wireless power transfer by high frequency resonating coils

Wireless power transfer by High

frequency resonating coils

http://www.edgefxkits.com/

Wireless power transfer by High frequency resonating

coilsIntroduction

The project is designed to develop a concept of wireless power transfer for several applications such as wireless powered electric vehicle in stores, airports, departmental stores etc. It can also charge a rechargeable battery or a cell phone wirelessly suitably modified for the purpose. AC 230V ,50 Hz mains is stepped down to low voltage ac by conventional 50 Hz iron cored transformer which is then rectified by a bridge rectifier to develop around 14 volt DC.

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Block Diagram


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Hardware Requirements HF-Transformer

HF-diodes rectifier Bridge-MOSFETs drive Two air filled inductor coils Voltage regulator BULB MOSFET driver PWM inverter IC


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Software Requirements

Keil compiler

Languages: Embedded C or Assembly


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Wireless power transmission

The transmission of energy from one place to another without using wires which is also known as “WiTricity”.

Generally conventional energy is transferred using copper wires which results in large Copper loss.

But now-a-days this wireless transmission is made possible in using various technologies based on Resonant frequency ,Inductive coupling etc.


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Need of Wireless power transmission As per studies, most electrical energy transfer is through wires.

Most of the energy loss is during transmission as copper losses

On an average, more than 30% In India, it exceeds 40%

Billions, trillions of $ is spend on wires and in their installation.

Waste management a challenge in 21 century.

40 billion disposal batteries added to e-waste every year.

PVC is non-biodegradable.


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Electro magnetic Inductive coupling It is based on the FARADAY’S LAW OF ELECTROMAGNETIC

INDUCTION

Make use of coils. The coils are not connected through wire or any other kind of material.

Transfer of energy is due to mutual induction.

Its based on the concept : that an oscillating electric field produces magnetic field and an oscillating magnetic field produces oscillating electric field


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RESONANT INDUCTIVE COUPLING


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Same inductive coupling(EMI) concept but the coils here operate at their resonating frequency.

Inductance induces current.

Resonance makes both the coil to operate at same frequency.

Fields are non-radiative in nature.






Types and Technologies Near-field techniques

• Inductive Coupling• Resonant Inductive Coupling• Air Ionization

Far-field techniques

• Microwave Power Transmission (MPT)

• LASER power transmission


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RIC VS INDUCTIVE COUPLING

RIC is highly efficient

RIC has much greater range than inductive coupling

RIC is directional when compared to inductive coupling

RIC can be one-to-many. but usually inductive coupling is one-to-one

Devices using RIC technique are highly portable


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HF transformers

Electric power transmission over long distances.

High-voltage direct-current HVDC power transmission systems.

Large, specially constructed power transformers are used for electric arc furnaces used in steelmaking.

Rotating transformers are designed so that one winding turns while the other remains stationary.


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HF transformers


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HF transformers

A common use was the video head system as used in VHS and Beta video tape players.

These can pass power or radio signals from a stationary mounting to a rotating mechanism, or radar antenna.


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RectifierRectifiers are used in various devices, including:

• DC power supplies

• Radio signals or detectors

• A source of power instead of generating current

• As flame rectification to detect the presence of flame

• High-voltage direct current power transmission systems


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Rectifier


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Voltage Regulator

A voltage regulator generates a fixed output voltage of a preset magnitude that remains constant regardless of changes to its input voltage or load conditions.

There are two types of voltage regulators: linear and switching.

A linear regulator employs an active (BJT or MOSFET) pass device (series or shunt) controlled by a high gain differential amplifier.


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Voltage Regulator

It compares the output voltage with a precise reference voltage and adjusts the pass device to maintain a constant output voltage.


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Description of HF transformers

Electric power transmission over long distances.

High-voltage direct-current HVDC power transmission systems

Large, specially constructed power transformers are used for electric arc furnaces used in steelmaking.

Rotating transformers are designed so that one winding turns while the other remains stationary.


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Description of HF transformers

A common use was the video head system as used in VHS and Beta video tape players.

These can pass power or radio signals from a stationary mounting to a rotating mechanism, or radar antenna.


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Working Principle

AC 230V ,50 Hz mains is stepped down to low voltage ac by conventional 50 Hz iron cored transformer.

Which is then rectified by a bridge rectifier to develop around 14 volt DC.

This DC is again made to ac by a PWM inverter using half bridge concept comprising of 2 MOSFETs.

And 2 capacitors being switched at 40 KHz which is then fed to a resonating high frequency coil acting as primary of an air core transformer.


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Working Principle

Another matching resonating coil formed as secondary drives a lamp load of 10 watts spaced at an air distance of 20 CMs.

The overall efficiency of the power transfer in this case is more than 90% for perfectly coupled and matched series resonators.

However, practically resonators with a Q of 1,000 should be able to send power over a distance 9 times the radius of the devices with an efficiency of 10%.


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Working Principle

The secondary coil develops a voltage of 40 KHz at 12volt while it is kept spaced from the primary coil where air is used as the core.

The output of the secondary can also be given to a high frequency bridge rectifier that can deliver DC which could then be regulated to maintain a constant voltage to a DC motor or current to feed to rechargeable battery or a cell phone.

However, the overall efficiency of the power transfer shall be less than 50% for all such weakly coupled series resonators.


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http://www.edgefxkits.com/pwm-based-speed-control-for-dc-motor






Air Ionization 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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APPLICATIONS Provides charging stations for handheld devices like phones ex: powermat,

removes the need for multiple power sockets

Can operate appliances like tv

Electric car manufacturers consider it for charging electric cars, currently using wires for this purpose is not entirely practical


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ADVANTAGES Non-radiative energy transfer is safe for people and animals.

Wastage of power is less.

Highly resonant strong coupling provides high efficiency over distance.

Does not interfere with radio waves.


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Conclusion Wireless power transfer by High frequency resonating coils was designed and

implemented. The project can be enhanced in future up to 1 meter distance in space using resonators with a Q factor of 1,000 enabling it to send power over a distance 9 times the radius of the coil of 11 CMs .


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http://www.edgefxkits.com/wireless-power-transfer-by-high-frequency-resonating-coils

http://www.edgefxkits.com/wireless-power-transfer-by-high-frequency-resonating-coils







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wireless power transfer by high frequency resonating coils

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