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HVDC Visby–Näs
The HVDC Visby–Näs is a bipolar HVDC electric power transmission system between Visby and a wind power centre near Näs on Gotland, Sweden. The project went into service in 1999. The system operates at 80 kV with a maximum power of 50 megawatts. This HVDC system allows for voltage regulation in the connected AC systems. Because obtaining a right-of-way for an overhead line is a lengthy and expensive procedure, the 70 kilometer line is constructed as an underground cable. Since an alternating current 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 w ... three-phase underground cable would have been more expensive, the HVDC system was selected for this project. Sites External links Gotland: the first commercial HVDC Light project HVDC transmission lines Electric power inf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HVDC
A high-voltage direct current (HVDC) electric power transmission system uses direct current (DC) for electric power transmission, in contrast with the more common alternating current (AC) transmission systems. Most HVDC links use voltages between 100 kV and 800 kV. HVDC lines are commonly used for long-distance power transmission, since they require fewer conductors and incur less power loss than equivalent AC lines. HVDC also allows power transmission between AC transmission systems that are not Synchronization (alternating current), synchronized. Since the power flow through an HVDC link can be controlled independently of the phase angle between source and load, it can stabilize a network against disturbances due to rapid changes in power. HVDC also allows the transfer of power between grid systems running at different frequencies, such as 50 and 60 Hz. This improves the stability and economy of each grid, by allowing the exchange of power between previously inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 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. Efficient long-distance transmission of electric power requires high voltages. This reduces the losses produced by strong currents. Transmission lines use either alternating current (AC) or direct current (DC). The voltage level is changed with transformers. The voltage is stepped up for transmission, then reduced for local distribution. A wide area synchronous grid, known as an ''interconnection'' in North America, directly connects generators delivering AC power with the same rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visby
Visby () is an urban areas in Sweden, urban area in Sweden and the seat of Gotland Municipality in Gotland County on the island of Gotland with 24,330 inhabitants . Visby is also the episcopal see for the Diocese of Visby. The Hanseatic League, Hanseatic city of Visby is arguably the best-preserved Middle Ages, medieval city in Scandinavia, and, since 1995, it has been on the UNESCO World Heritage Site list. Among the most notable historical remains are the long Visby City Wall, town wall that encircles the town center, and a List of church ruins on Gotland, number of church ruins. The decline as a Hanseatic city in the Late Middle Ages was the cause for many stone houses being preserved in their original medieval style. Visby is a popular vacation destination for Scandinavians during the summer and receives thousands of tourists every year. It is by far the most populous Swedish locality outside the Swedish mainland. The Campus Gotland, Gotland University is in Visby, and sinc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Power
Wind power is the use of wind energy to generate useful work. Historically, wind power was used by sails, windmills and windpumps, but today it is mostly used to generate electricity. This article deals only with wind power for electricity generation. Today, wind power is generated almost completely using wind turbines, generally grouped into wind farms and connected to the electrical grid. In 2024, wind supplied over 2,494 TWh of electricity, which was 8.1% of world electricity. With about 100 Gigawatt, GW added during 2021, mostly Wind power in China, in China and the Wind power in the United States, United States, global installed wind power capacity exceeded 800 GW. 30 countries generated more than a tenth of their electricity from wind power in 2024 and wind generation has nearly tripled since 2015. To help meet the Paris Agreement goals to Climate change mitigation, limit climate change, analysts say it should expand much faster – by over 1% of electricity generation p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gotland
Gotland (; ; ''Gutland'' in Gutnish), also historically spelled Gottland or Gothland (), is Sweden's largest island. It is also a Provinces of Sweden, province/Counties of Sweden, county (Swedish län), Municipalities of Sweden, municipality, and List of dioceses, deaneries and parishes of the Church of Sweden, diocese. The province includes the islands of Fårö and Gotska Sandön to the north, as well as the Karlsö Islands (Lilla Karlsö, Lilla and Stora Karlsö, Stora) to the west. The population is 61,023 (2024) of which about 23,600 live in Visby, the main town. Outside Visby, there are minor settlements and a mainly rural population. The island of Gotland and the other areas of the province of Gotland make up less than one percent of Sweden's total land area. The county formed by the archipelago is the second smallest by area and is the least populated in Sweden. In spite of the small size due to its narrow width, the driving distance between the furthermost points of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternating Current
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, Fan (machine), 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 ''Electric current, current'' or ''voltage''. The usual waveform of alternating current in most electric power circuits is a sine wave, whose positive half-period corresponds with positive direction of the current and vice versa (the full period is called a ''wave cycle, cycle''). "Alternating current" most commonly refers to power distribution, but a wide range of other appl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HVDC Transmission Lines
A high-voltage direct current (HVDC) electric power transmission system uses direct current (DC) for electric power transmission, in contrast with the more common alternating current (AC) transmission systems. Most HVDC links use voltages between 100 kV and 800 kV. HVDC lines are commonly used for long-distance power transmission, since they require fewer conductors and incur less power loss than equivalent AC lines. HVDC also allows power transmission between AC transmission systems that are not synchronized. Since the power flow through an HVDC link can be controlled independently of the phase angle between source and load, it can stabilize a network against disturbances due to rapid changes in power. HVDC also allows the transfer of power between grid systems running at different frequencies, such as 50 and 60 Hz. This improves the stability and economy of each grid, by allowing the exchange of power between previously incompatible networks. The modern form o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Power Infrastructure In Sweden
Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell's equations. Common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others. The presence of either a positive or negative electric charge produces an electric field. The motion of electric charges is an electric current and produces a magnetic field. In most applications, Coulomb's law determines the force acting on an electric charge. Electric potential is the Work (physics), work done to move an electric charge from one point to another within an electric field, typically measured in volts. Electricity plays a central role in many modern technologies, serving in electric power where electric current is used to energise equipment, and in electronics dealing w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Energy Infrastructure Completed In 1999
Energy () is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat and light. Energy is a conserved quantity—the law of conservation of energy states that energy can be converted in form, but not created or destroyed. The unit of measurement for energy in the International System of Units (SI) is the joule (J). Forms of energy include the kinetic energy of a moving object, the potential energy stored by an object (for instance due to its position in a field), the elastic energy stored in a solid object, chemical energy associated with chemical reactions, the radiant energy carried by electromagnetic radiation, the internal energy contained within a thermodynamic system, and rest energy associated with an object's rest mass. These are not mutually exclusive. All living organisms constantly take in and release energy. The Earth's climate and ecosystems processes are driven prima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1999 Establishments In Sweden
1999 was designated as the International Year of Older Persons. Events January * January 1 – The euro currency is established and the European Central Bank assumes its full powers. * January 3 – The Mars Polar Lander is launched by NASA. * January 25 – The 6.2 Colombia earthquake hits western Colombia, killing at least 1,900 people. February * February 7 – Abdullah II inherits the throne of Jordan, following the death of his father King Hussein. * February 11 – Pluto moves along its eccentric orbit further from the Sun than Neptune. It had been nearer than Neptune since 1979, and will become again in 2231. * February 12 – U.S. President Bill Clinton is acquitted in impeachment proceedings in the United States Senate. * February 16 ** In Uzbekistan, an apparent assassination attempt against President Islam Karimov takes place at government headquarters. ** Across Europe, Kurdish protestors take over embassies and hold hostages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
