During the restoration of a full system shutdown, what is the best practice to avoid re-collapsing the system?

During the restoration of a full system shutdown, what is the best practice to avoid re-collapsing the system?

• A. Maintain frequency between 59.5 Hz and 60.5 Hz
• B. Shed 15% - 20% of the load
• C. Avoid energizing loads in excess of 5% of online generation capacity
• D. Keep operating reserves to cover the largest generator

Answer: (C)

During the restoration of a full system shutdown, the best practice to avoid re-collapsing the system is to avoid energizing loads in excess of 5% of online generation capacity. This approach is critical because it ensures that the load being added to the system is manageable relative to the available generation. If loads that significantly exceed this threshold are restored, the sudden increase in demand can lead to instability, causing frequency fluctuations and potentially triggering another system collapse. In the context of system restoration, helping to maintain a balance between generation and load is crucial. By limiting the re-energization of loads to within this 5% limit, operators can carefully monitor system responses and make adjustments as needed, thereby promoting a gradual and stable restoration process. This cautious approach not only aids in maintaining frequency stability but also helps ensure that the system can handle any unforeseen circumstances that may arise during the restoration period. Other options present practices that could be relevant but do not specifically target the critical nature of managing load relative to generation capacity as effectively. For example, while maintaining frequency within a certain range is important for system stability, it does not directly address how much load can safely be restored without risking a re-collapse. Similarly, shedding a percentage of load or keeping reserves to cover

During the restoration of a full system shutdown, the best practice to avoid re-collapsing the system is to avoid energizing loads in excess of 5% of online generation capacity. This approach is critical because it ensures that the load being added to the system is manageable relative to the available generation. If loads that significantly exceed this threshold are restored, the sudden increase in demand can lead to instability, causing frequency fluctuations and potentially triggering another system collapse.

In the context of system restoration, helping to maintain a balance between generation and load is crucial. By limiting the re-energization of loads to within this 5% limit, operators can carefully monitor system responses and make adjustments as needed, thereby promoting a gradual and stable restoration process. This cautious approach not only aids in maintaining frequency stability but also helps ensure that the system can handle any unforeseen circumstances that may arise during the restoration period.

Other options present practices that could be relevant but do not specifically target the critical nature of managing load relative to generation capacity as effectively. For example, while maintaining frequency within a certain range is important for system stability, it does not directly address how much load can safely be restored without risking a re-collapse. Similarly, shedding a percentage of load or keeping reserves to cover