1) The document discusses linear motors used in maglev trains. Maglev trains use magnetic levitation to move along a track without touching the surface. 2) There are two main types of linear motors for maglev train propulsion: linear induction motors and linear synchronous motors. Linear induction motors use induction to generate a repulsive force that pushes the train along four individual linear motors. 3) Linear synchronous motor speed is determined by the frequency of alternating current powering the magnetic field, which can be reversed for braking without friction.

1. King Saud University College of Engineering Saudi Arabia Electrical EngineeringLinear Motors in Maglev trainDr. Essam Al- AmmarDr. IbraheemElshafieyProf. RizkHamoudaBy: Ahmad Ismail427101731EE-330 Electric Machine 2009-2010

2. Outlines:1 What is the (Maglev Train)?2How does the Maglev Train work?3 What is the difference between the Induction & the Linear motor?4 what are the types of The Linear motors which are used in Maglev train?

3. 1What is the (Maglev Train)?The Train(Maglev)is a Shortcut ofMagnetic LevitationLevitationSSSNNNTrack

4. The train and the track has magnetic poles andThey’re what repel and push the train to its destination.

5. Countries Which Use the Maglev Train

6. 2The Maglev Train is based on three types of systems which control the train’s move on the track:a- Guidance System:refers to the sideward forces that are required to make the vehicle follow the guideway. b- Propulsion Systems:propulsion using an electrically powered (LIM)Linear Inductoin Motor or )LSM) Linear Synchronous Motor winding in the guideway appears to be the favored option for high-speed maglev systems. c- Levitation System: which is keeping the train suspended against the gravity by the forces of the magnetic field. Look at figure number (3).

7. 3What is the ( Induction Motor)?is a type of alternating current motor where power is supplied to the rotor by means of electromagnetic induction.RotorwSNxxStatorx

8. What is the (Linear Motor)?Linear Motors can be considered as a conventional rotary motor with both the stator and the rotor split and rolled out flat. RotorwMotorSNxxStatorx

9. Induction MotorLinear MotorIs widely use, and now the most preferred choice for industrial drives motor,Is now used in all sorts of machines that require linear (as opposed to rotational) motion.

10. Induction MotorLinear MotorwSNxxxPermanent magnets forming the armature are held in the carriage. Stator poles are laid out along the track and excited by windings fed from a pulsed DC source.

11. The carriage moves along the track in response to pulses sent to the the stator windings in much the same way as the rotor turns in a brushless DC motor.

12. Closed loop control is possible by mounting a position sensor on the carriage.

13. Despite the elegance of the linear motor, linear motion is more often provided by the less expensive and more mundane method of using a rotary stepping motor driving a lead screw.Types of Linear motor which is used in the Propulsion System of the Maglev train:4There are two types of propulsion systems used in current MagLev trains. The Linear Induction Motor (LIM) is used to propel the Japanese EDS system.the Linear Synchronous Motor (LSM) propels the German Transrapid system. Both of the systems are move by the guideways themselves instead of the actual train car. Propulsion occurring in the Linear Induction Motor is caused from the sum of four individual linear motors. The motors induce voltages to the four motors. When these voltages are combined they produce a repulsive force that pushes the train car forward. The speeds for Linear Induction Motors is determined by “the ratio of length of the vehicle magnet system to the length of the energized block, the sum of the coupling coefficients between vehicled magnets and the guideway coils, applied voltage, and the current flowing in the superconducting coils .

14. The speed of MagLev trains in Linear Synchronous motors are determined by the frequency of the alternating current and the magnetic field directions. Propulsion is created when the current is in ‘synch’ with the frequency allowing for forward propulsion. In order for the train car to brake and slow down, the field simply has to be reversed allowing the train car to brake without the use of friction.

15. Conclousion:Linear motor can be considered as a conventional rotary motor with both the stator and the rotor split and rolled out flat. There are two types of propulsion systems used in current MagLev trains the (LIM) and the (LSM).Propulsion occurring in the (LIM) is caused from the sum of four individual linear motors.The speed of MagLev trains in (LSM) are determined by the frequency of the alternating current and the magnetic field directions.

16. Linear Motors in Maglev trainThank You!Ahmad IsmailEmail: ahmad_ismaeil@live.comTheEnd