Finite element analysis for power electronics EMC applications

A CAD system for the analysis of power electronic circuits for EMC applications is being developed. The system is based on 3-dimensional finite-element electromagnetic field computations, with the source currents or voltages extracted either from measurements or from standard circuit analysis. The finite-element solver for this application is configured in terms of magnetic vector potential (A_) and modified electric scalar potential (V'), incorporating, unusually, the Coulomb gauge /spl nabla/.A_=0. Comparisons of computed electromagnetic fields with measurements of fields emitted from a 600 V, 300 A IGBT switching circuit are reported. Agreement in magnetic field strength is fair (within 8 dB/spl mu/A/m) at the low frequencies (10 kHz-20 kHz) considered.