Technology beginning with F

Smart Grid Technology
Click one of the letters above to go to the page of all terms beginning with that letter.

A set of electrical equipment that operates as a single Bulk Electric System Element (e.g., a line, a generator, a shunt compensator, transformer, etc.)

Facility Rating

The maximum or minimum voltage, current, frequency, or real or reactive power flow through a facility that does not violate the applicable equipment rating of any equipment comprising the facility.

Facts Device

An electronic system and other static equipment that provide control of one or more AC transmission system parameters to enhance controllability and increase power transfer capability.


An event occurring on an electric system such as a short circuit, a broken wire, or an intermittent connection.

Fault Current Limiter

A fault current limiter prevents current in an electrical circuit from exceeding a predetermined level by increasing the electrical impedance of that circuit before the current through the circuit exceeds that level. Fault current limiters are designed so as to minimize the impedance of the circuit under normal conditions to reduce losses, but increase the impedance of the circuit under fault conditions to limit fault current.

Fault Current Limiting

Fault current limiting can be achieved through sensors, communications, information processing, and actuators that allow the utility to use a higher degree of network coordination to reconfigure the system to prevent fault currents from exceeding damaging levels. Fault current limiting can also be achieved through the implementation of special stand alone devices known as Fault Current Limiters (FCLs) which act to automatically limit high through currents that occur during faults.

Fault Location, Isolation, and Service Restoration

A distribution automation application utilizing sensors, information processors, communications and switches, designed to locate faults and minimize affects by switching portions of the affected circuit to other circuits. Fault location, isolation, and service restoration (FLISR) reduce the number of customers that experience a sustained power outage by quickly reconfiguring distribution circuits. FLISR can be initiated and managed from central control systems, or by distributed, local control systems.

Firm Demand

That portion of the Demand that a power supplier is obligated to provide except when system reliability is threatened or during emergency conditions.

Firm Transmission Service

The highest quality (priority) service offered to customers under a filed rate schedule that anticipates no planned interruption.

Flexible AC Transmission System Device

A power electronics-based system and other static equipment that provide control of one or more alternating current (AC) transmission system parameters to enhance controllability and increase power transfer capability.


A designated point on the transmission system through which the Interchange Distribution Calculator calculates the power flow from Interchange Transactions.

Forced Outage

The removal from service availability of a generating unit, transmission line, or other facility for emergency reasons., The condition in which the equipment is unavailable due to unanticipated failure.

Frequency Bias

A value, usually expressed in megawatts per 0.1 Hertz (MW/0.1 Hz), associated with a Balancing Authority Area that approximates the Balancing Authority Area's response to Interconnection frequency error.

Frequency Bias Setting

A value, usually expressed in MW/0.1 Hz, set into a Balancing Authority ACE algorithm that allows the Balancing Authority to contribute its frequency response to the Interconnection.

Frequency Deviation

A change in Interconnection frequency.

Frequency Error

The difference between the actual and scheduled frequency. (FA - FS)

Frequency Regulation

The ability of a Balancing Authority to help the Interconnection maintain Scheduled Frequency. This assistance can include both turbine governor response and Automatic Generation Control.

Frequency Response

(Equipment) The ability of a system or elements of the system to react or respond to a change in system frequency. (System) The sum of the change in demand, plus the change in generation, divided by the change in frequency, expressed in megawatts per 0.1 Hertz (MW/0.1 Hz).