Real-time market-to-market coordination in interregional congestion management

In an interconnected system (e.g., the Eastern Interconnection), there are multiple regional transmission organizations (RTOs) or independent system operators (ISOs) such as Midcontinent Independent System Operator, Inc. (MISO), New York Independent System Operator, Inc. (NYISO), PJM Interconnection, L.L.C. (PJM), and Southwest Power Pool, Inc. (SPP). The congestion management is a complex issue because the transmission congestion can be affected by more than one entity's market operations. The interregional congestion management among RTOs is needed to coordinately manage the transmission constraints for electricity market entities. In this paper, the real-time market-to-market (M2M) coordination is described in detail to ensure that congestion is managed by using least-cost generation redispatch. The market flow is used to quantity the impact of market operation on any constraint and plays a critical role in the M2M process. The M2M mechanism not only provides the most economical solution for controlling constraint, but also helps improve the power system reliability by utilizing the generation resources including renewal energy in both markets. It has been successfully adopted by RTOs such as MISO-PJM, PJM-NYISO, and MISO-SPP. A demonstration example is described to illustrate the real-time M2M coordination process and its effectiveness in managing the transmission congestion.