and public areas. Arc lighting circuits used up to thousands of volts with arc lamps connected in series. Carl Saltzmann Erste elektrische Strassenbeleuchtung.jpg
Berlin, 1884. With double the brilliance of gaslight, arc lamps were in high demand for stores and public areas. Arc lighting circuits used up to thousands of volts with arc lamps connected in series.

Prior to electricity, various systems had been used for transmission of power across large distances. Chief among them were telodynamic (cable in motion), pneumatic (pressurized air), and hydraulic (pressurized liquid) transmission. [1] Cable cars were the most frequent example of telodynamic transmission, whose lines could extend for several miles for a single section. Pneumatic transmission was used for city power transmission systems in Paris, Birmingham, Rixdorf, Offenbach, Dresden and Buenos Aires at the beginning of the twentieth century. Cities in the 19th century also used hydraulic transmission using high pressure water mains to deliver power to factory motors. London's system delivered 7,000 horsepower (5.2 MW) over a 180-mile (290 km) network of pipes carrying water at 800 pounds per square inch (5.5 MPa). These systems were replaced by cheaper and more versatile electrical systems, but by the end of the 19th century, city planners and financiers were well aware of the benefits, economics, and process of establishing power transmission systems.

In the early days of electric power usage, widespread transmission of electric power had two obstacles. First, devices requiring different voltages required specialized generators with their own separate lines. Street lights, electric motors in factories, power for streetcars and lights in homes are examples of the diversity of devices with voltages requiring separate systems. Secondly, generators had to be relatively near their loads (a mile or less for low voltage devices). It was known that longer distance transmission was possible the higher the voltage was raised, so both problems could be solved if transforming voltages from a single universal power line could be done efficiently.

Specialized systems

Streetcars created enormous demand for early electricity. This Siemens Tram from 1884 required 500 V direct current, which was typical. Electric tram- Siemens 1884 in Frankfurt.jpg
Streetcars created enormous demand for early electricity. This Siemens Tram from 1884 required 500 V direct current, which was typical.

Much of early electricity was direct current, which could not easily be increased or decreased in voltage either for long-distance transmission or for sharing a common line to be used with multiple types of electric devices. Companies simply ran different lines for the different classes of loads their inventions required. For example, Charles Brush's New York arc lamp systems required up to 10 kV for many lamps in a series circuit, Edison's incandescent lights used 110 V, streetcars built by Siemens or Sprague required large motors in the 500 volt range, [2] whereas industrial motors in factories used still other voltages. [3] Due to this specialization of lines, and because transmission was so inefficient, it seemed at the time that the industry would develop into what is now known as a distributed generation system with large numbers of small generators located near their loads. [4]

Early high voltage exterior lighting

High voltage was of interest to early researchers working on the problem of transmission over distance. They knew from elementary electricity principle that the same amount of power could be transferred on a cable by doubling the voltage and halving the current. Due to Joule's Law, they also knew that the power lost from heat in a wire is proportional to the square of the current traveling on it, regardless the voltage, and so by doubling the voltage, the same cable would be capable of transmitting the same amount of power four times the distance.

At the Paris Exposition of 1878, electric arc lighting had been installed along the Avenue de l'Opera and the Place de l'Opera, using electric Yablochkov arc lamps, powered by Zénobe Gramme alternating current dynamos. [5] [6] [7] Yablochkov candles required high voltage, and it was not long before experimenters reported that the arc lamps could be powered on a 14-kilometre (8.7 mi) circuit. [8] Within a decade scores of cities would have lighting systems using a central power plant that provided electricity to multiple customers via electrical transmission lines. These systems were in direct competition with the dominant gaslight utilities of the period. [9]

Brush Electric Company's central power plant dynamos powered arc lamps for public lighting in New York. Beginning operation in December 1880 at 133 West Twenty-Fifth Street, it powered a 2-mile (3.2 km) long circuit. Brush central power station dynamos New York 1881.jpg
Brush Electric Company's central power plant dynamos powered arc lamps for public lighting in New York. Beginning operation in December 1880 at 133 West Twenty-Fifth Street, it powered a 2-mile (3.2 km) long circuit.

