Glossary beginning with A

A distribution switch with built-in technology that can detect and interrupt faults more quickly and precisely. Such a device may rely on advanced fault detection techniques, and may not require full-line reclosing and sectionalizing to isolate faults.

A system of smart meters, two-way communications networks, and data management systems implemented to enable metering and other information exchange between utilities and their customers.

Software that utilizes synchrophasor information for real-time grid operations or planning and off-line analysis. These applications are aimed at providing wide-area situational awareness, grid monitoring, and detailed power system analysis and the improvement or validation of power system models.

Automated Capacitors can increase the voltage on a distribution circuit by providing reactive power (often referred to as volt-amperes-reactive or VArs). Capacitor banks are switched in discrete steps, either manually, or in response to the voltage at the location where they are connected. Typically, distribution capacitor banks are switched in a single step.

Distribution circuit switches operate automatically in response to control signals from local sensors, distribution automation systems, or grid control systems. Such switches can be installed as automated devices. Existing equipment can be retrofitted with controls and communications. These switches can be opened or closed to help locate a short circuit, or taken out of service for maintenance. When used in combination, these switches can reroute power from other substations or nearby distribution circuits.

Voltage regulators are transformers that can increase or decrease the voltage on a distribution circuit to help keep the voltage within a pre-determined band. Unlike capacitor banks, voltage regulators cannot adjust power factor. They typically monitor the voltage at the location where they are connected, comparing it to a programmed set point. If the voltage deviates too far from the set point, the voltage regulator can adjust its output voltage by moving the tap on the secondary side up or down.