What process is used to curtail an interchange transaction that crosses an interconnection boundary?

The process used to curtail an interchange transaction that crosses an interconnection boundary is Transmission Loading Relief (TLR). This method is implemented when there is a need to manage transmission constraints and ensure reliability across interconnected systems. TLR is specifically designed to handle situations where the transfer capability of the transmission lines is exceeded, requiring a reduction in power flows to maintain system stability.

When an interchange transaction is curtailed, TLR allows operators to prioritize or limit flows based on system needs while taking into account the reliability of both the sending and receiving areas. The process involves communication among system operators and follows established protocols to manage the situation effectively, ensuring that reliability is maintained without jeopardizing the stability of the grid.

In contrast, the other choices relate to different aspects of power system management. Interconnection Coordination refers to the collaborative efforts among different operators to ensure smooth operations across interconnections but does not specifically address the curtailment of transactions. Emergency Load Shedding is a response to immediate reliability threats, often involving the disconnection of loads during severe conditions, while Voltage Stability Analysis focuses on maintaining voltage levels rather than managing transactions.