During system restoration, capacitor banks should remain off until what percentage of the load is restored?

In system restoration, keeping capacitor banks offline until a certain percentage of the load is restored is crucial for ensuring the stability and reliability of the power system. The correct response indicates that capacitor banks should remain off until 40% of the load is restored.

This practice is employed to prevent issues such as waveform distortion and oscillations that can arise when reactive power sources like capacitor banks are energized without a substantial load to balance them. By waiting for 40% of the load to be restored, the system is better equipped to handle the additional reactive power introduced by the capacitors, which in turn helps maintain voltage stability and reduces the risk of system disturbances. This careful approach to restoration is part of a broader strategy to ensure a smooth transition back to normal operating conditions after a disturbance or blackout.

Overall, maintaining the capacitors in an offline state until a significant portion of the load is back in service creates a more controlled re-energization of the power system, enhancing its stability and reliability as it resumes full operation.