A Study on the Transformer Design considering the Inrush Current Reduction in the Arc Welding Machine

The transformer used in an inverter type arc welding machine is designed to use high frequency in order to reduce its size and cost. Also, selecting core materials that fit frequency is important because core loss increases in a high frequency band. An inrush current can occur in the primary coil of transformer during arc welding and this inrush current can cause IGBT, the switching element, to burn out. The transformer design was carried out in A(p) method and amorphous core was used to reduce the size of transformer. In addition, sheet coil was used for primary winding and secondary winding coil considering the skin effect. This paper designed the transformer core with an air gap to prevent IGBT burnout due to the inrush current during welding and proposed the optimum air gap length.This work was supported by the Human Resources Program in Energy Technology of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20154030200900). This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Science, ICT & Future Planning) (No. NRF-2016R1A2A1A05005392)