SOPD Power System Operations 5

Question 1

What is the function of a static VAR compensator (SVC) in a high-voltage transmission system?

Accepted Answer

To provide fast-acting dynamic reactive power support for voltage regulation

Answer

An SVC uses thyristor-controlled reactors and capacitor banks to rapidly inject or absorb reactive power, maintaining voltage stability during dynamic events.

Question 2

A dispatcher must coordinate an outage that requires taking a normally open bus tie breaker into service. What key check should be performed first?

Accepted Answer

Confirm that both buses are in synchronism (voltage magnitude, angle, and frequency match) before closing

Answer

Closing a bus tie between two live buses that are out of synchronism can cause severe mechanical shock to generators and damage equipment.

Question 3

What does 'islanding' mean in the context of power system operations, and why is it a concern?

Accepted Answer

A portion of the power system becoming electrically isolated from the main grid while still energized by local generation

Answer

An unintentional island can lead to uncontrolled frequency and voltage deviations, safety hazards for line workers, and equipment damage.

Question 4

Which of the following best describes the concept of 'thermal limit' on a transmission line?

Accepted Answer

The maximum current the conductor can carry before sag exceeds clearance limits or insulation is damaged

Answer

Thermal limits are determined by conductor heating from I²R losses, which increases conductor sag and can violate ground clearance requirements.

Question 5

During a major disturbance, an operator's SCADA system loses telemetry from a remote substation. What is the correct operational response?

Accepted Answer

Attempt voice communication with field personnel, apply conservative operating assumptions, and notify supervision

Answer

When telemetry is lost, operators must use all available alternative communication methods, assume worst-case conditions, and follow established outage procedures.

(SOPD) System Operator/Power Dispatching Practice Test

(SOPD) System Operator/Power Dispatching Practice Test

SOPD Power System Operations 5