The idea of investing in a central plant and a network to deliver energy produced to customers who pay a recurring fee for service was familiar business model for investors: it was identical to the lucrative gaslight business, or the hydraulic and pneumatic power transmission systems. The only difference was the commodity being delivered was electricity, not gas, and the "pipes" used for delivering were more flexible.

The California Electric Company (now PG&E) in San Francisco in 1879 used two direct current generators from Charles Brush's company to supply multiple customers with power for their arc lamps. This San Francisco system was the first case of a utility selling electricity from a central plant to multiple customers via transmission lines. [11] CEC soon opened a second plant with 4 additional generators. Service charges for light from sundown to midnight was $10 per lamp per week. [9] [12]

Grand Rapids Electric Light & Power Company, established in March 1880 by William T. Powers and others, began operation of the world's first commercial central station hydroelectric power plant, Saturday, July 24, 1880, getting power from Wolverine Chair and Furniture Company's water turbine. It operated a 16-light Brush electric dynamo lighting several storefronts in Grand Rapids, Michigan. [13] [14] It is the earliest predecessor of Consumers Energy of Jackson, Michigan.

In December 1880, Brush Electric Company set up a central station to supply a 2-mile (3.2 km) length of Broadway with arc lighting. By the end of 1881, New York, Boston, Philadelphia, Baltimore, Montreal, Buffalo, San Francisco, Cleveland and other cities had Brush arc lamp systems, producing public light well into the 20th century. [15] By 1893 there were 1500 arc lamps illuminating New York streets. [16]

Direct current lighting

Early arc lights were extremely bright and the high voltages presented a sparking/fire hazard, making them too dangerous to use indoors. [17] In 1878 inventor Thomas Edison saw a market for a system that could bring electric lighting directly into a customer's business or home, a niche not served by arc lighting systems. [18] After devising a commercially viable incandescent light bulb in 1879, Edison went on to develop the first large scale investor-owned electric illumination "utility" in lower Manhattan, eventually serving one square mile with 6 "jumbo dynamos" housed at Pearl Street Station. [7] [9] [19] [20] When service began in September 1882, there were 85 customers with 400 light bulbs. Each dynamo produced 100 kW enough for 1200 incandescent lights, and transmission was at 110 V via underground conduits. The system cost $300,000 to build with installation of the 100,000 feet (30,000 m) of underground conduits one of the most expensive parts of the project. Operating expenses exceeded income in the first two years and fire destroyed the plant in 1890. [21] Further, Edison had a three wire system so that either 110 V or 220 V could be supplied to power some motors.

Availability of large-scale generation

Availability of large amounts of power from diverse locations would become possible after Charles Parsons' production of turbogenerators beginning 1889. Turbogenerator output quickly jumped from 100 kW to 25 megawatts in two decades. [22] Prior to efficient turbogenerators, hydroelectric projects were a significant source of large amounts of power requiring transmission infrastructure.

Transformers and alternating current

When George Westinghouse became interested in electricity, he quickly and correctly concluded that Edison's low voltages were too inefficient to be scaled up for transmission needed for large systems. He further understood that long-distance transmission needed high voltage and that inexpensive conversion technology only existed for alternating current. Transformers would play the decisive role in the victory of alternating current over direct current for transmission and distribution systems. [23] In 1876, Pavel Yablochkov patented his mechanism of using induction coils to serve as a step up transformer prior to the Paris Exposition demonstrating his arc lamps. In 1881, Lucien Gaulard and John Dixon Gibbs developed a more efficient device which they dubbed the secondary generator, namely an early step down transformer whose ratio could be adjusted by configuring the connections between a series of wired bobbins around a spindle, from which an iron core could be added or removed as necessary to vary the power output. The device was subject to various critisims and was occasionally misunderstood as only providing a 1:1 turn ratio. [7] [24] [25]

The Hungarian "ZBD" Team (Karoly Zipernowsky, Otto Blathy, Miksa Deri). They were the inventors of the first high efficiency, closed core shunt connection transformer. The three also invented the modern power distribution system: Instead of former series connection they connect transformers that supply the appliances in parallel to the main line. ZBD team.jpg
The Hungarian "ZBD" Team (Károly Zipernowsky, Ottó Bláthy, Miksa Déri). They were the inventors of the first high efficiency, closed core shunt connection transformer. The three also invented the modern power distribution system: Instead of former series connection they connect transformers that supply the appliances in parallel to the main line.

