Modeling of Low Inductive Busbar Connections

The high power levels required by many power electronic applications well as the very low switching times encountered in new semiconductor devices have created a need for low wiring inductances. The busbar technology is an effective industrial way to reduce the interconnection inductance between (for instance) the feeding source and the converter. It consists of a stacking of several copper sheets, each separated from the other by a dielectric. The connections between these sheets and the different devices are made with screws. The authors present a way of modeling a busbar. Using a simulation tool, InCa, dedicated to inductance and resistance calculations, it is possible to obtain the L, R equivalent circuit of a busbar. Moreover, it allows the determination of the current density in any cross section of any busbar sheet. In order to validate the modeling, a chopper structure using this kind of connection has been realized and measurements have been made.