Characterization of IGBT Modules for System EMI Simulation

EMI filtering is a critical driver for volume and weight for many applications, particularly in airborne and other mobile platforms. Because of the lack of ability to accurately predict system EMI behavior, EMI filter design usually cannot start until prototype EMI measurement results become available. This often leads to costly schedule delay and disruption, and the resulting design is suboptimal at the best. To solve this problem, systematic EMI modeling method is needed to enable the development of optimal system EMI solutions concurrent with the design of the rest of the system. This paper proposes a piece-wise linear model for IGBT (Insulated Gate Bipolar Transistor) modules for EMI simulation with sufficient accuracy and simplicity. Instead of physics-based models the proposed model is composed of a simple piece-wise linear circuit with parameters that can be extracted from the datasheet or simple device measurement. While the model is simple and easy to use, it can achieve sufficient accuracy required for EMI modeling. The proposed model is applied to a three-phase PFC and validated by comparison of model prediction with experimental measurements.