Teacher

prof. Fabrizio BELLINA

Credits

6 CFU

Language

Italian

Objectives

The course gives the fundamentals knowledge of the main applications of electrical engineering, and it is devoted to the non electrical engineer, giving him the knowledge about some electrical machines and their drives. Some elements of electrical plants and safety is given also.In the end, in insight of the most recent and innovative electrical applications is given.

Acquired skills

- Capability to analyse the behaviour of some electrical machines and other objects of an electric industrial plant.
- Capability to understand the behaviour of the principal static conversion devices and drives.
- Capability to  understand the main technical and management problems and features of medium-size and large-size electrical plants.
- To acquire some knowledge of the most innovative application of electricity.

Lectures and exercises (topics and specific content)

Magnetic circuits: flux tubes, magnetic voltage, reluctance and permeance; Hopkinson's law, equivalent electrical network; self and mutual indiuctance coefficients in term of self and mutual permeances; use of ferromagnetic materials, air gap, magnetic field refraction; use of permanent magnets (6 hours).
Forces in the magnetic field: ponderomotive force on the electrically fed conductors in magnetic field; electro-mechanical conversion of the energy (2 hours).
Electrical network in sinusoidal regime: complex reluctance and permeance, parallel and series synthesis; losses in ferromagnetic plates; voltage drops at the leads of a double bipole (2 hours).
Three-phases networks: overview on polyphase systems; three-phase systems; voltages and currents; Delta and Y connections for loads and generators; power in a three-phases system, power measures; load reactive power compensation (6 hours).
Transformers: rated quantities; monophase transformer, manufacturing features, equivalent electrical circuits; no-load, short-circuit and under load working conditions; tests; three-phases transformers, manufacturing features, connections and groups; voltage and current measurement transformers (7 hours).
Static conversion: overview on semiconductors, PN junction, diodes, transistors, SCR; overview on power amplifiers; half-wave monophase rectifier, Graetz's monophase bridge; polyphase half and full bridges; full bridge and half bridge inverters; half bridge with transformer inverter; three-phases half bridge inverter;: pulse width modulation; AC/AC regulators (6 hours).
Introduction to rotating machines: overview of the common geometrical and manufacturing characteristics; magnetomotive force and magnetic circuits, non linearities; rotating magnetic field; induced e.m.f., torque (1 hour).
Synchronous machines: rated quantities; induction along the gap; no-load characteristic; working under load and in short circuit; effect of stator currents; synchronous impedance; electromechanical behaviour, control and stability (5 hours).
Asynchronous machines: rated quantities; three-phases asynchronous machines, working with clamped opened and short circuited rotor, workind under load; electrical equivalent circuit, mechanical behaviour and characteristic; starting and speed regulation; cage and double cage motor; monophase motor (5 hours).
Special motors:  asynchronous starting of a synchronous machine; brushless motor; switched reluctance motor, step motor (1 hour).
Electrical plants and photovoltaic plants: overcurrents and overvoltages; opening of an AC and DC circuit; interruptors and isolators; magnetic, thermal and differentials relays; electrical dangers and effects on the human body, protection; earth plant, working and principal components; systems for the power delivery in low-voltage systems, TT, TN, IT; solar irradiation; photovoltaic cells, series and parallel connections; connection to power lines (5 hours).
Power lines and HV electrical system: overhead power lines, cable lines, insulators; frequency and voltage control; stability, network blackouts; HVDC lines; overview of the italian electrical market (2 hours).
Innovative electrical applications: superconductors, SMES, thermonuclear fusion with magneti confinement (2 hours).
Exercises (6 hours).

References

- Lectures notes
- M. Fauri, F. Gnesotto, G. Marchesi and A. Maschio, “Lezioni di elettrotecnica – Applicazioni elettriche”, ed. Progetto Leonardo, Esculapio, Bologna 
- N. Faletti, P. Chizzolini, “Trasmissione e distribuzione dell'energia elettrica,” vol. I  and II, ed. Pàtron, Bologna, 2005
- R. Benato, L. Fellin, “Impianti elettrici,”  ed. UTET scienze tecniche, Torino, 2011
- G. Figini, U. Torelli, “Manuale di appplicazione delle norme CEI,” ed. Hoepli, Milano, 2000
- A. Paolucci, “Lezioni di trasmissione dell'energia elettrica,”  CEUP, Padova, 2005

Type of exam

Written and oral

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