A Numerical Determination of Power Distribution in the Resistance Welding Machine Output Circuit

One of the most important parts of a welding system is the current loop containing the current leads and electrodes. This paper is focused on a numerical analysis of equivalent parameters (mainly inductance) and power losses of the part of a spot welding system containing current leads, electrodes and welded steel. A numerical analysis is carried out using ANSYS Mechanical APDL. The geometry and parameters of the model are based on the parameters of real welding machines manufactured by the ASPA company. The analysis described in the paper is carried out assuming DC output current with a magnitude of 10 kA. The system is made of copper elements, while the welded elements are made of two sheets of steel, each 2 mm thick. Mechanical junctions between elements, e.g. the arm and the electrode are modeled as a layer of material with higher resistivity. Comparative analysis is carried out for different geometry parameters of the model, i.e. the length of the arms, vertical distance between the arms, the width of the arms and different operational temperatures. The results of the analysis show the inductance of the current loop, current density and power loss distribution, the voltage drop along the loop and finally resistances of selected elements in the system.