Educational guide
IDENTIFYING DATA 2024_25
Subject POLYFHASE SYSTEMS AND ELECTRICAL MACHINES Code 00708023
Study programme
0708 - GRADO EN INGENIERÍA MECÁNICA
Descriptors Credit. Type Year Period
6 Compulsory Third First
Language
Castellano
Prerequisites
Department ING.ELECTR.DE SIST. Y AUTOMATI
Coordinador
TRAPOTE DEL CANTO , FRANCISCO JAVIER
E-mail fjtrac@unileon.es
ralog@unileon.es
Lecturers
TRAPOTE DEL CANTO , FRANCISCO JAVIER
ALONSO GARCIA , RAUL MARCOS
Web http://
General description This course aims to introduce some initial notions of power systems with multi-phase study of the systems with special emphasis on the systems three-phase balanced and unbalanced. In the second part of the course will be studied electrical machines, static and rotary. We begin by studying the processors to continue with the rest of rotating electrical machines, generators and motors, AC and DC. On each machine will study its constitution, principles of operation, their equivalent circuits, performance characteristics and finally their applications.
Tribunales de Revisión
Tribunal titular
Cargo Departamento Profesor
Presidente ING.ELECTR.DE SIST. Y AUTOMATI BLANES PEIRO , JORGE JUAN
Secretario ING.ELECTR.DE SIST. Y AUTOMATI SERRANO LLAMAS , ESTEBAN
Vocal ING.ELECTR.DE SIST. Y AUTOMATI DIEZ SUAREZ , ANA MARIA
Tribunal suplente
Cargo Departamento Profesor
Presidente ING.ELECTR.DE SIST. Y AUTOMATI LOPEZ DIAZ , CARLOS
Secretario ING.ELECTR.DE SIST. Y AUTOMATI GONZALEZ ALONSO , MARIA INMACULADA
Vocal ING.ELECTR.DE SIST. Y AUTOMATI GONZALEZ MARTINEZ , ALBERTO

Competencias
Code  
A18146
B5632
B5633
B5634
B5643
B5644
B5646
B5647
B5651
C1 CMECES1 That students have demonstrated possession and understanding of knowledge in an area of study that is based on general secondary education, and is usually found at a level that, although supported by advanced textbooks, also includes some aspects that involve knowledge from the cutting edge of their field of study
C2 CMECES2 That students know how to apply their knowledge to their work or vocation in a professional manner and possess the skills that are usually demonstrated through the development and defense of arguments and the resolution of problems within their area of study.
C3 CMECES3 That students have the ability to gather and interpret relevant data (normally within their area of study) to make judgments that include reflection on relevant issues of a social, scientific or ethical nature.
C4 CMECES4 That students can transmit information, ideas, problems and solutions to both a specialised and non-specialised audience
C5 CMECES5 That students have developed those learning skills necessary to undertake further studies with a high degree of autonomy

Learning aims
Competences
A18146
 B5632
B5633
B5634
B5643
B5644
B5646
B5647
B5651
 C1
C2
C3
C4
C5
A18146
 B5643
B5644
B5646
B5647
B5651
 C1
C2
C4
C5

Contents
Topic Sub-topic
Block I. POLYPHASE SYSTEMS. Topic 1: POLYPHASE CURRENTS
Definition. Balanced Systems. Classification. Vector Representation. Phase Sequence. Grouping In Star And Polygon.

Topic 2: THREE-PHASE SYSTEMS
Introduction. Three-phase star system with four wires. Three-phase three-wire star system. Three-phase triangle system. Unbalanced three-phase systems, triangle, star with neutral wire, star without neutral wire, star with four legs. Power in a polyphase system. Measurement of active power in three-phase systems, three-phase system with neutral wire, three-phase system without neutral wire, two wattmeter method. Measurement of reactive power in three-phase systems, balanced system, balanced system without neutral wire and voltage balanced. Power factor of an installation, importance of it, measurement of power factor, correction of power factor.
Block II. ELECTRIC MACHINES. Topic 3: TRANSFORMERS
Generalities. Physical principle of the alternating current transformer. Utility of transformers. Types of transformers designation and symbolism. Constitution of a single-phase transformer, magnetic electrical circuits, windings, cooling, through insulators and other elements. Nominal power of a transformer. Operation of a transformer in vacuum, ideal transformer, real transformer, transformation ratio. Transformer on load. Equivalent circuit of a transformer. Tests of a transformer, no-load test, short-circuit test. Voltage drop of a transformer. Ferranti effect. Short-circuit current in a transformer. Losses and performance. Parallel work of single-phase transformers. Three-phase transformers, three-phase banks based on single-phase transformers, three-phase column transformers, balanced regime transformers, three-phase transformer connections, parallel coupling. Autotransformers. Measurement transformers.

