OVERVIEW

The course addresses the basic aspects related to electrical circuits and their analysis, electric machines, power electronic devices and power systems.

AIMS AND CONTENT

LEARNING OUTCOMES

The first part of the course provides the theoretical knowledge and tools for the study and the analysis of electric circuits in direct current and alternating current; the second part is aimed at providing a basic knowledge of electric machines, power electronic devices, electrical drives and power systems.

AIMS AND LEARNING OUTCOMES

Attending lessons and exercises, the students will be able to:

• have knowledge relative to theoretical bases and application instruments for the analysis of electric circuits in steady-state and sinusoidal regime (single phase and three-phase systems);
• have superficial knowledge of the mathematical instruments for the analysis of electric circuits in time-domain;
• have knowledge of the main physics phenomena who subtend to the operation of the electrical machines (transformers, synchronous and induction machines);
• have knowledge of first rudiments for the analysis of transformers and induction motors in operation;
• have knowledge of the main aspects relevant to power electronics and static converters;
• have knowledge, in descriptive way, of electrical drives and their applications;
• have knowledge of main aspects relative to the analysis of the electric power systems;
• have knowledge of simplified analysis techniques for low-voltage electric systems, with detailed knowledge about evaluation of: efficiency, voltage drop, power evaluations. They will know also the problems relevant to low-voltage power factor correction and power capacitors evaluation.

PREREQUISITES

Basics knowledge of Calculus and Physics.

TEACHING METHODS

The course mainly develops through frontal lessons with audiovisual aids (70 hours). Moreover sessions of exercises carried out in classroom are provided (about 30 hours). The students who attend the course must sign up on the AulaWeb site of the course, enrolling to the course. In such a way they will have access to the didactic material of the course, they will receive via email communications of the teacher and will have access to the results of the written tests.

A two hours lesson devoted to exercises will be held every week, in preparation of the practical tests, indicativally starting from the second week of October.

Students with valid certifications for Specific Learning Disorders (SLDs), disabilities or other educational needs are invited to contact the teacher and the School's contact person for disability at the beginning of teaching to agree on possible teaching arrangements that, while respecting the teaching objectives, take into account individual learning patterns. Contacts of the teacher and the School's disability contact person can be found at the following link Comitato di Ateneo per l’inclusione delle studentesse e degli studenti con disabilità o con DSA | UniGe | Università di Genova

SYLLABUS/CONTENT

Circuits

1. Introduction – Electrical power transmission -  Electrical generators, electrical users, Electrical lines.
2. Electromagnetic phenomena: General approach to the solution of the electromagnetic problems - Electric charge - Electrical current - Conductors - Continuity Law - Measure of the electrical current: ammeter - Electric field – Electric Voltage - Measure of the electric voltage: voltmeter.
3. Electrical Conduction:  Ohm’s  and Joule’s Laws  - Electrical resistivity and conductivity - Conductors of generic form - Bipolar resistor - Characterization of a bipolar resistor.
4. Electrical  Generators: Introduction – Behaviors of generators in open circuit - Behavior of generators with loads - Energy balance of generators – Electrical generators types.
5. Bipolar devices and energy balance: Introduction – Equations of bipolar devices – Special bipolar devices  (short circuit and open circuit) – Power  - Measure of the electrical power: wattmeter.
6. Electrical network Properties: Introduction - Regime of operation (stationary, variable, transitory) - Analysis of the electrical networks - Topology of the networks - Kirchhoff’s  Laws – Network analysis methods.
7. Steady state analysis: Introduction – Bipolar devices connected in series – Series connection of an ideal voltage generator  and a resistor - Resistors in series: equivalent resistance – Bipolar devices connected in parallel - Parallel connection of an ideal current generator and a resistor - Resistors in parallel: equivalent conductance - Network of resistors: equivalence concept - Star-delta transform – Steady-state analysis Methods  - Superposition method – Maxwell’s method  - Network reduction - Substitution Theorem – Thevenin’s transform – Norton’s transform – Millmann’s  Formula – Power matching - Maximum power transfer.
8. Dielectric phenomena – Capacitor : Introduction – Gauss’s Law - Capacitor – Parallel-plate capacitor- Bipolar  capacitor – Capacitor  in steady-state regime  - Capacitor  in transient regime - electrostatic Energy - Series and parallel of capacitors - Displacement current.
9. Magnetic phenomena - Inductor: Introduction - Magnetic materials - Ferromagnetic materials - magnetic Induction - Faraday-Neumann’s Law - Inductors – Inductor coils - Mutual inductors – Bipolar inductors  and two port inductors - Inductors in steady-state regime - Inductors in transient regime - Magnetic energy - Series and parallel of inductors.
10. Sinusoidal steady-state networks: Introduction – Sinusoidal quantities: Phasors and sinusoids – Phasors graphical operations - generalized Ohm’s Law  - Impedance – Sinusoidal steady-state network analysis – Thevenin’s and Norton’s  transforms - Power balance in steady-state sinusoidal regime (average power, reactive power, complex power) - Measuring instruments in a.c.
11. Three-phase network analysis: Introduction - symmetrical three-phase  voltages - Phase and line voltages – Three-phase balanced load – Currents in three-phase networks – Balanced load analysis – Single-phase equivalent - Powers in balanced three-phase systems.
12. Magnetic circuits: Introduction - Reluctance – Ferromagnetic materials - Air gap - Magnetic  circuit’s Laws - Network analysis of magnetic circuits.

