The Impedance Calculating Method of Steel Mill Short Net Conductors Based on Finite Element Method

The short net is a high-current system with complex geometric shapes in electric furnace steelmaking. The short net impedance calculation is a necessary foundation and basis for designing short net parameters. Traditional analytical methods can difficultly calculate the impedance of short net conductors with complex geometric models. Considering the skin and proximity effects, this paper proposes a finite element method (FEM) based impedance calculation method for short net conductors. Firstly, a frequency domain model of the electromagnetic field is established, and boundary conditions are provided. Then, the FEM based on the Galerkin weighted residual method is used to discretize the established electromagnetic field differential equations. Finally, the short net conductors of a 100-ton electric furnace are taken as the rest. The results show that sudden current density change caused by cross-section change in copper tubes and conductive arms is dramatic. The difference in AC and DC resistance between copper tubes, water-cooled cables, and conductive arms is significant.