Featured Research

from universities, journals, and other organizations

Wireless power transfer achieved at 5-meter distance

Date:
April 17, 2014
Source:
The Korea Advanced Institute of Science and Technology (KAIST)
Summary:
A great improvement has been demonstrated in the distance that electric power can travel wirelessly. Researchers developed the 'Dipole Coil Resonant System' for an extended range of inductive power transfer, up to 5 meters between transmitter and receiver coils. "Our technology proved the possibility of a new remote power delivery mechanism that has never been tried at such a long distance. Although the long-range wireless power transfer is still in an early stage of commercialization and quite costly to implement, we believe that this is the right direction for electric power to be supplied in the future. Just like we see Wi-Fi zones everywhere today, we will eventually have many Wi-Power zones at such places as restaurants and streets that provide electric power wirelessly to electronic devices," they say.

This is a simulation result of magnetic flux lines of DCRS coil configuration.
Credit: KAIST

The way electronic devices receive their power has changed tremendously over the past few decades, from wired to non-wired. Users today enjoy all kinds of wireless electronic gadgets including cell phones, mobile displays, tablet PCs, and even batteries. The Internet has also shifted from wired to wireless. Now, researchers and engineers are trying to remove the last remaining wires altogether by developing wireless power transfer technology.

Chun T. Rim, a professor of Nuclear & Quantum Engineering at KAIST, and his team showcased, on April 16, 2014 at the KAIST campus, Daejeon, Republic of Korea, a great improvement in the distance that electric power can travel wirelessly. They developed the "Dipole Coil Resonant System (DCRS)" for an extended range of inductive power transfer, up to 5 meters between transmitter and receiver coils.

Since MIT's (Massachusetts Institute of Technology) introduction of the Coupled Magnetic Resonance System (CMRS) in 2007, which used a magnetic field to transfer energy for a distance of 2.1 meters, the development of long-distance wireless power transfer has attracted much attention for further research.

However, in terms of extending the distance of wireless power, CMRS, for example, has revealed technical limitations to commercialization that are yet to be solved: a rather complicated coil structure (composed of four coils for input, transmission, reception, and load); bulky-size resonant coils; high frequency (in a range of 10 MHz) required to resonate the transmitter and receiver coils, which results in low transfer efficiency; and a high Q factor of 2,000 that makes the resonant coils very sensitive to surroundings such as temperature, humidity, and human proximity.

Professor Rim proposed a meaningful solution to these problems through DCRS, an optimally designed coil structure that has two magnetic dipole coils, a primary one to induce a magnetic field and a secondary to receive electric power. Unlike the large and thick loop-shaped air coils built in CMRS, the KAIST research team used compact ferrite core rods with windings at their centers. The high frequency AC current of the primary winding generates a magnetic field, and then the linkage magnetic flux induces the voltage at the secondary winding.

Scalable and slim with a size of 3 m in length, 10 cm in width, and 20 cm in height, DCRS is significantly smaller than CMRS. The system has a low Q factor of 100, showing 20 times stronger against the environment changes, and works well at a low frequency of 100 kHz. The team conducted several experiments and achieved promising results: for instance, under the operation of 20 kHz, the maximum output power was 1,403 W at a 3-meter distance, 471 W at 4-meter, and 209 W at 5-meter. For 100 W of electric power transfer, the overall system power efficiency was 36.9% at 3 meters, 18.7% at 4 meters, and 9.2% at 5 meters.

"With DCRS," Professor Rim said, "a large LED TV as well as three 40 W-fans can be powered from a 5-meter distance."

"Our technology proved the possibility of a new remote power delivery mechanism that has never been tried at such a long distance. Although the long-range wireless power transfer is still in an early stage of commercialization and quite costly to implement, we believe that this is the right direction for electric power to be supplied in the future. Just like we see Wi-Fi zones everywhere today, we will eventually have many Wi-Power zones at such places as restaurants and streets that provide electric power wirelessly to electronic devices. We will use all the devices anywhere without tangled wires attached and anytime without worrying about charging their batteries."

Professor Rim's team completed a research project with the Korea Hydro & Nuclear Power Co., Ltd in March this year to remotely supply electric power to essential instrumentation and control equipment at a nuclear power plant in order to properly respond to an emergency like the one happened at the Fukushima Daiichi nuclear plant. They succeeded to transfer 10 W of electricity to the plant that was located 7 meters away from the power base.

The research result was published in the March 2014 issue of IEEE Transactions on Power Electronics.

More information can be found on YouTube at: http://www.youtube.com/watch?v=R6UCwqjdpo0


Story Source:

The above story is based on materials provided by The Korea Advanced Institute of Science and Technology (KAIST). Note: Materials may be edited for content and length.


Cite This Page:

The Korea Advanced Institute of Science and Technology (KAIST). "Wireless power transfer achieved at 5-meter distance." ScienceDaily. ScienceDaily, 17 April 2014. <www.sciencedaily.com/releases/2014/04/140417124509.htm>.
The Korea Advanced Institute of Science and Technology (KAIST). (2014, April 17). Wireless power transfer achieved at 5-meter distance. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2014/04/140417124509.htm
The Korea Advanced Institute of Science and Technology (KAIST). "Wireless power transfer achieved at 5-meter distance." ScienceDaily. www.sciencedaily.com/releases/2014/04/140417124509.htm (accessed August 21, 2014).

Share This




More Matter & Energy News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Flower Power! Dandelions Make Car Tires?

Flower Power! Dandelions Make Car Tires?

Reuters - Business Video Online (Aug. 20, 2014) Forget rolling on rubber, could car drivers soon be traveling on tires made from dandelions? Teams of scientists are racing to breed a type of the yellow flower whose taproot has a milky fluid with tire-grade rubber particles in it. As Joanna Partridge reports, global tire makers are investing millions in research into a new tire source. Video provided by Reuters
Powered by NewsLook.com
Awesome New Camouflage Sheet Was Inspired By Octopus Skin

Awesome New Camouflage Sheet Was Inspired By Octopus Skin

Newsy (Aug. 19, 2014) Scientists have developed a new device that mimics the way octopuses blend in with their surroundings to hide from dangerous predators. Video provided by Newsy
Powered by NewsLook.com
Researcher Testing on-Field Concussion Scanners

Researcher Testing on-Field Concussion Scanners

AP (Aug. 19, 2014) Four Texas high school football programs are trying out an experimental system designed to diagnose concussions on the field. The technology is in response to growing concern over head trauma in America's most watched sport. (Aug. 19) Video provided by AP
Powered by NewsLook.com
Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

AFP (Aug. 19, 2014) A solar cell that resembles a flower is offering a new take on green energy in Japan, where one scientist is searching for renewables that look good. Duration: 01:29 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins