Máquinas Elétricas

Circuit Theory 1 and 2, Mathematics and Physics.

The teaching method consists of theoretical classes with projection of documents (Powerpoint, Word and similar) on the topics covered, complemented with explanations in the classroom. The laboratory practice classes are divided into exercise resolution classes on each machine studied and classes of laboratory tests performed by students, in groups of about 3 students, with assembly of the circuits and determination of the characteristic curves of the machines and equivalent circuit parameters.

For the Electrical Machines studied (Transformers, Induction Machines, DC Machines and Synchronous Machines), at the end of this course unit, the student is expected to be able to:

– Describe their constructional features, operation principles and to know their application fields;

– Know their steady-state equivalent circuits, perform experimental determination of the machine parameters and solve voltages, currents, power and efficiency analytical problems using the equivalent circuits and power flow and torque equations.

The learning outcomes, should contribute, along with those acquired in other’s Electromechanical Engineering Course Units, to obtain the following competences:

– Design, Execute and Exploit Industrial and Buildings Electrical Installations;

– Know the Operation of Electrical Machines and its Control Equipment;

– Know the principal aspects of the maintenance of electrical installations and industrial electrical equipment;

– Design and execute command and protection systems of industrial equipment;

– Define Electromechanical Equipment Maintenance Plans.

1-  Electrical Machines Principles

Electrical Machines overview. Importance and applications. Faraday, Lenz, Newton and Laplace laws. Materials.

 2-  Single-Phase and Three-Phase Transformers

Types and constructive aspects. Working Principle and Equivalent Circuit of a Transformer. Performance Characteristics. Economic Laboratory tests. Transformer’s parallel connection. Three-Phase Transformers. Three-Phase Transformers Connections.

 3-  Induction Machines

Introduction to Polyphase Induction Machines. Constitution, Operation Principle, Equivalent Circuit of an Induction Machine. Power and Torque. Mechanical and Electromechanical Characteristics. Stability. Economic Laboratory Tests. Starting, breaking. Squirrel-Cage Rotors. Induction Generator.  Single-Phase Induction Motor.

 4-  DC Machines

Introduction to DC machines. Operation Principles. EMF generated. Commutation. Power, Torque and Efficiency. Equivalent circuits and Forms of Excitation. DC generators: operation characteristics. DC motors: power flow and losses, operation characteristics. Starting and Control of DC motors.

 5-  Synchronous Machines

Introduction to Synchronous Machines. Operation Principles. Constructional Features. Cooling and Excitation. Equivalent Circuits. Synchronous Generators: Open Circuit and Steady-State Load Characteristics; Economic Laboratory Tests; Parallel Operation. Synchronous Motors: Load and Field Change Effects; V curves; Starting.  

NAO

Notes of Electrical Machines

  – Joaquim Carvalho, Transformadores, ISEC.
  – Joaquim Carvalho, Máquinas de Indução, ISEC.
  – Joaquim Carvalho, Máquinas Síncronas, ISEC (versão reduzida para esta unidade curricular por Paulo Pereirinha).
  – Joaquim Carvalho, Máquinas de Corrente Contínua, ISEC, (versão reduzida para esta unidade curricular por Paulo Pereirinha). 
  – Guia Laboratorial, ISEC.
  – Folhas de exercícios, ISEC

– S. J. Chapman (2012). Electric Machinery Fundamentals, Mcgraw Hill Higher Education; 5th Revised edition, 2012. ISBN 978-007-13258

– S. A. Nasar  (1984). Máquinas Eléctricas, McGraw-Hill, Brasil, 1984.

– D. P. L. Brandão (1984) , Máquinas Eléctricas – Introdução às Máquinas Eléctricas de Corrente Contínua, Fundação Calouste Gulbenkian, Lisboa, 1984.

– Jesus Fraile Mora, Jesus Fraile Ardanuy (2015).- Problemas de máquinas eléctricas. 2ª ed. Madrid : Garceta grupo editorial, cop. 2015. 390 p. ISBN 978-84-1622-814-0

– P. C. Sen (1996).  Principles of Electric Machines and Power Electronics, John Wiley & Sons, Inc., Singapore, 1997. ISBN 0-471-02295-0

– Ion Boldea, Syed A. Nasar (2006). Electric drives, Boca Raton, CRC Press, 2nd. Edition, 2006. ISBN 978-0-8493-4220-2