Politecnico di Torino
Politecnico di Torino
Politecnico di Torino
Academic Year 2015/16
Electrical machines II
Master of science-level of the Bologna process in Electrical Engineering - Torino
Teacher Status SSD Les Ex Lab Tut Years teaching
Cavagnino Andrea ORARIO RICEVIMENTO O2 ING-IND/32 70 30 0 0 13
SSD CFU Activities Area context
ING-IND/32 10 B - Caratterizzanti Ingegneria elettrica
Subject fundamentals
Aim of the course is to provide to the electrical engineering students an in-depth knowledge about the construction, design and dynamic behaviors of the main electrical machines (transformer, rotating field AC machines and DC machine).
The course is subdivided in two parts: the former will provide to the students the basis and the methodologies to a correct design of the electric machines, starting from assigned specifications; the latter is focused on methods and models for the analyses of the transient phenomena that occur in the modern applications of the electric machines.
Expected learning outcomes
The acquired knowledge and understanding capabilities represent a deepening of the student's preparation within the electrical machine topics, with respect to the machine design and their behaviors from the dynamic point of view.

The applying knowledge and understanding capabilities will allow at the graduate to rigorously approach the problems linked to the design and dynamic phenomena of the electrical machines. In particular, thanks to the proposed calculation algorithms, models and numerical simulations, the graduate will be able to solve the modeling and design of a broad range of electromagnetic devices.
The writing synthesis abilities of complex topics and the communication skills of the student, continuously stimulated by the teacher during the classrooms (also evaluated by the teacher during the possible oral examination), will allow the graduate to usefully participate at professional team constituted by people having different technical and scientific backgrounds.
Prerequisites / Assumed knowledge
The following knowledge are requested in order to understand the presented topics:
- Electrical circuit theory
- Electric machines (working principles, steady-state operations and theory)
- Electric drives (basic)
- Fundamentals of applied mechanics (basic)
Part course related to the electromagnetic design of the electrical machines [around 42 hours]:
- Basic aspects and main properties of materials adopted in the construction of electrical machines [8 hours]
- Design and construction of transformers [12 hours]
- Windings for AC machines [6 hours]
- Design and construction of induction machines [16 hours]

Part course concerning the dynamic behaviors of the electric machines [around 36 hours]:
- General issues of the electric machines [6 hours]: sign conventions, electric and magnetic equations, power balances, permanent magnet machines, electromagnetic general model, effects of the magnetic not linearity on the torque.
- DC Machine [6 hours]: recalls on the operation characteristics and application fields, dynamic linear model of the machine, basic modeling of the typical CC/CC converters and drives.
- Induction motors [12 hours]: electric and magnetic equations of the windings, three/two phase transformation, rotation transformation, machine equations related to arbitrary reference frames, power balance and torque equation, dynamic linear model of the machine, notes about the saturation phenomena.
- Synchronous machine [12 hours]: electric and magnetic equations for the windings, machine equations referred to synchronous reference frame, power balance and torque equations, dynamic linear model of the synchronous motor and generator. Simplified approach of the alternator short-circuit transient event.
Delivery modes
The two course parts will not be necessarily carried out in the aforementioned time order. In addition to the lectures, the course program includes exercises and simulations.

Part course on the electromagnetic design of the electrical machines [8 hours]: two numerical examples of the duration of about 4 hours each one are scheduled. The two design examples concern the oil-cooled three-phase transformer and the totally enclosed fan cooled induction motor, respectively. The exercises will be solved, step-by-step by the lecturer at the blackboard.

Part course on the dynamic behaviors of the electric machines [15 hours]. 10 practical lessons of 1.5 hours each will be held in the computer laboratory (LAIB) of the Politecnico. Aim of the practical activities is the use of the methods and models provided during the lessons. In particular, the dynamic models of several electric machines will be analyzed through computer simulations. At the beginning of each practical activities a short explanations of the implemented numerical model will be provided to the students, together with useful hints for a correct interpretation of the numerical results.
Texts, readings, handouts and other learning resources
Notes of the lessons and practical activities prepared by the lecturer will be provided to all the students registered to the course. The documentation, available at the Teaching Portal or directly provided in the classroom, is written in Italian and it is considered exhaustive for the preparation of the final exam.

On student demand, for in-depth studies, some books and publications on specific topics may be suggested, also in English if needed.
Just few examples are listed hereafter:
- A.E. Fitzgerald, C. Kingsley Jr., A. Kussko, 'Macchine elettriche', Franco Angeli Editore
- N. Bianchi, S. Bolognani, 'Metodologie di progettazione delle macchine elettriche', CLEUP
- J. Pyrhonen, T. Jokinen, V. Hrabovcova, 'Design of rotating electrical machines', John Wiley & Sons
Assessment and grading criteria
The examination is constituted by a written test of the duration of three hours. The on-line registration to the examination (through the Teaching Portal) is mandatory. Four questions will be proposed to the student; the questions will concern the topics introduced both during the theoretical and practical lessons. Among the four questions, all of the open typology, two questions will concern the course part related to the electromechanical design of electrical machines and the other two the part related to their dynamic behavior.
The student must answer to the questions on foolscaps, writing in detailed way (and in an orderly manner!) the concepts and the problems related to the required topic.
During the written test, textbooks and notes cannot be consulted. Therefore, it is not possible to bring in the classroom electronic devices having web access (e.g., smartphone, smartwatch and tablet).

The examination is passed if the written test gets a mark from 18/30 up to 30/30 (including the laude), with a minimum mark on each part of the course of at least 7/15.
The students will take vision of the written examination and its mark during a general meeting typically scheduled a week after the written test; the date of the meeting will be communicated to the students with messages (sms or email) sent through the Teaching Portal. During the aforementioned meeting, the student that gets a mark equal or great than 26/30 can ask for an integrative oral interview in which the mark of the written test can be improved or confirmed, but also worsened (the mark of the written test is not guaranteed).

On student demand, possible additional explanations of the course topics can be provided in English. Once again, on student demand, the exam questions can be translated in English.

Programma definitivo per l'A.A.2017/18

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