Emergency Response & System Restoration Procedures Flashcards
7 cards from real SOPD practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Emergency Response & System Restoration Procedures flashcards as text
During a widespread blackout, what is the correct sequence for restoring the transmission system?
Answer: Restore generation, establish transmission backbone, then pick up load
The standard black start sequence establishes generation and transmission backbone first before incrementally picking up customer load to avoid overloads.
A synchronizing check relay (25) prevents closing a breaker when:
Answer: The frequency difference between two systems exceeds the relay's set threshold
A sync-check relay monitors voltage magnitude, angle, and frequency difference, blocking closure when the differential exceeds its permitted threshold to prevent a damaging out-of-phase close.
What is 'islanding' in power system context during an emergency?
Answer: A portion of the system operating isolated from the main grid, potentially with uncontrolled frequency
Islanding occurs when a section of the power grid continues to operate independently after separation from the main grid, which can create unsafe frequency and voltage conditions.
Under NERC EOP-005, what must operators verify before energizing a transmission line during restoration?
Answer: That protection systems are in service and the line is clear of work tags
EOP-005 requires operators to confirm protection systems are in service and the element is free of clearances/tags before energizing during system restoration.
When frequency drops below the first stage of an Under-Frequency Load Shedding (UFLS) scheme, the scheme automatically:
Answer: Disconnects a pre-set block of customer load to arrest the frequency decline
UFLS automatically trips pre-programmed load blocks to reduce demand and arrest frequency decline when it falls below defined thresholds.
A system operator notices bus voltage is 8% below scheduled level during an emergency. The FIRST corrective action should be:
Answer: Raise generation reactive output (MVAr) and check capacitor bank status
Low voltage is primarily corrected by increasing reactive power supply — raising generator excitation or switching in capacitor banks — before resorting to load shedding.
During black start restoration, why is it important to control the rate of load pickup?
Answer: To avoid excessive frequency dips that could trip the black start unit off-line
Adding load too fast causes frequency to dip; if the dip is large enough it can trip the black start generator on under-frequency, losing the restoration anchor.