Effect of key physical structures on the laminated bus bar inductance

Due to the low stray inductance of the laminated bus bar, it is now widely used in power electronic applications with large power. The bus bar inductance can lead to voltage spikes on the switches and unequal current distribution on the DC capacitors connected to the bus bar. The bus bar inductance has been noticed for a long time, but without systematic investigation and even with some misleading conclusions. This paper addresses the effect of key physical structures on the laminated bus bar inductance, as a start of a systematic investigation on the bus bar inductance. The structures include the physical dimensions of the bus bar, the apertures through the bars and the terminals. The 3D finite element (FE) electromagnetic (EM) simulation is employed for the inductance calculation and the fundamental electromagnetic mechanism is studied for the effect. Some existing conclusions are corrected after the systematic analysis.