Control of Electrical Drives

Course Description

Dynamic model of induction and permanent magnet synchronous motor (PMSM) machine. Induction motor scalar and vector control, brushless DC machine. Vector control structures with voltage and current inverter. Pulse with modulation and vector modulation. Vector model variable and parameters estimation of induction machine. Direct torque and flux control of AC induction machine. Variables estimation. Control of the brushless DC motor. Electrical drives with complex mechanical load - significant impact of torsion, friction, backlash, inertia variation. Illustrative examples. Elasticity, friction and backlash modeling. Motion controller synthesis based on the damping optimum and modulus optimum. Improvement of the tracking accuracy using feedforward controller. Algorithms for friction and backlash compensation. Positioning: point to point positioning.

General Competencies

Understanding the structure and components of electrical drives. The knowledge about dynamical characteristics of drives with DC, knowledge about agorithms and drive control methods. Brushless DC and induction machines; Modeling, simulation and analysis applied to the basic types of machines and loads.

Learning Outcomes

  1. apply methods of variables estimation in drives with induction machines
  2. apply direct torque and flux control to induction machine
  3. apply vector control structure with voltage and current inverter
  4. analyze the behavior of electromechanical system with elastic coupling
  5. apply cascade control structure to electrical drives
  6. design control algorithm in constant torque and constant power regime for drive with brushless DC

Forms of Teaching


Lectures are organized in two cycles.


Brief tests during lectures.


Problem solving exercises at classes guided by the assistant.

Grading Method

Continuous Assessment Exam
Type Threshold Percent of Grade Comment: Percent of Grade
Quizzes 0 % 10 % 0 % 0 %
Mid Term Exam: Written 35 % 35 % 0 %
Final Exam: Written 35 % 35 %
Final Exam: Oral 20 %
Exam: Written 40 % 65 %
Exam: Oral 35 %

Week by Week Schedule

  1. Basic information about course. Structure and components of electrical drive systems. Dynamics of rotational and translational motion. Drive's mechanics, moment inertia, Steiner's statement. Static characteristics of specific loads, static stability of drives operation point. Mechanical interface, modeling.
  2. Drives based on DC machines. Types of drives concerning the types of the field excitation, dynamical characteristics. Drive's time constants, physical explanation. Control methods, motoring and braking, energy regeneration.
  3. Converters for DC drives. AC/DC converters (phase converters), transfer function, dead time, torque-speed characteristics, voltage and field control. Phase converters and DC/DC converters (choppers)
  4. Converters for AC drives. Direct AC/AC converters (cycloconverters) and indirect converters (with DC common bus).
  5. The model of induction machine adopted to the vector control. Relationships among model´s vectors in coordinate system with rotor flux orientation. Vector modulation. Model of SMPM.
  6. Induction machine (AC) drive vector control structures in rotor flux coordinate orientation. Control structures of drives with voltage and current inverter. Rotor speed and position estimation. Estimation of rotor flux angle and magnetizing current.
  7. Direct torque and flux control (DTC). Basic properties of DTC technique. Vector control vs. direct torque control. Position of specific vectors in stator flux and rotor flux coordinate system. Torque and flux controllers.
  8. Mid-term exam
  9. Cascade control structures. Magnitude optimum. Symmetrical optimum.
  10. Application of cascade structures in control of electrical drives.
  11. Damping optimum and its application to control of electrical drives.
  12. Modulus optimum and its application to control of electrical drives.
  13. Classical structures of control of electromechanical systems with elastic coupling.
  14. Application of polynomial controller (RST) in control of electrical drives.
  15. Final exam

Study Programmes

University graduate
Control Engineering and Automation (profile)
Theoretical Course (1. semester)
Electrical Engineering Systems and Technologies (profile)
Theoretical Course (1. semester)

Prerequisites for


Werner Leonhard (2001.), Control of Electrical Drives, Springer
B.K. Bose (1996.), Power Electronics and Variable Frequencies Drives, John Wiley and Sons
Peter Vas (1990.), Vector Control of AC Machines, Clarendon Press - Oxford
Martin Jadrić, Božidar Frančić (1997.), Dinamika električnih strojeva, Graphis Zagreb
Nedjeljko Perić, Joško Deur, Ivan Petrović, Danijel Pavković, Jadranko Matuško (2005.), Slijedni sustavi s izraženom elastičnošću, zračnošću i trenjem-Skripta, ZARI, FER Zagreb
(.), Slijedni sustavi - odabrani radovi Perić, N. i dr FER Zagreb 2005,

Grading System

ID 127429
  Winter semester
L1 English Level
L1 e-Learning
45 Lecturers
12 Exercises
0 Laboratory exercises


87.5 Excellent
75 Very Good
62.5 Good
50 Acceptable