Investigation of high-frequency ice-melting in overhead ground wires based on electromagnetic-thermal coupling and excitation probing: current-frequency relationship and regulation margin

• A method for conducting quantitative research on the relationship between the maximum and minimum ice-melting currents and frequencies of overhead ground wires covered with ice was proposed. • This paper systematically investigates the relationship between the ice-melting current, its regulation margin, and environmental changes. This fills the gap in the research on high-frequency ice-melting of overhead ground wires. • This study has provided a specific chart showing the relationship between the ice-melting current, its regulation margin, and frequency. At the same time, detailed data and specific conclusions have been obtained. This goes beyond the exploration of general principles in previous studies. • The detailed research in this paper provides specific data for the design and manufacture of the ice-melting power supply. There are also important theoretical guidelines for the formulation of the ice-melting strategy. The rising occurrence of extreme climate events worldwide is exacerbating power grid-related disasters. Ice accretion on overhead lines threatens the safe operation of power grids. Overhead ground wires are more prone to icing owing to the absence of electrical current and their higher installation height compared to transmission conductors. Utilizing an electromagnetic-thermal bidirectional coupling model, this research introduces a method for quantifying the minimum and maximum ice-melting currents across various frequencies via excitation probing. This study examines overhead ground wires in a Direct Current transmission project, quantitatively analyzing the relationship between ice-melting current and frequency, as well as the current regulation margin. The research also investigates how wind speed and ambient temperature affect both the ice-melting current and its regulation margin. Results indicate that the current displays a concave, monotonically decreasing relationship with frequency, while the regulation margin shows no monotonic behavior. Temperature exerts a more substantial influence on the regulation margin than wind speed. This work enriches the research on high-frequency ice-melting techniques for ground wires and provides valuable references for designing and manufacturing high-frequency ice-melting power supplies. Furthermore, it holds practical implications for the development of ice-melting strategies.