Device and Component Modeling
Technical Lecture Session
Wide Bandgap Device and Circuit Modeling
ground current, filter inductors, general three-terminal equivalent circuit, behavioral modeling, double-pulse test.
This paper addresses the phenomenon of ground current in filter inductors of medium-voltage SiC-MOSFET-based converters with a grounded core/frame. The inductor ground current is generated during the switching transients due to the capacitive coupling between the winding and the core/frame. A general three-terminal equivalent circuit is proposed for representing the capacitive couplings of the filter inductors, which allows the extraction of equivalent admittances between the terminals using the system identification tool, and thus the ground current can be accurately simulated in the frequency range of concern (up to 100 MHz in this paper). Time-domain simulations based on the identified behavioral model are performed. The simulated waveforms of ground current match closely with the experimental results measured in a medium voltage SiC MOSFET based double-pulse test.