Enhanced Weather Modelling for Dynamic Line Rating

  • Supervisor: Dr Keith Bell (University of Strathclyde), Prof David Infield (University of Strathclyde) and Prof Adrian Bowman (University of Glasgow)
  • Sponsoring Company: Scottish Power Energy Networks
  • PhD Student: Fulin Fan

The positive correlation between power flows and the ampacity of overhead lines has been widely noted for overhead lines that connect wind farms to the main interconnected transmission system (MITS). That is, when speeds are high, the output of a wind farm will be high meaning that power flows on overhead lines connecting it will be high. However, the same high wind speeds will provide cooling for the nearby overhead lines meaning that the safe level of power transfer will be higher than the standard, ‘static’ ratings set using conservative assumptions regarding wind speed and ambient temperature. These ‘dynamic’ or ‘real-time’ ratings can be exploited to reduce curtailment of available wind power or reduce or avoid reinforcement of the connection.

An earlier approach to estimation of ‘dynamic’ overhead lines ratings used real-time weather data plus a simple spatial interpolation method to infer the weather conditions for each span of the overhead line, and then a model of the overhead line. The primary objective of the Strathclyde project is to not only provide ‘real time’ ratings but also forecasts of ratings so that system or wind farm operators have time to take action to mitigate the consequences of limitations of power transfer or, alternatively and where possible, to exploit additional power transfer headroom. In addition, forecasts will provide not just as a single value for single future moment in time but in the form of percentiles describing the probability of being exceeded so that the system operator can make an informed judgement about risk.