Introduction to Electrical Drives

Recommended Prerequisites

Electric Machines I, Power Electronics

Teaching Methods

Theoretical classes with detailed presentation, using audiovisual means, of the concepts, principles and fundamental theories about the topics covered in the curricular unit. Besides the theoretical aspects, these classes include the resolution of problems and exercises that illustrate the practical interest of the topics covered and exemplify its application to real cases in the engineering world.

Laboratory classes allow the student to validate the majority of the theoretical concepts addressed in the unit.

Learning Outcomes

Presentation of the theoretical concepts underlying the generalized theory of electric machines and its application to the speed control of electric machines. Introduction to the basic concepts of speed/position control of the electric motors used in industry nowadays. Lastly, another goal is that students get a transversal/integrated view of different knowledge associated to the fields of electric machines and power electronics.

Work Placement(s)

No

Syllabus

Basic concepts about electric drives: main components and study of the mechanical part of a drive. Types of mechanical loads, equation of motion, gearboxes and reduction of the moment of inertia to the motor shaft.

Generalized theory of electric machines: space phasor – definition and basic properties; equations of voltage, flux, power and torque of synchronous and asynchronous machines using space phasors; reference frame transformations; alfa-beta-zero Transformation; Park’s Vector.

Speed control and scalar control: operation of asynchronous motors at variable frequency; methods of speed control of three-phase induction machines; soft-starters; scalar control.

Vector control: fundamentals of vector control; rotor field oriented control (RFOC) of a three-phase induction motor; direct torque control (DTC) of a three-phase induction motor; RFOC and DTC of a permanent magnet synchronous motor (PMSM).

Head Lecturer(s)

Sérgio Manuel Ângelo da Cruz

Assessment Methods

Assessment B
Laboratory test: 25.0%
Exam: 75.0%

Assessment A
Laboratory test: 25.0%
Two midterm tests: 75.0%

Bibliography

P. Vas (1998), Sensorless Vector and Direct Torque Control, Oxford University Press, New York.

I. Boldea, S. A. Nasar (2006), Electric Drives, 2nd edition, CRC Press, Boca Raton, 2006.

W. Leonhard (2001), Control of Electric Drives, 3rd edition, Springer-Verlag, New York.