In motor drive application the high voltage dc link between the rectifier and the inverter usually have:

  • a bank of aluminium electrolytic capacitor
  • a film capacitor near the inverter

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Is there a reason for using a film capacitor on the high voltage dc link instead of a ceramic capacitor?

Are ceramic capacitor suitable for this application in terms of performance? I have seen that nowadays smd high voltage ceramic capacitor are available at low price.

  • \$\begingroup\$ what kind of capacitance would you use? \$\endgroup\$ – Christian Feb 17 '17 at 14:32
  • \$\begingroup\$ I'm not 100% on this but x or y rated capacitors are not available in ceramic but they certainly are for film types. Now go check why x or y rated capacitors are needed for this type of application. \$\endgroup\$ – Andy aka Feb 17 '17 at 14:44
  • \$\begingroup\$ Y caps are found in ceramic and some are X as well. I don't believe DC link caps are usually X or Y however. The advantage of film caps is size. Film caps for link applications are found into the 10s of uf at least. There are DC link ceramics but I don't know to what size. The advantage of ceramics would be exceptionally low ESR and ESL, often a big deal for link caps. DC link films often have special construction to get low ESR/ESL. Sometimes VERY special. \$\endgroup\$ – Robert Endl Feb 17 '17 at 15:38

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