Grid Integration of Renewable Energy Sources: Utilization of Line Thermal Behavior

Conventionally-used transmission line static thermal ratings are often conservative and may therefore serve as an impediment to high penetration levels of renewable energy sources into the electric power grid. Utilizing actual weather conditions to dynamically determine the line thermal ratings can provide a better estimate of the power transfer capability of the existing transmission lines. In this work, the non-static thermal conditions of the overhead lines are considered during a change in weather conditions for maximum utilization of the transfer capacity of transmission lines. Changes in weather conditions result in a non-static thermal condition for the overhead conductors until the conductor reaches a new steady-state conductor temperature. Due to the thermal inertia of the line conductors, this change in conductor temperature does not happen instantaneously, rather it happens gradually over a certain period of time. This thermal property of the line conductors is coupled with the line electrical parameters in this work to maximize integration of renewable sources of energy, such as wind, into existing transmission lines.