Máquinas Elétricas

The teaching method of this curricular unit follows an active and integrated approach, aligned with the adopted pedagogical model, aiming
to promote the development of both theoretical and practical skills in students. The theoretical classes are structured around the projection
of documents, such as PowerPoint presentations, Word documents, and other multimedia materials, which illustrate the concepts
discussed. These resources are complemented with detailed explanations on the board, fostering active reflection and student participation.
The methodology aims not only to transmit theoretical knowledge but also to stimulate critical thinking and the practical application of
concepts.
The laboratory practical classes, an essential part of the learning process, are organized to allow direct application of the concepts learned
in the theoretical classes. These classes are divided into two components: the resolution of practical exercises, covering each electrical
machine studied, and the performance of laboratory experiments by the students, organized in groups of about two. During these sessions,
students have the opportunity to assemble circuits and carry out experimental work, enabling them to determine the characteristic curves of
the machines and the parameters of the equivalent circuits. This approach encourages collaborative work, experimentation, and critical
thinking, promoting active and meaningful learning.
By integrating both theoretical and practical components, the pedagogical model used ensures that students acquire a deep understanding
of the principles and applications of electrical machines, preparing them to solve practical problems and develop essential technical skills in
the field. The constant interaction between theory and practice, combined with ongoing guidance from instructors, enables a dynamic and
effective learning process, aimed not only at acquiring knowledge but also at developing problem-solving, analysis, and critical evaluation
skills, which are essential for the students’ professional success.

The goal is for students to acquire knowledge about the main types of classical electrical machines and their applications, with a strong
practical component in the laboratory. By the end of the semester, students should be able to describe the structure and operation of
machines such as transformers, three-phase and single-phase induction motors, DC generators and motors, alternators, and synchronous
motors, understanding their fields of application and performing calculations related to steady-state operation. This knowledge will enable
them to design, implement, and operate electrical installations, understand machines and control equipment, recognize key aspects of
industrial maintenance, design control and protection systems, and develop maintenance plans for power systems. The program combines
theory and practice to prepare students for technical challenges in the field.

1. Principles of Electrical Machines
Overview of key concepts. Faraday’s, Lenz’s, Newton’s, and Laplace’s laws. Materials.
2. Single-Phase and Three-Phase Transformers
Types, construction, working principles. Equivalent circuits, performance characteristics, losses, and efficiency. Economic tests, parallel
operation.
3. Induction Machines (IM)
Polyphase IM: construction, principles, equivalent circuits, power, and torque. Mechanical and electromechanical characteristics. Stability,
tests, starting methods, braking. Squirrel-cage rotors, induction generators, single-phase IM.
4. DC Machines
Principles of operation, EMF generation, and commutation. Power, torque, efficiency. Equivalent circuits and excitation. DC generators:
characteristics. DC motors: power flow, losses, operation, starting, control.
5. Synchronous Machines
Operating principles, construction, cooling, excitation. Equivalent circuits.

NAO