29244 - Foundations of Electrotechnics T

Learning outcomes

The aim of the course is to provide the students with a good methodological knowledge concerning the laws of electromagnetism, and their application to the interpretation of the working principles and modeling of electromagnetic devices.

Course contents

ProgramThe course program is divided into the sections below.Definitions and laws of electromagnetism

Electromagnetic field sources. Electromagnetic field vectors. Material constitutive laws. Laws of electromagnetism in integral form: fundamental laws and derived laws. Definition of electromotive force and electric voltage. Electromotive force induced on static and dynamic media. Fundamentals of vector analysis. The laws of electromagnetism in local form. Definition of electric and magnetic circuits according to the field theory. Classification of the electromagnetic field problems. Energy of the electromagnetic field.

Electrostatics

Equations and electrostatic potential. Electrostatic field of a system of conductors. Capacitance coefficients. Potential coefficients. Partial capacitances. Electrostatic shield. Capacitors and capacitance. Electrostatic energy stored in a capacitor. Calculation of the capacitance of simple structures. Capacitance of a coaxial cable and of a transmission line.

Stationary electrodynamics

Electric field and stationary current density field.

Determination of the current field in a conductor subjected to assigned potential difference. Ohmic resistance of a conductor. Analogy between the electrostatic field and the stationary current field.

Magnetic field generated by stationary currents

Equations and magnetic vector potential. Methods for the computation of the magnetic field generated by an assigned distribution of stationary currents. Self and mutual induction coefficients. Magnetic energy stored by an inductor. Calculation of the induction coefficients of structures. Self induction coefficients of a coaxial cable and a transmission line.

Quasi-stationary electrodynamics

Ohm’s law in time varying regimes.

Magnetic circuits. Properties of the ferromagnetic materials. Magnetic circuits in static conditions: assumptions for the analysis, direct and inverse problems. Permanent magnets: working principles and design principles.

Readings/Bibliography

F. Barozzi, F. Gasparini, 'Fondamenti di Elettrotecnica - elettromagnetismo', UTET, 1989.

H. A. Haus, J. R. Melcher, 'Electromagnetic Fields and Energy', Prentice-Hall Inc., New Jersey, 1988.

H. E. Knoepfel, 'Magnetic Fields', John Wiley & Sons, Inc., 2000.

Teaching methods

The course contents are illustrated during the lectures. Two hours of lecture per week will be dedica-ted to the solution of exercises and computer practice.

Assessment methods

The exam will consist of an oral examination at the end of the course. No partial exams are foreseen during the course. During the oral examination the topic discussed during the course will be treated by the student. The examination will be aimed at assessing that the student is able to adopt a correct technical language and has reached an organic knowledge of the topics developed during the course. The ability of the student to apply the acquired knowledge to the solution of new problems will be verified. The final mark will depend on the degree of fulfilling of the aforementioned requisites.

Teaching tools

The lecture notes of the course are available on the website Insegnamenti OnLine of the University of Bologna (https://iol.unibo.it). Presentations given during the course are also available on this website.

Office hours

See the website of Marco Breschi