Experimental Determination of Efficiency and Power Losses in Resistance Welding Machines

摘要

Analysis of efficiency and power losses experimentally determined in two different spot resistance welding systems is presented in the paper. Efficiency of the above named systems are result of influence of such components like power converters, transformers, current leads (arms) and electrodes, which generates power losses in welding system. The goal of the investigation is the qualitative and quantitative analysis of efficiency and power losses in the main parts of selected welding machines. The analysis was carried out for two different machines, i.e. an AC welding machine (operating at grid frequency) and a DC welding machine with internal power conversion system (switching frequency 1 kHz). Systems operated using the same output current of 10 kA and were supplied by power network voltage (3×400/230 V; 50 Hz). The results are obtained by measurements of a real welding systems.