SOPD Power Grid Operations & Management 3

Question 1

Which phenomenon causes power to flow on unscheduled parallel paths through neighboring control areas?

Accepted Answer

Loop flow (circulating power)

Answer

Loop flow occurs because power follows Kirchhoff's laws and divides among all parallel paths, often flowing through unintended transmission corridors.

Question 2

What is the function of a phase angle regulator (PAR) on a transmission system?

Accepted Answer

Control the magnitude and direction of real power flow by shifting the voltage angle

Answer

A PAR introduces a phase angle shift between sending and receiving end voltages to control real power flow on a specific transmission path.

Question 3

During restoration after a blackout, why must operators carefully match voltage and frequency before closing ties to an energized island?

Accepted Answer

To avoid a damaging fault current surge that occurs when two unsynchronized sources are connected

Answer

Connecting two asynchronous sources causes a large equalizing current that can damage equipment; synchronization checks ensure voltage magnitude, phase angle, and frequency are matched.

Question 4

What is the significance of the 'dead band' setting in a turbine governor?

Accepted Answer

The speed range within which the governor does not respond, reducing wear from hunting

Answer

A governor dead band prevents continuous hunting around the setpoint by ignoring small frequency deviations, balancing responsiveness with mechanical wear.

Question 5

A system operator needs to increase transmission capacity on an overloaded corridor. Which of the following is a valid operational tool?

Accepted Answer

Adjusting generation dispatch to shift flows away from the overloaded line (redispatch)

Answer

Redispatching generation re-routes power flows in accordance with physical network laws, relieving the overloaded corridor without removing equipment from service.

(SOPD) System Operator/Power Dispatching Practice Test

(SOPD) System Operator/Power Dispatching Practice Test

SOPD Power Grid Operations & Management 3