Wireless transmission of electric energy

Antoine Caillierez, PhD student, Supelec (France)Advisor: Daniel Sadarnac, Supelec (France)Co advisor: Alain Jaafari, Supelec (France)

PACIFIC’2011 International conference

Pantograph Catenary Interaction Framework for Intelligent Control

Introduction: The need:

An efficient method for transferring large power level over moderates distances to moving loads.

The principle: Mutually coupled coils. HF converter

Some projects over the world

Bombardier, Volvo, Van Hool

Some projects over the world

Serpentine until 2004 (Lausanne, CH) small public automated vehicle. Inductive power supply

OLEV Project (KAIST, Seoul, South Korea) Efficiency: 74% with 13cm

airgap.

OAK Ridge National Laboratory (Utah, USA)

Experimental model

Serie parallel resonant converter

Design for 100W with at 4 cm air gap.

42V; 75kHz switching frequency

Rectangular coils (primary and secondary) : 10x20cm

Magnetic transformer Secondary voltage:

Rectangular coils

parameter Limitation

Number of windings Joules effect losses

Geometry of coils efficiency

Working frequency Skin effect and semiconductors losses

Mutual Inductance

a1

a2

b1

b2

A

B

h

Rayon r1

Rayon r2

NB spires

NA spires

Coupling Factor:

Mutual inductance between two windings:

Neumann formula:

Results: Mutual InductanceAir gap Z=7cmAir gap Z=1cm

Results: Secondary power

0 5 10 15 20 25 300

10

20

30

40

50

60

70

80

90

100

np : number of turns in primary winding

max

imum

pow

er in

sec

onda

ry in

W

ns : number of turns in secondary winding

x ns=2- ns=6o ns=13+ ns=15

Conclusion

Efficiency. (>90%)

new lines of research for EV and transportation.

Potential for Wireless transfer of high power.

Questions?