Large time-scale electro-thermal simulation for loss and thermal management of power MOSFET

In power electronics systems the management of power loss and temperature of switching devices is indispensable for the reliability of the whole system. In this paper, a simple electro-thermal simulation model is presented. This simulation model is capable of predicting the power loss and estimating the junction temperature of power device in various environmental conditions. The electro-thermal model is composed of electrical network model, semiconductor device model and thermal network model. These parts interact with each other to calculate the loss and temperature of device and parameters of each model. By focusing on the slow dynamics of heat sink temperature, the proposed model can be employed for the large time-scale simulations. A 200 W boost converter using a power MOSFET as an active switch and adopting a natural convection cooling aluminum heat sink as a cooling device was taken as an example system. The experimental results are compared with the predicted values of the simulation model.