Investigation into the influence of environmental conditions on power system ratings

Abstract

This paper presents research which seeks to assist distribution network operators in the adoption of real-time thermal rating systems. The exploitation of power system rating variations is challenging due to the complex nature of environmental conditions such as wind speed. The adoption of a realtime thermal rating system may overcome this challenge and offers perceived benefits such as increased distributed generation accommodation and avoidance of component damage or premature ageing. Simulations, using lumped parameter component models, are used to investigate the influence of environmental conditions on overhead line, electric cable and power transformer ratings. Key findings showed that the average rating of overhead lines, electric cables and power transformers ranged from 1.70 to 2.53, 1.00 to 1.06 and 1.06 to 1.10 times the static rating, respectively. Since overhead lines were found to have the greatest potential for rating exploitation, the influence of environmental conditions on four overhead line types was investigated and it was shown that the value of a real-time thermal rating system is location dependent. Furthermore, the additional annual energy yield from distributed generation that could be accommodated through a real-time thermal rating system deployment was quantified for a specific case and found to be 54%.

Comparison between IEEE and CIGRE Thermal Behaviour Standards and Measured Temperature on a 132-kV Overhead Power Line

“…Thus, if the different conductor cooling and heating processes are measured in real time, the maximum instantaneous practical current can be measured (dynamic ampacity) without reaching the maximum thermal rating [13,14]. This is why dynamic ampacity is considered to be a more efficient control parameter of the power grid than static ampacity.…”

Dynamic Network Rating for Low Carbon Distribution Network Operation—A U.K. Application

“…Michiorri et al [26] discussed system ratings considering distributed generation accommodation. Although all types of assets were included in this literature, the network dynamic rating was not identified or analyzed.…”

A Comparison of Real-Time Thermal Rating Systems in the U.S. and the U.K.

“…The potential benefits of each of these components is discussed in [2]. However, for the trial site considered by this paper, only overhead lines are considered.…”