Aux 1 Unit 15 Q3

Correct Answer: B) Severe mechanical and electrical stress, leading to potential damage or failure of the generators

Explanation: Connecting generators that are out of phase can cause severe mechanical and electrical stress, leading to potential damage or failure of the generators, as they would try to force each other into phase, generating harmful currents and torque.

Correct Answer: B) It ensures that all generators share the load evenly and operate together without causing disruptions in the power system

Explanation: Synchronization ensures that all generators share the load evenly and operate together harmoniously, maintaining system stability and preventing disruptions in the power system.

Correct Answer: B) To ensure that the generators operate at the same frequency, voltage, and phase angle to avoid severe electrical disturbances, equipment damage, or generator tripping

Explanation: Synchronizing a.c. generators ensures that they operate at the same frequency, voltage, and phase angle. Failure to do so can result in severe electrical disturbances, equipment damage, or the tripping of generators due to phase mismatches or circulating currents.

Correct Answer: B) Synchronoscope and D) Frequency meter

Explanation: A synchronoscope is used to visually display the phase relationship between the generator and the busbar, ensuring they are synchronized before connection. A frequency meter measures the frequency of the generator and the busbar, ensuring they match.

Correct Answer: B) The needle or pointer is stationary and pointing to the 12 o'clock position, indicating that the generators are in phase and ready to be connected

Explanation: When the needle or pointer of the synchronoscope is stationary and pointing to the 12 o'clock position, it indicates that the generators are in phase and correctly synchronized, making them ready to be connected in parallel.

Correct Answer: B) The phase angle should be zero degrees or very close to it to ensure that the generators are in phase, preventing circulating currents and ensuring smooth power transfer

Explanation: The phase angle should be zero degrees (or very close to it) when synchronizing generators to ensure they are in phase. This minimizes circulating currents and ensures smooth and stable power transfer between the generators.

Correct Answer: B) The generator may experience out-of-phase conditions, leading to mechanical stress, high circulating currents, and potential damage to both the generator and the power system

Explanation: If a generator is connected without proper synchronization, it may operate out of phase with other generators, causing mechanical stress, high circulating currents, and potential damage to the generator and power system.

Correct Answer: A) The frequency readings of the generator and the busbar are identical

Explanation: A frequency meter indicates correct synchronization when the frequency readings of the generator and the busbar are identical. This ensures that both are operating at the same frequency, which is crucial for successful synchronization.

Correct Answer: B) The generators must be operating at the same frequency, voltage, and phase sequence

Explanation: For successful synchronization, a.c. generators must operate at the same frequency, voltage, and phase sequence. These parameters must match to ensure stable and safe parallel operation.

Correct Answer: B) It indicates the phase angle and synchronization status between the generator and the busbar

Explanation: The synchronoscope indicates the phase angle and synchronization status between the generator and the busbar. It shows whether the generator is in phase and ready to be connected to the busbar.