Analysis of Proportional Integral and Optimized Proportional Integral Controllers for Resistance Spot Welding System (RSWS) _ A Performance Perspective

International Conference on Materials, Alloys and Experimental Mechanics 2017

材料科学;金属学;机械制造

Rama Subbanna, S.^1 ; Suryakalavathi, M.^2

JNTUA, Anatapur, India^1

Departement of Electrical and Electronics Engineering, JNTUH, Hyderabad, India^2

关键词: Current control techniques;    Medium frequency transformer;    Piecewise-linear controls;    Proportional integral controllers;    Resistance spot welding;    Total harmonic distortion (THD);    Transformer secondaries;    Welding transformers;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/225/1/012175/pdf
DOI  :  10.1088/1757-899X/225/1/012175

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

This paper is an attempt to accomplish a performance analysis of the different control techniques on spikes reduction method applied on the medium frequency transformer based DC spot welding system. Spike reduction is an important factor to be considered while spot welding systems are concerned. During normal RSWS operation welding transformer's magnetic core can become saturated due to the unbalanced resistances of both transformer secondary windings and different characteristics of output rectifier diodes, which causes current spikes and over-current protection switch-off of the entire system. The current control technique is a piecewise linear control technique that is inspired from the DC-DC converter control algorithms to register a novel spike reduction method in the MFDC spot welding applications. Two controllers that were used for the spike reduction portion of the overall applications involve the traditional PI controller and Optimized PI controller. Care is taken such that the current control technique would maintain a reduced spikes in the primary current of the transformer while it reduces the Total Harmonic Distortion. The performance parameter that is involved in the spikes reduction technique is the THD, Percentage of current spike reduction for both techniques. Matlab/SimulinkTMbased simulation is carried out for the MFDC RSWS with KW and results are tabulated for the PI and Optimized PI controllers and a tradeoff analysis is carried out.