TET4120 - Electric Drives


Examination arrangement

Examination arrangement: Aggregate score
Grade: Letter grades

Evaluation Weighting Duration Grade deviation Examination aids
Project 30/100
School exam 70/100 4 hours D

Course content

In spite the fact that a variable speed drive will require increased investment cost, this will in most cases very quickly be balanced by large energy savings compared to fixed speed drives. Approximately 97 % of all new motors are sold without a frequency converter. This means that a large potential market exists. This course explains the energy savings potential and covers most of the commonly used types of electrical motor drives. Part I gives an overview of different type of electrical motor drives, type of loads and the impact of using mechanical gears/transmissions. In part II simplified models of the most commonly used power electronic converters are presented. Modulation methods are presented. In part III measurement techniques used in a motor drives are presented. In addition, how to choose type of controller and tuning of controller parameters are covered in details. Part IV is devoted to DC drives. Mathematical modelling is performed, analysis of steady state characteristics as well as choice and dimensioning of current- and speed-controllers. In part V a general model of AC machines are presented. This includes introduction of space vectors, coordinate transformations and transformed mathematical models. In section VI the three most commonly used AC drives are analyzed; Induction Motor Drives, Permanent Magnet Synchronous Motor Drives and Synchronous Motor Drives. It will be focus on controllers operating in a synchronous rotating coordinate system, i.e. operating with DC-quantities in steady state.

Learning outcome

The course is aiming to give a thorough understanding of control principles used in modern electrical motor drives. Knowledge: After having followed the course, the candidate shall have obtained thorough insight in and understanding of: - rotating electrical machines and their application - common load models for electrical motor drives - control principles and measurement methods used in electrical motor drives Skills: After having followed the course, the candidate shall be able to: - model and analyze electrical motor drives and their sub systems (converters, rotating machines and loads) - choose a suitable rotating machine for an electrical motor drive - choose a suitable control structure, measurement method and calculate control parameters for an electrical motor drive General competence: After completing the course, the candidate has increased: - skills in cooperation and interdisciplinary collaboration - ability to communicate effectively to professionals and non-specialists alike through reports and presentations - ability to contribute to innovation and innovation processes

Learning methods and activities

Lectures, compulsory exercises, project work and laboratory experiments.

Compulsory assignments

  • Exercises

Further on evaluation

The final evaluation will be based on a written examination (70%). The grading will be from A to F. In addition, a project report will count (30%) and graded A-F. Both parts have to be passed with at least an E. Laboratory experiment is part of the project work. If there is a re-sit examination, the examination form may change from written to oral. In the case that the student receives an F/Fail as a final grade after both ordinary and re-sit exam, then the student must retake the course in its entirety. A given number of exercises have to be accepted to be allowed to make the exam. Permitted examination aids, support material code D: No printed or hand-written support material is allowed. A specific basic calculator is allowed. In addition, calculator Casio fx-991EX is allowed.

Specific conditions

Compulsory activities from previous semester may be approved by the department.

Course materials

Compendium, lecture notes, manuals for simulation program.

More on the course



Version: 1
Credits:  7.5 SP
Study level: Second degree level


Term no.: 1
Teaching semester:  AUTUMN 2022

Language of instruction: English

Location: Trondheim

Subject area(s)
  • Electrical Power Engineering
  • Technological subjects
Contact information
Course coordinator: Lecturer(s):

Department with academic responsibility
Department of Electric Power Engineering


Examination arrangement: Aggregate score

Term Status code Evaluation Weighting Examination aids Date Time Examination system Room *
Autumn ORD School exam 70/100 D 2022-11-30 15:00 INSPERA
Room Building Number of candidates
Autumn ORD Project 30/100 INSPERA
Room Building Number of candidates
Summer UTS School exam 70/100 D INSPERA
Room Building Number of candidates
  • * The location (room) for a written examination is published 3 days before examination date. If more than one room is listed, you will find your room at Studentweb.

For more information regarding registration for examination and examination procedures, see "Innsida - Exams"

More on examinations at NTNU