See post #54.
I don't know if I explained it very well.
As it happens, I was a question I was asked on site today.
I've spent the last three days on site with my guys getting a couple of 3,000HP, 11,000V variable speed fan drives back up and running after a major supply problem had taken out much of the electronics.
Centrifugal fans have a cube law curve for power. Double the speed, eight times the power. (2^3)
So, at half rated speed, the motor ought to be at one eighth of rated power.
In this case, the speed range is from half speed to full speed. Ought to be under 400kW at minimum speed.
One guy, a sharp cookie from the customer's side asked why the stator current was still relatively high at such a relatively light load.
The answer is simply that the power factor is so much worse on lighter loads.