Glossary

Derating Factor

A reduction factor applied to the nominal capacity or rating of a component, such as a generator, transformer, or transmission line, to account for operating conditions or constraints that may limit its performance such as temperature, humidity, altitude, loading, and system configuration. These deviations can affect the performance and capability of power system components.

Economic Dispatch

Establishes the amount of power supplied by each unit.

Generation Mix

The combination of the various fuels used to generate electricity in a given geographic region.

Grid Dispatch

The process by which transmission system operators decide which power plants and generation facilities to deploy to meet current electricity demand.

N-1 Criterion

A reliability criterion used in power systems to ensure grid reliability by assessing the system’s ability to withstand the loss of a single component without causing a widespread blackout or cascading failures.

Spinning Reserve

The excess generating capacity that is immediately available and synchronized to the grid (but is not currently generating energy) to meet unexpected increases in electricity demand or compensate for sudden generator or transmission line outages.

Susceptance

Represents how much circuit is susceptible to conducting a changing current or simply how much circuit allows the changing current.

Unit Commitment

Determines when and which generating units to start-up and shut-down.