The first demonstrative long-distance (34 km, 21 mi) AC line was built for the 1884 International Exhibition of Turin, Italy. It was powered by a 2-kV, 130-Hz Siemens & Halske alternator and featured several Gaulard secondary generators with their primary windings connected in series, which fed incandescent lamps. The system proved the feasibility of AC electric power transmission over long distances. [7] Between 1884 and 1885, Hungarian engineers Zipernowsky, Bláthy, and Déri from the Ganz company in Budapest created the efficient "Z.B.D." closed-core coils, as well as the modern electric distribution system. The three had discovered that all former coreless or open-core devices were incapable of regulating voltage, and were therefore impractical. Their joint patent described two versions of a design with no poles: the "closed-core transformer" and the "shell-core transformer". [26] [27] Ottó Bláthy suggested the use of closed-cores, Károly Zipernowsky the use of shunt connections, and Miksa Déri performed the experiments. [7] [28] The new ZBD transformers were 3.4 times more efficient than the open-core bipolar devices of Gaulard and Gibbs. [29]

In the closed-core transformer the iron core is a closed ring around which the two coils are wound. In the shell type transformer, the windings are passed through the core. In both designs, the magnetic flux linking the primary and secondary windings travels almost entirely within the iron core, with no intentional path through air. The core consists of iron strands or sheets. These revolutionary design elements would finally make it technically and economically feasible to provide electric power for lighting in homes, businesses and public spaces. [30] Ottó Bláthy also discovered the transformer formula, Vs/Vp = Ns/Np. [31] Electrical and electronic systems the world over rely on the principles of the original Ganz transformers. The inventors are also credited with the first use of the word "transformer" to describe a device for altering the EMF of an electric current. [30] [32]

A very first operative AC line was put into service in 1885 in via dei Cerchi, Rome, Italy, for public lighting. It was powered by two Siemens & Halske alternators rated 30 hp (22 kW), 2 kV at 120 Hz and used 200 series-connected Gaulard 2-kV/20-V step-down transformers provided with a closed magnetic circuit, one for each lamp. Few months later it was followed by the first British AC system, which was put into service at the Grosvenor Gallery, London. It also featured Siemens alternators and 2.4-kV/100-V step-down transformers, one per user, with shunt-connected primaries. [33]

The concept that is the basis of modern transmission using inexpensive step up and step down transformers was first implemented by Westinghouse, William Stanley, Jr. and Franklin Leonard Pope in 1886 in Great Barrington, Massachusetts, resorting also to European technology. [34] [35] In 1888 Westinghouse also licensed Nikola Tesla's induction motor which they would eventually develop into a usable (2-phase) AC motor. The modern 3-phase system was developed by Mikhail Dolivo-Dobrovolsky and Allgemeine Elektricitäts-Gesellschaft and Charles Eugene Lancelot Brown in Europe, starting in 1889. [3] [33]

The International Electro-Technical Exhibition of 1891, in Frankfurt, Germany, featured the long-distance transmission of high-power, three-phase electric current. It was held between 16 May and 19 October on the disused site of the three former “Westbahnhöfe” (Western Railway Stations) in Frankfurt am Main. The exhibition featured the first long-distance transmission of high-power, three-phase electric current, which was generated 175 km away at Lauffen am Neckar. It successfully operated motors and lights at the fair. When the exhibition closed, the power station at Lauffen continued in operation, providing electricity for the administrative capital, Heilbronn, making it the first place to be equipped with three-phase AC power. Many corporate technical representatives (including E.W. Rice of Thomson-Houston Electric Company (what became General Electric)) attended. [36] The technical advisers and representatives were impressed. As a result of the successful field trial, three-phase current, as far as Germany was concerned, became the most economical means of transmitting electrical energy.

