Could you be a little more vague with your question?  What type of ripple?

No idea.  There is a doiade bridge creating the DC, so whatever makes that.  It will not change.  Some filtering is provided by the DC link caps. 

In general, it is not relevant.  Why do you ask? 

I was going through some of the technical pages and got to know a variable load on the drives generates the ripple in DC bus which cause the heating up of capacitor banks which is nothing but decrease in the life of our VFDs.

We have more than 1000 VFDs in our plant rangeing from 0.75Kw to 200Kws. This is why i am concerning about that. 

(Reputable) Drive manufacturers test their drives under greater than rated conditions. 

Yes, it is possible to heat up DC link capacitors under load. 

Yes, they are rated for this. 

No, this should not be concerned except by some academic who is publishing trivia under some publish or perish dictum.