Fundamentals of Electrical Machines I
Áreas Científicas |
Classificação |
Área Científica |
CNAEF |
Electricity and energy |
Ocorrência: 2022/2023 - 2S
Ciclos de Estudo/Cursos
Sigla |
Nº de Estudantes |
Plano de Estudos |
Anos Curriculares |
Créditos UCN |
Créditos ECTS |
Horas de Contacto |
Horas Totais |
TSPVE |
13 |
Plano de Estudos_2015_16 |
1 |
- |
6 |
60 |
162 |
Docência - Responsabilidades
Língua de trabalho
Portuguese
Objetivos
The UC Fundamentals of Electrical Machines is a basic course in the field of electromechanical energy conversion. Learning the methods and physical concepts that underlie it, aims to develop in students fundamental skills that allow them to understand the operating regimes of the Direct Current Machine (CCM) and Transformers (TR).
It is also intended that students are in possession of instruments (base knowledge and bibliographic guidelines) that allow the eventual continuation and deepening of studies. In structuring the UC, and in order to achieve the proposed objectives, laboratory-based exercises and problem solving are sought to consolidate and complement theoretical knowledge.
Resultados de aprendizagem e competências
Upon completion of this course, the student should be able to:
1-Understand/explain the constitution of the MCC and the TR and justify the respective operating principles with laws and rules;
2-Obtain/estimate the parameters of the MCC and TR in steady state;
3-Apply the mathematical model of MCC and TR to predict operating points.
4-Analyze the powers at play and predict the performance of MCC and TR.
Modo de trabalho
Presencial
Pré-requisitos (conhecimentos prévios) e co-requisitos (conhecimentos simultâneos)
It is important for the student to have previous knowledge of the analysis of electrical circuits in direct current and in alternating current.
Programa
I. Introduction to Electric Machines. Framework and objectives.
1. Principles and laws of Electromagnetism applied to electric machines (Ohm's Law, Hopkinson and Kirchhoff laws. Lorentz-Laplace force. Ampère's law and Faraday's law. Rules for determining directions.)
2. Importance of electromechanical energy conversion.
II. CONTINUOUS CURRENT MACHINE.
1. Working principle of an elementary DC machine.
2. Constitution and working principle of the direct current generator.Fundamental laws and rules.
3. Types of excitation circuit connections in direct current machines and their applications
4. Generator operation: Equivalent scheme. No-load and load test of the direct current generator. Representation and interpretation of magnetization characteristics and operation in
generator load. Magnetic reaction of armature and its compensation.
Energy diagram of the generator and efficiency.
5. Working principle of direct current motor. Speed and torque.
Electromechanical and mechanical characteristics of direct current motors.
Energy diagram of direct current motors and efficiency.
6.Calculation based on the rating plate.
7.Starting methods of direct current and braking motors. Notions of speed regulation of direct current motors.
III. TRANSFORMERS
1.Constitution and working principle. Fundamental laws and rules.
2.Types of transformers and their applications.
3.Ideal and real single-phase transformer. Relationships between effective currents and voltages.
4. Test of single-phase transformer in no-load, transformation ratio and representation of leakage fluxes. Measurement of winding resistances.
5 .Short-circuit test of single-phase transformer and joule losses.
6. Efficiency. Calculation based on the rating plate.
7. Three-phase transformer, its constitution and nominal magnitudes.
Bibliografia Obrigatória
M. Gaspar Guerreiro; Máquinas de CC - Folhas teóricas de apoio às aulas teóricas-práticas, ESTSetúbal, 2003
José Rodrigues e José Matias; Máquinas Elétricas: Transformadores, Didáctica Editora, 2003. ISBN: 972-650-183-0
Bibliografia Complementar
José Vagos Carreira Matias; Máquinas Eléctricas – Corrente Contínua, Didáctica Editora, 2000
M.Gaspar Guerreiro; Introdução aos Transformadores , ESTSetubal, 2002
Métodos de ensino e atividades de aprendizagem
Theoretical-practical classes, where a teaching methodology is used in which pedagogical techniques of active learning are applied, involving the student more in the process of acquiring knowledge. classes, interact and internalize the contents, developing the appropriate attitudes and competences in line with the proposed objectives. On the other hand, the greater involvement of the student in the learning process and in the construction of their competences contributes to the development of their critical spirit and greater autonomy.
Laboratory classes, where practical works are carried out that allow the experimentation and validation of the subjects taught in the theoretical classes.
Software
Octave ou Matlab
Tipo de avaliação
Distributed evaluation without final exam
Componentes de Avaliação
Designation |
Peso (%) |
Teste |
65,00 |
Trabalho laboratorial |
35,00 |
Total: |
100,00 |
Componentes de Ocupação
Designation |
Tempo (Horas) |
Estudo autónomo |
70,00 |
Frequência das aulas |
60,00 |
Trabalho laboratorial |
32,00 |
Total: |
162,00 |
Obtenção de frequência
1- The continuous assessment regime
Students who intend to attend the UC under continuous assessment are required to carry out all assessments of the two components:
- Theoretical-practical component (Tp) is evaluated by tests. The Tp component grade is given by the average of the tests.
- Laboratory Component (L) with mandatory completion of laboratory work. The evaluation of the laboratories is composed of the performance in class and the reports and other documents presented from the various laboratory works.
2- Assessment regime by exams with mandatory laboratory work
Students who choose the assessment system by exams will take a written test in which all the subjects corresponding to the Tp component will be evaluated. Examination tests are carried out at scheduled times at School level.
The minimum grade of the average of the Tests, the Laboratory Component and the Exam is 9.5 (nine point five values) .
3-Evaluation regime at the time of exams
The exam consists of two parts, one for the first part, and one for the second part. Students who did not pass the continuous assessment regime and are required to take an exam for their approval, may decide not to take one of the parts of that exam and, in that part, they will be assigned the classification obtained in the corresponding test. The ratings obtained in the parts carried out in the exam replace those eventually obtained in tests for the calculation of the average Tp.
Fórmula de cálculo da classificação final
Final grade (NF) in the continuous assessment regime is given by:
NF = 65% Tp + 35% L;
The final grade (NF) in the assessment system by exams will be the weighted average of the classification obtained at the time of the exam (NE) and that obtained in the mandatory Laboratory component (L) or equivalent,
NF = 65% NE + 35% L ;
Students who have obtained NF ≥9.5 values will be approved with the final classification (NF) determined by rounding up to units.
Melhoria de classificação
Once approved in continuous assessment, the student will only be able to improve the grade during the appeal period.
Observações
The contents and teaching materials to support the study can be found on the ME page on moodle. Students are registered by the head of the UC.
By the end of the second week of classes, students covered by special statutes (student worker, association manager, high-level athletes, etc.) must inform the UC responsible for their specific situation and respective implications for the evaluations.