The simplicity of polyphase generators and motors meant that besides their efficiency they could be manufactured cheaply, compactly and would require little attention to maintain. Simple economics would drive the expensive, bulky and mechanically complex DC dynamos to their ultimate extinction. As it turned out, the deciding factor in the war of the currents was the availability of low cost step up and step down transformers that meant that all customers regardless of their specialized voltage requirements could be served at minimal cost of conversion. This "universal system" is today regarded as one of the most influential innovations for the use of electricity. [3]

High voltage direct current transmission

The case for alternating current was not clear at the turn of the century and high voltage direct current transmission systems were successfully installed without the benefit of transformers. Rene Thury, who had spent six months at Edison's Menlo Park facility, understood his problem with transmission and was convinced that moving electricity over great distances was possible using direct current. He was familiar with the work of Marcel Deprez, who did early work on high voltage transmission after being inspired by the capability of arc lamp generators to support lights over great distances. [37] [38] Deprez avoided transformers by placing generators and loads in series [37] as arc lamp systems of Charles F. Brush did. Thury developed this idea into the first commercial system for high-voltage DC transmission. Like Brush's dynamos, current is kept constant, and when increasing load demands more pressure, voltage is increased. The Thury System was successfully used on several DC transmission projects from Hydro generators. The first in 1885 was a low voltage system in Bözingen, [39] and the first high voltage system went into service in 1889 in Genoa, Italy, by the Acquedotto de Ferrari-Galliera company. This system transmitted 630 kW at 14 kV DC over a circuit 120 km long. [40] [41] The largest Thury System was the Lyon Moutiers project that was 230 km in length, eventually delivering 20 megawatts, at 125 kV. [37] [38] [42]

Victory for AC

Ultimately, the versatility of the Thury system was hampered by the fragility of series distribution, and the lack of a reliable DC conversion technology that would not show up until the 1940s with improvements in mercury arc valves. The AC "universal system" won by force of numbers, proliferating systems with transformers both to couple generators to high-voltage transmission lines, and to connect transmission to local distribution circuits. By a suitable choice of utility frequency, both lighting and motor loads could be served. Rotary converters and later mercury-arc valves and other rectifier equipment allowed DC load to be served by local conversion where needed. Even generating stations and loads using different frequencies could also be interconnected using rotary converters. By using common generating plants for every type of load, important economies of scale were achieved, lower overall capital investment was required, load factor on each plant was increased allowing for higher efficiency, allowing for a lower cost of energy to the consumer and increased overall use of electric power.

By allowing multiple generating plants to be interconnected over a wide area, electricity production cost was reduced. The most efficient available plants could be used to supply the varying loads during the day. Reliability was improved and capital investment cost was reduced, since stand-by generating capacity could be shared over many more customers and a wider geographic area. Remote and low-cost sources of energy, such as hydroelectric power or mine-mouth coal, could be exploited to lower energy production cost. [43]

The first transmission of three-phase alternating current using high voltage took place in 1891 during the international electricity exhibition in Frankfurt. A 15 kV transmission line connected Lauffen on the Neckar and Frankfurt am Main, 175 km (109 mi) apart. [33] [44]

Willamette Falls to Niagara Falls

In 1882, the German Miesbach–Munich Power Transmission used 2kV DC over 57 km (35 mi). In 1889, the first long-distance transmission of DC electricity in the United States was switched on at Willamette Falls Station, in Oregon City, Oregon. [45] In 1890, a flood destroyed the power station. This unfortunate event paved the way for the first long-distance transmission of AC electricity in the world when Willamette Falls Electric company installed experimental AC generators from Westinghouse in 1890.

That same year, the Niagara Falls Power Company (NFPC) and its subsidiary Cataract Company formed the International Niagara Commission composed of experts, to analyze proposals to harness Niagara Falls to generate electricity. The commission was led by Sir William Thomson (later Lord Kelvin) and included Eleuthère Mascart from France, William Unwin from England, Coleman Sellers from the US, and Théodore Turrettini from Switzerland. It was backed by entrepreneurs such as J. P. Morgan, Lord Rothschild, and John Jacob Astor IV. Among 19 proposals, they even briefly considered compressed air as a power transmission medium, but preferred electricity. They could not decide which method would be best overall.

By 1893 the Niagara Falls Power Company had rejected the remaining proposals from a half dozen companies and awarded the generating contract to Westinghouse with further transmission lines and transformer contracts awarded to General Electric. [46] [47] Work began in 1893 on the Niagara Falls generation project: 5,000 horsepower (3,700 kW) was to be generated and transmitted as alternating current, at a frequency of 25 Hz to minimize impedance losses in transmission (changed to 60 Hz in the 1950s).