Electrical machines

1. Transformers: Single-phase transformers - Equivalent circuit of the transformer – No-load (open-circuit) and short circuit tests – Power transformer on load - Three-phase transformers - Equivalent circuit of the three-phase transformer.
2. Induction machines: Basic principles of a three-phase induction machine – Action of a three-phase induction machine - Simplified equivalent circuit - Speed-torque Characteristics – Starting of induction motors -  Induction machine acting as generator.
3. Synchronous Machines: Constructional features – Basic principles – No-load characteristics of a synchronous machine - Synchronous machine on load - Equivalent circuit of the synchronous machine - Electromechanical behavior.
4. Converters

Power systems

1. Basic notions on power grids 

RECOMMENDED READING/BIBLIOGRAPHY

Written support are available on-line on AulaWb site. There are various folder, where:

in folder "appunti del corso" are available for download pdf copies of teaching slides.

in folder "esercitazioni" are available for download pdf copies of solved exercises.

in folder "risultati delle prove scritte" are available for download pdf copies of past written exams.

It is also useful consulting of following books available from school CBA:

M. Guarnieri, A. Stella: “Principi ed applicazioni di Elettrotecnica (volume primo)”, Edizioni Libreria Progetto Padova.

C. K. Alexander, M.N.O. Sadiku: “Circuiti elettrici”, McGraw-Hill, ISBN 88 386 0853-9.

C. A. Desoer, S. Kuh: “Fondamenti di teoria dei circuiti”, Franco Angeli Editore, Collana di Ingegneria Elettrica.

M. Repetto, S. Leva: "Elettrotecnica - Elementi di teoria ed esercizi", CittàStudi Edizioni, Torino.

TEACHERS AND EXAM BOARD

LESSONS

LESSONS START

https://corsi.unige.it/en/corsi/8720/studenti-orario

Class schedule

The timetable for this course is available here: EasyAcademy

EXAMS

EXAM DESCRIPTION

The exam requires positive evaluation on a written test followed by an oral examination.

Written test: two written tests will be scheduled during the period of lesson (compitini). Each test require the solution of an exercise (one hour). Other written tests will be scheduled during the periods of examinations (January-February and June-September). Each test requires the solution of two exercises (two hours).

For every proposed exercise it must be answered to three questions, each of which it is worth a point, for a total on the two exercises of 6 points. Admission to oral test requires total score turns out to be ≥ 4 on 6. Regarding the intermediate written tests, students attending the course for the first time are admitted.

The overcoming of written tests guarantees the admission to the oral tests until the first written test of the following academic year. Exceeded such term the written test must be newly old.

Oral examination: talk of approximately 30 minutes on practical examples (exercises) and theoretical arguments. Oral test will be possible during the periods of interruption of the lessons, the registration to the examination sessions with a restricted number is carried out by means of the online procedure. The registrations is opened beginning from the week precedence to that of the session of examination chosen. In lessons periods oral tests are provided on appointment basis, only for students who have finished the triennial cycle (students who have already attended the third year courses).

Students with SLD, with disabilities, or with other regularly certified special educational needs will agree with the teacher on the exam method and the compensatory instruments, by contacting the instructor at least 10 days before the exam. They will also be able to take advantage of the additional time required by law.

ASSESSMENT METHODS

The examination tests have the scope to assess the level of students preparation with detailed emphasis on the following aspects:

• acquaintances with respect to the main basics elements that characterize the study of the electric circuits (for example: concept of two-terminal network, Ohm’s and Kirchhoff’s laws, Thevenin and Norton transform, Millmann’s formulas, sinusoidal analysis, etc) –acquaintances evaluated during the oral test;
• ability to apply them on specific problems (solution of numerical exercises: written test);
• acquaintances with respect to the main applicative aspects of electromagnetism (for example: transformers, induction machines, power electronics, electric power systems) – acquaintances evaluated during the oral test;
• ability to analyze simple problems relevant to low-voltage electric power systems, who involve the analysis of transformers, induction motors, electricity end-users, low-voltage power factor correction (solution of numerical exercises: written test).