Fundamentals of Electric Machines

After a brief introduction to the basic functional principle of electric machines and the three-phase system, the three main basic variants of electric machines, the induction machine, the externally excited, and the permanent magnet synchronous machine, are presented. This is followed by an overview of the designs of the stator and rotor of these three motor variants. The physical background of braking energy recovery (voltage generation) and motor operation (magnetic forces) is explained in more detail. The base speed range and the field weakening range, which were presented purely phenomenologically in the second chapter, are now introduced in detail on the basis of the magnetic properties of the motor. The chapter concludes with an overview of the properties of the materials used and the losses that occur in electric machines.