Westinghouse also had to develop a system based on rotary converters to allow them to supply all the needed power standards including single phase and polyphase AC and DC for street cars and factory motors. Westinghouse's initial customer for the power from the hydroelectric generators at the Edward Dean Adams Station at Niagara in 1895 were the plants of the Pittsburgh Reduction Company which needed large quantities of cheap electricity for smelting aluminum. [48] On November 16, 1896, electrical power transmitted to Buffalo began powering its street cars. The generating plants were built by Westinghouse Electric Corporation. The scale of the project had General Electric also contributing, building transmission lines and equipment. [48] That same year Westinghouse and General Electric signed a patent sharing agreement, ending some 300 lawsuits the companies were involved in over their competing electrical patents, and giving them monopolistic control over the US electric power industry for years to come. [49]

Initially transmission lines were supported by porcelain pin-and-sleeve insulators similar to those used for telegraphs and telephone lines. However, these had a practical limit of 40 kV. In 1907, the invention of the disc insulator by Harold W. Buck of the Niagara Falls Power Corporation and Edward M. Hewlett of General Electric allowed practical insulators of any length to be constructed for higher voltages.

Early 20th century

The first 110 kV transmission line in Europe was built around 1912 between Lauchhammer and Riesa, German Empire. Original pole. BTU Cottbus 100 kV Tragmast.jpg
The first 110 kV transmission line in Europe was built around 1912 between Lauchhammer and Riesa, German Empire. Original pole.

Voltages used for electric power transmission increased throughout the 20th century. [50] The first "high voltage" AC power station, rated 4-MW 10-kV 85-Hz, was put into service in 1889 by Sebastian Ziani de Ferranti at Deptford, London. [33] The first electric power transmission line in North America operated at 4000 V. It went online on June 3, 1889, with the lines between the generating station at Willamette Falls in Oregon City, Oregon, and Chapman Square in downtown Portland, Oregon stretching about 13 miles. [51] By 1914 fifty-five transmission systems operating at more than 70,000 V were in service, and the highest voltage then used was 150 kV. [52] The first three-phase alternating current power transmission at 110 kV took place in 1907 between Croton and Grand Rapids, Michigan. Voltages of 100 kV and more were not established technology until around 5 years later, with for example the first 110 kV line in Europe between Lauchhammer and Riesa, Germany, in 1912.

In the early 1920s the Pit RiverCottonwood – Vaca-Dixon line was built for 220 kV transporting power from hydroelectric plants in the Sierra Nevada to the San Francisco Bay Area, at the same time the Big CreekLos Angeles lines were upgraded to the same voltage. Both of those systems entered commercial service in 1923. On April 17, 1929 the first 220 kV line in Germany was completed, running from Brauweiler near Cologne, over Kelsterbach near Frankfurt, Rheinau near Mannheim, Ludwigsburg–Hoheneck near Austria. This line comprises the North-South interconnect, at the time one of the world's largest power systems. The masts of this line were designed for eventual upgrade to 380 kV. However the first transmission at 380 kV in Germany was on October 5, 1957 between the substations in Rommerskirchen and Ludwigsburg–Hoheneck.

The world's first 380 kV power line was built in Sweden, the 952 km HarsprångetHallsberg line in 1952. In 1965, the first extra-high-voltage transmission at 735 kV took place on a Hydro-Québec transmission line. [53] In 1982 the first transmission at 1200 kV was in the Soviet Union.

The rapid industrialization in the 20th century made electrical transmission lines and grids a critical part of the economic infrastructure in most industrialized nations. Interconnection of local generation plants and small distribution networks was greatly spurred by the requirements of World War I, where large electrical generating plants were built by governments to provide power to munitions factories; later these plants were connected to supply civil load through long-distance transmission. [54]

Small municipal electrical utilities did not necessarily desire to reduce the cost of each unit of electricity sold; to some extent, especially during the period 1880–1890, electrical lighting was considered a luxury product and electric power was not substituted for steam power. Engineers such as Samuel Insull in the United States and Sebastian Z. De Ferranti in the United Kingdom were instrumental in overcoming technical, economic, regulatory and political difficulties in development of long-distance electric power transmission. By introduction of electric power transmission networks, in the city of London the cost of a kilowatt-hour was reduced to one-third in a ten-year period. [55]

In 1926 electrical networks in the United Kingdom began to be interconnected in the National Grid, initially operating at 132 kV.

