What occurs to the Balancing Authority ACE Limit (BAAL) when frequency significantly deviates from the scheduled frequency?

When the frequency significantly deviates from the scheduled frequency, the Balancing Authority ACE Limit (BAAL) becomes more restrictive. This is an essential aspect of maintaining system reliability within a power grid.

The reasoning behind this is that a significant frequency deviation indicates an imbalance between generation and load. To mitigate the impacts of this imbalance and restore frequency to its scheduled value, the Balancing Authority may need to operate under stricter limits. This heightened restriction ensures that immediate corrective actions are taken to promote stability and reliability in the system.

Under normal operating conditions, the BAAL may allow more flexibility in generation and load adjustments. However, as frequency strays further from the scheduled frequency, the necessity to bring the system back into balance increases, warranting a more cautious approach.

Therefore, increasing the restrictiveness of the BAAL in the face of frequency deviations serves to prompt faster and more effective responses to rectify the situation, thus ensuring that grid stability is prioritized.