
24-1
24.1 Introductory Considerations
Variable speed electric drives are nowadays utilized in almost every walk of life, from the most basic
devices, such as hand-held tools and other home appliances, to the most sophisticated ones, such as
electric propulsion systems in cruise ships and high-precision manufacturing technologies. Depending
on the application, the control variable may be the motor’s torque, speed, or position of the rotor sha.
In the most demanding applications, the requirement is to be able to control the electric machine’s elec-
tromagnetic torque in order to be able to provide a controlled transition from one operating sp ...