Improving a project on wireless energy transfer

Mariemation

Joined Sep 26, 2016
18
Hello,

I have a school project (In the equivalent of sophomore year in college) about Wireless power transfer, and I am struggling to find an interesting experiment to do around the subject. I thought about comparing two different methods of WPT the first one being magnetic coupling and the second one magnetic coupling with resonance, and measure the effect of changing frequency and the relative positioning of the transmitter and receiver on their efficiency. But I still feel that this needs something to make it sand out, and I can't seem to find it (This project is supposed to reflect a sense of engineering and problem solving).

Can you please suggest ways I can make my experiment/project more interesting? And introduce me to new lines of thought around the subject?

PS: I am not allowed to change my project to another theme.

nsaspook

Joined Aug 27, 2009
7,724
Wireless power transfer is old technology so maybe you can show why there is a engineering history of its failures beyond a few watts of power transfer at close distances.

ArakelTheDragon

Joined Nov 18, 2016
1,350

MrAl

Joined Jun 17, 2014
7,849
Hello,

I have a school project (In the equivalent of sophomore year in college) about Wireless power transfer, and I am struggling to find an interesting experiment to do around the subject. I thought about comparing two different methods of WPT the first one being magnetic coupling and the second one magnetic coupling with resonance, and measure the effect of changing frequency and the relative positioning of the transmitter and receiver on their efficiency. But I still feel that this needs something to make it sand out, and I can't seem to find it (This project is supposed to reflect a sense of engineering and problem solving).

Can you please suggest ways I can make my experiment/project more interesting? And introduce me to new lines of thought around the subject?

PS: I am not allowed to change my project to another theme.

Hi there,

One thing you could do is look into the classical math behind the coil coupling. It is quite interesting.
One interesting consequence of driving a coil is that the magnetic field extends out to infinity (that means even past any what you might call an 'edge' to the universe) so you have to integrate from the wire out to an infinite distance. The consequence of that is sometimes that makes it simpler and sometimes more complicated. By comparing the integration out to some very very large distance but not infinite to the integration out to infinity you get a feeling that the field drops off so fast that even going all the way to infinity is not necessary for a very reasonable result.
You could also try different coil shapes, and look into the best shape for maximum coupling.
The math gets a little combersome but it's mostly just integration over distances, diameters, etc. The most accurate formula requires six integrations.

Mariemation

Joined Sep 26, 2016
18
Thank you so much for you help.

I am however curious as to why WPT over medium distances wasn't developed by researchers, i mean why didn't it become a revolutionizing technologie just like WIFI? Is there a scientific or economic obstacle?

nsaspook

Joined Aug 27, 2009
7,724
Thank you so much for you help.

I am however curious as to why WPT over medium distances wasn't developed by researchers, i mean why didn't it become a revolutionizing technologie just like WIFI? Is there a scientific or economic obstacle?
Yes, basic physics and economics. The electrical energy transfer from the generation power source to a typical home uses several WPT devices called transformers where the energy is coupled via magnetic fields. This is an efficient process because almost all energy coupling 'flux' lines are confined to the magnetic core because of its high relative permeability (thousands) to vacuum (1). As @MrAl has pointed out across space (air, vacuum) the magnetic field coupling between any possible combination of coils drops off fast as distance increases. This decreases the coupling efficiency by a large factor resulting in large losses in power transmission across space. Large scale high energy Witricity type wireless energy transfers would waste huge amounts on energy, increase our carbon footprint and increase the chances for human induced global warming problems. It's very non-green when millions are wasting (and paying for) an extra 20% to 40% of energy for a wireless option.

BR-549

Joined Sep 22, 2013
4,938
The problem is lack of permeability. Find a non conductive, high permeable gas, or liquid, or small granular solid.....that you can submerged the chargeable device in.

You might need to invent or recipe the permeable media.

Do something different. Use physics to solve the problem. You need a high permeability circuit path.