First cycle
degree courses
Second cycle
degree courses
Single cycle
degree courses
School of Engineering
Course unit
ELECTRICAL MACHINES (Ult. numero di matricola dispari)
IN06105497, A.A. 2018/19

Information concerning the students who enrolled in A.Y. 2016/17

Information on the course unit
Degree course First cycle degree in
IN0515, Degree course structure A.Y. 2014/15, A.Y. 2018/19
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Degree course track Common track
Number of ECTS credits allocated 9.0
Type of assessment Mark
Course unit English denomination ELECTRICAL MACHINES
Website of the academic structure
Department of reference Department of Industrial Engineering
E-Learning website
Mandatory attendance No
Language of instruction Italian
Single Course unit The Course unit can be attended under the option Single Course unit attendance
Optional Course unit The Course unit can be chosen as Optional Course unit

Teacher in charge MAURO ANDRIOLLO ING-IND/32

ECTS: details
Type Scientific-Disciplinary Sector Credits allocated
Core courses ING-IND/32 Electrical Convertors, Machines and Switches 9.0

Course unit organization
Period First semester
Year 3rd Year
Teaching method frontal

Type of hours Credits Teaching
Hours of
Individual study
Lecture 9.0 72 153.0 No turn

Start of activities 01/10/2018
End of activities 18/01/2019
Show course schedule 2019/20 Reg.2019 course timetable

Examination board
Board From To Members of the board
19 A.A. 2019/20 (numerosità canale 2) 01/10/2019 30/11/2020 ANDRIOLLO MAURO (Presidente)
TORTELLA ANDREA (Membro Effettivo)
18 A.A. 2019/20 (numerosità canale 1) 01/10/2019 30/11/2020 TORTELLA ANDREA (Presidente)
ANDRIOLLO MAURO (Membro Effettivo)
17 A.A. 2018/19 (matricole dispari) 01/10/2018 30/11/2019 ANDRIOLLO MAURO (Presidente)
TORTELLA ANDREA (Membro Effettivo)
16 A.A. 2018/19 (matricole pari) 01/10/2018 30/11/2019 TORTELLA ANDREA (Presidente)
ANDRIOLLO MAURO (Membro Effettivo)
15 A.A. 2017/18 (matricole pari) 01/10/2017 30/11/2018 TORTELLA ANDREA (Presidente)
ANDRIOLLO MAURO (Membro Effettivo)
14 A.A. 2017/18 (matricole dispari) 01/10/2017 30/11/2018 ANDRIOLLO MAURO (Presidente)
TORTELLA ANDREA (Membro Effettivo)

Prerequisites: Knowledge of electrotechnics:
- sinusoidal steady-state circuit analysis with application of the phasor calculus to the single and three-phase systems
- electromagnetism laws and their application
Target skills and knowledge: Knowledge of basic principles on theory of steady state operation of electrical transformers and rotating machines
Outlines of technical details
Numerical application of the theory formulations
Examination methods: The examination consists of a preliminary multiple choice quiz and in a subsequent written test based on a numerical application exercise and on theory questions.
Detailed exam description and scheduling are available at the Moodle page
Assessment criteria: Grade of student learning outcome is assigned taking into account:
- comprehensions and acquirement of theory subjects
- ability in the description of the electrical machines operation by proper terminology supported by graphical examples
- proficiency in solving numerical application exercises on transformers and induction machines
Course unit contents: TRANSFORMERS (2.5 CFU)
Basics on transformer construction details. Single-phase transformer: no-load, load and short-circuit operation. Phasor diagrams. Equivalent circuit. Parameter evaluation by no-load and short-circuit tests and by design formulations: no-load and short circuit reactance for concentric coils. Ideal transformer and rated quantities. Voltage drop at load. Efficiency. Single phase auto transformer. Three-phase transformers: phase displacement between primary and secondary voltages, balanced load operation, equivalent circuit, rated quantities.

Electrical machines at steady-state generator/motor operation. Basics on rotating machine construction. Concentrated and distributed windings. Magnetomotive force (m.m.f.) generated by a concentrated and by a single-phase distributed winding. Distribution factor. M.m.f. generated by a three-phase distributed winding. Rotating magnetic field. Electromotive force (e.m.f.) induced in a winding. Pitch factor.

Basics on construction details. Working principle. Simplified equivalent circuit: torque and power formulations. Motor, generator and brake operation. Torque-speed characteristic. Simplified circle diagram. Squirrel cage, deep bar and double-cage rotors. Speed regulation of induction motors.

Basics on construction details. Phase induced e.m.f. at no-load operation and magnetization characteristic. Load operation: stator voltage drop, armature reaction m.m.f. and electromagnetic braking torque at generator operation. Cylindrical rotor machine: Potier and Behn-Eshenburg vector diagrams. Salient pole rotor machine: Blondel and “two-reactance” vector diagram. Grid connection considering both motor/generator operation. Polar diagram of a cylindrical rotor machine. Torque and power formulations.

Basics on construction details. Commutator winding. No-load operation: e.m.f induced in a single conductor and applied to the brushes. Load operation of the DC motors.
Planned learning activities and teaching methods: The course unit is based on:
- lectures on theory
- classroom exercises on numerical applications for transformers and induction machines
- demonstrations by software tools or by experimental tests
Additional notes about suggested reading: Supplementary teaching material - as well as the previous exam tests - is available at the Moodle page
Textbooks (and optional supplementary readings)
  • Andriollo, Mauro; Martinelli, Giovanni; Morini, Augusto; Tortella, Andrea, I trasformatori. Teoria ed esercizi per Corsi di Laurea in Ingegneria.. Bologna: Esculapio, 2016. Cerca nel catalogo
  • Andriollo, Mauro; Martinelli, Giovanni; Morini, Augusto; Tortella, Andrea, Macchine elettriche rotanti. Teoria ed esercizi. Bologna: Esculapio, 2016. Cerca nel catalogo

Innovative teaching methods: Teaching and learning strategies
  • Auto correcting quizzes or tests for periodic feedback or exams
  • Use of online videos
  • Loading of files and pages (web pages, Moodle, ...)

Innovative teaching methods: Software or applications used
  • Moodle (files, quizzes, workshops, ...)
  • One Note (digital ink)

Sustainable Development Goals (SDGs)
Affordable and Clean Energy Industry, Innovation and Infrastructure