EE 283!! – Electrical Machines (2)

Course lecturer :

Prof. Dr. Mohammed Yousry

Course assistant :

Eng.Mohamed Elsayed

Course objectives :

To study and understand the theory of dc and synchronous machines operating in both modes generator and motor

Course description :

1.DC machines: construction, winding, armature reaction, commutation, interlopes, compensating winding.

2.DC generators: types, characteristics, efficiency.

3.DC motors: types, characteristics, speed control, starting, efficiency.

4. Synchronous machines: – Construction. – Principles of operation. – AC windings.

5. MMFs: – Breathing MMF. – Rotating MMF.

6. EMF calculation: – Air gap magnetic field. – Voltage induced in one coil. – Voltage induced in one phase. – Winding factors. – Voltage of the complete stator winding. – Space harmonics and winding factors.

7. Equivalent circuit: – Leakage impedance and equivalent circuit. – Circuit model.

8. The per-unit system.

9. Power and torque as related to power angle.

10. Synchronous generators: – Alternator serving an isolated load. – Alternator connected to An infinite bus. – Open-circuit characteristic. – Short-circuit characteristic. – Synchronous reactance. – Short-circuit ratio. – Calculating excitation requirements. – The Potier method of measuring leakage reactance.

11. Synchronous motors: – Synchronous motor equivalent circuit. – Motor V-curves. – Operation as a synchronous condenser. – Synchronous motor starting. – Speed control of synchronous motors.

12. Phasor diagram for synchronous machine on infinite bus (Electrical Load Diagram).

13. Salient pole machines: – Effect of saliency. – Power transfer in salient-pole machines.

14. Three-phase short circuit: – Short-circuit current. – DC component.

Course assessment :

Mid Term Exam: 20 Marks Class Work (assignments – attendance – Quizzes): 20 Marks Practical Work: 10 Marks Final Exam: 50 Marks

Recommended text books :

\”Introduction to Electrical Machines and Transformers,\” George McPherson and Robert D. Laramore, John Wiley & Sons.

Recommended refrences :

[1] \”Introduction to Electrical Machines & Transformers\” George McPherson & Robert D. Laramore, John Wiley & Sons [2] \”Electric Machinery Fundamentals, \” Stephen J. Chapman, McGraw-Hill.