[SOLVED] What is a DC Link Capacitor?

[mrinalmani]

While searching for polypropylene capacitors, I came across some DC Link capacitors. Their datasheet specifies absolute ratings in DC voltages. My question is:
1. Since these are polypropylene capacitors without any electrolyte, can they be used for AC applications (eg. motor starting)
2. If they can be used for AC, why are they called DC Link capacitors?
3. If they can NOT be used for AC, then why? Do they have some polarity specific construction?
4. What is the advantage of a DC link capacitor over 'normal' polypropylene capacitor?

 

[FvM]

DC link capacitors are capacitors with a DC specification. They can be used for AC as well, but you'll probably miss a specification for AC voltage rating.

There's nothing special with "DC link capacitors". They'll have low series inductance according to the application requirements, but the same can be said for other polypropylene capacitors, too.

Motor starter applications don't involve high frequent currents and AC current ratings are low relative to the capacitance. You won't particularly use PP capacitors for this application, but you can of course.

I believe that you can answer the questions yourself by reading capacitor application literature from major manufacturers, e.g. Epcos or Kemet.