353 articles
Fault level
Fault level is the prospective current that would flow into a short circuit at a point in a power system, expressed in kiloamperes or megavolt-amperes.
Fault passage indicator
A fault passage indicator (FPI), also called a faulted circuit indicator, is a device on medium-voltage distribution lines that detects fault current, helping crews localize the faulted section.
Feeder terminal unit
A feeder terminal unit (FTU), in Chinese practice 馈线终端, is a remote terminal unit on distribution feeders that measures electrical conditions and switch status for a central control system.
Flexible AC transmission system
A flexible AC transmission system (FACTS) is an AC transmission system with power electronic-based static controllers that enhance controllability and increase power transfer capability, a definition given by the IEEE.
FLISR
FLISR, or fault location, isolation, and service restoration, is a distribution automation function in which electric utilities automatically locate feeder faults, isolate the faulted section, and restore power to unfaulted sections within about a minute.
Frederick J. Ellert
Frederick J. Ellert was an American electrical engineer at General Electric who led the development of high-voltage direct current transmission and was elected to the National Academy of Engineering in 1987.
Frequency stability
Frequency stability is a power system's ability to maintain steady frequency after a severe generation-load imbalance, like losing a large generator, and restore it to nominal value.
Fulong converter station
Fulong converter station (复龙换流站), located at Fulong in Sichuan Province, China, is the sending-end (rectifier) station of the Xiangjiaba–Shanghai ±800 kV UHVDC link, commissioned in 2010.
Furnace transformer
A furnace transformer is a special-purpose power transformer delivering very high current at low secondary voltage to industrial melting furnaces, most commonly electric arc furnaces.
g³ (gas mixture)
g³, pronounced g-cubed, is a dielectric and arc-quenching gas mixture of carbon dioxide, oxygen, and fluoronitrile developed by GE Vernova and 3M to replace SF₆.
Gas-insulated line
A gas-insulated line (GIL) is a high-voltage power transmission system in which a conductor inside a compressed insulating gas carries large amounts of power underground or through tunnels.
Generator circuit breaker
A generator circuit breaker (GCB) is a switching device between a power plant generator and its step-up transformer, rated above 1 kV and designed to interrupt very large, heavily asymmetrical fault currents.
Gezhouba converter station
Gezhouba converter station (葛洲坝换流站) near Yichang, Hubei, is the sending-end rectifier station of China's first long-distance HVDC link, a ±500 kV bipolar scheme carrying 1,200 MW about 1,045 km to Shanghai.
Glass insulator
A glass insulator is a glass component that electrically isolates and mechanically supports the conductors of overhead telegraph, telephone, and power lines, usually in cap-and-pin disc form.
Golmud converter station
Golmud converter station, also known as the Chaidam converter station, is the sending-end HVDC station near Golmud, Qinghai, that first connected the Tibet grid to China's network in 2011.
Grid frequency
Grid frequency is the rate at which alternating current in a power system oscillates, 60 Hz in North America and 50 Hz in most of the world.
Ground and neutral
Ground and neutral are two distinct conductors in electrical wiring: the neutral carries current back to the source, while the ground provides a safe fault-current path.
Ground fault
A ground fault is an unintended electrical connection between an energized conductor and ground, letting current escape its normal path, sometimes through a person, and can start fires in solar arrays.
Hao Huang (electrical engineer)
Hao Huang is an electrical power engineer and Distinguished Adjunct Professor at the University of Houston, elected to the National Academy of Engineering in 2021 for aerospace electrical systems work.
Harmonic filter
A harmonic filter is electrical equipment that reduces harmonic distortion in power systems by diverting or canceling harmonic currents from nonlinear loads such as variable frequency drives, rectifiers, and arc furnaces.
Harmonic resonance
Harmonic resonance in power systems occurs when the system's natural frequency, set by inductance and capacitor banks, matches a harmonic source like a variable-frequency drive, amplifying harmonic voltages far above normal levels and damaging equipment.
Harmonic restraint
Harmonic restraint is a technique in transformer differential protection that uses the harmonic content of inrush current, especially the second harmonic, to prevent relay tripping.
Harmonics (electrical power)
Power system harmonics are voltage or current components at integer multiples of the 50 or 60 Hz fundamental, produced by non-linear loads and measured as total harmonic distortion (THD).
Harold N. Scherer Jr.
Harold N. Scherer Jr. (1929–2017) was an American electric power engineer who led the design and energization of the first 765-kV transmission line, then the world's highest voltage.
High-frequency transformer
A high-frequency transformer transfers power at frequencies far above the 50 or 60 Hz grid, typically tens of kilohertz, providing galvanic isolation in switched-mode power supplies, DC-DC converters, and solid-state transformers.
High-voltage direct current
High-voltage direct current (HVDC), also called high-voltage DC, transmits electrical power as direct current at high voltage, used for long-distance bulk transmission, submarine cables, and connecting unsynchronized AC grids.
Hybrid HVDC breaker
A hybrid HVDC breaker is a high-voltage direct current circuit breaker combining a mechanical switch with power electronics to clear DC faults in milliseconds with low losses.
Ice shedding
Ice shedding is the sudden detachment of ice from overhead transmission line conductors due to melting, wind, or de-icing, causing jumping conductors, flashovers, and tower damage.
IEC 60287
IEC 60287 is a series of IEC standards, Electric cables – Calculation of the current rating, giving formulae for the continuous current, or ampacity, of power cables in ground, ducts, or air.
IEC 60320
IEC 60320, the international appliance coupler standard family (Parts 1, 2-1 to 2-4, 3) from IEC/TC 23/SC 23G, covering detachable inlets and connectors rated up to 250 V AC and 16 A, with the 2021 fourth edition adding Annex E for use up to +90 °C.