Lumped-parameter-based thermal analysis for virtual prototyping of power electronics systems

Virtual prototyping of power electronics systems can enable rapid and iterative design process, and can satisfy the need for higher power density. Thermal modelling is a key part in the multi-physics virtual prototyping. In this paper, the T-type steady-state lumped-parameter model (LPM) for a naturally cooled heat sink with a power device on top is established. Empirical equations for the convection heat-transfer coefficient calculation are provided, which prove to be much faster compared with computational fluid dynamics (CFD) with acceptable error. The sensitivity of the predicted temperature to the mesh size of the heat sink for the LPM method is analysed, providing a way to find the most efficient mesh size. Lastly, the LPM is compared to the finite difference method (FDM) in steady state and shows competitive advantages in terms of speed and accuracy.