[attachment=13155]
WIRELESS POWER TRANSMISSION
Basic Idea:
Wireless Power Transmission is based on the simple concept of transmitting power without wires i.e. , transmitting power as microwaves from one place to another.
Basically known as Microwave power Transmission.
MPT is most interesting because microwave devices offer the highest efficiency of conversion between DC-electricity and microwave power.
Wireless Power Transmission:
Nikola Tesla ,”Father of Wireless”, was the one who first conceived the idea of WPT and demonstrated the transmission of electrical energy without wires.
In 1893,Tesla demonstrated the illumination of vacuum bulbs without using wires in Chicago.
Functional Block Diagram of WPT:
Explanation:
In the transmission side , the microwave power source generates microwave power and the output power is controlled by electronic control circuits.
The waveguide circulator which protects the microwave source from reflected power is connected with the microwave power source through the coax- waveguide adaptor.
The tuner matches the impedence between the transmitting antenna and the microwave source .
The transmitting antenna radiates the power uniformly through free space to the rectenna .
Components of WPT:-
The primary components of Wireless power transmission are- Microwave Generator
Transmitting Antenna
Receiving Antenna(Rectenna)
MICROWAVE GENERATOR
The microwave transmitting devices are classified as Microwave Vacuum Tubes(magnetrons).
Magnetron is widely used for experimentation of WPT
The microwave transmission often uses 2.45Ghz or 5.8Ghz frequency.
Magnetron
A microwave tube in which electrons generated from a heated cathode are affected by magnetic and electric fields in such a way as to produce microwave radiation .
The anode of a magnetron is fabricated into a cylindrical solid copper block.
The cathode and filament are at the center of the tube and are supported by the filament leads.
Continued…
The electric and magnetic fields interact to exert force upon the electrons.
Components of WPT….
TRANSMITTING ANTENNA
The slotted waveguide antenna and parabolic dish antenna are the most popular type of transmitting antenna.
RECEIVING ANTENNA
The Rectenna consisits of antenna , rectifying circuit with a low pass filter between the antenna and rectifying diode.
Wireless Power Reception throughRectenna…
Brief introduction of Schottky Barrier Diode
Rectenna…
Rectenna Issues..
Size- Miles across
Location- Near population centre
Health and environmental side effects- Although claim that microwaves would be safe , how do you convince people
Wireless Charging of Mobile phones using microwaves
Continued..
The basic addition to the mobile phone is going to be the rectenna and a sensor.
The Microwave signal is transmitted from the transmitter using special kind of antennas called slotted wave guide antenna at a frequency is 2.45 GHz.
The transmitting Base station is equipped with a Microwave transmitter such as the powerful Magnetron.
Sensor acts as a switch for triggering the rectenna circuitry.
Advantages..
WPT system completely eliminates the existing high tension power transmission line cables , towers and substations .
The cost of transmission and and distribution become less.
The power could be transmitted to the places where the wired transmission is not possible.
Loss of transmission is negligible in WPT and therefore the efficiency is much higher than the wired transmission.
Disadvantages..
The capital cost for practical implementation of WPT seems to be very high.
The other disadvantage of the concept is interference of microwave with present communication systems.
Applications…
Generating power by satellites with giant solar arrays in earth orbit and transmitting the power as microwaves to the earth known as Solar Power Satellites.
Fuel free airplanes , fuel free electric vehicles , fuel free rockets etc.
Mobile charging by using additional elements such as rectenna and sensor.
Conclusion..
The concept of Wireless Power Transmission Via microwaves offers greater possibilities for transmitting power with negligible losses and ease of transmission than any other invention or discovery heretofore made
We can expect with certitude that in years next few years ,wonders will be wrought by its applications if the conditions are favourable.