Power System Operations 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 Power System Operations flashcards as text
What is the function of a static VAR compensator (SVC) in a high-voltage transmission system?
Answer: To provide fast-acting dynamic reactive power support for voltage regulation
An SVC uses thyristor-controlled reactors and capacitor banks to rapidly inject or absorb reactive power, maintaining voltage stability during dynamic events.
A dispatcher must coordinate an outage that requires taking a normally open bus tie breaker into service. What key check should be performed first?
Answer: Confirm that both buses are in synchronism (voltage magnitude, angle, and frequency match) before closing
Closing a bus tie between two live buses that are out of synchronism can cause severe mechanical shock to generators and damage equipment.
What does 'islanding' mean in the context of power system operations, and why is it a concern?
Answer: A portion of the power system becoming electrically isolated from the main grid while still energized by local generation
An unintentional island can lead to uncontrolled frequency and voltage deviations, safety hazards for line workers, and equipment damage.
Which of the following best describes the concept of 'thermal limit' on a transmission line?
Answer: The maximum current the conductor can carry before sag exceeds clearance limits or insulation is damaged
Thermal limits are determined by conductor heating from I²R losses, which increases conductor sag and can violate ground clearance requirements.
During a major disturbance, an operator's SCADA system loses telemetry from a remote substation. What is the correct operational response?
Answer: Attempt voice communication with field personnel, apply conservative operating assumptions, and notify supervision
When telemetry is lost, operators must use all available alternative communication methods, assume worst-case conditions, and follow established outage procedures.
What is 'load flow' (power flow) analysis used for in power system operations?
Answer: Calculating steady-state voltage, current, and power at every bus and branch under given generation and load conditions
Load flow (or power flow) analysis solves the network equations to find voltages, currents, and power flows throughout the system for a specified operating condition.
What is the primary operational significance of the 'P-V curve' (nose curve) for a load bus?
Answer: It identifies the maximum loadability limit of a bus and the onset of voltage instability
The nose of the P-V curve marks the maximum power that can be delivered to a load bus; operating near or beyond the nose risks voltage collapse.