29246 - Electrical Plants T

Learning outcomes

As the course is delivered in Italian, the reader is encouraged to refer also to the corresponding box written in Italian. For convenience, however, the relevant translation in English is provided below.

Fundamentals for the analysis of the performance and functionalities of an electrical installation. Transmission lines theory, line parameters appraisal and choice of the main characteristics/features of overhead lines and cables. Electric arc and short circuit current interruption. Manoeuvre and protection devices and apparatuses. Electrical safety. Main criteria for the design of MV and LV users electrical installations.          

Course contents

As the course is delivered in Italian, the reader is encouraged to refer also to the corresponding box written in Italian. For convenience, however, the relevant translation in English is provided below.

The course is divided into two modules pf 60 and 30 hours respectively: in the 60 hours of lecture (docent: Professor Carlo Alberto Nucci, oral examination) the principles, the structure of the electrical systems, as well as the theoretical basis for their design and the connection to them of renewable source generators is provided; the module of 30 hours (Professor Fabio Napolitano , written examination ) is devoted to exercises on the design of electrical systems of medium and low voltage (MV and LV).

The course program is as follows:

• Structure of transmission and distribution networks;
• Transmission line theory: primary and secondary parameter, wave equations, equivalent circuits, appraisal of voltage drops;
• Transformers and synchronous generators (brief survey on fundamentals);
• Sequence method for the solution of unbalanced three-phase systems
• Thermal analysis of operation conditions of overhead lines and cables and Joule integral;
• Electro-dynamic effects of short circuit currents;
• Electric arc theory
• Switch-gears, control-gears, and protection devices for medium voltage (MV) and low voltage (LV) levels
• Electrical safety in electrical installations: electric shock safety curves (current and voltage), protection against direct and indirect electric contact; 
• Neutral conductor earthing methods;
• Lightning protection of lines and structures;
• Emergency Power Systems Units and UPS;
• Design and sizing of electrical LV and MV plants and their connection to the grid, with particular reference to dispersed/renewable generation, layout definition, sizing of electrical ducts/lines, short circuit calculation, protections selection and relevant coordination , power factor correction systems, relevant standards.

More in detail, the 60 hours module (prof. C.A. Nucci) deals with the theoretical basis relevant to plant design and sizing. In particular the following subjects are covered: transmission line theory, primary and secondary line parameters, wave equations and their integration, propagation constant and characteristic/surge impedance, reflection and transmission coefficients, line equivalent circuits, appraisal of voltage drops for short lines, sequence (Fortescue) method for the solution of unbalanced three-phase systems, line insulators, thermal analysis of operation conditions of overhead lines and cables, line ampacity, Joule integral, electro-dynamic effects of short circuit currents, transient recovery voltage, interruption of small inductive and capacitive currents, electric arc theory, switch-gears, control-gears, circuit breakers, fuses and protection devices for MV and LV levels, electrical safety in electrical installations, electric shock safety curves (current and voltage), grounding systems and their functions, hemispherical electrode at the surface and embedded on the ground surface and relevant potential distribution on the ground surface, real grounding electrodes and relevant resistance, foundation earthing, touch and step voltages, independent earth electrodes, functional insulation, double insulation, main and secondary equipotential bonding, protection by electrical separation, neutral conductor earthing methods, Extremely Low Voltage (ELV) systems, residual current devices, protection against direct and indirect electric contacts, lightning protection of lines and structures, emergency power systems units and UPS.

The second module of 30 hours (Prof. Fabio Napolitano deals with the following topics, laboratory sessions on design and sizing of electrical LV and MV plants and their connection to the grid, with particular reference to dispersed/renewable generation, layout definition, sizing of electrical ducts/lines, short circuit calculation, protections selection and relevant coordination application examples, power factor correction systems, relevant standards.

Readings/Bibliography

As the course is delivered in Italian, the reader is encouraged to refer also to the corresponding box written in Italian. For convenience, however, the relevant translation in English is provided below.

• D. Zanobetti, M. Pezzi, Lezioni di impianti elettrici, CLUEB, Bologna, 1981.
• V. Carrescia, Fondamenti di sicurezza elettrica, Torino: TNE, 1999.
• V. Cataliotti, Analisi dei sistemi di distribuzione a media e bassa tensione, Palermo: Flaccovio, 2004
• R. Benato, L. Fellin, “Impianti elettrici”, UTET, 2011.
• Copies of the slides illustrated during the course are provided to students before each relevant lecture; written notes prepared by the docents of the Electric Power Systems laboratory of the University of Bologna are provided to students too.

Teaching methods

As the course is delivered in Italian, the reader is encouraged to refer also to the corresponding box written in Italian. For convenience, however, the relevant translation in English is provided below.

Lectures (black board, and ppt presentations)

Exercises at the blackboard

Laboratory sessions with the aid of MV and LV devices

Laboratory sessions with the aid of professional software for the design of electrical installations and the selection of protection devices

 

Assessment methods

As the course is delivered in Italian, the reader is encouraged to refer also to the corresponding box written in Italian. For convenience, however, the relevant translation in English is provided below.

For 6 CFU Module (Professor Carlo Alberto Nucci) an oral test is required to be successfully accomplished. To this aim, students must demonstrate solid preparation concerning the main concepts discussed in the lectures and in particular in relation to the theoretical basis, the methods of calculation and assessment of the equipment and the operating principles used. A higher score will be awarded to students who demonstrate that they understand and are able to apply all the methodological content by exposing them with mastery. The test is failed when the insufficient knowledge of the main concepts of matter and of the technical language are evident from their oral exposition. For Module 3 CFU (Professor Fabio Napolitano ) it is necessary to pass a written test regarding the design and sizing of an electrical system of MV/LV in which  the presence of generation from renewable sources is expected to be included.

Teaching tools

As the course is delivered in Italian, the reader is encouraged to refer also to the corresponding box written in Italian. For convenience, however, the relevant translation in English is provided below.

Lecture notes by the faculty of the Power Systems Laboratory of the University of Bologna.

Slide ppt.

Multimedia didactical material, MOOCS

Technical visit to a local Distribution System Operator station  

Seminars by experts from professional associations and major electric players.

 

Office hours

See the website of Carlo Alberto Nucci

See the website of Fabio Napolitano