1. Motor ELECTRICAL ENERGY Mechanical Energy

8. Interaction of two magnetic fields

10. + When Current positive and going into · When Current negative and coming from

12. A machine which converts AC electrical energy into Mechanical energy

15. Stator Wound Rotor Start Resistance

16. AC Machine Stator

17. Squirrel Cage Rotor

19. Principle of Induction Motor

20. Slip in Induction Motor slip speed = synchronous speed - rotor speed measured in RPM Slip = (synchronous speed - rotor speed ) /synchronous speed expressed as a percentage The greater the slip speed, the greater is the force on each conductor and the torque exerted by the whole. 

22. phase voltage is 1/ √3 of the normal voltage phase voltage is equal to the line voltage.

26. Wire Wound Rotor Connected To Resistor

27. Torque –Speed Characteristic

28. Two Phase Induction Motor

29. Two Phase RMF

30. Single Phase Pulsating Field

36. Induction Motor Example A 100 hp, 8 pole, 60 Hz, 3 phase induction motor runs at 891 rpm under full load. Determine the synchronous speed in rpm, slip speed and Slip. Solution on white board

39. Synchronous Motor-Principle The rotor acting as a bar magnet will turn to line up with the rotating magnet field. The rotor gets locked to the RMF and rotates unlike induction motor at synchronous speed under all load condition

40. Changing The Load An increase in the load will cause the rotor to lag the stator field but still maintain synchronous speed. Increase in load has increased the torque component, but the field strength has decreased due to the increase in length of the air gap between the rotor and the stator. If the synchronous motor is overloaded it pulls out of synchronism and comes to rest. The minimum amount of torque which causes this is called the “ pull out torque”. Lightly loaded motor Heavily loaded motor

43. Synchronous Machine Construction

44. Synchronous Machine Phasor Diagram

45. Excitation and Stator induced voltage

46. V curves

47. Torque versus Speed