Electrical Machines Dynamics

Scholar Year: 2019/2020 - 1S

Courses

Head Teacher Responsability Armando José Pinheiro Marques Pires Head

Weekly workload Hours/week T TP P PL L TC THE EL OT OT/PL TPL S Type of classes 2,5 2,5 Lectures Type Teacher Classes Hours Theorethical and Practical classes Totals 1 2,50 Armando Pires   2,50 Laboratories Totals 1 2,50 Armando Pires   2,50

Teaching language

Portuguese

Intended learning outcomes (Knowledges, skills and competencies to be developed by the students)

The course aims to contribute to the scientific training of students in the area of electrical and electromechanical energy conversion and interpret the steady state or dynamic operation of electric machines.
Skills:
The student should be able to:
- Interpret mathematical models of electric machines;
- Implement in numerical simulation of the operation of electric machines;
- Foresee the consequences of changes of parameters or quantities applied (voltage, frequency, electrical or mechanical loads, etc.) originate in the machine operation.
In general terms, with this course the student should be able, in the future, approach to mathematical modeling of electrical machines, know relevant aspects of its dynamics, and, if necessary, get their integration in more elaborated control systems.

Syllabus

1. Introduction to models and numerical simulation
Notion of state model and state variable. Analytical representation of electrical circuits and its simulation.
2. Machines direct current (DC)
Electromotive force and electromagnetic torque. Modeling of dc machine and its application in various situations (starts, braking, control).
3. Transformer
Magnetically coupled circuits. Equivalent circuit. Transformer modeling and its simulation.
4. Induction machines
Energy balance based on the principle of conservation of energy. Energy and co-energy. Torque Force. Sinusoidally distributed windings and their magnetomotive forces. Pulsating, rotating and traveling fields. Equations of tensions in real coordinates. Transformations abc-0-dq0 and inverse transformations. Three-phase induction machine state-model. Analysis of the behavior of the machine under changes of load torque and changes of the power supply characteristics.

Demonstration of the syllabus coherence with the UC intended learning outcomes

The course has a theoretical-practical component and a laboratory (simulation) component. Professor presents general guidelines and introductory chapters being promoted the independent work of the student in the development of themes. Solving problems and numerical simulation are privileged resources of the learning process.
Three machines are studied and modeled: DC machine, transformer and three-phase induction motor. Modeling involves knowing the differential equations that describe their behavior. Some nonlinearities are also included in the modeling. The models are tested in a laboratory simulation using the program Matlab/Simulink. After implementation of the simulation models, the behavior of the machine is analyzed when under disturbances, or under variations of the inputs, or changes of its parameters. This approach achieves the objective that is to contribute to the scientific training of students in the field of energy conversion and interpret the steady-state or dynamic operation of electric machines.

Teaching methodologies

Avaliação distribuída com exame final

Assessment methodologies and evidences

The course is divided into two parts S (Simulation) and TE (Test and / or Exam). There are two optional tests T1 machine (DC and Transformer) and T2 (three-phase induction machine). The exam has two parts corresponding to the tests.
S (Simulation) means implementation of mathematical model, (Matlab / Simulink), observation and interpretation of the main features of operation of the machine under study. S is the result of evaluating the implementation of computer simulations, the justification of the followed strategies and the discussion of results.
TE component is equal to the highest rating of TAP or T, where T is the average of the two tests, or corresponding parts of the exam and TAP also includes assessing attendance AP (maximum 2 points) according to expressions T = (T1 + T2) / 2 and TAP = (T1 + T2 + AP) / 2.1.
Students with TE <9.5 will fail with the classification and C = TE (rounded to units).
For students who obtain TE> 9.5 the course classification C is obtained by C = (2 * TE + S) / 3. The student will be approved if C> 9.5. The final classification is C rounded to units.
If the student has not been approved for testing can make one or two parts of the exam. The obtained result in each part of the exam replaces the corresponding test result.