B002350 - ELECTRICAL MACHINES

Italian

1) Analysis of two-phase and three-phase circuits;
2) Single-phase and three-phase transformers;
3) Synchronous machines;
4) Asynchronous machines;
5) Direct-current machines.

1) A.E. Fitzgerald, C. Kingsley, and A. Kusko, " Electric Machinery", New York: McGraw-Hill Book Company, 1971.
2) L.W. Matsch and J.D. Morgan: Electromagnetic and Electromechanical Machines, New York: John Wiley & Sons, 1987.
3) S. Crepaz, "Macchine Elettriche", CittàStudi, 1997

For Electrical and Automation Engineering students:
Knowledge and ability to understand:
1) Electromagnetism laws, AC single-phase, two-phase and three-phase circuits and DC circuits both in transient and steady-state behavior.
2) Operating principles, electromagnetic and mechanical behaviors of the main static and rotating electrical machines: transformers, AC motors and generators, DC motors and generators.
3) Methods to test the electrical machines.
Ability to apply knowledge in order to derive the mathematical models of
the electrical machines in the different operating conditions.
Ability to apply knowledge in order to define the equivalent circuits parameters and the operating conditions of the electrical machines.
Ability to apply knowledge in order to select the electrical machines for different applications on the basis of the electrical requirements.

For Energy Engineering students:
CA1: Ability of analysis and modeling of mechanical/electrical/propulsive components and systems: basic problems and models for industrial engineering, with special reference to mechanical and energy engineering.
CA8: Ability of analyzing plants, components and process technologies and methods of engineering and their economic implications
CC1: In-depth knowledge in the field of energy and electricity
CC9: Generation of cold, electrical systems and electrical machines.

High skills with Calculus,Physics and Electromagnetism, Electrotechnics, Good understanding of steady-state and transient analysis techniques of single-phase and three-phase circuits.

Lectures supported by projector and PC, laboratory team-works, personalized feedback and coaching to improve every aspect of the student's work.

At the end of the course a successful student should have developed a good ability to choose transformers, generators and motors for industrial applications, should know the testing procedures of the electrical machines in order to determine the principal characteristics

Intermediate tests just for students attending the course;
Oral exam based on theoretical questions oriented to assess:
- knowledge of the operating principles, electromagnetic and mechanical behaviors of the main static and rotating electrical machines:
transformers, AC motors and generators, DC motors and generators.
- knowledge of the methods to test the electrical machines.
- ability to apply knowledge in order to derive the mathematical models of the electrical machines in the different operating conditions.
- ability to apply knowledge in order to define the equivalent circuits parameters and the operating conditions of the electrical machines.
- ability to apply knowledge in order to select the electrical machines for different applications on the basis of the electrical requirements.

1) Preliminary part:
Electromechanical energy conversion. Analysis of two-phase and three-phase circuits. Power of two-phase and three-phase circuits. AC circuit relationships.
2) Transformer in ?, ? stationary reference frame and d,q rotating reference frame:
Two-winding transformer. Core loss current, magnetising current. Leakage reactance. Linear equivalent circuit. Phasor diagrams. Voltage drop. Three-phase transformer connections. No-load current distortion. Vector group. Determination of equivalent circuit parameters. Efficiency. Autotransformers. Instrument transformers.
3) Synchronous machine in ?, ? stationary reference frame and d,q rotating reference frame:
Cylindrical-rotor synchronous machine. Representation of airgap m.m.f. waves. Phase inductances. Mutual inductances. Vector equation of cylindrical-rotor synchronous machine. Magnetizing inductance. Synchronous inductance. Phasor equation. Steady-state equivalent circuit. Rotating magnetic fields. Vector and phasor diagram of cylindrical-rotor synchronous generator. Torque, power versus angle characteristic. Potier triangle. Saturated reactances. Salient-pole machines. Permanent magnet machines.
4) Asynchronous machine in ?, ? stationary reference frame and d,q rotating reference frame:
Wound rotors and squirrel cage rotors. Vector equations of asynchronous machine, slip frequency. Magnetizing inductance. Steady-state equivalent circuit. Slip-torque relationship. Determination of equivalent-circuit parameters. Efficiency. Starting and braking, speed control. Variable-voltage, variable-frequency control. Brief overview about single-phase induction motors.
5) Direct-current machine:
Armature windings, field excitation, armature reaction. Interpoles, compensating winding. Separately excited machine, shunt machine, series machine, compound machine. Load characteristics of generators. Speed-torque characteristics of motors. Motor starting and braking, speed control. Variable-voltage speed control.
6) Laboratory activity: transformer tests.
7) Simulated tests of the electrical machine: execution criteria of electrical-machine tests to determine machine parameters and operating characteristics. Data processing of electrical-machine tests.