**Paweł Górecki and Krzysztof Górecki \***

Department of Marine Electronics, Gdynia Maritime University, Morska 83, 81-225 Gdynia, Poland; p.gorecki@we.umg.edu.pl

**\*** Correspondence: k.gorecki@we.umg.edu.pl

Received: 18 May 2020; Accepted: 10 June 2020; Published: 12 June 2020

**Abstract:** This study proposes an electrothermal averaged model of the diode–transistor switch including insulated gate bipolar transistor (IGBT) and a rapid switching diode. The presented model has the form of subcircuits dedicated for simulation program with integrated circuit emphasis (SPICE) and it makes it possible to compute characteristics of DC–DC converters at the steady state considering self-heating phenomena, both in the diode and in IGBT. This kind of model allows computations of voltages, currents and internal temperatures of all used semiconductor devices at the steady state. The formulas used in this model are adequate for both: continuous conducting mode (CCM) and discontinuous conducting mode (DCM). Correctness of the proposed model is verified experimentally for a boost converter including IGBT. Good accuracy in modeling these converter characteristics is obtained.

**Keywords:** IGBT; DC–DC converter; electrothermal model; averaged model; thermal phenomena; self-heating; diode–transistor switch; power electronics
