Objectives and competences
Objectives:
The objective of this course is for students to be able to demonstrate the understanding of fundamental laws of physics on which are based working principles of electrical machines, to be able to calculate electrical machines characteristics and to be able to evaluate their capability in practice.
Competences:
Ability to learn and to solve problems; transfer of theory to practice; ability to use instruments and procedures; ability of individual and group-work; work organizing and planning; verbal and written communication, safety at work.
Content (Syllabus outline)
• Introduction: basic types of transformers and rotating electric machines, properties of soft magnetic materials, non-oriented and grain-oriented electrical steel, eddy currents effect in electrical steel, materials for electric conductors and skin effect, losses and efficiency, heating and cooling, insulation classes.
• Electric transformers: components of single and three-phase transformers, operation principle of single phase transformer at no-load and full load, circuit equations and equivalent circuit; phasor diagram; phase connections of three-phase transformers, no-load current asymmetry, unbalanced load in steady state; transients in transformers; instrument voltage and current transformers; autotransformers.
• Synchronous machines: applications and topologies; distributed three-phase stator windings; rotor excitation windings; principle of operation; armature reaction; synchronous reactances; steady-state equations and phasor diagram; synchronous generator at autonomous grid, no-load curve characteristic, short-circuit curve characteristic and load curve characteristic; synchronous generator at power grid, active power capability curve, reactive power capability curve; static stability; topologies of permanent magnet synchronous machines; synchronous reluctance motors.
• Induction machines: applications and construction elements; cage rotor windings; principle of operation, induction machine inductances; motor operation at load; three-phase induction machine circuit equations; equivalent circuit, phasor diagram; power generation at power grid; autonomous generator mode; power capability curves in motor, generator and electric brake operation mode; different starting methods; speed control methods; capacitor split single phase induction motors.
• Brush-commutator machines: stator and rotor construction elements; excitation and armature windings design; electromotive force; commutation process; DC brush motor/generator with separate excitation; DC brush motor with parallel excitation; DC brush series motor; AC brush series motor; speed control methods.
Learning and teaching methods
• Lectures by using power-point slides and whiteboard.
• Auditory exercises.
• Laboratory exercises.
Intended learning outcomes - knowledge and understanding
Knowledge and understanding:
On completion of this course the student will be able to
• define different types electrical machines and their field of application;
• explain the operation of electrical transformers, motors and generators;
• explain the role of the magnetic field in energy conversion;
• explain the operating characteristics of electrical machines;
• calculate equivalent electric circuit parameters of electrical machines in steady-state from measurement results;
• calculate the basic characteristics of electrical machines;
• analyse and evaluate the performance of electrical machines based on measurements.
Intended learning outcomes - transferable/key skills and other attributes
Transferable/Key Skills and other attributes:
• Communication skills: manner of written expression at written examination, manner of oral expression at oral examination, oral lab wok defence.
• Use of measurement instruments: use of measurement instruments and sensors for measuring of current, voltage, electric power, shaft torque and speed.
• Problem solving: problem analysis, design and execution of tests, interpretation of results.
Learning and teaching methods:
• Lectures by using power-point slides and whiteboard.
• Auditory exercises.
• Laboratory exercises.
Readings
Temeljna literatura in viri/Fundamental reading materials:
I. Zagradišnik, B. Slemnik: Električni rotacijski stroji, FERI Maribor, 2012.
D. Žarko, B. Ćućić: Transformatori u teoriji i praksi, Graphis Zagreb, 2020.
Dodatna literatura in viri/Additional reading materials:
D. Miljavec, P. Jereb: Električni stroji: temeljna znanja, Ljubljana, 2005.
H. A. Toliyat, G. B. Kliman: Handbook of Electric Motors, CRC Press, 2004.
I. Boldea: The Electric Generators Handbook, Synchronous Generators, CRC Press, 2005.
A.E. Fitzgerald, C. Kingsley, S.D. Umans: Electric Machinery, Mc Grow Hill, 2003.
I. Boldea, L. Tutelea: Electric Machines, CRC Press, 2010.
Additional information on implementation and assessment Method (written xamination, oral examination, laboratory exercises):
• written exam
• oral exam
• laboratory work
Notes:
The student must finish each part of the exam (written part of the exam, oral part of the exam, defence of laboratory work) with at least 50%.
In the case of two midterm tests, which can replace written exam, each of them has to be done with at least 50% to pass the written exam successfully.
