Electromechanical Systems

Code:

EEC0109

Acronym:

SELM

Keywords
Classification	Keyword
OFICIAL	Power

Instance: 2013/2014 - 1S

Active?	Yes
Responsible unit:	Department of Electrical and Computer Engineering
Course/CS Responsible:	Master in Electrical and Computers Engineering

Cycles of Study/Courses

Acronym	No. of Students	Study Plan	Curricular Years	Credits UCN	Credits ECTS	Contact hours	Total Time
MIEEC	89	Syllabus (Transition) since 2010/2011	4	-	6	63	162
		Syllabus	4	-	6	63	162

Teaching language

Portuguese

Objectives

The C.U. aims to deepen the student's knowledge in the area of electrical machines and their integration in electromechanical systems, in this case focused on the electric three-phase generator sets (synchronous and asynchronous).

The emphasis will be placed on: a) design  and constructive specifics; b) theory and operating characteristics; c) modelling and test procedures; d) command and operationof three-phase generators,

Learning outcomes and competences

This C.U. approval  assumes that the student:

1. Deepens nuclear and advanced engineering knowledge (skills CDIO 1.2 and 1.3), develop systemic thought, with particular focus on conception, design, and operation of electric generator sets (skills CDIO 2.3, 4.3, 4.4 and 4.6), which will be promoted throughout all periods (theoretical and practical sessions, including laboratory ones) and will be assessed in final individual examination.

2. Develops efficient work group (skill CDIO 3.1), which is reached along the laboratory sessions, including through the elaboration of the corresponding test reports, and will be assessed by monitoring the student behavior during laboratory works and by the quantitative assessment of the respective group reports.

Working method

Presencial

Program

Chapter 1 - Introduction

Generating function and common requirements-; drive-machines and technological alternatives; main quantities and symbology.

Chapter 2 - Three-phase Synchronous Generators.

1. Fields of application. 2. Working principle. 3. Constructive aspects: the inductor system, constructive and exciter variants; field circuit m.m.f. and e.m.f. production (at no load); the armature system and its windings (main rules for design, classification; winding factors and their effects; armature reaction and induced m.m.f.; hhe air-gap and its effects; structural parts.

4. Theory and steady-state modelling; Blondel (Simplified) and Behn-Eschenburg models; the concept of synchronous reactance; Potier and Bondel models; procedures for its application.

5. Steady-state operating characteristics: at no load, short-circuited, with zero power factor; under load; voltage regulation (V-curves), aa a function of the load angle.

6. Generating set command: a) the isolated generator: the P/Q adjustment; the use of frequency and voltage regulators; technological solutions; b) the generator in parallel with an infinite bus: synchronization process  and maneuvers; the P/Q adjustment; oscillations and stability limits; diagram of limits; c) generators in parallel: prerequisites; the P/Q distribution; individual and global settings.

7. Transient behavior: a) the dq model and the corresponding reactances and time constants (physical, meanings, mathematical definitions and typical values);  b) three-phase sudden short-circuit (physical analysis and current and torque time evolutions); c) reference to other transient phenomena (fast excitation and voltage recover).

Chapter 3 - Three-phase Asynchronous (induction) Generators

1. Theoretical principle of operation, power-flow and phasor diagrams; design specifics and consequences.

2. Generating set command: a) the isolated-generator: self-exciting process and maneuvers;  b) the generator in parallel with an infinite bus: networking process and meneuvers.

3. Transient behavior: the dq model, reference frames and the corresponding reactances and time constants (physical meanings, mathematical definitions and typical values).

Mandatory literature

Jesús Fraile Mora; Máquinas eléctricas. ISBN: 84-481-3913-5
Stephen J. Chapman; Electric machinery fundamentals. ISBN: 0-07-100972-8
Carvalho, Carlos de Castro; Máquinas síncronas
Carlos Araújo Sá; Máquinas síncronas trifásicas
Carlos Araújo Sá; Máquinas síncronas trifásicas
Carlos Araújo Sá; Máquinas síncronas trifásicas
Guedes, Manuel Alves de Bacelar Vaz; Sistemas electromecânicos de conversão de energia

Complementary Bibliography

Carlos Araújo Sá; Regimes Transitórios Electromagnéticos do Gerador Síncrono Trifásico, DEEC - FEUP, 2007
Carlos Araújo Sá; Método dos Fasores Espaciais, DEEC - FEUP, 1999

Teaching methods and learning activities

Face-to-face work:

a) Theoretical Sessions — Teacher lectures.

b) Laboratory Sessions - development of experimental work by groups of students (as a rule, up to 3 students/group), in the laboratory, supervised by the teacher and by the laboratory technician.

c) Practical Sessions - analysis and resolution of numerical applications by students with teacher supervision. 

Independent work: regular study developed by the student during the academic semester and reporting of some of the laboratory activities. Such reports shall constitute knowledge assessment parts. In the independent work, students will have the support of the teacher in the corresponding periods of service.

keywords

Technological sciences

Evaluation Type

Distributed evaluation with final exam

Assessment Components

Designation	Weight (%)
Exame	70,00
Trabalho laboratorial	30,00
Total:	100,00

Amount of time allocated to each course unit

Designation	Time (hours)
Estudo autónomo	80,00
Frequência das aulas	60,00
Trabalho laboratorial	20,00
Total:	160,00

Calculation formula of final grade

Final grade = 0.7 Final Examination + 0.3 Frequency grade

1 Final Test: written, individual, with an estimated 2.5 hours duration; consists of a theoretical part (50%) and a numerical one (20%).

2. frequency Grade: Classification resulting from the evaluation in laboratory component, covering the preparation/implementation of 5 laboratory works  (15%) and 2 dedicated reports (15%).

Important Notice: all lack a laboratory session, if not retrieved by authorised replacement on a case by case basis, will entail the allocation of ZERO in the relevant work and, if applicable, in the corresponding report.