After the successful completion of the course, the students should be able to:
1) Determine the power-speed and torque-speed relationship of various mechanical loads.
2) Calaculate the size and type of the electric motor as a function of the size and type of the mechanical load. Then, they should be able to calculate the size and type of the power-electronics converter as a function of the electric motor characteristics.
3) Calculate the thermal stress of an electric motor under various starting methods or under speed variation conditions.
4) Calculate the electrical parameters of an induction motor when fed from a source of variable voltage magnitude and frequency
5) Design an algorithm based on the field-orientation method for controlling a synchronous motor
Course Content (Syllabus)
Basic motion principles, especially the rotational motion. Types of mechanical loads and the associated torque/power-speed characteristics. Influence of load acceleration or deceleration on the electromagnetic torque, currents and losses of the motor. Behavior of induction motors under dynamic conditions such as starting under load or at no load and the under step change in rotational speed. How the change of the voltage amplitude and/or frequency affect the electromagnetic torque and rotational of an induction motor. Linear control of induction motors at speeds below or the above the nominal. Starting methods of induction motors and their thermal stress under (1) direct on line start, (2) starting with reduced voltage, (3) continuously variable voltage magnitude (soft-starting) and (4) variable voltage magnitude and frequency. Breaking of induction motors and its influence on the converter sizing. Control of synchronous motors with the field-orientation method.
rotating motion, starting if electric motors, losses in electric motors, mechanical loads
Course Bibliography (Eudoxus)
1)Π. Μαλατέστας, "Ηλεκτρική Κίνηση", ISBN: 978-960-418-251-0, ΕΚΔΟΣΕΙΣ Α. ΤΖΙΟΛΑ & ΥΙΟΙ Α.Ε.
2)R. Krishnan, (μετάφραση Αθ. Καρλής)"Ηλεκτρικά Κινητήρια Συστήματα, Μοντελοποίηση,
Ανάλυση και Έλεγχος", ISBN: 978-960-461-233-8, ΕΚΔΟΣΕΙΣ ΚΛΕΙΔΑΡΙΘΜΟΣ ΕΠΕ, 2009