Study on the Direct Current Temperature Rise Law of Contact Wire and Supporting Cable Under Icing Conditions

In winter, the overhead contact line (OCL) of rail transit systems is highly susceptible to icing during periods without train traffic, leading to train suspensions and passenger delays. Currently, de-icing of overhead lines is mainly performed manually, as the current-based de-icing techniques used in power systems cannot be directly applied to rail transit OCLs. Therefore, this paper analyzes the temperature rise mechanism during the OCL de-icing process and establishes a thermal balance equation for OCL de-icing. After denoising with MATLAB, curve fitting and simulation are conducted. Finally, an artificial climate chamber is used to simulate the temperature rise test during the de-icing process, and the current-temperature rise curve obtained during the OCL de-icing process is validated. The study shows that the temperature rise process of the OCL and load-bearing cable during direct current (DC) de-icing is positively correlated with DC current and negatively correlated with ice thickness and external environmental conditions. Under the same current, the temperature rise of the rail transit OCL and load-bearing cable is smaller compared to power transmission lines, and the simulated temperature rise curve strongly correlates with the experimentally derived curve. The research results provide theoretical guidance for OCL de-icing.