Synchronous Machines and Excitation Systems

Course Description

Synchronous generator as an object of control. Parallel operation of synchronous generator. Excitation control systems with static and rotating exciters. Systems with independent and self-excitation. Brushless excitation systems. Criterions for selection of the type and parameters of excitation systems. Digital voltage control of synchronous generators. Multiparameter excitation control and its influence on stability of the power system. Group control of synchronous generator excitation systems. Electromechanical oscillations. Static and transient stability. Torsional oscillations. Asynchronous operation of turbogenerators and hydrogenerators. Critical speeds of the power generator. Autonomous operation of a synchronous generator. Pumped-storage power generators. Synchronous motors, characteristics, types of initial startup.

General Competencies

Achieving a level of knowledge to master synchronous machines, excitation systems and voltage control

Learning Outcomes

  1. recognize the typical scheme of excitation of synchronous machines
  2. explain the physical interpretation of synchronous motors and generators
  3. compute the typical parameters of synchronous machines
  4. apply power chart for hydrogenerators and turbogenerator
  5. distinguish the concept of work on its own network and parallel operation of synchronous generators
  6. connect the meaning of the parameters of synchronous generator and dynamics of its behavior in the work
  7. compare the behavior of the excitation system and emergency power generators with synchronous
  8. -

Forms of Teaching


Classes are organized in two teaching cycles. The first cycle consists of 7 weeks of classes and mid-term exams, while the second cycle contains 6 weeks of classes and final exams. Classes are conducted through a total of 15 weeks with a weekly load of 2 hours.


Knowledge test consists of a mid-term exams and 4 short test (blic)


Exercises are carried out in 4 terms each lasting 2 hours.


Possible consultation after class each week.

Internship visits

1st Electrical machinery factories KONČAR - GIM 2nd Thermal power plant or a hydro-power plant (in or outside of Zagreb in Croatia)

Grading Method

Continuous Assessment Exam
Type Threshold Percent of Grade Threshold Percent of Grade
Quizzes 0 % 6 % 0 % 6 %
Seminar/Project 0 % 10 % 0 % 10 %
Attendance 0 % 4 % 0 % 4 %
Mid Term Exam: Written 0 % 20 % 0 %
Final Exam: Written 0 % 20 %
Final Exam: Oral 40 %
Exam: Written 0 % 40 %
Exam: Oral 40 %

Presence is required only for students visiting the factory and power plant

Week by Week Schedule

  1. Basic dimensions of the synchronous machine. Armature and excitation windings. Characteristics of no-load and short circuit, Swedish chart.
  2. The role of a synchronous generator and an excitation system in the power system. Power chart. Limitations in the power chart of the generator concerning the excitation system.
  3. Equivalent scheme of synchronous generator. Parameters of a synchronous machine as an object of voltage and reactive power control.
  4. Mathematical models of synchronous machines.
  5. Electromechanical oscillations. Static and transient stability.
  6. Torsional oscillations. Critical speeds of the power generator.
  7. Autonomous operation of a synchronous generator.
  8. Mid-term exam
  9. Autonomous operation of a synchronous generator.
  10. Pumped-storage power generators. Synchronous motors, characteristics, types of initial start-up.
  11. Types of excitation systems, systems with independent excitation, self-excitation systems with or without compound. Static and brushless excitation systems.
  12. Components of the synchronous generator excitation systems. Voltage and current characteristics of exciters. Forced excitation, speed of response of excitation voltage.
  13. Different implementations of digital generator voltage control. Power system stabilizers.
  14. Models of voltage control systems, classification of models.
  15. Final exam

Study Programmes

University graduate
Electrical Engineering Systems and Technologies (profile)
Specialization Course (2. semester)
Electrical Power Engineering (profile)
Specialization Course (2. semester)


Zvonimir Sirotić, Zlatko Maljković (1996.), Sinkroni strojevi, Element
Martin Jadrić, Božidar Frančić (2004.), Dinamika električnih strojeva, Graphis
Ion Boldea (2005.), Synchronous Generators, CRC Taylor & Francis
Thomas A. Lipo (2008.), Analysis of Synchronous Machines, CRC Taylor & Francis



ID 86524
  Summer semester
L1 English Level
L1 e-Learning
30 Lectures
8 Exercises
0 Laboratory exercises
0 Project laboratory

Grading System

85 Excellent
70 Very Good
60 Good
50 Acceptable