High power, short distance electrical transmission problem

[taylaron]

I’m in a situation where I need to power 150 machines, each one consuming 2kW of power. The trick is that it rolls on a metal track at high velocities. I am concerned about transmission loss and type of contact.

I could power the machine with a physical contact via carbon bushings to a track which has conductors mounted on it. This is the most simple and traditional way to solve this problem. The downside is that the bushings wear out and the polished surface is filthy. My solution needs to be low maintenance. Bushings may be the best option to power my machine; but consider the following idea.

(I'm not an electrical engineer yet, so I don't have a solid education on the following areas.)

I'm aware that by using resonate inductive coupling, one can set up a primary (source) and secondary (target) coil of wire; here the primary has high frequency electricity running through it, and the other resonates at that frequency, inducing current in the secondary coil and viola, wireless electricity. This is a basic explanation. The downside for my application is that I would have to place countless coils of wire on the surface of the track. I’m not sure this would work because there would be fluctuations in the field strength as the machine rolls along the track. The necessary wire would also be expensive. My solution also needs to be relatively affordable. Pretty sure this is not practical for my application.

Another method which I don't fully understand is one that uses RF waves to transmit power. To my understanding, an antenna emits RF waves and some of that energy is inherently absorbed by the environment. Unfortunately, power is lost even when no electronics are on (next to ohmic heating.) Field strength diminishes with the square root of the distance from the source. Correct? The upside here is that the range on my application is near zero. Current applications are limited to devices like cell phones… But I need 2kW of power... big problem. Is using RF waves possible without frying everything that lives?
*******************
Another requirement is that the field emitted needs to be short range. I cannot have foreign electronics nearby sucking energy from my power system. The track will be elevated to about 20ft off the ground, about the height of a two story house. This application would be placed in well populated areas.
What is my best option?

Thank you for your time, I appreciate your help.
-Taylaron

 

[vk6kro]

Your application is similar to the case of electric trains.

They find the best approach is to use a mechanical contact to a third rail or an overhead wire but at a high voltage to keep the current down.

RF and inductive power transfer work best when very small coupling distances are needed.

 

[oswaler]

I understand your concerns about high power, short distance electrical transmission for your 150 machines. Based on the information provided, it seems that the traditional method of using carbon bushings may not be the most feasible option due to maintenance and cost concerns. Wireless electricity using resonate inductive coupling and RF waves also have limitations and may not be practical for your application.

One potential solution that may work for your situation is to use power strips or busbars instead of individual carbon bushings. These strips or busbars can be mounted along the track and provide a continuous power supply for the machines. This would eliminate the need for individual bushings and reduce maintenance and wear-and-tear issues.

Additionally, you could consider using superconducting materials for the track and the machines. Superconductors have very low resistance, which would reduce transmission loss and increase efficiency. However, this may be a more expensive option and may require specialized equipment for installation and maintenance.

Another alternative to consider is using magnetic resonance coupling. This method uses magnetic fields to transfer energy between two objects. One object, such as the track, would have a primary coil, while the machines would have a secondary coil. This would allow for wireless power transmission without the need for individual coils on the track. However, there may still be concerns about interference from other electronics in the area.

Ultimately, the best option for your situation will depend on a variety of factors, including cost, maintenance, interference, and efficiency. It may be helpful to consult with an electrical engineer or conduct further research to determine the most suitable solution for your specific needs.

 

[oswaler]

I would suggest considering a combination of both inductive coupling and RF waves for your high power, short distance electrical transmission problem. Here are some potential solutions to consider:

1. Use a hybrid system: You could combine the traditional method of physical contact through carbon bushings with inductive coupling. This would allow for a more reliable and low maintenance power source, while also reducing the wear and tear on the bushings. The inductive coupling could be used to supplement the power and reduce the reliance on the bushings.

2. Utilize superconducting materials: Superconducting materials have the ability to transmit electricity with little to no resistance, which would greatly reduce transmission loss. This could be applied to the track or the machines themselves, allowing for a more efficient power transfer.

3. Implement a track-side power source: Instead of relying on wireless transmission, you could consider installing a power source along the track itself. This would eliminate the need for any wireless transmission and reduce the potential for interference from foreign electronics.

4. Explore alternative methods of wireless power transmission: While RF waves may not be practical for your specific application, there are other methods of wireless power transmission that could be more suitable. For example, laser-based systems have been proposed for high-power, short-distance transmission. However, these methods may also have their own limitations and challenges.

Ultimately, the best option for your situation will depend on a variety of factors, including cost, efficiency, and potential interference. I would recommend consulting with an electrical engineer or conducting further research to determine the most feasible and effective solution for your specific needs.