Topic 4: DIRECT CURRENT ELECTRICAL MACHINES
Constitution and principle of operation. Excitation systems. Fundamental quantities, e.m.f. induced, electromagnetic torque, internal power of the armature. Armature reaction, load operation, transverse armature reaction, longitudinal armature reaction, means for compensation of the transverse armature reaction. Commutation, generalities, conditions to obtain a good commutation, general equation of commutation, means to improve commutation. Direct current generators, characteristics of the generators. DC motors, general information, automatic adaptation of motor torque to resistance, starting, characteristics, speed regulation, braking, reversing the direction of rotation, applications.


Topic 5: ASYNCHRONOUS MACHINES
Constitution of the three-phase induction machine. Operating principle as motor generator and brake. Fundamental quantities, internal electromagnetic torque, general equations, equivalent circuits, vector diagrams. Induction motor characteristics. Induction motor starting: methods. Speed ??regulation: electronic regulation methods. Braking. Special motors, double cage motors, deep groove motor. Single-phase motor, constitution, operating principle, starting, functional characteristics.

Topic 6: SYNCHRONOUS MACHINES.
Constitution and classification. Principle of operation as a generator and as a motor. The inductor system and its generator. Idle operation and vacuum characteristic. Useful and dispersion flow, dispersion reactance. Regulation of an alternator: methods. Power characteristic. Exterior feature. Regulation feature. Self-excitement. Parallel operation, introduction, coupling maneuvers, synchronization, the synchronous machine coupled to an infinite power network. Synchronous machine in an isolated network. Power distribution between synchronous generators. Methods for starting a synchronous motor. Synchronous motor applications.
Block III: LABORATORY PRACTICES. PRACTICE Nº 1: Low voltage switchgear. Direct start of squirrel cage asynchronous motor.

PRACTICE Nº 2: Starting and reversing the rotation of a squirrel cage asynchronous motor.

PRACTICE Nº 3: Star-delta starting of a squirrel cage asynchronous motor.

PRACTICE Nº 4: Assembly of three-phase circuits with balanced and unbalanced star and delta loads. Relationships of simple and compound tensions and intensities. Measurements.

PRACTICE Nº 5: Measurement of active and reactive powers in three-phase three-wire and four-wire systems, balanced and unbalanced. Power factor improvement.

PRACTICE Nº 6: Testing of a transformer. Vacuum and short circuit test. Obtaining the equivalent circuit.

PRACTICE Nº 7 Tests of the three-phase asynchronous motor.

Planning
Methodologies  ::  Tests
  Class hours Hours outside the classroom Total hours
Problem solving, classroom exercises 13 26 39
 
Laboratory practicals 14 18 32
Personal tuition 0 2 2
 
Lecture 29 40 69
 
Mixed tests 4 4 8
 
(*)The information in the planning table is for guidance only and does not take into account the heterogeneity of the students.

Methodologies
Methodologies   ::  
  Description
Problem solving, classroom exercises Formulation, analysis, resolution and debate of a problem or exercise, related to the topic of the subject.
Laboratory practicals They are developed in a Department Laboratory. Groups will be created with a very small number of students to carry out practical work, entrusted to each group, consisting of carrying out the practices indicated, as well as the preparation of the corresponding practice report. Students will have at their disposal the documentation and material necessary to carry out the practices. In this way, with the clarifications made in a timely manner by the teacher, the student will be in a position to carry out the practical work. Students will take note of the results and prepare a report that must contain the theoretical bases, the practical implementation, the results obtained and the particular conclusions of their work.
Personal tuition Students will be attended to in a personalized way, at their request, to guide them in how to study or to clarify doubts.
Lecture A theoretical exposition of all the concepts included in the program is proposed. Subsequently, the concepts are justified and their application to specific cases is shown.

