Multitimescale Thermal Network Model of Power Devices Based on POD Algorithm

The heat transfer of power devices has the characteristics of multitimescale. However, the traditional thermal network model is difficult to predict the temperature information of power devices at multitimescale accurately. This article proposes a multitimescale thermal network model for power devices, with metal-oxide-semiconductor field-effect-transistor (
mosfet
) as an example. First, we establish a finite-element model for temperature calculation of power devices and then reduce the order of the finite-element model based on the proper orthogonal decomposition algorithm. The reduced-order model is converted into an equivalent circuit model by the node voltage method and integrated into the circuit simulation software. To demonstrate its general applicability, this article also establishes thermal network models for both insulated gate bipolar transistor (IGBT) and SiC
mosfet
devices, and validates the multitimescale thermal network models through ANSYS/transient thermal software and experiments. The temperature calculation results of the three power devices all indicate that the proposed multitimescale thermal network model can calculate the temperature of power devices faster than the ANSYS/transient thermal model and has less than 5% error under test conditions. This article is accompanied by a video demonstrating a comparison of the computational speed of the multitimescale thermal network model with a finite-element model. Finally, a case study of junction temperature calculation in a buck converter is presented to illustrate the application method of the thermal network model.