Simulation of a uniform energy control strategy of single-phase AC resistance spot welding

A uniform energy control strategy for single-phase AC resistance spot welding (RSW) was proposed in this paper. Through seriously analyzing the welding process, a variable, which is the product of square of welding current and welding time (I²t), can be considered as an ideal control variable to ensure the uniform energy delivery. It can be translated to constant current control in reality. However, when the winding ratios of the welding transformer are different, direct translation can obtain incorrect result. Then, the effect of different winding ratios on welding current was studied, and a method which can obtain a corresponding constant welding current when different number of windings were employed was proposed. Final simulation and corresponding analysis validated the proposed method, and the method can be employed to facilitate the current welding production. This work provides a convenient and effective method for welding control when different ratios of welding transformer are employed.