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Educational guide | |||||||||||||||||||||||||||||||||||||||
IDENTIFYING DATA | 2024_25 | |||||||||||||||||||||||||||||||||||||||
Subject | POLYFHASE SYSTEMS AND ELECTRICAL MACHINES | Code | 00708023 | |||||||||||||||||||||||||||||||||||||
Study programme |
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Descriptors | Credit. | Type | Year | Period | ||||||||||||||||||||||||||||||||||||
6 | Compulsory | Third | First |
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Language |
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Prerequisites | ||||||||||||||||||||||||||||||||||||||||
Department | ING.ELECTR.DE SIST. Y AUTOMATI |
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Coordinador |
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fjtrac@unileon.es ralog@unileon.es |
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Lecturers |
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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 |
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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 |
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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 |
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 |
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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% |
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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: |
Sources of information |
Access to Recommended Bibliography in the Catalog ULE |
Basic | |
Complementary | |
Recommendations |
Subjects that it is recommended to have taken before | ||||
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