What are you inverting? Is this a battery to mains (UPS or portable) application, or high frequency?
For switching converters, if you're going to go to the trouble, it's traditional to forego the link cap altogether and feed somewhat rippled DC current, right from the inductor into the inverter. I which case it's a current fed inverter, and the switching and snubber physics is somewhat upside down from the usual voltage-fed case.
If you heard anything about the Google Little Box competition, literally
25% of that project was input filtering: the rules required fairly low input ripple, which requires a certain amount of energy storage to smooth out the output current pulses. Energy storage is energy storage; doing it passively requires quite a bit of electrolytics. Active, you can use a smaller, denser capacitor (one build used $1000 worth of special electret (polarized) ceramic capacitors), but you need a whole 'nother converter stage and inductor(s), costing efficiency and almost the same space.
Tim
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: http://seventransistorlabs.com
"Yzordderrex" wrote in message
news:f8e0ccb6-7211-4149-918e-0864b017602f@googlegroups.com...
I am curious if there any guidelines or rule of thumb for inverter input
current. I can design an inverter with a very small DC link capacitor and
control the current going into the inverter to a high degree with a
full-bridge converter. Essentially this current will mimic the output
current so the capacitors see little ripple current. This will of course
result in a large 120Hz component and some higher order harmonics from the
battery. The other option is to place a large amount of capacitance on the
bus and pull DC current out of battery with little AC current.
I suppose the answer lies somewhere between the two - I am just looking to
hear of any experience with commercial, military or ??
regards,
Yzordderrex