During system restoration, which strategy is used to maintain frequency above 59.5 Hz?

During system restoration, maintaining frequency above 59.5 Hz is crucial for ensuring the stability and reliability of the power grid. Activating synchronized reserves is an effective strategy because it involves bringing additional generation resources online or ramping up existing resources that are capable of rapidly responding to changes in system demand.

Synchronized reserves are designed to immediately respond to frequency deviations. When the system frequency drops, these reserves can help to quickly restore the balance between supply and demand, thereby stabilizing the frequency. This rapid response is essential during restoration periods when the grid is vulnerable to fluctuations due to changes in generation and load as services are restored.

While reducing system load, isolating non-critical loads, and increasing generation output are also tactics that can be employed, they might not be as effective in maintaining frequency during restoration. Reducing load or isolating non-critical loads can lower demand, which may indirectly stabilize frequency but does not provide the immediate additional generation needed to respond to sudden losses or changes. Increasing generation output is a valid approach, but it may not always be feasible or quick enough to address immediate frequency issues without the predefined synchronized reserves in action.

Therefore, activating synchronized reserves is the most direct and effective means of maintaining frequency above 59.5 Hz during system restoration