Critical span identification model for dynamic thermal rating system placement

DTR system is one of the efficient ways to increase the utilization of the transmission line capacity. Ideally, its application requires the deployment of sensors on each span of the transmission line. This is because a transmission line normally traverses a large geographical area and is affected by various weather conditions. Consequently, each span elongates differently and has different thermal ratings from one another. However, due to the large number of spans, it is uneconomical to place sensors in each span. Whilst doing that, it is also vital to ensure that the ratings given by the DTR system do not cause overrating in any spans to the point of causing ground clearance infringement. Among the spans, some appear to have lower thermal capacity due to its undesirable surrounding weather conditions. These spans may also have smaller ground clearances. In this paper, these spans are also known as the critical spans. By monitoring only these critical spans, the transmission line ratings obtained can be safely applied to all other spans without the risk of ground clearance infringement. Hence, this paper proposes a novel critical span identification technique for the optimum placement of DTR sensors. By monitoring only the critical spans, we manage to show that ground clearance infringement was avoided and high correlation with actual line ratings was achieved.