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
Mercury commonly refers to:
* Mercury (planet), the nearest planet to the Sun
* Mercury (element), a metallic chemical element with the symbol Hg
* Mercury (mythology), a Roman god
Mercury or The Mercury may also refer to:
Companies
* Mercury ...
in 1902, used to convert AC into DC. From the 1920s on, research continued on applying
thyratrons and grid-controlled mercury arc valves to power transmission. Grading electrodes made them suitable for
high voltage direct current
A high-voltage direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for electric power transmission, in contrast with the more common alternating curren ...
(HVDC) power transmission. In 1933, selenium rectifiers were invented.
Transistor
upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink).
A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch e ...
technology dates back to 1947, with the invention of the
point-contact transistor
The point-contact transistor was the first type of transistor to be successfully demonstrated. It was developed by research scientists John Bardeen and Walter Brattain at Bell Laboratories in December 1947. They worked in a group led by physicis ...
, which was followed by the
bipolar junction transistor (BJT) in 1948. By the 1950s, higher power semiconductor
diode
A diode is a two-terminal electronic component that conducts current primarily in one direction (asymmetric conductance); it has low (ideally zero) resistance in one direction, and high (ideally infinite) resistance in the other.
A diode ...
s became available and started replacing
vacuum tube
A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied.
The type kn ...
s. In 1956, the
silicon controlled rectifier (SCR) was introduced, increasing the range of power electronic applications.
A breakthrough in power electronics came with the invention of the
MOSFET
The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a type of field-effect transistor (FET), most commonly fabricated by the controlled oxidation of silicon. It has an insulated gate, the voltage of which d ...
(metal-oxide-semiconductor field-effect transistor) in 1959. Generations of MOSFETs enabled power designers to achieve performance and density levels not possible with bipolar transistors. In 1969,
Hitachi
() is a Japanese multinational corporation, multinational Conglomerate (company), conglomerate corporation headquartered in Chiyoda, Tokyo, Japan. It is the parent company of the Hitachi Group (''Hitachi Gurūpu'') and had formed part of the Ni ...
introduced the first vertical
power MOSFET
A power MOSFET is a specific type of metal–oxide–semiconductor field-effect transistor (MOSFET) designed to handle significant power levels. Compared to the other power semiconductor devices, such as an insulated-gate bipolar transistor (IG ...
, which would later be known as the
VMOS (V-groove MOSFET).
The power MOSFET has since become the most common
power device in the world, due to its low gate drive power, fast switching speed,
easy advanced paralleling capability,
wide
bandwidth, ruggedness, easy drive, simple biasing, ease of application, and ease of repair.
While HVDC is increasingly being used to transmit large quantities of electricity over long distances or to connect adjacent
asynchronous
Asynchrony is the state of not being in synchronization.
Asynchrony or asynchronous may refer to:
Electronics and computing
* Asynchrony (computer programming), the occurrence of events independent of the main program flow, and ways to deal with ...
power systems, the bulk of electricity generation, transmission, distribution and retailing takes place using alternating current.
Organization
The electric power industry is commonly split up into four processes. These are
electricity generation
Electricity generation is the process of generating electric power from sources of primary energy. For electric utility, utilities in the electric power industry, it is the stage prior to its Electricity delivery, delivery (Electric power transmi ...
such as a
power station
A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the generation of electric power. Power stations are generally connected to an electrical grid.
Many p ...
,
electric power transmission
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 ...
,
electricity distribution and
electricity retailing. In many countries, electric power companies own the whole infrastructure from generating stations to transmission and distribution infrastructure. For this reason, electric power is viewed as a
natural monopoly. The industry is generally heavily
regulated
Regulation is the management of complex systems according to a set of rules and trends. In systems theory, these types of rules exist in various fields of biology and society, but the term has slightly different meanings according to context. Fo ...
, often with
price control
Price controls are restrictions set in place and enforced by governments, on the prices that can be charged for goods and services in a market. The intent behind implementing such controls can stem from the desire to maintain affordability of good ...
s and is frequently
government-owned and operated. However, the modern trend has been growing deregulation in at least the latter two processes.
