Application of a dynamic thermal rating system to a 132kV distribution network

This paper presents learning points from the application of a dynamic thermal rating (DTR) system to a 132kV distribution network. The DTR system incorporates over 90km of 132kV overhead lines and is being deployed to facilitate the connection of in excess of 200 MW of wind generation. The benefits and principles of this DTR system are stated, and initial results from the deployment are presented. The system architecture is discussed and the process by which it evolved from a single-circuit field trial to a geographically disperse system, covering seven meshed circuits, is described. Key elements of the DTR system approach include (i) the system architecture (using intelligent remote terminal units (RTUs) to process and condition the system data); (ii) the system data requirements; (iii) the methodology used for locating the meteorological stations (which underpin the DTR system); (iv) the use of direct conductor temperature sensors to provide additional thermal visibility of the network; and (v) the requirements to ensure that long-term system reliability is maintained, whilst also considering the repeatability of the system for other network areas. The experiences described in this paper may serve as a useful reference for any other DNOs looking to adopt DTR systems.