DESIGN OF A MODEL OF MAGLEV TRAIN USING SUPERCONDUCTOR

Supervisor-Prof. Neeraj Khare Naveeen Khandelwal 2008ph10628

OBJECTIVE

To prepare superconductor(YBCO) pellets in Lab.

To study the properties of superconductor (YBCO)

Design of Maglev Vehicle.

Design of magnetic track (Halbach array) for the

Maglev.

SUPERCONDUCTOR (YBCO) SYNTHESIS

½ Y2O3 + 2 BaCO3 + 3CuO YBa2Cu3O6.5+x + 2CO2 Perovskite structure

1. Mixing the chemicals (7 hrs in mortar & pestle) 2 Calcination (925-950 0C,18-24 hrs, forms basic crystal structure of YBa2Cu3O6.5) 3 Grinding (6-7 hrs) & Pelletization

(1.5 cm diameter) 4 Oxygen annealing (1000 0C ,25-

30hrs, sufficient oxygen supply)

HEATING CYCLE (ANNEALING)

Oxygen is absorbed during cool down. Therefore, it is important to keep the sample in contact with plenty of oxygen during the cool-down.

The absorption is maximum around 550oC so sample is kept for a longer time at this temp.

Cooling rate < 100 oC/hr Heating Rate < 300 oC/hr to avoid thermal stress.

X- RAY DIFFRACTION 2 d sin (θ) = n λ For Cu λ = 1.54060 Å

XRD Various peaks were observed at different

angles. Lattice parameters were calculated using

these peaks. The calculated a,b,c were similar to the

actual lattice parameter. Higher values of a 3.871 instead of 3.821 shows that the sample have mixed phases with varying Tc and oxygen deficient.

Lattice const.

Calculated Actual

a 3.871 Ao 3.821 Ao

b 3.89 Ao 3.891Ao

c 11.66Ao 11.67Ao

CRITICAL TEMP. MEASUREMENT Resistance as a function of temp. were measured using four

probes. A sharp transition was observed at 91 K.

FROZEN IMAGE METHOD• In ZFC, the PM produces its

diamagnetic mirror image below the HTS top surface,

• while in FC, two images appear: one is the diamagnetic mirror image and the other is the frozen image

(1)where; z and h are MH (measuring height) and CH(cooling height)

respectively.

FORCE VS HEIGHT CURVE

Height (cm)

Verti

cal L

evita

tion

forc

e (N

x10)

m1 =m2 =1.2 A m2

Cooling Height (h) = 0.5 cm

MAGNETIC LEVITATION IN OUR SAMPLE

Around 4-5mm of levitation was observed in our sample. NdFeB magnets of grade N-35 were used with magnetic strength around 1.2 T.

DESIGN OF GUIDE WAY

o Along the length of the track, in the y-direction, there is no variance in the field, which allows the superconductor to move back and fourth with no energy loss.

o Perpendicular to the length of the track, the bar magnet’s poles are aligned anti-parallel to each other.

o This alignment produces a considerably strong gradient in the x-direction

HALBACH ARRAY Makes optimal use of

permanent-magnet material by concentrating the field on the front face of the array, while nearly cancelling the field on the back face of the array.

VEHICLE DESIGN designed to enable keeping of YBCO pellets in

considerable amount of liquid Nitrogen. Two big pellets act as main levitators, which lifts the

vehicle above the guide way. 4 small pellets act as Auxiliary levitators, which

stabilize the lateral swinging of vehicle. vehicle is made out of polyurethane foam with very

good thermal properties (thermal insulation).YBCO pellets (Main levitators)

YBCO pellets (Auxiliary levitators)

WORK DONE Qualitative and Quantitative Analysis of

levitation force and Stiffness using frozen image method.

Preparation of YBCO sample using solid state method.

XRD and Critical temperature measurement of YBCO sample

Schematic design of track and vehicle.

CONCLUSION XRD of YBCO sample shows that Oxygen

content has significant role in determining the superconducting behavior of YBCO

Due to oxygen deficiency in the sample, it contain mixed phases with varying Tc .

Levitation force was very weak in comparison to the theoretical prediction.

levitation force was not enough to suspend the maglev model's weight, so we were not able to implement the design.

REFERENCES John R. Hull and Ahmet Cansiz "Vertical and lateral

forces between a permanent magnet and a high temperature superconductor" JOURNAL OF APPLIED PHYSICS VOLUME 86, NUMBER 11

http://www.futurescience.com/scpart1.html P. Strehlow and M. C. Sullivan “Levitation and Suspension

of a Superconductor over a Magnetic Track” Charles American Journal of Physics -- September 2009 -- Volume 77, Issue 9

Čermák, R.; Bartoň, L.; Spal, P.; Barták, J. & Vavřík, J. “Overview of magnetic levitation principles and their application in Maglev trains ” Advance engineering 2(2008) ISSN 1846-5900