An Algorithm for Calculating the RMS Value of the Non-Sinusoidal Current Used in AC Resistance Spot Welding

• Journal title : Journal of Power Electronics
• Volume 15, Issue 4,  2015, pp.1139-1147
• Publisher : The Korean Institute of Power Electronics
• DOI : 10.6113/JPE.2015.15.4.1139
Title & Authors
An Algorithm for Calculating the RMS Value of the Non-Sinusoidal Current Used in AC Resistance Spot Welding
Zhou, Kang; Cai, Lilong;

Abstract
In this paper, an algorithm based on a model analysis of the online calculation of the root-mean-square (RMS) value of welding current for single-phase AC resistance spot welding (RSW) was developed. The current is highly nonlinear and typically non-sinusoidal, which makes the measuring and controlling actions difficult. Though some previous methods focused on this issue, they were so complex that they could not be effectively used in general cases. The electrical model of a single-phase AC RSW was analyzed, and then an algorithm for online calculation of the RMS value of the welding current was presented. The description includes two parts, a model-dependent part and a model-independent part. Using a previous work about online measurement of the power factor angle, the first part can be solved. For the second part, although the solution of the governing equation can be directly obtained, a lot of CPU time must be consumed due to the fact that it involves a lot of complex calculations. Therefore, a neural network was employed to simplify the calculations. Finally, experimental results and a corresponding analysis showed that the proposed algorithm can obtain the RMS values with a high precision while consuming less time when compared to directly solving the equations.
Keywords
Model-independent;Neural network;Nonlinear;RMS value;Single-phase AC RSW;
Language
English
Cited by
1.
Design of integrated neural network model for weld seam tracking and penetration monitoring, Cluster Computing, 2017
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