The nature and state of market reform of the
electricity market
In a broad sense, an electricity market is a system that facilitates the exchange of electricity-related goods and services. During more than a century of evolution of the electric power industry, the economics of the electricity markets had un ...
often determines whether electric companies are able to be involved in just some of these processes without having to own the entire infrastructure, or citizens choose which components of infrastructure to patronise. In countries where electricity provision is deregulated, end-users of electricity may opt for more costly
green electricity.
Generation
All forms of electricity generation have positive and negative aspects.
Technology
Technology is the application of knowledge to reach practical goals in a specifiable and reproducible way. The word ''technology'' may also mean the product of such an endeavor. The use of technology is widely prevalent in medicine, science, ...
will probably eventually declare the most preferred forms, but in a
market economy
A market economy is an economic system in which the decisions regarding investment, production and distribution to the consumers are guided by the price signals created by the forces of supply and demand, where all suppliers and consumers ...
, the options with less overall costs generally will be chosen above other sources. It is not clear yet which form can best meet the necessary energy demands or which process can best solve the demand for electricity. There are indications that
renewable energy
Renewable energy is energy that is collected from renewable resources that are naturally replenished on a human timescale. It includes sources such as sunlight, wind, the movement of water, and geothermal heat. Although most renewable energy ...
is rapidly becoming the most viable in economic terms. A diverse mix of generation sources reduces the risks of electricity price spikes.
Electric power transmission
Electric power transmission is the bulk movement of
electrical energy
Electrical energy is energy related to forces on electrically charged particles and the movement of electrically charged particles (often electrons in wires, but not always). This energy is supplied by the combination of electric current and electr ...
from a generating site, such as a
power plant
A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the generation of electric power. Power stations are generally connected to an electrical grid.
Many pow ...
, to an
electrical substation
A substation is a part of an electrical generation, transmission, and distribution system. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions. Between the generating station and ...
. The interconnected lines which facilitate this movement are known as 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 known as the "
power grid
An electrical grid is an interconnected network for electricity delivery from producers to consumers. Electrical grids vary in size and can cover whole countries or continents. It consists of:Kaplan, S. M. (2009). Smart Grid. Electrical Power ...
" in
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, or just "the grid". In the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...
,
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
,
Malaysia
Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...
and
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
, the network is known as the National Grid.
A
wide area synchronous grid
A wide area synchronous grid (also called an "interconnection" in North America) is a three-phase electric power grid that has regional scale or greater that operates at a synchronized utility frequency and is electrically tied together during no ...
, also known as an "interconnection" in North America, directly connects many generators delivering AC power with the same relative ''frequency'' numerous consumers. For example, there are four major interconnections in North America (the
Western Interconnection, the
Eastern Interconnection, the
Quebec Interconnection and the
Electric Reliability Council of Texas (ERCOT) grid). In Europe
one large grid connects most of continental Europe.
Historically, transmission and distribution lines were owned by the same company, but starting in the 1990s, many countries have
liberalized the regulation of the
electricity market
In a broad sense, an electricity market is a system that facilitates the exchange of electricity-related goods and services. During more than a century of evolution of the electric power industry, the economics of the electricity markets had un ...
in ways that have led to the separation of the electricity transmission business from the distribution business.
Electric power distribution
Electric power distribution is the final stage in the
delivery of
electric power
Electric power is the rate at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second. Standard prefixes apply to watts as with other SI units: thousands, millions and billions o ...
; it carries electricity from the
transmission system to individual consumers. Distribution substations connect to the transmission system and lower the transmission voltage to medium
voltage
Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to m ...
ranging between 2
kV and 35 kV with the use of
transformer
A transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer' ...
s.
''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
Mains electricity or utility power, power grid, domestic power, and wall power, or in some parts of Canada as hydro, is a general-purpose alternating-current (AC) electric power supply. It is the form of electrical power that is delivered to h ...
used by lighting, industrial equipment or 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.
Electric retailing
Electricity retailing is the final sale of
electricity
Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described ...
from
generation to the end-use consumer.
