Area Control Error

ACE. The instantaneous difference between net actual and scheduled interchange.

Area Control Error (ACE)

The instantaneous difference between an entity’s Actual Net Interchange (NIA) and Scheduled Net Interchange (NIS), taking into account the effects of Frequency Bias, of correction for meter error, and of Inadvertent Interchange Management (IIM) if operating in the IIM mode. For compliance usage, refer to the term Reporting ACE.

ACE (p6) The mismatch between demand and generation is represented via a real-time value called ACE, estimated in MW.