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

To solve problems related to the analysis of the operation of electrical systems, with emphasis on load-flow calculations and the evaluation of the effects of series and shunt faults, using dimensional values and in "per unit" system. 

To design and verify various interconnected components of electrical power systems, considering thermal criteria, quality of service requirements, energy and economic aspects. 

To define properties and characteristics of power line protection systems by evaluating possible alternative solutions. 

PREREQUISITES

Skills in solving AC electrical circuits, algebraic and differential equations, calculations using trigonometry and complex numbers. 

TEACHING METHODS

Theoretical and practical lectures (5 hours per week), with examples to solve examination problems. 

Laboratory activities and seminars (additional hours not used for assessment). 

SYLLABUS/CONTENT

• Architecture of electricity generation, transmission and distribution systems: characteristics and needs of energy consumers; load diagrams for single and complex users; power generation: power plant types, classification and scheduling strategies to meet load demand; references to distributed generation and polygeneration microgrids. 

• Electrical circuit modelling and design. Calculation of electrical line parameters. Theory of long lines. 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): calculation of symmetrical short-circuit currents. Definition of short circuit power. Analysis of dissymmetrical faults. Method of symmetrical components. Definition of sequence impedances. Sequence filters. 

• Electrical system faults (overvoltages): Disconnection and interruption of circuits. Arc characteristics and properties, extinguish strategies and devices. Recovery voltages. Dielectric regeneration curves for circuit breakers. 

• Power system protection. Types and attributes of protection systems associated with various operating conditions and system components. Characteristics of selective protection systems. Protection systems against short circuit and overload. Automatic circuit breakers and fuses. 

• Designing and test criteria for cable lines. 

• General background on electrical safety. Reliability and safety definitions. Safety of persons, direct and indirect contacts. Description of earthing 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)

For students with specific needs (workers, non-attending, with SLD) recorded lessons and exercises are available on request.