WIRELESS POWER TRANSFER(ELECTRICITY OUT OF THIN AIR)

Transcription

1 WIRELESS POWER TRANSFER(ELECTRICITY OUT OF THIN AIR) PROJECT REFERENCE NO. : 37S1336 COLLEGE : JAIN COLLEGE OF ENGINEERING BELGAUM BRANCH : ELECTRONICS AND COMMUNICATION ENGINEERING GUIDE : PRAVEEN CHITTI STUDENTS : MEGHANA KODKANI DIVYA GUDAGI UDAYKUMAR KATTI KUNAL PATIL Introduction: Electricity by today s standards is considered essential to life. Electricity has been the fuel for technological development. Wireless Power Transfer is exactly what the name states, to transfer electrical power from a source to a device without the aid of wires. The founder of AC electricity, Nikola Tesla, was first to conduct experiments dealing with WPT. Wireless energy transfer or wireless power transmission is the process that takes place in any system where electrical energy is transmitted from a power source to an electrical load without interconnecting wires. Wireless transmission is useful in cases where instantaneous or continuous energy transfer is needed but interconnecting wires are inconvenient, hazardous, or impossible. Wireless power transfer can make an extraordinary change in the field of the electrical engineering which eliminates the use of conventional copper cables and current carrying wires. Based on a concept, the project is developed to transfer power within a small range. The power is transferred without any connection. Current wireless power transmitters are capable of transmitting current at distances of up to one foot. These distances allow for use in small consumer electronic devices. Nikola Tesla, who is seen by as the "Father of Wireless", is also credited for his remarkable AC generation and was the first person to conceive the idea of wireless power transmission and successfully demonstrated the transmission of electricity without wires 1

2 as early as In 1893 Tesla won to illuminate the World Columbian Exposition in Chicago, where he demonstrated the success of illuminating the vacuum tubes bulbs without using wires. Objective: The overall goal of this project is to design and successfully implement a wireless power transmission system for residential purpose. The system will work by using resonant coils to transmit power from an AC line in the ceiling to various devices. The major objective is to achieve Wireless power transfer via resonant inductive coupling between the transmitting and receiving coils in the near field. To demonstrate that power is successfully transferred wirelessly, an LED, a battery and a DC fan is used. There are several benefits for the use of such a system: Elimination of cords on the ground that make tripping hazards. Allows no wire installation A necessary step towards consumer wireless power. Methodology: Ac Source High Frequency Transforming Primary Coil Secondary Coil Rectifier Regulator Load Fig1: Block Diagram 2

3 Transmitter: Fig2: Transmitter Section The AC source voltage supplies the ac voltage at input of the coil. But before directly applying it to the coil a high frequency transformation is performed by which the frequency gets increased from 50hz to several khz. This is effectively done in order to achieve long distance and to reduce the power consumption. This frequency transformation is done by using switching devices by which alternately the devices can be made to generate the pulses and given as input to transmitting inductor (primary coil) & the voltage flow through this coil is in the form of electromagnetic waves which is then transmitted towards receiving inductor(secondary coil). Receiver: Fig3: Receiver Section The receiving inductor (secondary coil) is used to receive the electromagnetic waves which produce the voltage inside the coil which is in AC form. This voltage passed through rectifier & filter circuitry which converts the AC voltage in DC form & removes the unwanted contents using filter. This circuit used to provide smooth DC voltage. The received voltage may 3

4 be in unregulated form which must be regulated using Voltage regulator so at the output we get regulated DC voltage. This regulated voltage is then given to the load which drives it. Results & Conclusion: Tabulation For Led SL No. Distance(cm) Voltage(v)

5 Results of LED Tabulation for Dc Fan SL NO. Distance(cm) Voltage(v)

6 Results of DC fan Tabulation for Mobile Charging SL NO. Distance(cm) Voltage(v) Result of Mobile Charging 6

7 Tabulation for Led, Dc Fan & Mobile Charging SL NO. Distanc e(cm) LED Voltag e(v) Fan Voltage(v ) Mobile voltage (v) Off Off (off) off Off off 8 28 off Off off Results of Led fan and mobile 7

8 Conclusion: WiTricity's technology is a mode of energy transfer which uses magnetic flux. Magnetic fields interact very weakly with biological organisms, people and animals are scientifically regarded to be safe. Hence witricity is technologically safe. Wireless power transfer depends on the source and receivers. If it is relatively close to one another power transferred is more and decreases as the distance increases. Efficiency is primarily determined by the distance between the power source and capture device, however, the capacity may impact the efficiency. It can transfer the power through walls also because any barrier in between will not hamper the transfer. WiTricity technology is based on resonant coupling, and is able to transfer power efficiently even when the distances between the power source and capture device are several times the size of the devices themselves. Moreover one primary coil can be shared to power up few devices which can get powered up simultaneously thereby decreasing the amount of power required when each device is connected separately. Future Scope: The researchers are currently working on the health issues related to this concept and have said that in another three to five year time, they will come up with a WiTricity system for commercial use. WiTricity, will definitely change the way we live. This technique can be used in number of applications, like to charge a mobile phone, ipod, laptop battery and other devices. This kind of charging provides a far lower risk of electrical shocks, short circuit. Imagine cell phones, laptops, digital camera's getting self-charged! The concept of wireless power transfer can therefore be modified in future in the field of communication for selfcharging the devices where in the devices get charged by using backscattered signals from various devices. This involves converting the RF waves received by the device to power that can be used to power up the device. With this technology in the future there will be no need of power cables and batteries. The city just has to be covered with witricity hot spots wherein you can use your electric gadget battery and wire free making it more convenient to carry around and much lighter. 8