[blattimwind]

Worth pointing out that due to their efficiency, what this has to be about is not making the motors more efficient, but reducing the power output, e.g. by making the driven mechanical load more efficient.

Edit: Skimming the article makes it sound like they switched from U/f control to vector control.

[_trampeltier]

Yes, every AC motor with IE3 has already an effciency something like 90 to 92%. For the double price you can get a synchron motor with an effciency around 95%. Inverters for the drive generate heat in the cabinet .. so you do need active cooling quickly in the cabinet. So somebody also has to change and clean the filters. Just be careful with all the numbers.