What action is required if system voltage drops below .87 p.u. for 10 minutes?

What action is required if system voltage drops below .87 p.u. for 10 minutes?

• A. Increase generation capacity
• B. Manual load reduction actions
• C. Notify the Reliability Coordinator
• D. Disconnect all non-firm loads

Answer: (B)

When the system voltage drops below 0.87 per unit (p.u.) for an extended period, such as 10 minutes, it indicates a significant issue that could lead to voltage instability. In this situation, manual load reduction actions are essential to help stabilize the system. Reducing the load can alleviate stress on the transmission system and facilitate a recovery in voltage levels. This could involve the operator manually disconnecting certain non-essential or non-critical loads to balance the system and prevent further voltage collapse. While notifying the Reliability Coordinator or increasing generation capacity may be necessary actions in different scenarios, the immediate and most effective response to a sustained voltage drop is to manage the load directly. Disconnecting all non-firm loads might be too drastic and could disrupt expensive and essential services, thus making the manual load reduction a more strategic approach.

When the system voltage drops below 0.87 per unit (p.u.) for an extended period, such as 10 minutes, it indicates a significant issue that could lead to voltage instability. In this situation, manual load reduction actions are essential to help stabilize the system.

Reducing the load can alleviate stress on the transmission system and facilitate a recovery in voltage levels. This could involve the operator manually disconnecting certain non-essential or non-critical loads to balance the system and prevent further voltage collapse.

While notifying the Reliability Coordinator or increasing generation capacity may be necessary actions in different scenarios, the immediate and most effective response to a sustained voltage drop is to manage the load directly. Disconnecting all non-firm loads might be too drastic and could disrupt expensive and essential services, thus making the manual load reduction a more strategic approach.