Normal System Conditions (N-0)
Represents the grid operating normally with all expected elements online and no unexpected events.
Abnormal System Conditions (N-1)
Represents the grid operating abnormally after a single event such as line outages, breaker faults, or transformer failures.
Importance of studying both conditions
Grid reliability is at the heart of all transmission studies. Studying both normal and abnormal grid conditions is essential to identify potential limitations and provide a realistic view of grid challenges. Because equipment outages and failures are a routine aspect of grid operations, interconnection studies must consider representative grid conditions to be truly valuable.
Note
To align with the ISO/RTO interconnection request evaluation process, which considers both N-0 and N-1 contingencies, it’s critical that project developers also evaluate capacity the same way, otherwise you may end up with far higher capacity than how the grid operator will see it when they evaluate the project in the queue.
To align with the ISO/RTO interconnection request evaluation process, which considers both N-0 and N-1 contingencies, it’s critical that project developers also evaluate capacity the same way, otherwise you may end up with far higher capacity than how the grid operator will see it when they evaluate the project in the queue.