Method for rating power cables buried in surface troughs

An alternative method is detailed by which the ambient temperature paramete r as applied to the calculation of ratings of cables buried in surface trou gh installations can be determined. Improvement in the accuracy of cable ra ting calculations will allow greater utilisation of the cable asset and ass ist for example in the planning of system outages for maintenance work. The proposed model calculates the temperature at the cable burial depth based on measurements of solar radiation, windspeed and air temperature. The mode l is based on physical laws rather than empirical approaches that have been shown to be generally conservative in application. Results based on weathe r data monitored over a two-year period show that the ambient temperature o f the soil at cable depth can be accurately determined and the model provid es a significant improvement on existing methods.