In the case of large ACE errors affecting frequency, what action should the Reliability Coordinator take?

The appropriate action for the Reliability Coordinator to take in the case of large Area Control Error (ACE) errors affecting frequency is to direct its Balancing Authority to comply with the Disturbance Control Standard (DCS) or Control Performance Standard (CPS). This is crucial because large ACE errors suggest that there is an imbalance between generation and load, which can lead to frequency disturbances.

By directing the Balancing Authority to adhere to these standards, the Reliability Coordinator is ensuring that the balancing of generation and load is prioritized to maintain system reliability and stability. The DCS outlines the necessary response requirements for maintaining frequency, while the CPS ensures that Balancing Authorities operate within acceptable performance levels regarding their control actions.

In contrast, issuing an Energy Emergency Alert (EEA) might be more appropriate in scenarios where there are shortages of energy supply or capacity, rather than specifically addressing ACE errors and frequency control. Purchasing power on behalf of Balancing Authorities could also be part of managing energy shortages but does not address the direct operational standards governed by ACE and frequency control. Lastly, issuing Transmission Loading Relief (TLR) measures to terminate non-firm transactions relates more to managing transmission congestion and is not specifically aimed at correcting ACE errors and frequency disturbances. Thus, directing compliance with D