Power electronics

Power electronics is the application of solid-state electronics to the control and conversion of electric power. Power electronics started with the development of the mercury arc rectifier. Invented by Peter Cooper Hewitt in 1902, it was used to convert alternating current (AC) into direct current (DC). From the 1920s on, research continued on applying thyratrons and grid-controlled mercury arc valves to power transmission. Uno Lamm developed a mercury valve with grading electrodes making them suitable for high voltage direct current power transmission. In 1933 selenium rectifiers were invented. [56]

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">Three-phase electric power</span> Common electrical power generation, transmission and distribution method for alternating currents

Three-phase electric power is a common type of alternating current (AC) used in electricity generation, transmission, and distribution. It is a type of polyphase system employing three wires and is the most common method used by electrical grids worldwide to transfer power.

<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">Direct current</span> Unidirectional flow of electric charge

Direct current (DC) is one-directional flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors, insulators, or even through a vacuum as in electron or ion beams. The electric current flows in a constant direction, distinguishing it from alternating current (AC). A term formerly used for this type of current was galvanic current.

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

George Westinghouse Jr. was an American entrepreneur and engineer based in Pennsylvania who created the railway air brake and was a pioneer of the electrical industry, receiving his first patent at the age of 19. Westinghouse saw the potential of using alternating current for electric power distribution in the early 1880s and put all his resources into developing and marketing it. This put Westinghouse's business in direct competition with Thomas Edison, who marketed direct current for electric power distribution. In 1911 Westinghouse received the American Institute of Electrical Engineers's (AIEE) Edison Medal "For meritorious achievement in connection with the development of the alternating current system". He founded the Westinghouse Electric Corporation in 1886.

<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">Alternator</span> Device converting mechanical into electrical energy

An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature. Occasionally, a linear alternator or a rotating armature with a stationary magnetic field is used. In principle, any AC electrical generator can be called an alternator, but usually the term refers to small rotating machines driven by automotive and other internal combustion engines.

<span class="mw-page-title-main">Single-phase electric power</span> Type of electric power distribution

In electrical engineering, single-phase electric power is the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison. Single-phase distribution is used when loads are mostly lighting and heating, with few large electric motors. A single-phase supply connected to an alternating current electric motor does not produce a rotating magnetic field; single-phase motors need additional circuits for starting, and such motors are uncommon above 10 kW in rating.

<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">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.

<span class="mw-page-title-main">Power engineering</span> Subfield of electrical engineering

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.

<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.

<span class="mw-page-title-main">Electrical grid</span> Interconnected network for delivering electricity from suppliers 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.