World electricity industries
The organization of the electrical sector of a country or region varies depending on the economic system of the country. In some places, all electric power generation, transmission and distribution is provided by a government controlled organization. Other regions have private or investor-owned utility companies, city or municipally owned companies,
cooperative
A cooperative (also known as co-operative, co-op, or coop) is "an autonomous association of persons united voluntarily to meet their common economic, social and cultural needs and aspirations through a jointly owned and democratically-control ...
companies owned by their own customers, or combinations. Generation, transmission and distribution may be offered by a single company, or different organizations may provide each of these portions of the system.
Not everyone has access to grid electricity. About 840 million people (mostly in Africa) had no access in 2017, down from 1.2 billion in 2010.
Market reform
The
business model
A business model describes how an organization creates, delivers, and captures value,''Business Model Generation'', Alexander Osterwalder, Yves Pigneur, Alan Smith, and 470 practitioners from 45 countries, self-published, 2010 in economic, social, ...
behind the electric utility has changed over the years playing a vital role in shaping the electricity industry into what it is today; from generation, transmission, distribution, to the final local retailing. This has occurred prominently since the reform of the electricity supply industry in England and Wales in 1990.
United States
In 1996 - 1999 the
Federal Energy Regulatory Commission
The Federal Energy Regulatory Commission (FERC) is the United States federal agency that regulates the transmission and wholesale sale of electricity and natural gas in interstate commerce and regulates the transportation of oil by pipeline in ...
(FERC) made a series of decisions which were intended to open the U.S. wholesale power market to new players, with the hope that spurring competition would save consumers $4 to $5 billion per year and encourage technical innovation in the industry. Steps were taken to give all market participants open access to existing interstate transmission lines.
Order No. 888ordered vertically integrated electric utilities to functionally separate their transmission, power generation and marketing businesses to prevent self-dealing.
Order No. 889set up a system to provide all participants with timely access to information about available transmission capacity and prices.
* The FERC also endorsed the concept of appointing independent system operators (ISOs) to manage the electric power grid - a function that was traditionally the responsibility of vertically integrated electric utility companies. The concept of an independent system operator evolved into that of
regional transmission organizations (RTOs). FERC's intention was that all U.S. companies owning interstate electric transmission lines would place those facilities under the control of an RTO. In it
Order No. 2000''(Regional Transmission Organizations)'', issued in 1999, FERC specified the minimum capabilities that an RTO should possess.
These decisions, which were intended to create a fully interconnected grid and an integrated national power market, resulted in the restructuring of the U.S. electricity industry. That process was soon dealt two setbacks: the
California energy crisis of 2000, and the
Enron scandal and collapse. Although industry restructuring proceeded, these events made clear that competitive markets could be manipulated and thus must be properly designed and monitored. Furthermore,
the Northeast blackout of 2003 highlighted the need for a dual focus on competitive pricing and strong reliability standards.
Other countries
In some countries, wholesale electricity markets operate, with
generators and
retailers trading electricity in a similar manner to
shares and
currency
A currency, "in circulation", from la, currens, -entis, literally meaning "running" or "traversing" is a standardization of money in any form, in use or circulation as a medium of exchange, for example banknotes and coins.
A more general def ...
. As
deregulation
Deregulation is the process of removing or reducing state regulations, typically in the economic sphere. It is the repeal of governmental regulation of the economy. It became common in advanced industrial economies in the 1970s and 1980s, as a ...
continues further, utilities are driven to sell their
asset
In financial accountancy, financial accounting, an asset is any resource owned or controlled by a business or an economic entity. It is anything (tangible or intangible) that can be used to produce positive economic value. Assets represent value ...
s as the energy market follows in line with the gas market in use of the
futures
Futures may mean:
Finance
*Futures contract, a tradable financial derivatives contract
*Futures exchange, a financial market where futures contracts are traded
* ''Futures'' (magazine), an American finance magazine
Music
* ''Futures'' (album), a ...
and
spot markets and other financial arrangements. Even
globalization
Globalization, or globalisation (Commonwealth English; see spelling differences), is the process of interaction and integration among people, companies, and governments worldwide. The term ''globalization'' first appeared in the early 20t ...
with foreign purchases are taking place. One such purchase was when the
UK's
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...
National Grid, the largest private electric utility in the world, bought several electric utilities in
New England
New England is a region comprising six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York to the west and by the Canadian provinces ...
for $3.2 billion. Between 1995 and 1997, seven of the 12 Regional Electric Companies (RECs) in England and Wales were bought by U.S. energy companies.
