wireless power transmission

1. Wireless PowerTransmission
Methods ofWireless PowerTransmission
Ranges ofWireless PowerTransmission
Losses InWireless PowerTransmission
Merits and Demerits ofWireless PowerTransmission

2. Wireless PowerTransmission
• The idea ofWPT is not new. First time in 19th century NikolaTesla built a
tower that was capable ofWPT.
• Wireless PowerTransmission uses an electromagnetic field of a certain
frequency as a medium of transfer.This frequency depends upon the ranges
of transmission in order to transmit power wirelessly a source and a receiver
is required which must be in resonance condition.The frequencies of the
two systems must match.

3. Methods ofWireless PowerTransmission
Wireless Power
Transmission
Near Field
Techniques
Inductive
Coupling
Resonant
inductive
Coupling
Far Field
Techniques
Microwave
MPT
Laser
LPT

4. Inductive coupling
• Primary and Secondary coils are not connected with wires
• EnergyTransfer is due to mutual induction
• Examples:Transformer,Wireless Charging Pads etc.
• Wireless charging pads: the primary pad and the secondary pad must be
kept very near.

5. Resonant Inductive Coupling
• Combination of inductive coupling and resonance.
• Resonance make two objects interact very strongly.
• Inductance induces current.

6. Losses inWireless PowerTransmission
• One of the major problems in the wireless power system is the losses occurring
during the transmission.The loss of percentage during transmission is
approximated as 26%.
• Eddy current loss and coupling mechanism offset in transmission are the two main
factors of low efficiency.
• Coupling mechanism basically focuses on winding mode of the coil as well as
material and structure of magnetic core.

7. Ranges ofWPT
• Long ranges: long range is typically power transmission of 100’’s of meter or
across kilometers. One technique of power transmission is using antennas
to send electromagnetic beams, like microwaves or laser.
• Short range is typically power transmission within centimeters and meters.
The most commonWPT technique is with inductive power transmission,
where power is transferred by magnetic field using inductive coupling.

8. Merits ofWireless PowerTransmission
• Comparatively, simple in design.
• Lower frequency operation (for short distance)
• Low cost
• Practical for short distances.
• Safe to use.
• More convenient and comfortable for users.

9. Demerits ofWireless PowerTransmission
• High power losses
• Inefficient for long distances
• Ionization of air
• Non dirctionality