Critical span identification model with critical periods for dynamic thermal rating equipment arrangement

¹ Key Laboratory of Power System Intelligent Dispatch and Control Ministry of Education (Shandong University), Jinan, Shandong Province, 250061, China
² Shandong Electric Power Dispatching and Control Center, Jinan, Shandong Province, 250022, China

^* Corresponding author: wangmx@sdu.edu.cn

Abstract

Compared with static thermal rating (STR), dynamic thermal rating (DTR) technology can explore the potential current-carrying capacity of overhead lines and bring considerable economic benefits. Considering that there are many spans of the overhead line, it is uneconomical to arrange equipment on each span. It is necessary to balance the investment cost and evaluation accuracy, and select the spans that can represent the current-carrying capacity of the whole line for monitoring. These spans are called ‘critical spans’. The critical spans are the spans with low DTR, and these current-carrying capacities limit the increase of the current of the whole line, which are most likely to exceed the current limit. The current along the overhead line is constantly fluctuating, and it is possible to exceed the current limit only when the current is large and exceeds the STR. In this paper, the periods are filtered before selecting the critical spans, which are called the ‘critical periods’. Considering the above factors, this paper proposes a critical span identification model of overhead line considering the critical periods. While selecting the critical spans, it also ensures that each span does not violate the ground clearance.