Modeling of Conducted EMI Emissions in 10 kV SiC MOSFET Based Power Electronics Building Blocks

The concept of power electronics building block (PEBB) aims to partition and compartmentalize power converters from power processing and functionality standpoints. This allows PEBB-based converters to be configured into different topologies carrying out multiple power conversion functions. However, some design aspects such as insulation and electromagnetic interference (EMI) cannot be modeled into the same concept, as ultimately, the rating and capabilities per PEBB are dependent on the power, voltage, current, and switching frequency of the whole converter assembly and its specific power conversion function. In this paper, the high-frequency model of the PEBB 6000, an >20 MW/m
³
specific power, 1 MW, 6 kV medium-voltage (MV) power converter is developed to assess the common mode (CM) current and EMI-related issues caused by high voltage and extremely high slew rates, that can be as high as 200 V/ns. In this regard, direct measurements and finite element method (FEM) analysis are done to develop the lumped circuit model considering all nonlinearities of the 10 kV, 240 A SiC MOSFETs employed in the converter. Once the power stage and noise propagation paths models are established, simulation and experimental results are presented and compared, and the noise currents and the impact of the heatsink-to-midpoint connection are also assessed and predicted.