Glossary by "T"
T&D ISee: I
Energy losses that occur within electric transmission and distribution (T&D) systems.Source: ESA Technical Working Group
Any terminal where an electric connection is established. Most commonly a terminal is a connection that draws a rated amount of current from a circuit. Just as a water tap allows one to draw a certain amount of water from the total supply, an electrical tap serves the same function for drawing electricity from a source of supply. Tapping a circuit can mean to 1. run/string a line or cable from a point in a circuit or 2. draw electricity from that circuit.Source: Energy Vortex
A device that can increase or decrease a transformer’s operating voltage to vary the amount of current that the transformer draws (taps) from the circuit supplying the electricity.Source: ESA Technical Working Group
Cell or battery charging involving a relatively charge rate (current) when the cell or battery is at a low state of charge and a tapering off of the charge rate (current) as the battery reaches a higher state of charge.Source: ESA Technical Working Group
A document that characterizes types and magnitude of levies that are assessed (e.g. electric service prices) and related terms and conditions such as eligibility. Utility tariffs are amended periodically and are approved by regulatory agencies. Also known as a , tariff schedule.Source: ESA Technical Working Group
The process by which measurable electrical quantities from substations and generating stations are instantaneously transmitted to the control center, and by which operating commands from the control center are transmitted to the substations and generating stations.
The parts of a cell/battery to which the external electric load is connected and through which current flows.Source: ESA Technical Working Group
Test entryAcronym(s): TE
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Texas Reliability EntityAcronym(s): Texas RE
Texas RE develops, monitors, assesses, and enforces compliance with North American Electric Reliability Corporation (NERC) Reliability Standards within the geographic boundaries of the ERCOT region. Texas RE is also authorized by the Public Utility Commission of Texas (PUCT) and is permitted by North American Electric Reliability Corporation (NERC) to investigate compliance with the ERCOT Protocols and Operating Guides, working with PUCT staff regarding any potential protocol violations.
The North American Electric Reliability CorporationAcronym(s): NERC
Mission: Ensure the reliability of the North American bulk power system. North American Electric Reliability Corporation (NERC) is the electric reliability organization (ERO) certified by the Federal Energy Regulatory Commission to establish and enforce reliability standards for the bulk-power system. North American Electric Reliability Corporation (NERC) develops and enforces reliability standards; assesses adequacy annually via a 10-year forecast, and summer and winter forecasts; monitors the bulk power system; and educates, trains and certifies industry personnel. ERO activities in Canada related to the reliability of the bulk-power system are recognized and overseen by the appropriate governmental authorities in that country.
The North American Synchrophasor InitiativeAcronym(s): NASPI
A consortium of government and industry that is working to prevent another major blackout in North America by installing synchrophasors that will provide real-time situational awareness of electric grid conditions by helping to get the most out of projects funded by the Smart Grid Investment Grants awarded as part of the 2009 American Recovery and Reinvestment Act.
The maximum amount of electrical current that a transmission line or electrical facility can conduct over a specified time period before it sustains permanent damage by overheating or before it sags to the point that it violates public safety requirements.
A condition whereby a cell on charge or discharge will destroy itself through internal heat generation caused by high overcharge or high rate of discharge or other abusive conditions.Source: BatterySpace
Electrical energy supplied by 3 out of phase sinusoidal voltage wave forms that are 120 degrees out of phase. Usually used in industrial applications and may have some energy efficiency characteristics.Source: ESA Technical Working Group
A solid-state semiconductor device that incorporates four layers of alternating N and P-type semiconductor material. Thyristors act as “bistable switches” that conduct when a current trigger is applied to their “gate,” They continue to conduct until the voltage across the device is reversed (i.e. while they are forward biased). See also silicon controlled rectifier.Source: ESA Technical Working Group
A circuit connecting two Balancing Authority Areas.
Time of use (energy prices)Acronym(s): TOU
Price for electric energy that is specific to the time (season, day of week, time-of-day) when the energy is purchased.Source: ESA Technical Working Group
Total harmonic distortionAcronym(s): THD
The ratio of the sum of the powers of all harmonic components to the power of the fundamental frequency. See harmonic distortion.Source: Wikipedia
Total transfer capabilityAcronym(s): TTC
The amount of electric power that can be moved or transferred reliably from one area to another area of the interconnected transmission systems by way of all transmission lines (or paths) between those areas under specified system conditions.
The measure of the ability of interconnected electric systems to move or transfer power in a reliable manner from one area to another over all transmission lines (or paths) between those areas under specified system conditions. The units of transfer capability are in terms of electric power, generally expressed in megawatts (MW). The transfer capability from
Energy that couples to other parts of the system, typically appearing as a short burst of oscillation of possibly various frequenciesSource: Wikipedia
An interconnected group of lines and associated equipment for the movement or transfer of electric energy between points of supply and points at which it is transformed for delivery to customers or is delivered to other electric systems.
Transmission access charges
Fees/charges imposed on parties seeking to use another party’s transmission system to “wheel” electricity from the source to the end-use location.Source: ESA Technical Working Group
A limitation on one or more transmission elements that may be reached during normal or contingency system operations.
A system of structures, wires, insulators and associated hardware that carry electric energy from one point to another in an electric power system. Lines are operated at relatively high voltages varying from 69 kV up to 765 kV, and are capable of transmitting large quantities of electricity over long distances.
The entity responsible for the reliability of its “local” transmission system, and that operates or directs the operations of the transmission facilities.
The entity that develops a long-term (generally one year and beyond) plan for the reliability (adequacy) of the interconnected bulk electric transmission systems within its portion of the planning authority area.
Transmission reliability marginAcronym(s): TRM
The amount of transmission transfer capability necessary to provide reasonable assurance that the interconnected transmission network will be secure. TRM accounts for the inherent uncertainty in system conditions and the need for operating flexibility to ensure reliable system operation as system conditions change.
Services provided to the transmission customer by the transmission service provider to move energy from a point of receipt to a point of delivery.
Transmission service providerAcronym(s): TSP
The entity that administers the transmission tariff and provides transmission service to transmission customers under applicable transmission service agreements.
Electrochemical cell or battery charging involving a continuous or an intermittent constant-current supply which keeps the cell/battery fully charged while the cell/battery is not being used (discharged).Source: ESA Technical Working Group