In pre-contingency scenarios, how long can normal voltage limits be maintained?

In pre-contingency scenarios, the maintenance of normal voltage limits for 15 minutes is aligned with industry practices and standards. During this time, system operators can implement corrective actions to manage voltage levels and prevent potential issues that may arise if voltage deviations occur. This timeframe allows for sufficient evaluation and response measures to be enacted, enabling operators to address and resolve any impending reliability concerns effectively without immediate risks to the transmission system.

Understanding why this specific duration is standard involves recognizing that it provides a balance between operational flexibility and ensuring the reliability of the electrical grid. A longer time frame could lead to operational inefficiencies, whereas a shorter time would not allow enough time to implement necessary interventions before transitioning to contingency protocols. Hence, the 15 minutes serves as a crucial window for actions to stabilize the grid under normal operating conditions prior to any contingencies.