NERC IDC: Managing congestion in the North American Eastern Interconnection

The NERC Interchange Distribution Calculator (IDC) has become the de-facto interconnection-wide congestion management and seams coordination tool in the North American Eastern Interconnection (EI). Since its commissioning in October 1999, the IDC has supported the NERC Reliability Coordinators in the administration of the NERC Transmission Loading Relief Procedures. The IDC has evolved to become a critical tool for the reliability of the bulk electric system in the EI, interfacing in near real time with market systems to coordinate congestion relief and inter-market seams issues. This paper introduces the NERC IDC, provides its historical background, a high level overview of the IDC transaction and power system modeling, and of the IDC information technology systems, and a view into the future evolution of the IDC.