Presented by

Raghavendra1bg12ee404

Department of Electrical and electronics Engineering

BNM Institute of Technology, bangalore

What is wireless power transmission(WPT)?

Why is WPT?

History of WPT

Types of WPT Techniques to transfer energy wirelessly

Advantages and disadvantages

Applications

Conclusion

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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

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As per studies, most electrical energy transfer is through wires.

Most of the energy loss is during transmission• On an average, more than 30%

• In India, it exceeds 40%

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ReliableEfficientFastLow maintenance costCan be used for short-range or

long-range.

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Nikola Tesla in late 1890s

Pioneer of induction techniques

His vision for “World Wireless System”

The 187 feet tall tower to broadcast energy

All people can have access to free energy

Due to shortage of funds, tower did not operate

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Near-field techniques Inductive Coupling

Resonant Inductive Coupling

Air Ionization

Far-field techniquesMicrowave Power Transmission (MPT)

LASER power transmission

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Primary and secondary coils are not connected with wires.

Energy transfer is due to Mutual Induction

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Transformer is also an example

Energy transfer devices are usually air-cored

Wireless Charging Pad(WCP),electric brushes are some examples

On a WCP, the devices are to be kept, battery will be automatically charged.

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Combination of inductive coupling and resonance

Resonance makes two objects interact very strongly

Inductance induces current

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Coil provides the inductance

Capacitor is connected parallel to the coil

Energy will be shifting back and forth between magnetic field surrounding the coil and electric field around the capacitor

Radiation loss will be negligible

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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

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No wires

No e-waste

Need for battery is eliminated

Efficient energy transfer using RIC

Harmless, if field strengths under safety levels

Maintenance cost is less

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Distance constraint

Field strengths have to be under safety levels

Initial cost is high

In RIC, tuning is difficult

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Electric automobile charging

Consumer electronics

Industrial purposes

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It permits long range of energy transfer

Aim at high power transfer

LASER or microwave

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Transfer high power through outer atmosphere without the need of wire

Efficiency is high at receiver and transmitter end

Attenuation is less

Used to transmit energy point to point

Also known as laser power beaming

Simple receiver Photovoltaic cell

Cost-efficient

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To provide energy to earths increasing energy need

Solar energy is captured using photocells

Each SPS may have 400 million photocells

Transmitted to earth in the form of microwaves/LASER

Using rectenna/photovoltaic cell, the energy is converted to electrical energy

Receives power on earth by using rectennas

Efficiency exceeds 95% if microwave is used.

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Stands for rectifying antenna

Consists of mesh of dipoles and diodes

Converts microwave to its DC equivalent

Usually multi-element phased array

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Rectenna in US receives 5000MW of power from SPS

It is about one and a half mile long

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Efficient

Easy

Low maintenance cost

More effective when the transmitting and receiving points are along a line-of-sight

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Initial cost is high

When LASERs are used, Absorption loss is high

When microwaves are used, interference may arise

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Far-field energy transfer Solar Power Satellites

Laser power beaming is used in military weapon aerospace

Spacecraft , satellites , etc

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Transmission without wires- a reality

Efficient

Low maintenance cost. But, high initial cost

Better than conventional wired transfer

Energy crisis can be decreased

Low loss

In near future, world will be completely wireless

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