"Electricity companies in the United Kingdom – a brief chronology," Electricity Association, 30 June 2003
/ref> Domestically, local electric and gas firms have merged operations as they saw the advantages of joint affiliation, especially with the reduced cost of joint-metering. Technological advances will take place in the competitive wholesale electric markets, such examples already being utilized include fuel cells used in space flight; aeroderivative gas turbines used in jet aircraft
A jet aircraft (or simply jet) is an aircraft (nearly always a fixed-wing aircraft) propelled by jet engines.
Whereas the engines in propeller-powered aircraft generally achieve their maximum efficiency at much lower speeds and altitudes, je ...
; solar engineering and photovoltaic
Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially us ...
systems; off-shore wind farms; and the communication advances spawned by the digital world, particularly with microprocessing which aids in monitoring and dispatching.[Borberly, A. and Kreider, J. F. (2001). Distributed Generation: The Power Paradigm for the New Millennium. CRC Press, Boca Raton, FL. 400 pp.]
Outlook
Electricity is expected to see growing demand in the future. The Information Revolution is highly reliant on electric power. Other growth areas include emerging new electricity-exclusive technologies, developments in space conditioning, industrial processes, and transportation
Transport (in British English), or transportation (in American English), is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land (rail and road), water, cable, pipeline, ...
(for example hybrid vehicle
A hybrid vehicle is one that uses two or more distinct types of power, such as submarines that use diesel when surfaced and batteries when submerged. Other means to store energy include pressurized fluid in hydraulic hybrids.
The basic princip ...
s, locomotive
A locomotive or engine is a rail transport vehicle that provides the Power (physics), motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, Motor coach (rail), motor ...
s).
See also
* AC power
* Distributed generation
* Emissions & Generation Resource Integrated Database
* Meter Point Administration Number
A Meter Point Administration Number, also known as MPAN, Supply Number or S-Number, is a 21-digit reference used in Great Britain to uniquely identify electricity supply points such as individual domestic residences. The system was introduced in ...
, a unique UK supply number
* National Grid (disambiguation)
National Grid or National grid may refer to:
Power transmission
* Electrical grid, an interconnected network for delivering electricity
** National Grid (Great Britain), the electricity transmission network of Great Britain
*** National Grid plc, ...
* North American Electric Reliability Corporation
The North American Electric Reliability Corporation (NERC) is a nonprofit corporation based in Atlanta, Georgia, and formed on March 28, 2006, as the successor to the North American Electric Reliability Council (also known as NERC). The original N ...
* Rate Case
Utility ratemaking is the formal regulatory process in the United States by which public utilities set the prices (more commonly known as "rates") they will charge consumers. Ratemaking, typically carried out through "rate cases" before a public ut ...
* Reddy Kilowatt
Reddy Kilowatt is a cartoon character that served as a corporate spokesman for electricity generation in the United States and other countries for over seven decades. Currently, the Reddy Kilowatt trademark is owned by Xcel Energy.
Description
R ...
, a U.S. electricity corporate logo
* Samuel Insull
Samuel Insull (November 11, 1859 – July 16, 1938) was a British-born American business magnate. He was an innovator and investor based in Chicago who greatly contributed to create an integrated electrical infrastructure in the United States ...
References
Further reading
* P. Strange, "Early Electricity Supply in Britain: Chesterfield and Godalming", ''IEEE Proceedings'' (1979).
* D. G. Tucker, "Hydro-Electricity for Public Supply in Britain", ''Industrial Archaeology Review'', (1977).
* B. Bowers, ''A History of Electric Light & Power'', Peregrinus (1982).
* T. P. Hughes, ''Networks of Power'', Johns Hopkins Press London (1983).
* IRENA
The International Renewable Energy Agency (IRENA) is an intergovernmental organization mandated to facilitate cooperation, advance knowledge, and promote the adoption and sustainable use of renewable energy. It is the first international organis ...
,
INNOVATION LANDSCAPE FOR A RENEWABLE-POWERED FUTURE: SOLUTIONS TO INTEGRATE VARIABLE RENEWABLES
', (2019).
{{Authority control
Electric power
Energy industry
Industries (economics)