A short-term dynamic thermal rating for accommodating increased fluctuations in conductor current due to intermittent renewable energy

摘要

Implementation of a dynamic thermal rating (DTR) which periodically re-calculates conductor ampacity as ambient weather conditions change can increase line loadability when compared to the static thermal rating (STR). However, in recent years the direct use of temperature limits, whether directly or indirectly measured, has been shown to provide even higher loadability because of the conductor thermal inertia characteristic. This paper presents a short-term dynamic thermal rating referred to as dynamic electro-thermal rating (DETR), which incorporates both conductor thermal dynamics and changes in ambient weather conditions in its calculation. In this way, DETR is able to include the conductor's thermal inertia characteristics in the determination of maximum allowable current and consequently result in loadability limits that are less conservative than the DTR. Presented simulation results show that DETR would allow for higher fluctuations in conductor current as compared to the DTR and can therefore be especially useful for conductors that experience large power fluctuations due to increased intermittent renewable energy sources in the network.