ERCOT frequency control system

The entire ERCOT interconnection has become one control area, and one of ERCOT´s major responsibilities is to maintain the interconnection frequency. This function is carried out by the frequency control system (FCS), which is part of the power operating system (POS). The POS/FCS interfaces with the market operating system (MOS). This paper presents the overview, implementation, tuning, and operational experience of the FCS. The ERCOT FCS actually represents the top level of a hierarchical AGC. Mr. Nelson presented this subject in a panel session of 2002 IEEE PES winter meeting. This paper reports both what Mr. Nelson had presented at the 2002 winter meeting and the updates and enhancements that have been made to the FCS since that presentation.