Selecting film bus link capacitors for high performance inverter applications

For years design engineers have chosen electrolytic capacitor technology for use as the bus link capacitor on inverter designs. The main attraction has always been the low cost per farad associated with electrolytic capacitors. This paper will present a practical mathematical approach on how to properly size a bus link capacitor for a high performance hard switched DC to AC inverter using film capacitors and will show how film capacitors are advantageous over electrolytic capacitors in terms of size, weight, lifetime, inverter efficiency and cost.