Analysis of thermal mode of transistors in welding inverter

  • 1 Institute of Metal Science, Equipment, and Technologies with Center for Hydro- and Aerodynamics “Acad. A. Balevski” at the Bulgarian Academy of Sciences – (IMSETHC-BAS), Bulgaria


A methodology for thermal analysis of the operation of transistors in a welding inverter is proposed. The results for heating of the transistors obtained by numerical modelling using the finite element method (FEM) are presented. A thermal problem has been solved taking into account the forced movement of air. Based on the obtained solutions, the maximum temperatures on the surface of the heat sink and in the crystal of the field-effect transistor are presented, depending on the speed of air movement and the temperature of the environment in continuous mode of operation of the power source. The presented analysis is applicable to select appropriate heat sink and fan. Results are useable during design of the power source oriented to wire arc additive manufacturing.



  1. Heat Sink Design Facts and Guidelines for Thermal Analysis.
  2. M. Imran and S.A. Moeed, IJERT, 10, 06 (2021), DOI : 10.17577/IJERTV10IS060362
  3. I. Mehmedagic and J. Krug ARMET-TR-15036, (2015)
  5. T. Fedorov Silovaia elektronika 1 (2018) (in Russian)
  6. 5610/Application_Notes_Proton_Electrotex_ru.pdf
  7. Simplified method for estimating heat sink thermal resiatance – ӨSA in forced convection applications,
  8. Current and temperature ratings. Coilcraft, Document 361, Revised 12/04/18
  10. J. Bartl and M. Baranek, Measurement science review 4 3 (2004)
  11. Total emissivity of various surfaces (web resource)
  12. M. Ghane and E. Ghorbani, Autex Research Journal, 16, 3 (2016) DOI: 10.1515/aut-2015-0021
  13. F.P. Incropera and D.P. DeWitt Fundamentals of Heat and Mass Transfer, 5th ed. (John Wiley & Sons) (2002)
  14. N. Bankov and T. Grigorova Modeling of a Control System of a Transistor Resonant Inverter (ICEST 2004 16-19 June 2004 Bitola, Macedonia) p 391-394 (2004)
  15. A.V. Lebedev The Paton Welding Journal 9 (2012) p30-36 (2012)
  16. G.M. Kunov, M. Popov and E. Gadjeva, Comparison of Energy Factors of Transistor Invertors for Induction Heating Using PSpice (ICEST 2004 16-19 June 2004 Bitola, Macedonia) p 517-520 (2004)
  17. H. Mecke, W. Fischer and F. Werther, Soft Switching Inverter Power Source for Arc Welding (European Conference on Power Electronics and Applications 4 (1997)

Article full text

Download PDF