1 Main Parameters of Induction Motors.- 2 Electromagnetic Space Vectors and General Equivalent Circuits.- 3 Steady-State Three-Phase Induction Motors.- 4 Steady-State Single-Phase Induction Motors.- 5 Induction Motors in Transient Regimes.- 6 Inverter-Fed Induction Motors.- 7 Induction Motors Torque Control.- Appendix A Field-Oriented Control.- A.1 Introduction.- A.2 Preliminary Investigations.- A.3 Field-Oriented Control.- Appendix B Direct Torque Control.- B.1 Introduction.- B.2 Direct Torque Control Principle.- Appendix C Double-Cage Induction Motors.- C.1 Introduction.- C.2 Voltage Equations in Double-Cage Induction Motors.- C.3 General Equivalent Circuit of Double-Cage Induction Motors.- C.4 Steady-State Equivalent Circuit of Double-Cage Induction Motors.- Appendix D Transient Analysis in Single-Phase Induction Motors.- D.1 Introduction.- D.2 Transients in Three-Phase Induction Motors.- D.3 Transients in Single-Phase Induction Motors.- Appendix E Synchronous Motors Torque Control.- E.1 Introduction.- E.2 Operating Equations of Cylindrical-Rotor Synchronous Motors.- E.3 Torque Control of Cylindrical-Rotor Synchronous Motors.- E.4 Examples of Simulations.- E.5 Operating Equations for Salient-Pole Synchronous Motors.- E.6 Torque Control of Salient-Pole Synchronous Motors.- E.7 Operating Equations for Synchronous Machines with Damper Cages and Field Winding.- E.7.1 Cylindrical-Rotor Synchronous Machines.- E.7.2 Salient-Pole Synchronous Machines.- References.

It has been more than a century since the principle of the operation of induction motors was discovered. The first industrial motors of this type were constructed at the end of the Nineteenth Century and soon gained the favor of users who appreciated their raggedness, simplicity and relatively low manufacturing cost compared to DC commutator motors. The design and performance of induction motors were improved during the Twentieth to Century, reaching maturity around the late 1930s. Further improvements date principally concern the use of modern construction material, specially for winding isolation, and deeper knowledge of certain phenomena regarding harmonics and noise reduction, more efficient cooling techniques, and so on. Nevertheless, fed by fixed-frequency and fixed-magnitude mainlines, induction motors do not lend themselves to easy speed regulation, and in this respect they have always seemed inferior to DC commutator motors, which had no serious competitors in the field of variable speed applications.