During system restoration, what frequency must be maintained above by shedding load?

Maintaining frequency above 59.5 Hz during system restoration is critical for ensuring the stability and reliability of the power grid. The frequency of an electrical system reflects the balance between supply and demand; if the frequency drops too low, it indicates that the load exceeds the capabilities of the generation resources.

When the system is restored, operators actively manage the frequency to avoid a further decline, which can lead to system instability or even blackout conditions. Shedding load at frequencies below this threshold is a protective measure that helps avoid grid failure, allowing for the gradual restoration of services while ensuring that the balance between generation and consumption is achieved.

By keeping the frequency above 59.5 Hz, the grid can operate safely without triggering severity protocols, and it allows for a more controlled approach to bringing generation back online as demand increases. Thus, maintaining this frequency level contributes significantly to the overall health and performance of the electrical system during the critical phases of restoration.