OVERVIEW

66117 – ELECTRICAL INSTALLATIONS

Scientific domain: ING-IND/33 Electrical Power Systems

European Credit Transfer System Credits (ECTS): 12

Length: 12 + 12 weeks (along two semesters)

Lecturers: Marco INVERNIZZI – Stefano BRACCO

AIMS AND CONTENT

LEARNING OUTCOMES

Introduction to the basic topics related to the operation, the design and the planning of electrical systems, analysed as systems of interconnected elements and represented by mathematical or circuital models. Special attention is paid to practical operating conditions

AIMS AND LEARNING OUTCOMES

The main purpose of the course is to provide students with basic knowledge of planning, design and  operation of electrical power systems. Systems made up of different interconnected components are analysed by means of mathematical and/or circuital models, with a particular focus on practical cases. At the end of the course, students should know the main operating principles of electrical power systems, both in normal and fault conditions. Moreover, students should be able to solve exercises about the design and verification of electric lines and cables. In particular, after the first module of the course students should express and solve load-flow problems as well as be able to calculate currents and voltages in networks subjected to faults. On the other hand, after the second module of the course students will know the main designing criteria for power networks and should be able to define protection systems for power systems.

PREREQUISITES

Skills in solving alternating current electrical circuits, algebraic and differential equations, calculations dealing with trigonometry and complex numbers, matrix calculus.

TEACHING METHODS

Theoretical and practical lectures (5 hours a week)

Laboratory activities and seminars (extra hours)

During the first semester of A.A. 2020/2021, theoretical and practical lectures will be held via remote facilities. For what concerns the second semester, lectures’ modes will adhere to the University guidelines.

SYLLABUS/CONTENT

• Architecture of electricity production, transmission and distribution systems: characteristics and needs of energy users; load diagrams for single and complex users; power generation: types of power plants, classification and scheduling strategies to meet the load demand; notes on distributed generation and polygeneration microgrids.
• Electrical circuit modelling and design. Calculation of electrical line parameters. Long line theory. Wavelength concept. Modelling and analysis of electrical lines.
• Per-unit system: definitions and static applications.
• Steady-state sinusoidal regime for the electrical system. Load-flow problem.
• Electrical system faults (overcurrents): Symmetrical short-circuit current calculation. Short-circuit power definition. Analysis of asymmetrical faults. Method of symmetrical components. Definition of sequence impedances. Sequence filters.
• Electrical system faults (overvoltages): Disconnection and breaking of electrical circuits. Electric arc properties, strategies and devices for electric arc extinguishing. Restriking and recovery voltages. Dielectric regeneration curves for circuit breakers.
• Power system protection. Types and attributes of protection systems in connection with different operating conditions and plant components. Characteristics of selective protection systems. Protection systems against short-circuits and overloads. Automatic circuit brakers and fuses.
• Design and check criteria applied to cable lines.
• General background on electrical safety. Reliability and safety definitions. Safety of people, direct and indirect contacts. Description of grounding systems.
• Power factor correction systems: technical and regulatory aspects.

RECOMMENDED READING/BIBLIOGRAPHY

R. Marconato, “Electric Power Systems”

W.D. Stevenson, “Elements of Power System Analysis”

F. Saccomanno, ”Electric Power Systems – Analysis and Control”

G. Pratesi, “Le Protezioni dei Sistemi Elettrici di Potenza” (in Italian)

R. Benato, L. Fellin, “Impianti Elettrici” (in Italian)

TEACHERS AND EXAM BOARD

Exam Board

MARCO INVERNIZZI (President)

ROBERTO ARESI

ANDREA BONFIGLIO

GIO BATTISTA DENEGRI

RENATO PROCOPIO

STEFANO BRACCO (President Substitute)

LESSONS

LESSONS START

September 21, 2020

Class schedule

ELECTRICAL INSTALLATIONS

EXAMS

EXAM DESCRIPTION

For each semester, students have to do a written exam (duration: 2 hours) which consists of exercises. Both written exams can be done on the same day (duration: 4 hours). Students who successfully pass the written exam are allowed to take the oral exam (duration: about 1 hour). Both the oral exams, one for each semester, can be taken on the same day.

ASSESSMENT METHODS

Evaluation of the acquisition of practical and theoretical skills in calculation methods for the design and operation of electrical power systems. The written exam aims at evaluating the ability of students to solve numerical excercises. The oral exam permits to ckeck students’ knowledge on theoretical and applied aspects related to electrical power systems; moreover, critical reasoning skills and the use of an appropriate language are also considered.

Exam schedule