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.
Alternating current (AC) is an electric current which 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.
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.
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.
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.
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.
Electrocution is death or severe injury caused by electric shock from electric current passing through the body. The word is derived from "electro" and "execution", but it is also used for accidental death.
The Westinghouse Electric Corporation was an American manufacturing company founded in 1886 by George Westinghouse. It was originally named "Westinghouse Electric & Manufacturing Company" and was renamed "Westinghouse Electric Corporation" in 1945. The company acquired the CBS television network in 1995 and was renamed "CBS Corporation" until being acquired by Viacom in 1999, a merger completed in April 2000. The CBS Corporation name was later reused for one of the two companies resulting from the split of Viacom in 2005.
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.
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.
Southern California Edison (SCE), the largest subsidiary of Edison International, is the primary electric utility company for much of Southern California. It provides 15 million people with electricity across a service territory of approximately 50,000 square miles. However, the Los Angeles Department of Water and Power, San Diego Gas & Electric (SDG&E), Imperial Irrigation District, and some smaller municipal utilities serve substantial portions of the southern California territory. The northern part of the state is generally served by the Pacific Gas & Electric Company of San Francisco. Other investor-owned utilities (IOUs) in California include SDG&E, PacifiCorp, Bear Valley Electric, and Liberty Utilities.
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.
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.
Croton Dam is an earth-filled embankment dam and powerplant complex on the Muskegon River in Croton Township, Newaygo County, Michigan. It was built in 1907 under the direction of William D. Fargo by the Grand Rapids - Muskegon Power Company, a predecessor of Consumers Energy. The 40-foot-high (12 m) dam impounds 7.2 billion U.S. gallons (6 billion imp. gal/27 billion L) of water in its 1,209-acre (489 ha) reservoir and is capable of producing 8,850 kilowatts at peak outflow. It was listed on the National Register of Historic Places in 1979.
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.
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."
The Upland–San Bernardino Line was an interurban line operated by the Pacific Electric Railway between Downtown Los Angeles and San Bernardino, California. This line also had shorter service that terminated before the end of the line at Baldwin Park, Covina, and San Dimas. Though service along this line in its entirety was discontinued in November 1941, it stands as the fourth-longest rapid transit line in American history, after the Sacramento Northern Chico and Colusa services, and the Pacific Electric's own Riverside–Rialto Line.
Cyrus Grandison Baldwin was an American minister in the Congregational Church, the first official president of Pomona College, and a pioneer of hydroelectric power in Southern California.
Henry Harbinson Sinclair (1858–1914) was a pioneer of the hydro-electric industry in the U.S. state of California.
