A Physical RC Network Model for Electrothermal Analysis of a Multichip SiC Power Module

作者：Li Jianfeng; Castellazzi Alberto; Eleffendi Mohd Amir; Gurpinar Emre; Johnson Christopher Mark; Mills Liam

来源：IEEE Transactions on Power Electronics, 2018, 33(3): 2494-2508.

DOI：10.1109/TPEL.2017.2697959

• Curve fitting
• finite-element (FE) methods
• MOS-FETs
• resistor-capacitor (RC) network
• SiC power module
• three-phase inverters

This paper is concerned with the thermal models which can physically reflect the heat-flow paths in a lightweight three-phase half-bridge two-level SiC power modulewith six MOS-FETs and can be used for coupled electrothermal simulation. The finite-element (FE) model was first evaluated and calibrated to provide the raw data for establishing the physical resistor-capacitor (RC) networkmodel. Itwas experimentally verified that the cooling condition of the modulemounted on a water cooler can be satisfactorily described by assuming the water cooler as a heat exchange boundary in the FE model. The compact RC network consisting of 115 R and C parameters to predict the transient junction temperatures of the six MOSFETS was constructed, where cross-heating effects between theMOSFETs are represented with lateral thermal resistors. A three-step curve fitting method was especially developed to overcome the challenge for extracting the R and C values of the RC network from the selected FE simulation results. The established compact RC network model can physically be correlated with the structure and heat-flow paths in the power module, and was evaluated using the FE simulation results from the power module under realistic switching conditions. It was also integrated into the LTspice model to perform the coupled electrothermal simulation to predict the power losses and junction temperatures of the six MOSFETs under switching frequencies from 5 to 100 kHz which demonstrate the good electrothermal performance of the designed power module.

• 出版日期2018-3