We are working on a project of designing a 10KW Battery Charger to be powered by a 12.5KW, 3 phase wind generator. The frequency of the generator output varies from about 24Hz at 120A AC to 90Hz at 440V AC for min. to max. wind speed.

While researching on the subject, I came across an article by Dr. Ray Ridley on implementation of a wide range 3 phase PFC circuit using three single phase units.

Whether anyone can throw more light on PFC with variable frequency input.