North American Electric Reliability Corporation (NERC) Practice Exam: Prep & Practice Test

Energizing shunt reactors is the best method for addressing high MVAR (reactive power) and MVA (apparent power) alarms in a 345 kV system during restoration because these reactors effectively absorb excess reactive power from the system. In situations where there is a surplus of reactive power, it can lead to voltage stability issues, which may trigger alarms. By activating shunt reactors, the system can mitigate these voltage spikes, stabilize the grid, and restore it to operational norms.

This approach is particularly relevant in high-voltage systems like 345 kV, where maintaining voltage levels within specified limits is crucial for reliability and operational safety. By absorbing reactive power, shunt reactors help balance the power flow, preventing overvoltage conditions that could disrupt service or damage equipment.

While decreasing load and disconnecting non-essential loads can also be measures taken to reduce stress on the system, these are more about reducing demand rather than addressing the issue of excess reactive power directly. Utilizing capacitor banks alone may not be suitable either, as they can increase reactive power in cases where there is already an excess, potentially worsening the situation. Therefore, energizing shunt reactors stands out as a proactive and effective solution for restoring system stability during such alarms.