Which procedure is used to curtail transactions and reduce power flows?

Transmission Loading Relief is a procedure implemented by system operators to manage the flow of electricity on power transmission lines that are nearing their capacity limits. When the transmission system becomes overly congested, meaning that the power flows exceed the allowed limits for safety or reliability, Transmission Loading Relief helps to reduce those flows.

This is achieved by curtailing certain transactions, which can involve reducing the amount of power being transmitted from one point to another or limiting the generation from certain plants. The goal is to ensure that the power system remains stable and reliable, preventing potential outages and ensuring compliance with operational limits.

In contrast, load shedding is a method used predominantly during severe supply shortages, where power distribution to certain consumers is intentionally curtailed to maintain system stability. Emergency operations refer to a broader set of protocols that may be activated during crises, dealing with more than just transmission loading. Phase angle regulation involves managing the angles of phase voltages to maintain system stability and balance but isn’t specifically a method for curtailing transactions or reducing power flows in the same manner as Transmission Loading Relief.