Electrical Machines and Electricity

Recommended Prerequisites

Physics II, Linear Algebra

Teaching Methods

Classes are taught in a theoretical and practical scheme, where theoretical concepts are illustrated with examples. The theoretical modules have an expository tutorial character, using multimedia. The practical classes are used to develop, illustrate and deepen the application in practical problems of the theoretical and methodological concepts presented in the lectures. It can be proposed to the students to carry out a seminar work, an experimental work or a problem solving on selected topics of the syllabus.

Learning Outcomes

Analysis and characterization of AC single and three phase circuits. Understanding Electrical power in AC systems, power factor and power factor compensation. Understanding the magnetics phenomena that supporting the working principle of the electrical machinery. Description and analysis of the working principle of the transformers, synchronous generators, synchronous motors, induction motors and drives. The student should be able to describe and predict operation point of a motor, to choose the correct motor according to an industrial task and evaluate the energy consumption of an electric machine. The aim is the development of instrumental skills (oral and written communication), personal (critical thinking) and systemic (apply in practice the theoretical knowledge).

Work Placement(s)

No

Syllabus

Single-phase circuits with resistors, inductors and capacitors, impedance and impedance associations. Notion of instantaneous power, apparent power, real and reactive power, power factor compensation. Basic three-phase circuits, delta connection and star with and without neutral. Magnetic field and magnetic induction. Magnetic circuits, fundamental equations, flux, magnetomotive force and reluctance. Working principle of the transformer, voltage regulation and efficiency. Principle of operation of the rotary electric machine such as a generator and motor. Three Phase Synchronous Motor and Generator - construction, working principle, equations, and operating characteristics, starting, regulating the power factor. Three-phase Induction Motor - construction, working principle, slip and speed, operating characteristics, start-up procedures, engine rotor cage or short-circuited, wound-rotor motor or rings. Variation of speed. Motor selection based on load curve

Head Lecturer(s)

Ricardo António Lopes Mendes

Assessment Methods

Final Assessment
100% - 80% according to the possible realisation of a synthesis work or problem solving (0-20%)): 100.0%

Continuous Assessment
Frequency: 100.0%

Bibliography

- Nilson, James W., Electric Circuits, Addison Wesley Pub. 12th Ed., 2022.

- Charles Alexander and Matthew Sadiku, Fundamentals of Electric Circuits 7th Edition, 2020

- Meireles, Vitor Cancela; Circuitos Elétricos, LIDEL, 5ª ed. 2009.

- Chapman, S., Electric Machinery Fundamentals, Mc Graw Hill, 5th ed., 2012.

- Mendes, Ricardo, PDF’s de apoio às aulas teóricas, 2024.