A Coupled 3D FEM-Distribute Circuit Model for Numerical Analysis of Small Time Scale Transients of an IGBT Based Inverter

Abstract

In order to quantitatively analyze the voltage and current overshoots caused by circuit stray parameters in the fast switching-on and -off transients of an inverter, a high-order distributed circuit model of the entire power electronics system is developed, and the numerical method for stray parameter computations is included. Moreover, a novel projection technique, i.e. an enhanced Structure- Preserving Reduced-order Interconnect Macromodeling (SPRIM) methodology by integrating Input-Output structure Preserving Order Reduction (IOPOR) methodology is proposed to reduce the order of the equation sets of the aforementioned full-order circuit model. To consider the influence of the skin effect of the electromagnetic phenomenon as well the stray parameters on the transient performance of an IGBT based inverter in small and extreme small time scales, a coupled 3D finite element-circuit model is developed and an its iterative solution methodology is proposed. The comparisons between the simulated and the tested results have validated the feasibilities and merits of the proposed work.