Abstract

The thermal analysis and management is an important issue for power semiconductor devices especially as increasing current density and power dissipation in modern power electronics applications. Nearly sixty percent of electrical and mechanical failures of power electronics devices are temperature-induced. An accurate junction temperature prediction plays an essential role in the design and optimization of power semiconductor devices.

In this dissertation, a new thermal model based on Fourier-series solution of heat conduction equation was presented in detail. One-dimensional and two-dimensional Fourier-series thermal model have been programmed in Matlab/Simulink. Compared with traditional finite difference thermal model and equivalent RC thermal network, the new thermal model can provide high simulation speed with high accuracy, which has been proved to be more favorable in dynamic thermal characterization on power semiconductor switches.

A complete electro-thermal simulation model of IGBT and power diodes under inductive load switching condition has been successfully implemented in Malab/Simulink environment. The experimental results on IGBT and power diode with clamped inductive load test have validated the new electro-thermal simulation model. The advantage of Fourier-series thermal model over widely-used equivalent RC thermal network in dynamic thermal characterization has also been proved by the measured junction temperature.