37772 - Design Methodologies of Electrically-Operated Machines M

Learning outcomes

The aims of the Course are to train the students to the specific knowledge regarding the traditional methodologies for the analaysis and the design of the electrical machines. Furthermore, the appropriate use of simulation software and thermal and electromagnetic field analysis will be presented and discussed. After passing this course, students will be familiar with issues involved in design techniques, thermal and electromagnetic field analysis.

Course contents

NTRODUCTION

General considerations on the sizing of electrical machines. Technical specifications. Nameplate data and parameters involved in the design of the electric motors. Parameters involved in the calculation of electric machines. Design and verification phases.

ELECTRICA ENGINEERING MATERIALS

Physical and technological properties of the materials used in the construction of electric machines. Conductive materials. Dielectrics. Magnetic Materials:Soft magnetic materials (Laminations, Composites), Permanent magnets. 

THERMAL PROBLEMS RELATED TO THE DESIGN OF ELECTRIC MACHINES

Heat transfer by conduction, convection and radiation. Equivalent thermal networks. Thermal transients in electric machines. Types of service.

TRANSFORMERS

Magnetic cores for power transformers. Effect of atmospheric induced voltage distribution on transformer windings. Design criteria of power transformers.

INDUCTION MACHINES

Design equations for a.c. machines. Leakage reactance of a.c windings with coil- and bar-type. Equivalent circuit and parameter calculation of squirrel cage motors. Design calculations, effects of the parameter design selection. Free and restricted design. Samples of design calculation. Design validation via analytical and numerical approach.

BRUSHLESS MOTORS

Design relationships for surface mounted permanent magnet machines. Basic design choices, cogging torque reduction, fractional slot windings, demagnetization. Design validation via analytical and numerical approach, effects of non-linear materials.

Readings/Bibliography

K.Hameyer and R.Belmans: Numerical modelling and design of Electrical machines and devices, WITpress, Southampton, Boston.

M. Ramamoorty: Computer-aided Design of Electrical Equipment. John Wiley & Sons, New York.

E. S. Hamdi: Design of Small Electrical Machines. John Wiley & Sons, New York.

J. F. Gieras, M. Wing: Permanent Magnet Motor Technology. Marcel Dekker, Inc., New York, Basel.

D. Hanselman: Brushless Permanent Magnet Motor Design. The Writers' Collective, Cranstone, Rhode Island.

J. R. Hendershot, Jr. , T. J. E. Miller: Design of Brushless Permanent-Magnet Motors. Magna Physics Publishing and Clarendon Press, Oxford.

E. Di Pierro: Costruzioni Elettromeccaniche, Ed. Siderea, Roma.

The pdf files of the slides utilized during the lessons are indispensable and sufficient for the preparation for the exam.

Teaching methods

The course includes classroom lessons (italian lenguage), numerical exercises on the computer and experimental exercises in the laboratory.

Assessment methods

The examination consists in the presentation and discussion of a report of design procedures for specific motors, following the methodology studied during the course.

Teaching tools

Overhead projectors, and PC based presentations are employed during lessons.

Office hours

See the website of Gabriele Rizzoli