Optimal operating point of medium frequency resistance spot welding systems

Resistance spot welding manuals provide a range of recommended Welding Parameters (WP) which produce a strong weld. The weld's strength is tested out with, e.g. the tensile-shear strength test. Because different sets of WP can produce a weld with the same strength, the operator can select different sets of WP. However, the welding system's efficiency might be different when using different sets of WP. Therefore, this paper investigates the efficiency of the Medium-Frequency Direct-Current Resistance-Spot-Welding (MFDC RSW) system when operating with different sets of WP. Because the released heating energy in the welding spot is determined by the welding current value and the welding time, only these two WP are analyzed. The aim of this paper is to determine the set of WP at which the MFDC RSW system operates at the highest possible efficiency.