Characterization of power electronics system interconnect parasitics usingtime domain reflectometry

The significance of interconnect parasitics of power electronics systems is their effects on converters' electromagnetic interference (EMI)-related pe rformances, such as voltage/current spikes, dv/dt,di/dt, conducted/radiated EMI noise, etc. In this paper, a time domain reflectometry (TDR) measureme nt-based modeling technique is described for characterizing interconnect pa rasitics in switching power converters. Experiments are conducted on power components of a prototype high-power inverter, including insulated gate bip olar transistor (IGBT) modules, busbar, and bulk capacitors. It is shown th at the interconnect inductance of the IGBT module can be extracted complete ly using TDR, It is also shown that the busbar equivalent circuit can he mo deled as transmission line segments or L-C filter sections, and the bulk ca pacitor contains a significant equivalent series interconnect inductance.