<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. Edwin James Houston; Arthur Edwin Kennelly (1896). The Electric Motor and the Transmission Power. The W. J. Johnston Company. p.  14 . Retrieved 2009-01-07.
  2. Jim Harter (2005). World Railways of the Nineteenth Century. JHU Press. p. 488. ISBN   978-0-8018-8089-6.
  3. 1 2 3 Thomas P. Hughes (1993). Networks of Power: Electrification in Western Society, 1880–1930. Baltimore: Johns Hopkins University Press. pp. 119–22. ISBN   978-0-8018-4614-4.
  4. "Electricity Transmission: A primer" (PDF). National Council on Electricity Policy. Archived from the original (PDF) on 2008-12-01. Retrieved 2009-01-06.
  5. David Oakes Woodbury (1949). A Measure for Greatness: A Short Biography of Edward Weston. McGraw-Hill. p. 83. Retrieved 2009-01-04.
  6. John Patrick Barrett (1894). Electricity at the Columbian Exposition. R. R. Donnelley & sons company. p.  1 . Retrieved 2009-01-04.
  7. 1 2 3 4 5 Guarnieri, M. (2013). "The Beginning of Electric Energy Transmission: Part One". IEEE Industrial Electronics Magazine. 7 (1): 57–60. doi:10.1109/MIE.2012.2236484. S2CID   45909123.
  8. Engineers, Institution of Electrical (1880-03-24). "Notes on the Jablochkoff System of Electric Lighting". Journal of the Society of Telegraph Engineers. IX (32): 143. Retrieved 2009-01-07.
  9. 1 2 3 Guarnieri, M. (2013). "Switching the Light: From Chemical to Electrical" (PDF). IEEE Industrial Electronics Magazine. 9 (3): 44–47. doi:10.1109/MIE.2015.2454038. hdl: 11577/3164116 . S2CID   2986686.
  10. Gorman, Mel. "Charles F. Brush and the First Public Electric Street Lighting System in America". Ohio History Connection. Ohio History Center. Retrieved 25 May 2021.
  11. Richard Shelton Kirby; Frances A. Davis (1990). Engineering in History. Courier Dover Publications. p. 358. ISBN   978-0-486-26412-7 . Retrieved 2009-01-04.
  12. PG&E passage no longer available quoted in blog. "PG&E: Our History" . Retrieved 2009-01-04. At 27, George Roe had founded the first electric company in the PG&E family tree. By September [1879] a little building at Fourth and Market was completed and two tiny Brush arc-light dynamos were installed. Together they could supply 21 lights. Customers were lured by the unabashed offer of service from sundown to midnight (Sundays and holidays excluded) for $10 per lamp per week. Yet in light-hungry San Francisco, customers came clamoring. By the first of the next year, four more generators with capacity of more than 100 lights had been added. Electricity had come to the West.
  13. "Energy Timelines Hydropower".
  14. "History of Hydropower Department of Energy".
  15. Charles Francis Brush. Hebrew University of Jerusalem. Archived from the original on 2009-02-24. Retrieved 2009-01-04.
  16. Richard Dennis (2008). Cities in Modernity: Representations and Productions of Metropolitan Space, 1840–1930. Cambridge University Press. p. 132. ISBN   978-0-521-46470-3 . Retrieved 2009-01-04.
  17. The First Form of Electric Light History of the Carbon Arc Lamp (1800–1980s)
  18. Howard B. Rockman, Intellectual Property Law for Engineers and Scientists, John Wiley – 2004, p. 131
  19. Ahmad Faruqui, Kelly Eakin, Pricing in Competitive Electricity Markets, Springer Science & Business Media – 2000, p. 67
  20. "A brief history of Con Edison: 'Electricity'". Coned.com. January 1, 1998. Archived from the original on October 30, 2012. Retrieved December 31, 2013.
  21. "Pearl Street Station". IEEE Global History Network. Institute of Electrical and Electronics Engineers . Retrieved 2009-01-04.
  22. Vaclav Smil (2005). Creating the Twentieth Century: Technical Innovations of 1867–1914 and Their Lasting Impact . Oxford University Press. p.  65. ISBN   978-0-19-516874-7 . Retrieved 2009-01-03. Transformer coltman 1988.
  23. Coltman, J. W. (January 1988). "The Transformer". Scientific American. pp. 86–95. OSTI   6851152.
  24. Stanley Transformer. Los Alamos National Laboratory; University of Florida. Archived from the original on 2009-01-19. Retrieved 2009-01-09.
  25. Thomas Parke Hughes, Networks of Power: Electrification in Western Society, 1880–1930, p. 89, (1993)
