Abstract:

The estimation of the junction temperature (Tj) is very important factor for improving the reliability and efficiency of the power electronic converters. A new electro-thermal (ET) model of low voltage power MOSFET is described in this paper. The electro-thermal model allows fast estimation of the junction temperature, based on the transient thermal impedances (Zth) using the (RC) Foster thermal network model and total power losses. The parameters of the (RC) Foster thermal network model are extracted from the data provided by the manufacturer’s datasheet using particle swarm optimization (PSO) method. Moreover, a dc/dc Buck converter is also analyzed by simulation to evaluate the electro-thermal model. The simulation results indicate a good agreement between the proposed model and manufacturer’s data. Finally, the electro-thermal (ET) model simulation using this (RC) Foster thermal network model shows a reasonable accuracy for estimating the junction temperature in a Dc/Dc buck converter.

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