Study Guide

Objective

The student:
- knows and understands the use and need of transformers of various kinds
- is able to understand and explain the basic functions of different types of transformers
- is able to calculate losses, voltage drops and efficiency of transformers
- knows and understands the functions of different peripherals.

Content

Magnetic circuits.
Application of magnetic circuits for different types of transformers.
Basic functions and connections for transformers.
Calculation of losses, voltage drops and efficiency of transformers.
Single-phase transformers
Three-phase transformers
Special transformers
Instrument transformers

Location and time

Lessons in class and laboratory sessions in Technobothnia according to the schedule in Peppi.
Time for submission of laboratory reports and any additional information: within two weeks after the last lessons according to the schedule.

Materials

Compendiums, degree projects and info from transformer manufacturers.
Info and links are available in Moodle for the course.

Teaching methods

Lectures, calculations, laboratory work and self-study.
Information and study material are presented in Moodle for the course.

Exam schedules

The time for the joint exam and any extra exam is determined in agreement with the students during the course. Lessons in class and laboratory sessions according to the established schedule in Peppi. Laboratory reports are submitted within two weeks of each laboratory.

Completion alternatives

Assessment of assignments, laboratory work, laboratory reports and theoretical tests.

Student workload

A total of 81 hours divided into lessons in class (22h), laboratory sessions (16h), self-study and preparation of laboratory reports.

Content scheduling

Theory during weeks 1-8, Laboratory work during weeks 5-8.

Evaluation scale

H-5

Assessment criteria, satisfactory (1)

Knows the significance of transformers historically and in the present.
Can describe the structure and properties of the transformer in an electrical grid.
Can describe three-phase transformer connections.
Can name and explain the principle for different special transformers.
Can calculate voltage drop in single phase and three phase transformers

Assessment criteria, good (3)

Can describe the function of transformers with physical grounding.
Can calculate voltage drops and losses under load.
Can calculate voltage drop and efficiency at different loads.
Can describe the operating principles for eg. spark-coupled transformers.

Assessment criteria, excellent (5)

Master the relationships between electrical quantities in the operation of transformers.
Master different ways of describing and calculating transformer equivalent schemes.
Can calculate and describe transformer coupling index and turnover for different couplings.
Can describe and calculate important limiting data for current transformers

Assessment methods and criteria

The main basis for the grade in the course is determined by the points in the course test. The course test consists of questions that are answered in writing and calculations. (Max 40 points). The laboratory work and the reports are assessed. (Max 20 points)

Assessment criteria, fail (0)

Less than 30% of the total points in the test or omitted laboratory reports.

Assessment criteria, satisfactory (1-2)

Grade 1: 30 - 39% of the total points
Grade 2: 40 - 52% of the total points

Assessment criteria, good (3-4)

Grade 3: 53 - 72% of the total points
Grade 4: 73 - 86% of the total points

Assessment criteria, excellent (5)

Grade 5: 87 - 100% of the total points

Qualifications

Electric and magnetic fields.