Optimization of Electromagnetic Circuits

Lecturer:

Tutor:

Supervisor:

Department of Electric Drives and Traction

Synopsis:

The finite element method and its use for numerical calculation of magnetic fields of electric machines. Electromagnetic design of induction motors. Stator and rotor winding design. Air-gap length determination and magnetic core design. Resistor and leakage reactance calculations. Influence of skin effect and magnetic saturation of leakage flux path. Temperature and ventilation calculations. Design of induction motor series.

Requirements:

Syllabus of lectures:

1. Numerical calculation of magnetic fields. The finite element method, boundary conditions

2. Type of elements, material characteristics, networking, display of results

3. Electromagnetic design of induction motors, solution technique

4. Basic dimensions and choice of electromagnetic loading of machine

5. Stator winding design, number of slots, phase turns, conductor, slot geometry choice

6. Squirrel cage rotor design, number of slots, cross-sections of bars and end-rings

7. Winding design of wound rotors, number of slots, phase turns, conductor choice

8. Air-gap length determination, magnetic core design, magnetizing current

9. Winding resistance, permeance coefficients, leakage-reactance calculations

10. Losses and efficiency calculation. Magnetic saturation of leakage-flux path

11. Starting and load characteristics, its influencing

12. Temperature and ventilation check. Mechanical check

13. Design of induction motor series, unification

14. Electromagnetic design of induction motors by computers

Syllabus of tutorials:

1. Magnetic fields calculation by a conform representation (Schwarz transformation)

2. Magnetic field and magnetic density form in the air-gap over open slot

3. Magnetic fields calculation by means of the finite element method (FEM)

4. Magnetic field of no-load transformer

5. Magnetic field in the air-gap over an open slot by means of the finite element method

6. Specified induction motor calculation, choice of basic dimensions, el.mag. charging

7. Stator winding design, number of slots, phase turns, conductor and slot geometry choice

8. Winding design of a rotor, number of slots, conductor and slot geometry choice

9. Air-gap length determination, magnetic core design, magnetizing current

10. Magnetic field geometry of specified no-load induction motor by means of the FEM

11. Resistance of winding, permeance coefficients, leakage-reactance calculations

12. Circle diagram. Starting and load characteristics calculation

13. Temperature and ventilation check. Mechanical check

14. Adaptation of longitudinal section drawing of an induction motor by means of AutoCAD

Study Objective:

Study materials:

Literature will be specified by the lecturer

Note:

Further information:

No time-table has been prepared for this course

The course is a part of the following study plans: