The benefits of using step-wise rating based on the trending of solar radiation and ambient temperature for high voltage transmission line in Malaysia

Abstract

Traditional static line ratings for transmission lines usually take into account the worst case assumptions when determining line capacity rating. In Malaysia, these conservative ratings have been around for approximately 40 years. The values used for ambient temperature, wind speed, solar radiation and other parameters have never been reviewed and thus the same ratings have been used for the past decades. In this regard, it is uncertain if the values assigned to the parameters are still relevant for the present and future application due to the fact that solar radiation values are not static and changes over time. Therefore, the level of certainty in which grid infrastructure is utilised in a highly efficient manner in transmitting power and electrical energy is debatable. This paper looks into the benefits that would be gained, in terms of added capacity and monetary gains by implementing a Step-Wise line rating on Malaysia’s overhead transmission line based on the annual trending of actual solar radiation and ambient temperature values. It is found overhead lines that is operated under voltage levels above 132 kV and more bundles configurations shows promising financial benefits.