2. Power supply for rolling mill motors

The frequency converters used are the same for both asynchronous and synchronous machines. At least in terms of topology, the differences lie in the controls. Converters must be reversible, either because of the reversibility of the process, or for braking reasons. Motors must be supplied with no additional stresses likely to shorten their service life, and the supply network must be free of harmonics, or as free as possible. Inverters must be capable of absorbing or supplying reactive power (supplying an asynchronous machine means supplying it with both active and reactive power).