Learning Outcomes
After the successful completion of the course the students should be able to:
1) design, in their basic form, the stator and rotor of a synchronous machine so that the created magnetic fields produce the proper electromagnetic torque.
2) Calculate the various electrical parameters and the operating limits of a synchronous machine under steady-state conditions
3) Calculate the behavior of a synchronous machine under symmetrical and non-symmetrical short-circuit conditions at its terminals.
4) Determine the appropriate control on the machine excitation so as to change the reactive power, the magnitude of the voltage and the power factor at the machine terminals.
5) Differentiate the aforementioned methodologies according to the rotor type (cylindrical or salient-pole).
Course Content (Syllabus)
The course analyzes the construction and operation of Synchronous Electrical Machines (Generators and Motors). Their steady-state operation and their behavior under short-circuit conditions is mainly analyzed.
Specifically, the course analyzes:
1) The main construction parts of a Synchronous Machine (SM) such as the rotor, the stator, the excitation system, the cooling system, the damper windings, etc
2) an elementary SM aiming to the understanding of the creation of the various magnetic fields with it.
3) the creation of a rotating magnetic filed. The creation of electromagnetic torque from the interaction of the stator and rotor magnetic fields is also analyzed.
4) the development of the stator windings so that a sinousoidal voltage waveform is induced on them.
5)the derivation of the electric equivalent circuit of a SM. The differences between cylindrical-rotor and salient-pole machines are demonstrated.
6)the magnetic saturation on the operation of a SM in steady-state conditions.
7)the power losses developed in a SM in steady-state conditions.
8) the regulation of the active and reactive power of a SM.
9) the safe operating margins of a SM
10) the synchronization with the grid procedures.
11) the operation in parallel of multiple SM in order to cover an electric load in the absence of grid.
12) the operation of a SM (generator or motor) when connected to an infinite bus.
13) the behavior of a SM when a short-circuit (symmetrical or non-symmetrical) happens at its electrical terminals. The electrical equivalent circuits during each time phase of a short-circuit are extracted.
Keywords
Synchronous electrical machines, filed excitation, synchronization, interaction of magnetic fields, symmetrical and non-symmetrical short-circuits.
Course Bibliography (Eudoxus)
1) Χ. Δημουλιάς, "Ηλεκτρικές Μηχανές", ISBN: 978-960-418-431-6,
ΕΚΔΟΣΕΙΣ Α. ΤΖΙΟΛΑ & ΥΙΟΙ Α.Ε., κωδικός στον ΕΥΔΟΞΟ: 32997559
2)Ι. Ξυπτεράς, "Ηλεκτρικές Μηχανές, Τόμος ΙΙ, Σύγχρονες Μηχανές",
ISBN: 960-431-308-8, ΕΚΔΟΣΕΙΣ ΠΕΛΑΓΙΑ ΖΗΤΗ & ΣΙΑ ΟΕ, κωδικός στον ΕΥΔΟΞΟ:11049