  26. "Hungarian Inventors and their Inventions in the Field of Heavy-Current Engineering". energosolar.com. Archived from the original on 21 January 2007. Retrieved 26 December 2008.
  27. Patent No. US352105, U.S. Patent Office, 1886-11-02, retrieved 2009-07-08
  28. Smil, Vaclav, Creating the Twentieth Century: Technical Innovations of 1867–1914 and Their Lasting Impact, Oxford University Press, 2005, p. 71.
  29. Jeszenszky, Sándor. "Electrostatics and Electrodynamics at Pest University in the Mid-19th Century" (PDF). University of Pavia. Archived from the original (PDF) on 27 June 2022. Retrieved Mar 3, 2012.
  30. 1 2 Bláthy, Ottó Titusz, Hungarian Patent Office.
  31. "Technology - History - Closed-core lighting transformers". Elma tt - Factory of transformers and devices. Serbia . Retrieved August 31, 2023.
  32. Nagy, Árpád Zoltán, "Lecture to Mark the 100th Anniversary of the Discovery of the Electron in 1897" (preliminary text), Budapest 1996-10-11, retrieved 2009-07-09.
  33. 1 2 3 4 Guarnieri, M. (2013). "The Beginning of Electric Energy Transmission: Part Two". IEEE Industrial Electronics Magazine. 7 (2): 52–59. doi:10.1109/MIE.2013.2256297. S2CID   42790906.
  34. http://edisontechcenter.org – Great Barrington 1886 The first practical AC power delivery system
  35. Thomas Parke Hughes, Networks of Power: Electrification in Western Society, 1880–1930, p. 103, (1993)
  36. The Schenectady Museum , Schenectady, New York.
  37. 1 2 3 Jos Arrillaga (1998). High Voltage Direct Current Transmission. Institution of Engineering and Technology (IET). p. 1. ISBN   978-0-85296-941-0 . Retrieved 2009-01-06.
  38. 1 2 Guarnieri, M. (2013). "The Alternating Evolution of DC Power Transmission". IEEE Industrial Electronics Magazine. 7 (3): 60–63. doi:10.1109/MIE.2013.2272238. S2CID   23610440.
  39. "René Thury" (in German). Electrosuisse, a Swiss organization of Electrotechnical professionals. Archived from the original on 2009-09-14. Retrieved 2009-01-05.
  40. ACW's Insulator Info – Book Reference Info – History of Electrical Systems and Cables
  41. Robert Monro Black (1983). The History of Electric Wires and Cables. London: Institution of Engineering and Technology (IET). pp. 94–96. ISBN   978-0-86341-001-7.
  42. Notice d'autorité – Thury, René (CH.AVG.ThuryISAAR) (PDF) (in French). Archives de la Ville de Genève. December 2006. Retrieved 2009-01-07.
  43. Thomas P. Hughes, Networks of Power: Electrification in Western Society 1880–1930, The Johns Hopkins University Press, Baltimore 1983 ISBN   0-8018-2873-2
  44. Kiessling F, Nefzger P, Nolasco JF, Kaintzyk U (2003) Overhead power lines. Springer: Berlin, Heidelberg, New York, p. 5
  45. "History of Station A". Willamette Falls Heritage Foundation. 2008. Archived from the original on July 16, 2012.
  46. Bradley, Robert L. Jr. (2011). Edison to Enron: Energy Markets and Political Strategies. New York: John Wiley & Sons. p. 40. ISBN   978-0-47091-736-7.
  47. Skrabec, Quentin R. (2012). The 100 Most Significant Events in American Business: An Encyclopedia. Santa Barbara, California: ABC-CLIO. p. 113. ISBN   978-0-31339-863-6.
  48. 1 2 Essig, Mark (2009). Edison and the Electric Chair: A Story of Light and Death. New York: Bloomsbury Publishing USA. p. 274. ISBN   978-0-80271-928-7.
  49. Skrabec, Quentin R. (2007). George Westinghouse: Gentle Genius. New York: Algora Publishing. p. 190. ISBN   978-0-87586-506-5.
  50. Page, Arthur W. (June 1907). "The Age of Electric Servants: The Beginning of An Era In Which The Labor Problems Of City and Country Will Be Solved By Cheap Electric Power". The World's Work: A History of Our Time . XIV: 9111–9116. Retrieved 2009-07-10.
  51. Furfari, F. A.; Nichols, R. S. (2003). "The First Electric Power Transmission Line in North America – Oregon City, Oregon". IEEE Industry Applications Magazine. 9 (4): 7–10. doi:10.1109/MIA.2003.1206911. ISSN   1077-2618.
  52. Bureau of Census data reprinted in Hughes, pp. 282–83
  53. Sood, Vijay K. (Spring 2006). "IEEE Milestone : 40th Anniversary of 735 kV Transmission System" (PDF). IEEE Canadian Review. pp. 6–7. Retrieved 2009-03-14.
  54. Hughes, pp. 293–95
  55. Hughes pp. ?
  56. Thompson, M.T. "Notes 01" (PDF). Introduction to Power Electronics. Thompson Consulting, Inc.