Electrotechnics and Electrical Machines


The students, through rigorous scientific deduction, should become aware of the mathematical and physical foundations of applied electrotechnics, namely, of the electric power’s production, distribution and use, and of the composition and characteristics of the most relevant industrial electrical machines.

On the other hand, students must become competent to model, analyse and calculate simple electric power circuits and networks, including balanced three-phase ones. Students will become able to make technically based choices of simple electrical equipments.

General characterization





Responsible teacher

Pedro Miguel Ribeiro Pereira


Weekly - 3

Total - 48

Teaching language



Students should have basic knowledge of electromagnetism and mathematical analysis, including complex number analysis.


¨ Vítor Meireles, Circuitos Eléctricos 6ª Edição, LIDEL, 2010
¨ John Bird, Electrical Circuit Theory and Technology 2nd Ed, Newnes, 2003
¨ Stephen J. Chapman, Electric Machinery Fundamentals, McGraw-Hill (20xx)
¨ George McPherson & Robert D. Laramore, An Introduction to Electric Machines and Transformers, Wiley (1990)

Teaching method

The distinct concepts, techniques and theories are explained by the lecturer with the support of slides and practical demonstrations with different equipments.

Students assess their skills through semiautonomous resolution of sets of problems, available in the slides.

Experimental work at lab.

Evaluation method


Includes a theoretical component (TP) and a practical component (CP), with weights of 75% and 25%, respectively, for the Final Classification (CF). The classification in each component (TP and P) must be greater than 9,5.

CF = 0,80*TP + 0,20*P  >= 9,5

The practical component is composed by two experimental work(TA1 and TA2):

The theoretical component  is composed by two Tests (T1 and T2) or by an Exame (Ex)

TP = (0,40*T1 + 0,40*T2) ou  TP = Ex

Subject matter

Electrical Quantities. Voltage-current equations of capacitors, inductors and resistors.

DC electrical networks. Kirchhoff’s laws.

AC circuit analysis. Sinusoidal functions. Complex representation. Phasors and complex Amplitudes.

Complex impedance. Active, reactive, apparent and complex powers. Complex Poyting’s Theorem. Ressonance. Power factor correction.

Three-phase systems. Fundamentals of power production and transportation.

Magnetostatics. Magnetic circuit

Magnetic linkage in mono and three-phase transformers. Transformer theory. Steinmetz equivalent circuit.

Induction machine.

DC Motor.

Sincronous machine.


Programs where the course is taught: