Wireless power transfer (WPT), wireless power transmission, wireless energy transmission, or electromagnetic power transfer is the transmission of electrical energy without wires. Wireless power transmission technologies use time-varying electric, magnetic, or electromagnetic fields. Wireless transmission is useful to power electrical devices where interconnecting wires are inconvenient, hazardous, or are not possible.

1. Presented By
Ismile Hossain
1403EEE00052
Department of Electrical & Electronic Engineering
Manarat International University

2.  What is wireless Power Transmission(WPT)?
 Why is WPT?
 Types of WPT
 Techniques to transfer energy wirelessly
 Advantages & Disadvantages
 Applications

3.  The transmission of energy from one
place to another without using wires
 Conventional energy transfer is using
wires
 But, the wireless transmission is made
possible by using various technologies

4.  As per studies most electrical energy
transfer is through wires
 Most of the energy loss is during
transmission
 On an average, more than 30%

5.  Reliable
 Efficient
 Fast
 Low maintenance cost
 Can be used for short range or long range

6.  Near-field techniques
 Inductive Coupling
 Resonant Inductive Coupling
 Air Ionization
 Far-field techniques
 Microwave Power Transmission
 LASER Power Transmission

7.  The transfer of energy
 Magnetic Coupling
 Inductive Coupling
 Simplest wireless energy coupling is a transformer

8.  Primary & secondary coils are not connected with
wires.
 Energy transfer is due to mutual induction
 Wireless Charging Pad(WCP), Electric Brushes are
some examples.

9. The capacitor and inductor forms the resonator. Charge
oscillates between inductor (as magnetic field) &
capacitor (as electric field).
 This type of oscillation is called resonance if the
reactance’s of the inductor and capacitor are equal.

10.  Coil provides the inductance
 Capacitor is connected parallel to the coil
 Energy will be shifting back & forth between magnetic
field surrounding the coil & electric field around the
capacitor.
 Radiation loss will be negligible

12.  Toughest technique under near field energy transfer
techniques
 Air ionizes only when there is a high field
 Needed field is 2.11MV/m
 Natural Example: Lightening
 Not feasible for practical implementation

13.  Advantages
 No wire, No e-waste
 Need for battery eliminated
 Efficient & Harmless
 Disadvantages
 Distance constraint
 Field should be under safety level
 High initial cost
 Tuning is difficult in RIC

14.  Transfer high power from one place to another. Two
places being in line of sight usually
Steps:
 Electrical energy to Microwave energy
 Capturing microwaves using rectenna
 Microwave energy to electrical energy
 AC is converted to DC first
 DC is converted to microwaves using magnetron
 Transmitted waves are received at rectenna which
rectifies, gives DC as the output
 DC is converted back to AC

15.  LASER is highly directional, coherent
 Not dispersed for very long
 But gets attenuated when it propagates through
atmosphere
 Simple receiver
 Photovoltaic cell
 Cost efficient

16.  Advantages
 Efficient, Easy
 Need for grid eliminated
 Low maintenance cost
 Can reach the places which are remote
 Disadvantages
 Radiate
 When LASERs are used; Conversion is inefficient &
Absorption loss is high
 When microwaves are used interference may arise

17.  Near-filed energy transfer
 Electric automobile charging
 Consumer electronics
 Industrial purposes
 Harsh environment
 Far-field energy transfer
 Solar power satellites
 Energy to remote areas
 Can broadcast energy globally (In Future)

18. Thank You