Time-frequency analysis of the current measurement by hall effect sensors for electric arc welding machine

Abstract

In this study, electrical current drawn by an electric arc welding machine (EAWM) is analyzed in frequency domain as a spectral approach. A hall effect sensor is used to get the current drawn by the welter in terms of measurement component. During this study, the stages of the welding process, defined between the material and electrode, are examined. These stages are initial case; transient case and operation case respectively. In this manner, some frequency components are determined for these cases to define the welter behavior. According to the results, side band, which appeared between the 45 - 55 Hz with difference of 5 Hz at around the fundamental frequency 50 Hz, is dominant characteristic. Also, another current related property is the second harmonic of the fundamental frequency. Other band effects are also observed at the outside of the first band between 45 - 55 Hz however these effects are minor. All frequency characteristics are presented on the time-frequency plane and hence, the time-frequency relationship components are easily determined in this way.