Which of the following is vital for maintaining transmission voltage during system restoration?

Generating adequate reactive power is crucial for maintaining transmission voltage during system restoration because reactive power plays a key role in voltage regulation across the power system. Electrical systems require both active power (real power) and reactive power to function effectively. Reactive power helps to support voltage levels, particularly in transmission lines, which may experience voltage drops due to line losses and increased demand.

During system restoration, the network can often experience instability and requires sufficient reactive power to ensure that voltage levels are within acceptable limits. If there is insufficient reactive power, voltage levels can drop, leading to further instability or even blackouts. By ensuring adequate generation of reactive power, the system can maintain the necessary voltage levels to support ongoing operations and gradually restore load.

Maintaining minimal load levels or adhering to transmission schedules may not directly support voltage stability, and disconnecting reactive resources would likely have the opposite effect, increasing the risk of voltage decline. Thus, generating adequate reactive power is vital for ensuring a steady and reliable voltage during the restoration process.