Decrease of inductance and electromagnetic interference in power electronics capacitors

Abstract

Pierron and Glaize (1992) have demonstrated that it is possible to decrease drastically parasitic inductances of wiring in commutation cells. But the inductance of capacitors still remains. Furthermore, in power electronics, problems of capacitors' inductance are well known: peaks of voltage in snubber capacitors (L dI/dt); output voltage ripples; perturbations in DC power supplies; low self-resonant frequencies (beyond this frequency, capacitors behave like an inductance), reduction of the lifetime of the whole circuit; switching capacitor disruption of operation of adjustable-speed drives; and especially electromagnetic interference (EMI). Here, from the study of standard capacitors, the authors have looked for solutions to reduce both inductance and EMI.