06793 - Electrotechnics

Learning outcomes

At the end of the course the student has the basic knowledge of the theory of electrical and magnetic circuits, he knows how to apply the main methods for the analysis of circuits in steady, transient and periodic regime, he knows the properties and methods of analysis of three-phase systems, knows the principle of operation of the single-phase and three-phase transformer.

Course contents

Teaching is essentially formative and basic for Engineering studies. The teaching subject is divided into three chapters: Electromagnetism, Circuit Theory, Handling and Electrical Machines.

The 9 CFU course is divided into three 3 CFU modules, each of 30 hours of lessons. Modules 1 and 2 are in the first cycle and are for students of the Degree Courses in Electronic Engineering for Energy and Information and Biomedical Engineering based in Cesena. Module 3 is in the second cycle and is for students of the Degree Course in Electronic Engineering for Energy and Information. The following is a proposal of the programs of the three modules.

Module 1 (First cycle - Electronic and Biomedical Engineering)

1. Electromagnetism:

• Quantities ed equations of the Electromagnetisms
• Fundamental laws of Electromagnetisms
• Material laws

2. Circuit theory:

• Circuit element and electrical circuit
• Kirchhoff's laws and circuit element laws

3. Circuit elements:

• The resistor, the capacitor and the ideal inductor
• Coupled inductors
• The independent generators and the piloted generators
• Series-parallel, star-delta

4. Circuit analysis methods:

• General method of analysis,  tension elimination, nodal analysis, superposition of effects
• Transfer function, Thèvenin theorem, Norton theorem, Tellegen theorem and adherence of powers

5. The sinusoidal regime:

• Phasor method: equality, linear combination and derivation Material relationship in the phase domain
• Serie and parallel resonance
• Active, reactive, complex and apparent power
• Power factor
• Power factor correction

Module 2 (First cycle - Electronic and Biomedical Engineering)

6. Operational amplifiers:

• Ideal operational amplifier
• Inverting and non-inverting amplifier
• Amplifier for the sum, the difference, the derivative and the integral
• Circuit analysis with operational amplifiers
• Digital-to-analog converter

7. Transient in electrical circuits:

• Circuit elements with transient memory
• Time domain transient calculation
•  First and second order circuits

8. Three-phase systems

• Phase voltages, line voltages and line currents
• Symmetric systems, balanced systems and balanced systems
• Power in balanced three-phase systems
• Power factor in three-phase systems

9. Magnetic systems

• Magnetic circuits and Hopkinson's law
• Calculation of the self and mutual induction coefficients
• Magnetic energy and magnetic forces
• Ferromagnetic materials

10. Electromagnetic movement and electric machines

• Transformer FEM and motional FEM
• The transformer
• Conversion of EM energy into motion energy
• The rotating field
• The asynchronous machine and the synchronous machine
• DC machines

Module 3 (Second cycle - Electronic Engineering)

11. Three phase systems

• Wye and delta connections
• Symmetrical and balanced systems, asymmetrical and unbalanced systems
• Power in three phase systems
• Power factor correction
  

12. Magnetic circuits

• Review of stationary magnetic field laws
• Ferromagnetic materials and magnetic hysteresis
• Reluctance and permeance, Hopkinson's law, and magnetic circuit analysis
• Self and mutual induction.
  

13. Transformers

• Operating principle
• Energy losses
• Internal equations, equivalent circuits, open-circuit and short-circuit tests
• Efficiency of the transformer
• Parallel connection of transformers
• Three-phase transformers, special transformers.

During the lessons, exercises will be carried out on the following topics

• Solution methods for direct current circuits (Module 1)
• Solution methods for alternating current circuits (Module 1)
• Methods of solution of circuits with operational amplifiers (Module 2)
• Transient calculation (Module 2)
• PSpice ùutilisation (Module 3)

 

Readings/Bibliography

On the website: Lecture notes of a part of the course, prepared by the teacher, a part of the slides projected during the lectures and the exercises are available on the web site "http://www.die.ing.unibo.it/pers/borghi/didattica.htm". Moreover the following texts are suggested:

For consultation:

• K. Alexander and M.N.O. Sadiku, “Fundamentals of Electric Circuits”, McGraw Hill, New York, 2009
• G. Rizzoni, “Principles and Applications of Electrical Engineering”, McGraw Hill, New York, 2007
• F. Ciampolini: “Elettrotecnica generale”, Ed. Pitagora, Bologna
• P.R. Ghigi, M. Martelli, F. Mastri, “Esercizi di Elettrotecnica”, Ed. Esculapio, Bologna

For consultation:

• C.A. Desoer, E.S. Kuh, “Fondamenti di teoria dei circuiti”, Ed. Angeli, Milano
• L.O. Chua, C.A. Desoer, E.S. Kuh, ”Circuiti lineari e non lineari”, Milano
• J.D. Jacksoni,"Classical Electrodynamics",John WWiley & Sons, New York, 1975
  
• J.A. Stratton, "Electromagnetic Theory", McGRAw-Hil New York

Teaching methods

The course is based on theoretical lectures and exercises held by the teacher.

It is also recommended, in addition to the exercises held in class, to personally solve during the preparation of the course, exercises of the type of ones solved by the teacher.

Assessment methods

The exam consists of a written tests and oral interviews that coverboth theoretical questions and exercises. The theory and exercises are exclusively on topics treated during the lessons.

The outcome is given given out of thirty.

Class attendance is not required. The attendance, however, if accompanied by the continuous comprehension of the topics covered, contributes very effectively to the preparation of the course.

Teaching tools

On the lecturer's website "http://www.die.ing.unibo.it/pers/borghi/didattica.htm" the lecture notes on the topics covered in class for Module 1 and 2 are available and exercises related to theory are proposed. Slides projected in class and further information on the course are given too.

Office hours

See the website of Carlo Angelo Borghi

See the website of Arturo Popoli