Modeling and simulation of IGBT thermal behavior during a short circuit power pulse

The thermal behavior knowledge of IGBT devices is very important to address issues related to the thermal management. Experimental measurements could provide the junction temperature of the devices in transient or steady state conditions. However, in case of short circuit, it became very difficult to get the temperatures because of the very short time in which the phenomenon happens (order of microseconds). Fortunately, thermal models represent a valid aid for the designers to predict the junction temperature but such models fail when used to study the short circuit. This paper deals with a new thermal model to address the temperature prediction in short circuit condition and it is composed by two different sub-models. The first can predict the heating phase of the phenomenon in a limited volume of the device without heat exchange, while the second is generated by taking into account a greater volume with the parameter values and physical sizes of the layers affected by the heat produced in short circuit.