Note! Not all drives allow the use of a ferrite sleeve around power conductors. Refer to your manuafacturer’s manual for specific applications.
If you are confused by me saying that the current flows from positive to negative, that just happens to be a historical convention. People like Benjamin Franklin, who helped figure out the mystery of electricity back in the 18th century, believed it was a flow of positive charges, so it flowed from positive to negative. We call this idea conventional current and still use it to this day in things like Fleming Left-Hand Rule.
It is important to keep this struggle between performance and cost in mind when you talk to customers about energy-efficient motor-driven equipment. Yes, efficiency is probably more important to homeowners now than ever, but that efficient operation comes at a price. And motor manufacturers will keep working to strike that balance between motor performance, efficiency, and cost.
One way to overcome this situation is by using "magnetically soft" material. Magnetically soft material has atoms that readily reverse polarity (a docile herd?) when exposed to alternating current. Naturally, since the reversing process happens more quickly, there is less wasted energy.