Voltage Control & System Reliability 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 Voltage Control & System Reliability flashcards as text
A system operator observes a sudden voltage collapse on a transmission corridor. What is the FIRST corrective action to take?
Answer: Insert reactive power support such as capacitor banks or SVCs
Voltage collapse is primarily a reactive power deficiency; inserting reactive support (capacitor banks, SVCs) is the first corrective action.
What does the term 'voltage stability margin' represent in power system operations?
Answer: The distance in MW or MVAR loading from the current operating point to the voltage collapse point
Voltage stability margin is the MW or MVAR distance from the current operating point to the nose point (collapse point) on the P-V or Q-V curve.
Under NERC Reliability Standards, which entity is primarily responsible for maintaining voltage within acceptable limits on the bulk electric system?
Answer: Transmission Operator (TOP)
The Transmission Operator (TOP) is responsible for maintaining transmission voltages within limits specified in their Operating Procedures.
A generator is operating at rated MVA with a lagging power factor. To raise terminal voltage, the operator should:
Answer: Increase field excitation
Increasing field excitation raises the generator's internal EMF, which increases terminal voltage and causes the machine to supply more reactive power.
Which phenomenon describes a situation where voltage actually rises as load increases, indicating a potential instability condition?
Answer: Voltage inversion
Voltage inversion occurs when a lightly loaded long line with shunt capacitance raises receiving-end voltage above sending-end voltage, indicating an unstable operating region.
What is the primary purpose of a Static Var Compensator (SVC) in voltage control?
Answer: To provide fast-acting continuous reactive power support to maintain bus voltage
An SVC provides fast, continuous reactive power compensation (capacitive or inductive) to regulate bus voltage dynamically.
During a high-load summer afternoon, reactive reserves are critically low. Which action would MOST effectively restore reactive reserve margin?
Answer: Switch in shunt capacitor banks and bring additional generators online for reactive support
Energizing shunt capacitors and bringing reactive-capable generators online directly increases available reactive reserve to prevent voltage collapse.