SEMINAR ON

WITRICITY(WIRELESS POWER TRANSMISSION)

PRESENTATION BY: RITESH2012UEE1347

MNIT JAIPUR

Supervised by:Dr. K. R. Niazi

WIRELESS POWER TRANSMISSION Wireless power transmission dates back to the

19th century when Nikola Tesla used conduction based systems based on his research of Tesla coil to transfer wireless power.

A couple of techniques of wireless power transmission are known now:

1) Direct induction2) Resonant magnetic induction3) Electromagnetic radiation

DIRECT INDUCTION Similar to transformer, having

primary and secondary coils.

E.g. An electric Toothbrush, uses traditional magnetic induction to recharge its batteries.

Tooth brush needs to be placed in its cradle in order to be recharged because coils must be within millimeters of each other to couple and transfer power

RADIATIVE POWER TRANSFER E.g. Microwave radiations , LASER , solar

radiations

Basically radiative form of power transfer like in microwave oven and most of the power gets wasted during transfer

Less efficient and may interact with biological organism

Require line of sight between power source and capture device.

Can be employed for far distances

WITRICITY Basically refers to Resonant induction coupling

method i.e. employed basic induction principle of transformer as well as RESONANCE

Different from Tesla’s technology of wireless power transmission

Different from traditional magnetic induction

Different from traditional radiative power transfer

Useful for near field transmission purposes that is up to few meters

.

FIRST EXPERIMENT – WITRICITY The first experiment of witricity was conducted

in the year 2006 by a five member team of researches from Massachusetts Institute of Technology

It was led by Assistant Professor Marin.

It was funded by Army Research Office, National Science Foundation and Department of

Atomic Energy.

BASIC PRINCIPLES:

Resonance as well as induction coupling

Resonance is a tendency of system to oscillate with larger magnitude at some frequencies than at others.

At resonant frequencies, even small periodic deriving forces can produce large amplitude oscillation

Two objects having similar resonance tends to exchange energy without causing any effects on the surrounding objects.

Just like in acoustic resonance, where there is chance of glass breaking if you strike a right tone.

A glass captures sound energy that oscillates at its natural resonant frequency, convert it to mechanical energy that causes glass to deform at that same frequency and eventually causing it to shatter

FIRST EXPERIMENTS- WIRELESS LIGHTTwo copper coils of diameter two feet.

The transmitter coils was attached to a power sources.

The receiver coil was placed about seven feet away from transmitter.

The receiver was attached to light bulb.

Two coils was tuned to same frequency.

Power was switched on at the transmitter.

The coils magnetically coupled and resonated at 10 MHz

Electric energy was transmitted over a distance of two meters through the air and around an obstacle

With each cycles more voltage built up in the coil till the accumulation of voltages provided enough pressure and energy to flow to the light bulb.

Data collected through measurement showed that there was transference of 40% electricity through wiTricity.

The bulb glowed despite the fact that wood, metal and other device were placed in between the two coils

The blue lines shows magnetic near field induced by power source.

The yellow lines shows the flow of energy from the source to the WiTricity capture coil.

The magnetic field lines can wrap around a obstacles between the power source and capture devices.

BENEFITS OF WITRICITY WiTricity mode of wireless power transfer is

highly efficient over distances ranging from centimeters to several meters. In many applications, efficiency can exceed 90%

WiTricity sources only transfer energy when it is needed

When a WiTricity powered device no longer needs to capture additional energy, the WiTricity power source will automatically reduce its power consumption to a power saving ‘‘idle’’ state

BENEFITS OF WITRICITY Energy transfer via magnetic near field can

penetrate or wrap around obstacles

WiTricity’s technology is non-radiated mode of energy transfer, relying instead on magnetic field.

Magnetic field interact very weakly with biological organism- people and animal- are scientifically regarded to be safe.

Wirelessly powering up an appliance will not add up appreciably to the cost i.e. cost efficient

APPLICATION WiTricity’s wireless power transfer technology can be

applied in wide variety of applications and environment It can be used to provide: Direct Wireless Power : When all

power required by device is wirelessly provided, and no batteries are required. This mode is for device which are always used within range of it’s WiTricity power source.

Automatic Wireless Charging : when a device with rechargeable batteries charge itself while still in use or at rest, without requirement power cord or battery replacement. This mode is for mobile device which can be used both in and out of range of its witricity power source.

VARIOUS USAGE AREAS CAN BE…… Mobile phones Electric cars Medicals Computers

THANK YOU