Subject description
Components of electrical drives. Past, present and future trends in drive systems. Stationary and transient states of electrical drives. Characteristics of electric motors, typical load torques. Moments of inertia of complex drive systems, accelerating torque. Electrical and mechanical transients, stability problem of drive system. Types of electric motors, their supplying, connection, selecting and cooling.
Electric motors in drive systems:
DC (commutator and brushless) machines. Induction (slip ring, squirrel cage, solid rotor) machines. Synchronous (field winding, permanent magnet, reluctance) machines. Principles of operation, speed-torque characteristics and possibilities of their modifications. Starting and breaking dynamics, classical and modern principles of speed and motion control. 4Q operation.
Methods for selecting the drive types. Sizing and dimensioning electric motors. Thermal conditions, cooling principles, standard and user defined duty types. Reactive power compensation.
Energy efficient motors and drive systems – technical and economical aspects, principles of energy savings. Electrical drives with increased reliability and fault tolerant operation. Standard protection of drive systems.
The subject is taught in programs
Objectives and competences
Student will be provided with the knowledge and procedures for design, optimization and maintenance of grid supplied and controlled electrical drives in industrial and traction systems. They will be able to choose and carry out energy efficient, reliable and cost effective electrical drives.
Teaching and learning methods
The lectures provide a theoretical background on discussed topics. A complete study material is available to the students.
Successful practical work on laboratory excercises, which take place in smaller groups, enables prior acquaintance of the students with computational and demo tasks.
Expected study results
After successful completion of the course, students should be able to:
– Evaluate state-of-the-art and perspectives of electrical drives.
– Explain the difference between grid supplied and inverter fed electrical drives.
– Clarify physical operational principles of basic drive types.
– Describe main components of integrated drive systems.
– Explain in details behaviour of electrical motor and mechanical load connection.
– Research the influence of control parameters on static and dynamic characteristics of drive motors.
– Establish the optimal selection of electrical motor type.
– Estimate the importance of energy efficiency operation of controlled electrical drives.
– Recognize the significance of reliability and safety in drive operation.
– Manipulate with modern types of electrical drives which are most used in industry practice.
Basic sources and literature
1. R. Fišer, Interno študijsko gradivo v pisni in elektronski obliki (Internal study material).
2. J. Weidauer, R. Messer, Electrical Drives – Principles, Planning, Applications, Solutions,
Publicis Publishing, Siemens, 2014
3. A. Hughes, B. Drury, Electric Motors and Drives – Fundamentals, Types, Applications, 4th Ed.,
Newness, Elsevier, 2013.
4. B. Drury, The Control Techniques Drives and Controls Handbook, 2nd Ed., IET, 2009.
5. A. Emadi, Energy-Efficient Electric Motors, Marcel Dekker, 2005.
6. T. Wildi, Electrical Machines, Drives, and Power Systems, Pearson, Prentice Hall, 2006.
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University of Ljubljana, Faculty of Electrical Engineering Tržaška cesta 25, 1000 Ljubljana