The Influence of Wind Speed on the Thermal Imaging Clarity Based Inspection for Transmission Line Conductors

Infrared thermal inspection is the primary way to detect transmission line conductor faults. Nevertheless, the conventional inspections are carried out at low wind speeds, causing high investment and low efficiency. Besides, the relationship between wind speed and infrared image clarity of transmission lines has yet to be investigated. In this paper, a temperature difference-based definition of infrared imaging contrast that quantifies image clarity is firstly proposed. To explore the relationship between thermal imaging contrast and wind speed, thermal cycling tests are carried out. Based on tests and membership frequency research, a method for predicting whether a clear image could be obtained is derived. In addition, the accuracy of the proposed method is verified in a natural environment. The results show that wind speed is the only variable that affects infrared imaging contrast. High clarity image can be acquired when the contrast ranges from 0.35 to 0.78. Moreover, the average error between the practical and calculated values of contrast in the natural test is 9.1%, indicating that the proposed method is effective. The conclusion in this work provides feasible guiding significance for the infrared thermal imaging inspection engineering of overhead transmission lines.