Electrical Machines Control Practicum

Course Description

Induction machine: physical principles, working principle, mathematical model. Torque-speed characteristics of an induction machine. V/f control, different V/f characteristics. Speed control of induction motor by using frequency converter. Frequency converter structure, operating principle, energy flow direction. Open and closed loop control. Laboratory setup for control of induction machines. Digital and analog inputs, digital, relay and analog outputs, encoder interface. Specific functions of the industrial frequency converter. Individual work with the industrial frequency converter - commissioning, gain tuning of speed controller, connection to programmable logic controller via industrial communication protocol.

General Competencies

Fundamentals of electrical machines control. Experience in the application of frequency converter for AC induction machine and BLDC machine control. Experience in application of industrial software tools for parameter tuning of frequency converters, commissioning of frequency converter for AC induction motor and BLDC motor control, recording and analysis of measured values.

Learning Outcomes

  1. explain the operating principle of induction motor
  2. explain the basic principle of AC/DC/AC converter
  3. distinguish V/f characteristics
  4. select appropriate V/f control structure with respect to load requirements
  5. apply industrial software tools to adjust the parameters of frequency converter
  6. use industrial frequency converter for speed control of induction motor
  7. solve specific tasks regarding control of induction drive by adapting industrial frequency converter to address particular application

Forms of Teaching

Lectures

One hour lecture is held each week.

Exercises

Exercises are held in the first cycle 4 times for 1 hour.

Laboratory Work

Laboratory exercises consist of six exercises, each lasting for 5 hours. Laboratory exercises are conducted on a laboratory model based on industrial frequency converter Siemens Sinamics G120. Two laboratory exercises are held in the first cycle and four in the second cycle.

Experiments

The lectures will take place through experimentally commissioning of industrial converter for induction motor control. Voltage and current waveforms of an induction motor powered by a frequency converter are analyzed during motor operation.

Consultations

Consultations are arranged via email.

Acquisition of Skills

Each student conducts laboratory exercises independently on his laboratory model which qualifies him to independently do commissioning of industrial frequency converters.

Grading Method

   
By decision of the Faculty Council, in the academic year 2019/2020. the midterm exams are cancelled and the points assigned to that component are transferred to the final exam, unless the teachers have reassigned the points and the grading components differently. See the news for each course for information on knowledge rating.
   
Continuous Assessment Exam
Type Threshold Percent of Grade Threshold Percent of Grade
Laboratory Exercises 0 % 30 % 0 % 30 %
Mid Term Exam: Written 0 % 30 % 0 %
Final Exam: Written 0 % 30 %
Final Exam: Oral 10 %
Exam: Written 50 % 40 %
Exam: Oral 30 %
Comment:

In order to pass the course students are required to do all laboratory exercises.

Week by Week Schedule

  1. Course rules.
  2. Induction machines: construction, physical principles, working principle.
  3. Induction machines: mathematical model, torque-speed characteristics.
  4. Speed control of induction motor.
  5. V/f control, V/f control characteristics.
  6. Induction motor speed control by using frequency converter.
  7. Operating principle of AC/DC/AC frequency converter. Braking module.
  8. Mid-term exam
  9. Open and closed loop V/f control.
  10. Tuning rules for P and PI controllers in closed loop V/f control structure.
  11. Laboratory setup for the control of induction machines based on Siemens Sinamics G120 frequency converter.
  12. Digital and analog inputs, digital, relay and analog outputs, encoder interface.
  13. Specific functions of industrial frequency converters.
  14. Integrated safety functions of industrial frequency converters.
  15. Final exam

Study Programmes

University undergraduate
Control Engineering and Automation (module)
Elective Courses (6. semester)
Electrical Power Engineering (module)
Elective Courses (6. semester)

Literature

Gorislav Erceg (2002.), Inžinjerski priručnik IP3", (20. Elektromotorni pogoni str. 1017-1074), Školska knjiga Zagreb
Werner Leonhard (2001.), "Control of Electrical drives", Springer
Z. Benčić (2009.), Danfoss:Najvažnije o frekvencijskim pretvaračima, Graphis Zagreb

Exercises

Laboratory exercises

General

ID 86502
  Summer semester
4 ECTS
L1 English Level
L1 e-Learning
13 Lectures
4 Exercises
30 Laboratory exercises
0 Project laboratory

Grading System

90 Excellent
75 Very Good
60 Good
50 Acceptable