Aux 1 Unit 15 Q1

Correct Answer: A) Reverse power relay

Explanation: A reverse power relay is critical for detecting when a generator running in parallel begins to draw power instead of supplying it. This situation can occur if the generator fails to supply enough power, leading to potential damage or instability in the power system.

Correct Answer: B) To ensure the generator operates within its designated frequency range, preventing damage and ensuring stable parallel operation with other generators

Explanation: An under/over-frequency relay is necessary to ensure the generator operates within its designated frequency range. Deviations from the correct frequency can cause instability and damage, particularly when multiple generators are running in parallel.

Correct Answer: A) Under/over-frequency relay

Explanation: An under/over-frequency relay is fitted to prevent a generator from operating outside its designated frequency range. This device ensures that the generator maintains a stable frequency, which is essential for parallel operation with other generators.

Correct Answer: B) By providing comprehensive protection against overcurrent, reverse power flow, and frequency deviations, ensuring the generators operate safely and efficiently in parallel

Explanation: The combination of these protective devices ensures the safe and efficient operation of generators running in parallel. Each relay addresses a specific risk—overcurrent, reverse power flow, and frequency deviations—helping to prevent damage and maintain system stability.

Correct Answer: B) To protect the generator from damage by disconnecting it in the event of excessive current, which could occur due to faults or overload conditions

Explanation: An overcurrent relay is essential for protecting the generator from damage caused by excessive current. If a fault or overload occurs, the relay disconnects the generator to prevent overheating, insulation failure, or other damage.

Correct Answer: B) To prevent a generator from drawing power instead of supplying it, which can lead to mechanical damage or destabilization of the power system

Explanation: A reverse power relay is crucial in preventing a generator from consuming power (drawing power from the grid) instead of supplying it. This condition can cause mechanical damage to the generator and destabilize the parallel operation of the power system.