magnetic levitation

A SEMINAR ON

ELECTRO MAGNETIC LOCOMOTIVES

Indian Institute Of Information Technology Design & Manufacturing, Kancheepuram.

BySikharam Uday Kiran

EDS12M008

IIITDM KANCHEEPURAM 2

Introduction Line Diagram Of Power Flow Conventional Rail Engine

How Maglev Works Power Supply Superconductors Halbach Array’s Application Information Maglev Vs. Conventional Train Pros & Cons Summery Reference

PRESENTATION OUTLINE


Line diagram of power flow


Conventional Rail Engine


How MagLev Works

The electromagnets on the underside of the train pull it up to the ferromagnetic stators on the track and levitate the train.

The magnets on the side keep the train from moving from side to side.

A computer changes the amount of current to keep the train 1 cm from the track.

This means there is no friction between

the train and the track!


Levitation System’s Power Supply

Batteries on the train power the system, and therefore it still functions without propulsion.

The batteries can levitate the train for 30 minutes without any additional energy.

Linear generators in the magnets on board the train use the motion of the train to recharge the batteries.

Levitation system uses less power than the trains air conditioning.


Propulsion System

The system consists of aluminum three-phase cable windings in the stator packs that are on the guide way.

When a current is supplied to the windings, it creates a traveling alternating current that propels the train forward by pushing and pulling.


When the alternating current is reversed, the train brakes.

Different speeds are achieved by varying the intensity of the current.

Only the section of track where the train is traveling is electrified.


Propulsion: An alternating current through coils on the guide walls of

the guide way. This creates a magnetic field that attracts and repels the superconducting magnets on the train and propels the train forward.

Braking is done by sending current in the reverse direction

Levitation:

The passing of the superconducting magnets by levitation coils on the side of the tract induces a current in the coils and creates a magnetic field.

This pushes the train upward

It can levitate 10 cm above the track.


Lateral Guidance:

This keeps the train in the center.


Superconductors

It conduct’s electricity without resistance below a certain temperature i.e., 150K.

In a closed loop, an electrical current will flow continuously.


Made out of aluminum to minimize weight.

4 rows of 8 magnets arranged in a Halbach Array.

2 rows for levitation.

2 rows for lateral guidance and propulsion.

Train:

These are a special arrangement that cancels the magnetic field above the magnets, but still allows a field below the magnets.

The permanent magnets that will be using are made out of Neodymium Iron Boron (NdFeB)

Halbach Array’s


Source :http://www.gaussboys.com/Halbach Array

http://www.gaussboys.com/



Germanymph279

ChinaMph302


Sample Output PWM Switching Graphs


A SampleHysteresis Switching Techniques


Application InformationSafety

The trains are virtually impossible to derail because the train is wrapped around the track.

Collisions between trains are unlikely because computers are controlling the trains movements.

Maintenance

There is very little maintenance because there is no contact between the parts.


Comfort

The ride is smooth while not accelerating..

Economic Efficiency

The initial investment is similar to other high speed rail roads. (Maglift is $20-$40 million per mile and I-279 in Pittsburg cost $37 million per mile).

Operating expenses are half of that of other railroads.

A train is composed of sections that each contain 100 seats, and a train can have between 2 and 10 sections.


The linear generators produce electricity for the cabin of the train.

Speed The train can travel at about 300 mph. (Acela can only

go 150 mph)

For trips of distances up to 500 miles its total travel time is equal to a planes (including check in time and travel to airport.)

It can accelerate to 200 mph in 3 miles, so it is ideal for short jumps. (ICE needs 20 miles to reach 200 mph.)

Source: www.eurail.com/trains-europe/high-speed-trains/ice

http://www.eurail.com/trains-europe/high-speed-trains/ice

http://www.eurail.com/trains-europe/high-speed-trains/ice


MagLev vs. Conventional Trains

MagLev Trains Conventional Trains

No Friction = Less Maintenance

Routine Maintenance Needed

No Engine = No fuel required

Engine requires fossil fuels

Speeds in excess of300 mph

Speeds up to 110 mph


Advantages:

It is 250 times safer than conventional railroads.

700 times safer than automobile travel.

Speeds up to 500 km/h.

A accident between two maglev trains is nearly impossible because the linear induction motors prevent trains running in opposite directions.


Disadvantages:

The big problem about this is that the pieces for the maglev are really expensive

The procedure to build it up is very expensive as well.


Other MagLev Applications:

Military is looking into using MagLev. Possible uses could include:

Aircraft carrier launching pad Rocket launching Space craft launching

Future scope: Under water rails (continental).


Summary

Maglev trains use magnets to levitate and propel the trains forward.

Since there is no friction these trains can reach high speeds.

It is a safe and efficient way to travel.

Governments have mixed feelings about the technology. Some countries, like China, have embraced it and others like Germany have balked at the expense.


References:

http://www.gaussboys.com/Halbach Array http://en.wikipedia.org/wiki/Magnetic_levitation http://science.howstuffworks.com/magnet3.htm http://www.howstuffworks.com/electromagnet.htm


http://en.wikipedia.org/wiki/Magnetic_levitation

http://science.howstuffworks.com/magnet3.htm

http://www.howstuffworks.com/electromagnet.htm


Thank you…

BySikharam Uday Kiran

EDS12M008


OPTIMUM MAGNET THICKNESS =.2*wavelength (lambda)

Optimum wavelength = 4*pi*y1 (m)

y1 = levitation height (lambda)

Br = (Tesla) remanent field of the permanent magnet

1

2

77.Mag of Wt.

lev Wt.

y

Br

Equations used:


LEVITATION FORCES

vkv 2

Excitation Frequency

Peak Strength of Magnetic Field M

MeBB kd

ro /

)/sin(*]1[


)2(* 1

0

2max Co ykB

A

F e

dL

d

c

y

LL

L

P

w

F

F

*

max


L

Rvt *

2

C

Cd kd

PL

20

turns

P

A

lR C*

R

Ltan


LEVITATION FORCES

Levitation Height = .75 cm

Transition Velocity = 3.9 m/s

Approximately 14,200 m of wire will be needed for 24 ft of track.


Thickness of Wire # of Turns Approx Amps

.0315 in 1 492 mA

.10189 in10 awg

1 3.8 A

.10189 in10 awg

5 9.9 A

Coil Estimations: