353 articles
Phasor measurement unit
A phasor measurement unit, also called a synchrophasor device, is a precision instrument that measures voltage and current phasors and frequency in power grids with GPS time-stamping.
PJM Demand Response
PJM Demand Response is a set of voluntary programs that pay electricity customers for reducing their use when PJM requests it during high prices or grid emergencies.
Planar transformer
A planar transformer is a transformer whose primary and secondary windings are flat copper traces etched on a printed circuit board, used in compact, high-frequency power converters.
Pollution flashover
Pollution flashover is an unwanted electrical discharge across the surface of an outdoor insulator coated with conductive pollution, typically sea salt, industrial dust, or desert sand, and then dampened.
Porcelain insulator
A porcelain insulator is a ceramic electrical insulator made of vitrified porcelain, used to support and isolate overhead power line conductors and substations; wet-process designs dominated high-voltage use after 1896.
Power flow calculation
A power flow calculation, also called load flow, is a numerical method that computes the steady-state operating point of an electrical grid, giving bus voltages and line power flows.
Power quality monitor
A power quality monitor is an instrument that analyzes voltage and current signals to detect, record, and quantify disturbances such as sags, swells, harmonics, flicker, and transients.
Power synchronization control
Power synchronization control is a grid-forming control method for voltage-source converters that synchronizes to the AC grid through a power loop instead of a phase-locked loop.
Power system stabilizer
A power system stabilizer (PSS) is a supplementary controller on a synchronous generator's excitation system that damps low-frequency electromechanical rotor oscillations by modulating field voltage, extending power transfer capability.
Power system state estimation
Power system state estimation is a computational method that estimates voltage magnitudes and phase angles at every bus of an electric network from redundant, noisy power and voltage measurements.
Power transformer
A power transformer transfers energy between AC circuits at different voltage levels, stepping voltage up for transmission and down for distribution in the power grid.
Power-flow study
A power-flow study, or load-flow study, computes voltages, currents, and power flows in an electrical network, checking that delivery stays within voltage and thermal limits.
Power-from-shore
Power-from-shore is the supply of onshore grid electricity to offshore oil and gas installations via subsea cables, replacing gas turbines; it is Norway's most important measure for cutting petroleum emissions.
Power-line communication
Power-line communication, also known as power-line networking or broadband over powerline, carries data signals over existing electrical power lines for smart grids, smart metering, home automation, and in-home networking.
PowerCON
PowerCON is a family of locking three-conductor AC mains connectors made by Neutrik, introduced in 1996 and now standard on professional moving-head light systems and other AV equipment.
Primary frequency response
Primary frequency response is the rapid, automatic action of grid generators to arrest and stabilize frequency deviations within seconds, until secondary control restores normal frequency.
Protective earth (ground)
A protective earth, or equipment ground, is a conductor connecting exposed metal parts of equipment to earth so an insulation fault cannot leave them at a dangerous voltage.
Protective relay
A protective relay, also called a protection relay, is a device that monitors current and voltage, detects faults, and trips circuit breakers to isolate the faulted section.
Radisson Converter Station
Radisson Converter Station is an HVDC converter station in northern Manitoba, owned by Manitoba Hydro near Gillam, which converts AC from Nelson River hydroelectric stations to DC for transmission to Winnipeg.
Rate of change of frequency (RoCoF)
Rate of change of frequency (RoCoF) measures how quickly grid frequency changes, in Hz/s, after a generation-demand imbalance; it rises as inverter-based renewables displace synchronous generators.
Reactive power
Reactive power is the portion of AC electricity that sustains the electric and magnetic fields of equipment like motors and transformers, and it directly influences grid voltage.
Reactive power optimization
Reactive power optimization, also known as optimal reactive power dispatch or Volt/VAR optimization, adjusts generator voltages, transformer taps, and VAR sources to cut grid power losses.
Recloser
A recloser is an automatic switching device on electric power lines that interrupts fault current and recloses to test whether the fault has cleared, locking open if it persists.
Reconductoring
Reconductoring is the replacement of the wires on an existing overhead transmission or distribution line with new conductors, reusing existing towers and rights of way to increase capacity.
Rectifier transformer
A rectifier transformer is a specialized power transformer that supplies AC from the grid to a rectifier converting it to DC, serving electrolysis, plating, and DC drives.
Relay coordination
Relay coordination is the process of choosing protective relay settings and time delays so devices trip in sequence during a fault, isolating the smallest part of the power system.
Resonant transformer
A resonant transformer is a high-voltage test transformer operated in a resonant circuit, producing large test voltages from a small power source for testing cables and switchgear.
Right-of-way (transmission)
A right-of-way in electric power transmission is the strip of land under a transmission line over which the utility holds rights to build, operate, and maintain the line.
Rihand converter station
The Rihand converter station is the sending-end terminal of the Rihand–Dadri HVDC link, a 1,500 MW system carrying power from Uttar Pradesh toward Delhi since 1990.
Ring main unit
A ring main unit (RMU) is a compact, factory-assembled switchgear unit used at load points of a ring distribution network, typically rated 11 to 24 kV.