901 articles
Utility Powertech Ltd.
Utility Powertech Ltd. is an Indian power-sector services company incorporated in 1995 as a 50:50 joint venture between NTPC and Reliance Infrastructure, providing operation and maintenance services for power plants.
Uttar Pradesh Power Corporation
Uttar Pradesh Power Corporation Limited (UPPCL) is the state-owned utility that procures, transmits, and supplies electricity across Uttar Pradesh, India, headquartered in Lucknow and created in 1999.
Vacuum interrupter
A vacuum interrupter is a switching component for power circuits in which separable contacts operate in a vacuum, extinguishing the arc without air, oil, or SF₆.
Variable autotransformer
A variable autotransformer, commonly called a Variac, is a transformer with a sliding brush that adjusts AC output voltage continuously from zero to above the input.
Vattenfall
Vattenfall is a Swedish state-owned energy company founded in 1909, one of Europe's largest electricity and heat producers with about 21,000 employees across Sweden, Germany, and the Netherlands.
Vault transformer
A vault transformer is a liquid-immersed, three-phase distribution transformer installed in underground vaults, where it steps a medium-voltage feed down to 600 V or less to supply secondary networks through network protectors.
Vermont Transco LLC
Vermont Transco LLC is a Vermont limited liability company, formed in 2006 and based in Rutland, that owns Vermont's high-voltage electric transmission system on behalf of VELCO and 17 utilities.
Vickie A. VanZandt
Vickie A. VanZandt is an American electric power transmission engineer who spent 35 years at the Bonneville Power Administration, rising to senior vice president of Transmission Services.
Vietnam Electricity
Vietnam Electricity (Tập đoàn Điện lực Việt Nam, or EVN) is the state-owned power utility of Vietnam, founded in 1994 and headquartered in Hanoi, serving nearly 31.4 million customers.
Viking Link
Viking Link is a 1.4 GW HVDC electricity interconnector between Bicker Fen in Lincolnshire and Revsing in Denmark, the world's longest land and subsea interconnector, operational since 2023.
Vincent S. Boyer
Vincent S. Boyer (1918–2001) was an American nuclear power engineer who led Philadelphia Electric Company's nuclear program and joined the National Academy of Engineering in 1980.
Virtual Power Plant
A virtual power plant (VPP) is a group of dispersed energy resources like rooftop solar, batteries, and electric vehicles coordinated by software to act as a single power plant.
Vistra
Vistra Corp. is a Fortune 500 integrated retail electricity and power generation company headquartered in Irving, Texas, serving about 5 million customers with a 44,000 MW fleet.
Volt/var optimization
Volt/var optimization (VVO) is a distribution-engineering method that coordinates voltage regulators, load tap changers, and capacitor banks to minimize power losses and keep feeder voltages within limits.
Volta River Authority
The Volta River Authority (VRA) is Ghana's state-owned electricity generation company, established in 1961 to build the Akosombo Dam, which created Lake Volta, the world's largest man-made lake.
Voltage flicker meter
A voltage flicker meter, or flickermeter, is an instrument that converts rapid mains voltage fluctuations into indices of perceived light flicker, as specified by the international standard IEC 61000-4-15.
Voltage fluctuation
Voltage fluctuation is a power quality disturbance, a continuous variation of RMS voltage caused by arc furnaces, welders, and rapidly changing loads, and linked to flicker.
Voltage ride-through
Voltage ride-through is the ability of a generator, inverter, or large load to stay connected through short voltage dips, required by grid codes such as IEEE 1547.
Voltage sag
Voltage sag, also called a voltage dip, is a short reduction in AC voltage to between 10 and 90 percent of nominal, lasting from half a cycle to 1 minute.
Voltage spike
A voltage spike is a short, high-magnitude transient rise in voltage on an electrical circuit, lasting microseconds to milliseconds and often reaching tens of kilovolts, caused by lightning, switching, or faults.
Voltage stability
Voltage stability is the ability of a power system to maintain steady, acceptable voltages at all buses after a disturbance; its loss can cause cascading blackouts.
Voltage stability analysis
Voltage stability analysis is a power systems engineering method for assessing whether a grid can maintain acceptable voltages, identifying conditions under which voltage collapse would begin.
Voltage swell
A voltage swell is a short-duration rise in RMS voltage to 110% to 180% of nominal lasting up to one minute, classified by IEEE 1159 as a power quality problem.
Voltage transformer
A voltage transformer, also called a potential transformer, is an instrument transformer that supplies meters and protective relays with an accurate scaled replica of system voltage.
Voltage unbalance
Voltage unbalance, also called voltage imbalance, is a power quality condition in three-phase electrical systems where voltages differ in magnitude or deviate from their ideal 120-degree phase angles.
Wallace B. Behnke
Wallace B. Behnke was an American engineer with Commonwealth Edison, where he was Vice Chairman from 1980, and chaired the consortium managing the Clinch River Breeder Reactor Project.
Walsin Lihwa
Walsin Lihwa Corporation (华新丽华) is a Taiwanese manufacturer of wires, cables, and stainless steel, founded in 1966 as a power wire maker and now a leading cable company in Greater China.
War of the currents
The War of the currents was the late-1880s American rivalry between Thomas Edison's direct current and George Westinghouse's alternating current, which prevailed after the 1893 Chicago World's Fair.
Wataynikaneyap Power
Wataynikaneyap Power is an electricity transmission company in northwestern Ontario, majority owned by 24 First Nations with Fortis Inc., connecting remote communities to the provincial grid to end diesel reliance.
Water treeing
Water treeing is a degradation process in polymeric power cable insulation, chiefly XLPE, where tree-shaped regions of water-filled microcavities grow slowly under an alternating electric field.