Emergency Response & System Restoration Procedures Flashcards

A black‑start resource is defined as a generating unit that can:

Answer: Start without off‑site power

A black-start resource is a generating unit or set of units that has the capability to start up independently without requiring an external electrical supply from the grid. These units are critical for system restoration after a widespread blackout, as they can energize portions of the grid to bring other non-black-start generators online.

Under‑frequency load shedding (UFLS) is automatically triggered when system frequency drops below:

Answer: 59.3 Hz

Under-frequency load shedding (UFLS) is an automatic protection scheme designed to prevent a complete system collapse during severe generation-load imbalances. When the system frequency drops to a predetermined critical level, typically around 59.3 Hz, UFLS relays automatically trip pre-selected blocks of load to quickly restore the frequency balance and stabilize the grid.

NERC standard that requires each Balancing Authority to have a restoration plan is:

Answer: EOP‑005

NERC Reliability Standard EOP-005, titled 'System Restoration from Blackstart Resources,' specifically requires each Balancing Authority and Transmission Operator to develop, maintain, and implement a system restoration plan. This plan outlines the procedures for restoring the bulk electric system following a partial or total blackout, including the use of blackstart resources.

During storm damage, operators first prioritize:

Answer: Isolating faulted segments to secure the system

During storm damage or any system disturbance, the immediate priority for operators is to isolate the faulted sections of the grid. This action prevents further damage, limits the extent of the outage, and secures the remaining healthy parts of the system, creating a stable foundation for subsequent restoration efforts.

A cascading outage is defined as:

Answer: Sequential protective trips leading to widespread loss

A cascading outage occurs when the failure of one component or a small number of components triggers a sequence of subsequent failures throughout the power system. This chain reaction typically involves protective relays tripping lines or generators, leading to widespread power loss that extends far beyond the initial fault location.

A cranking path is:

Answer: Transmission route to energize a non‑black‑start unit

A cranking path refers to the specific transmission route or sequence of lines and substations that are energized from a black-start resource to bring a non-black-start generating unit online. This path provides the necessary auxiliary power to start the non-black-start unit, allowing it to then contribute to the overall system restoration.

Effective emergency communication uses the Incident Command System (ICS) because it:

Answer: Provides common terminology and structure

The Incident Command System (ICS) is a standardized, on-scene management system designed to enable effective and efficient incident management by integrating a combination of facilities, equipment, personnel, procedures, and communications operating within a common organizational structure. Its use of common terminology and a clear hierarchical structure ensures coordinated and efficient communication during emergencies.

Synchronizing an islanded grid with the main grid requires matching voltage, frequency, and:

Answer: Phase angle

Synchronizing an islanded grid with the main grid requires precise alignment of several electrical parameters to prevent damage and ensure stability. Besides matching voltage and frequency, the phase angle between the two systems must be nearly identical. This ensures that the voltage waveforms are in sync when the connection is made, allowing for a smooth and stable power transfer without sudden current surges.

Post‑event analysis reports are typically required within how many days after a major disturbance?

Answer: 30 days

In the power industry, particularly under NERC (North American Electric Reliability Corporation) standards, specific timelines are often mandated for reporting and analysis of significant events. A 30-day window for post-event analysis reports is a common requirement. This timeframe allows for thorough investigation into the cause and impact of a major disturbance while ensuring timely documentation and lessons learned are captured to improve system reliability.