Air-Gap & Wireless Power Transmission Efficiency

[Fatima Hasan]

Summary:: How does the air-gap affect the efficiency ?

For a wireless power transmission system, to what extend does the efficiency and coupling parameters get affected by the distance between the coils?
What can be done to increase the power transmission or efficiency regardless of the value of air gap?

[Thread moved from the technical forums, so no Homework Template is shown]

 

[berkeman]

What are your thoughts? And is this question also for schoolwork?

 

[Fatima Hasan]

What are your thoughts? And is this question also for schoolwork?

It's for a project as well.
I found that the length of the gap between the coils of 20m is suitable, but I'm looking for an optimum gap for the coils. So, I am asking if the length is reduced to 10m, for example, would the difference on the efficiency, the losses, .. be too much? Is it worth it ?

 

[hutchphd]

I found that the length of the gap between the coils of 20m is suitable

By what specific criteria (numbers please) was this assessment reached ?

You may then apply the same criteria to make a new assessment of a different geometry. Numbers (and an assessment of their accuracy) are required.

 

[berkeman]

I found that the length of the gap between the coils of 20m is suitable, but I'm looking for an optimum gap for the coils. So, I am asking if the length is reduced to 10m, for example, would the difference on the efficiency, the losses, .. be too much?

10-20 meter gap? That seems like an excessive gap to try to trasfer any significant amount of power. Please show your calculations that show that 20m is "suitable".

 

[alan123hk]

I found that the length of the gap between the coils of 20m is suitable, but I'm looking for an optimum gap for the coils. So, I am asking if the length is reduced to 10m, for example, would the difference on the efficiency, the losses, .. be too much? Is it worth it ?

I think it is almost impossible to realize the wireless charging of the vehicle at a distance of 20m between the TX coil and the RX coil. In most cases (from private cars to large trucks), I believe that the distance between the bottom of the vehicle and the ground may not exceed 50 cm.

Generally speaking, the smaller the gap, we can design a more efficient wireless charging system. If you want to find the best gap distance within the limits of other parameters, I would be curious about this design method and requirement. Hope you can provide more information for reference.

 

[Fatima Hasan]

I think it is almost impossible to realize the wireless charging of the vehicle at a distance of 20m between the TX coil and the RX coil. In most cases (from private cars to large trucks), I believe that the distance between the bottom of the vehicle and the ground may not exceed 50 cm.

Generally speaking, the smaller the gap, we can design a more efficient wireless charging system. If you want to find the best gap distance within the limits of other parameters, I would be curious about this design method and requirement. Hope you can provide more information for reference.

I was meant to write "cm" not "m" but I can't edit now.

 

[berkeman]

I was meant to write "cm" not "m" but I can't edit now.

Ah, that's much better. So with a gap of 10-20cm, what is the radius of the two coils? How much power do you want to transfer? What frequency are you planning on using and why?