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EJ2400 Electric Traction 6.0 credits

Course memo Spring 2022-60344

Version 1 – 03/06/2022, 10:02:43 PM

Course offering

Spring 2022-1 (Start date 21/03/2022, English)

Language Of Instruction


Offered By

EECS/Electrical Engineering

Course memo Spring 2022

Course presentation

The course gives an introduction to electric railway traction including traction mechanics, rail systems, electrical drives, and power supplies.

Headings denoted with an asterisk ( * ) is retrieved from the course syllabus version Spring 2020

Content and learning outcomes

Course contents

Historical overview. General principles of electric traction and in particular electric railway systems. Tractive and braking effort. Power requirements and energy consumption. Traction vehicles; electric drives, transformers and  converters, control and mechanical transmission. Power supply systems; ac and dc supplies. Power capacity, overhead catenary systems, overvoltages, line interference and electromagnetic compability, EMC.

Intended learning outcomes

Students should after course can:

  • account for fundamental issues in electric railway traction including runninig resistance, tractive effort, adhesion, power and energy consumption,
  • calculate tractive effort, power, acceleration and velocity of rail vehicles,
  • describe the components in electric drives with induction motors and dc motors,
  • make estimations of voltages, currents and power in the electric drives for rail vehicles with induction motors and dc motors,
  • be familiar with other types of electric drives for rail vehicles,
  • describe the design of ac and dc power supplies for electric traction,
  • calculate the power capacity for different railway power supply systems,
  • describe the background of electromagnetic interferences (EMI) in electric railway traction and give an account of important concepts and parameters.

Learning activities

The course consists of 22 hours of lectures.

The examination consists of three assignments and a final written examination.

Preparations before course start

Recommended prerequisites

One of the following courses are recommended; EJ2200 Electrical Machines and Drives, EJ1200 Electric Power Systems or EJ2300 Power Electronics.


Östlund, S. Electric Railway Traction, KTH 2019.

The text book will be provided for free at the lectures.

Examination and completion

Grading scale

A, B, C, D, E, FX, F


  • TEN2 - Home assignments and written exam, 6.0 credits, Grading scale: A, B, C, D, E, FX, F

Based on recommendation from KTH’s coordinator for disabilities, the examiner will decide how to adapt an examination for students with documented disability.

The examiner may apply another examination format when re-examining individual students.

The section below is not retrieved from the course syllabus:

The examination consists of three assignments and one written exam. Both the written exam and the assignments contribute to the final grade of the course.

The written exam has a maximum of 30 points whereas the assignments give a maximum of 5 points each. The points for the written exam are added to the assignments and the maximum number of points for the course thus is 45.

To pass the course requires at least 20 points.

Written exam

The written exam is scheduled for Friday June 3rd, 14.00-18.00.

The written exam equals 67% of the total grade of the course.

At the exam you are allowed to use a calculator. Mathematics and Physics handbooks are not permitted.

Re-sit in August by appointment with the examiner (Registration for Stefan Östlund).

Registration for the exam is done at ”My pages”0F0F[1]

The written exam consists of 5 problems each valued 3 points and 3 problems each valued 5 points that is, in total 30 points.


In the three assignments the tractive effort diagram as well as some basic data is given for a specific train/locomotive. Each assignment comprises calculations of different key figures and quantities for a specified operating condition.

Each assignment can give a maximum of 5 points corresponding to 11% of the total grade, that is, in total the assignments contribute to 33% of the course whereas the written exam constitutes 67% of the course.

Assignment 1 has to be submitted at the latest on Tuesday April 26

Assignment 2 has to be submitted at the latest on Tuesday May 3

Assignment 3 has to be submitted at the latest on Tuesday May 17

Grading criteria/assessment criteria

00-17 = F

18-19 = Fx

20-24 = E

25-29 = D

30-34 = C

35-39 = B

40-45 = A

Ethical approach

  • All members of a group are responsible for the group's work.
  • In any assessment, every student shall honestly disclose any help received and sources used.
  • In an oral assessment, every student shall be able to present and answer questions about the entire assignment and solution.

Further information

No information inserted

Round Facts

Start date

21 Mar 2022

Course offering

  • Spring 2022-60344

Language Of Instruction


Offered By

EECS/Electrical Engineering


Course Coordinator


Teacher Assistants