Subject description
Magnetic field , force and torque. Induced voltage. Heating of electrical machines. Heat Transfer. The use of modern computer tools based on the finite element method to calculate magnetic, electrostatic and thermal fields. Losses in the core, windings and additional losses in electric machines.
Calculation of the core and windings of the transformer. Short circuit forces on transformer windings. Switch-on phenomenon in transformer. Different types of cooling systems. Basic tests of transformer. Atmospheric and switching over-voltages. Elements of power transformers protection.
Forms of excitation windings of rotating machines. Calculation of the windings of synchronous machines. Design of synchronous machine magnetic circuit.
Equivalent circuit of induction machine. Circle diagram of induction machine. Design of induction machine magnetic circuit.
Direct current machine winding design. The problem of commutation. Design of direct current machine.
The subject is taught in programs
Objectives and competences
Obtain detailed knowledge of the nature, design features and possibilities of the use of different types of electrical machines. The emphasis is on the practical knowledge that prospective designer and end user needs when selecting, sizing and use of electrical machines.
Teaching and learning methods
Lectures, tutorials included in lectures and laboratory work.
Laboratory exercises are with heightened risk (high voltage, rotating parts, …).
The course consists of 30 hours of lectures and 30 hours of laboratory exercises with heightened risk.
Expected study results
After successful completion of the course, students should be able to:
– describe the physical events in electrical devices,
– understand the phenomena of core losses, windings and additional losses in electrical machines,
– calculate the physical quantities of the magnetic, electric and thermal fields,
– calculate magnetic, electrostatic and thermal fields with modern computer tools based on the finite element method,
– evaluate electromagnetic states in electrical machines,
– classify the basic problems in the production and use of each electric machine.
Basic sources and literature
- Scott D. Sudhoff, Power Magnetic Devices: A Multi-Objective Design Approach Wiley-Blackwell, 2014.
- Juha Pyrhonen, Tapani Jokinen, Valeria Hrabovcova: Design of Rotating Electrical Machines, Wiley-Blackwell; 2nd Edition edition, 2013.
- Austin Hughes, Bill Drury:Electric Motors and Drives: Fundamentals, Types and Applications, Newnes, 4th Revised edition edition, 2013
- Nicola Bianchi, Electrical Machine Analysis Using Finite Elements, CRC Press, 2005
- S.V. Kulkarni, S.A. Khaparde: Transformer Engineering: Design, Technology, and Diagnostics, CRC Press; 2 edition, 2012.
- Stephen L. Herman: Electrical Transformers and Rotating Machines, Delmar Cengage Learning; 3rd Revised edition edition,2011.
- Bharat Heavy Electrical Limited, Transformers: Design, Manufacturing, and Materials (Professional Engineering), McGraw-Hill Professional, 2004.
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University of Ljubljana, Faculty of Electrical Engineering Tržaška cesta 25, 1000 Ljubljana