Personalized attention
 
Personal tuition
Description
It will serve to resolve doubts that have arisen during the study of the subject. It will enhance the student's capabilities, so that they are able to "learn to learn." It is intended that they be able to create their own mechanisms, so that based on what they have learned, they can expand, complete and experiment with their concepts, procedures and skills in both the academic and professional fields.

Assessment
  Description Qualification
Others A.- Theoretical and problem contents:
Mastery of knowledge and understanding of the subject.
A final exam, objective test, of problems and theoretical questions.

Practical and seminar contents:
Participation in the proposed activities
Carrying out the proposed work
Assessment of participation and, where appropriate, the proposed work.

B.- Practical contents in the laboratory:
Attitude in materials handling
Participation in assemblies and data collection
Results analysis
Assessment of participation and, where appropriate, the proposed works or reports.		 A.- Theoretical contents, problems, seminars and possible proposed works: 80%











B.- Practical contents and reports: 20%
 
Other comments and second call 
The sum of the theory and laboratory grades, in the percentages expressed in the previous table, will result in the final grade for the subject. This must be equal to or greater than 5 to obtain a passing grade or higher. But it is a necessary condition to carry out this weighting, and therefore pass the subject, that the average grade of both partial theory and problems is greater than or equal to 4.5 points out of 10. 1.- Evaluation in the 1st call. The evaluation of theory and problems will be composed of two parts (partials) corresponding to a convenient partition of the contents of the subject, each with the same weight in the final grade. To pass the subject, it will be a necessary but not sufficient condition to obtain a minimum grade of 3.5 out of 10 in each of the midterms and an average grade greater than 4.5 points. If the minimum is reached in both parts (and the average of both is greater than 4.5 points), the corresponding grade for the laboratory part will be added to this average grade, each of the parts weighted according to the previous table. The final grade must give a grade equal to or greater than 5 to pass the subject. Otherwise, the parts of theory and problems not passed in the 1st call must be repeated in the 2nd call. Attendance at laboratory practices and delivery of the corresponding reports is mandatory. Failure to comply with this condition will imply a grade of zero in the part corresponding to the practices not carried out. 2.- Evaluation in the 2nd call. The evaluation procedure in the 2nd call will coincide with what was expressed in the 1st call with the following exceptions:
THEORY AND PROBLEMS: If a partial exam is passed in the first call, the student will keep his or her grade for the 2nd call and will only have to take the exam for the pending partial exam. LABORATORY: The grade obtained in the laboratory practices in the 1st call will be saved for the student. If you have not completed them, and given that the evaluation is continuous, you will not obtain any grade in this section. Qualification for 2nd call: The qualification of each of the parts (theory/problems and laboratory) corresponding to this 2nd call, or saved from the 1st call, weighted according to the previous table, must give a grade equal to or greater than 5 to pass the exam. subject. In this call the same requirements mentioned in the first will be applied (average grade for theory and problems equal to or greater than 4.5 points out of 10, to be weighted with the laboratory grade) OTHER COMMENTS: The professor will inform prior to the celebration of the evaluation tests and through the teacher-student communication channel that is considered appropriate (Moodle, bulletin board, classroom, email...) of the additional materials, media and resources necessary for the development of the evaluation exams or tests. . The use and mere possession of electronic devices that enable communication with the outside of the room (mobile phones, radio transmitters, etc.) are expressly prohibited. Communication between students or passing anything during the evaluation tests is expressly prohibited. If any irregularity occurs during the evaluation test, the corresponding Regulations will apply.

Sources of information
Access to Recommended Bibliography in the Catalog ULE

Basic

Complementary


Recommendations


Subjects that it is recommended to have taken before
DIFFERENTIAL AND INGTEGRAL CALCULUS / 00707002
heat and electromagnetism / 00707007
PRINCIPLES OF ELECTRICAL MACHINERY AND CIRCUITS / 00707013