Introduction: The Dynamic Thermal Rating (DTR) concept is based on the observation that the first limit for the current carrying capacity of a circuit is its temperature, influenced by its ability to dissipate to the environment the heat produced by the joule effect, and by external conditions such as ambient temperature, or wind speed, which are constantly varying. Even though the mechanisms of heat exchange involved are well understood, determination of the correct value of the circuit temperature is non-trivial. For this reason, static ratings based on the worst case scenario are often used.

Objectives: The implementation of a DTR system in an electrical network could potentially increases its average rating whilst also reducing, the risk of component thermal overload. However, successful implementation requires a number of challenges to be overcome. Not least the measurement, estimation and communication of real time component temperatures and prevailing weather conditions over a wide geographical area containing a significant number of power system components distributed around a complex terrain.

A successful DTR system could be used as a decision support tool for DNOs. This tool could be used both at the planning stage and in real time within potential future active network management philosophies in order to safely increase the utilization of power systems and facilitate Distributed Generation (DG).