Subject name: Electrical Machines Credits: 9 Requirement : Course director: Dr. Vajda István Position: Assessment and verification procedures: NEPTUNE -code: KAUVG11ONC Prerequisites:... Number of hours: 4 lec + 0 pr + 4 lab Faculty and institution name: Kandó Kálmán Faculty of Electrical Engineering, Institute of Automation Knowledge description: 1. Chapter 1: Basic concepts 1.1. Concepts and terms 1.1.1. power, rated power 1.1.2. Medium and process of electrical energy conversion 1.1.3. Coils with and without iron cores 1.1.4. Understanding of the term electrical machines. 1.2. Laws of electrical energy conversion 1.2.1. Why magnetic field? 1.2.2. Three laws 1.3. Scaling laws 1.3.1. Dependence of size vs power 1.3.2. Variation of parameters vs power 2. Chapter 2 Main dimensions of electrical machines 2.1. Fundamental concepts of design 2.1.1. Steps of the design process 2.1.2. Design goals, objects 2.1.3. Design factors, 2.1.4. Loadings 2.1.5. Limitations 2.2. Main dimensions of transformers 2.2.1. Nominal power vs loadings
2.2.2. Determination of limb cross section 2.2.3. Utilisation factor 2.2.4. Considerations for the window size 2.3. Main dimensions of rotating machines 2.3.1. Loadings 2.3.2. Electrical losses 2.3.3. Iron losses 2.3.4. Linear current 2.3.5. Utilisation factor 2.3.6. Determination of main dimensions 3. Chapter 3 Reference direction system 3.1. Symbolic (complex) calculation method 3.2. Positive directional system 3.2.1. Meaning of active, reactive and apparent powers 3.2.2. Consumers positive directional system 3.2.3. Signs of generator s and consumer s power 3.3. Three phase power networks 3.3.1. Symmetrical three phase system 3.3.2. Phase and line voltages and currents 3.3.3. Understanding and expressions for three phase powers 4. Chapter 4 Rotating field 4.1. Basic ideas 4.1.1. Concept of torque creation 4.1.2. Windings for AC machines 4.1.3. Vector of flux density 4.2. Creation of sinusoidal field distribution 4.2.1. Application of Ampere s law to rotating machines 4.2.2. Spatial distribution of mmf 4.2.3. Kirchhoff s law for magnetic voltage drops for rotating machines
4.2.4. Cylindrical and salient-pole machines 4.2.5. Improving the sine-form of flux density distribution 4.3. Creation of rotating fields 4.3.1. Stationary field 4.3.2. Pulsating field 4.3.2.1. Principle of Ferraris 4.3.3. Rotating field 4.3.3.1. Mathematical derivation 4.3.3.2. Graphical (physical) derivation 4.3.4. Properties of rotating field 4.3.4.1. Synchronous speed 4.3.4.2. Phase number, invariance of mmf-s 4.3.4.3. Equality of pole numbers. 4.4. Induced voltage 4.4.1. Calculation of the fundamental component 5. Chapter 5 Soft magnetic materials 5.1. Main properties of soft magnetic materials 5.1.1. Magnetisation curve for DC and AC 5.1.2. Loss curve 5.2. Magnetic hysteresis 5.2.1. Isotropic and anisotropic magnetic materials 5.3. Iron loss 5.3.1. Hysteresis loss 5.3.2. Eddy current loss 5.3.3. Static and dynamic hysteresis curve 5.4. Model of Coils (Windings) with Iron Core 5.4.1. Excitation current of coil with nonlinear magnetic core (no hysteresis) 5.4.2. Excitation current of coil with hysteretic magnetic core.
5.4.3. Equivalent circuit representations. 5.5. Generalized steady-state model (equivalent circuit) of electrical machines 6. Chapter 6 Permanent magnets 6.1. Properties 6.1.1. Types of PMs 6.1.2. Main parameters of PMs 6.1.3. Demagnetisation curve of PMs 6.1.4. Working lines on the demagnetisation curve; working points 6.1.5. Concept and representation of energy product 6.1.6. Permanency of PMs 6.1.7. Properties of NdBFe 6.1.8. Process of magnetisation of PMs 6.2. Fundamentals of PM machines design 7. Chapter 7: Operation of electromechanical converters 7.1. Concept and understanding of frequency condition 7.2. Derivation of fundamental machines from the frequency condition 7.2.1. Synchronous machine 7.2.1.1. Basic designs 7.2.1.2. Way of induction 7.2.1.3. Equivalent circuit 7.2.2. Asynchronous machine 7.2.2.1. Basic designs 7.2.2.2. Frequency conversion 7.2.2.3. slip, slip frequency 7.2.2.4. Equivalent circuit 7.2.3. DC machine 7.2.3.1. DC machine as a system 7.2.3.2. Mechanical and electronic commutator
7.2.3.3. Flux density distribution 7.2.3.4. Induced voltage, derivation 7.2.3.5. Torque, derivation 7.2.3.6. Equivalent circuit 8. Simulations are available at: 8.1. http://www.ipes.ethz.ch/ipes/2002feldlinien/felder.html 8.2. http://www.ece.umn.edu/users/riaz/