Re: [AWES] Re: One wire electricity transfer for needs of Airborne Wind Turbines
- >>Maybe someone has expertise on the one-wire no-earth-return transmission?
Alex has indeed found for the Forum a new conceptual twist on AWE transmission. "One Wire" is a case of electromagnetic waves travelling along a conductor as external surface waves, no ground required, with the conductor acting as an EM waveguide, rather than the common circulation of electrons in a "Two Wire" loop. Thus "one wire" has much in common with beamed power, but is guided to its destination by a conductive channel rather than aimed through free-space. Therefore an AWES based on this would not need beam tracking, the tether would do. The power density and overall capacity of the thin waveguide needs to be very high (probably too high to beat optimized mechanical transmission), and you can't turn sharp curves without high losses. Efficiency can be high, even if capacity is limited. Weight and capital cost of the high-frequency power electronics are concerns. There are losses converting in and out of the transmission frequency. There may in fact be favored niches for this method, perhaps as a robust possibly jam- resistant hi bandwidth avionic signalling over an electrical power cable, but the optimization problems are daunting. Its an open topic to watch over a long term...
- If this research develops further, perhaps we may expect some "expert" to come forward with a concept that combines airborne generators and wire-free power transmission to the ground.
Date: Fri, 15 Jun 2012 00:11:34 +0000
Subject: [AWES] Re: One wire electricity transfer for needs of Airborne Wind TurbinesMy background holds http://www.allaboutcircuits.com/and one-wire with earth return,but is short on one-wire with no-earth return transmission.Maybe someone has expertise on the one-wire no-earth-return transmission?
- We also have had posted notes on:1. Physical oscillation of the tether set for transmission.2. Early patents describe "listening" to the wind via the oscillations of the tether set.3. And DaveS has noted a couple of time the realm of high-frequency signal and energy transfer through high-tension tethers.4. And we have seen in the patents the transfer of gases in the tether, chemical liquids in the tether, light in optical fibers in the tether, control signals in complex tethers,Thanks, Alex, for adding to the tether-transmission options.
- A clarification: By "High Frequency", lets be sensitive to context. In the separate case of mechanical high-frequency vibration of tethers we are considering, at most, kilohertz. In the case of "One Wire" operation, gigahertz is typical. Also, lets not conflate power with signaling applications, as the two are quite different, and power is our focus.My studied conviction is that nothing at present even comes close to the power and simplicity of mechanical transmission, and the many freakish options are just interesting side shows until real world performance in any analogous app is evident. One wire is worth testing if only to confirm mainstream engineering pessimism for the doubters. I think Alex will find that the weight* of the airborne transformer is considerable, comparable to the odd choice of a low-efficiency Savonius turbine over a high performance HAWT in terms of a handicap. Testing the "best of breed" options alongside the weak oddball contenders quickly settles any doubt. I am sure Alex will sort all this out soon; he is a very fast learner and capable experimenter.*Weight-to-power as the top predictor of AWES kite efficiency
- This was long on time, and short on information. Perhaps you could read from a script, and just publish it for those on slow links, or wanting to fit it in a filing system? What voltages and frequencies are you using? Are you heating up the line? Pushed to the max, you'd have lightning, na? It tends to be hard on the apparatus.Bob StuartOn 14-Jun-12, at 1:09 PM, Muzhichkov wrote:
- Ok, the power supply is 12V. According to characteristics of coil, the second winding produces 2000V. Frequency of current is 10000Hz. Detail of scheme you can see here http://jnaudin.free.fr/html/afep01.htm
Today I try a 0,08 one line cable 300m long. It was in coil and may be test not correct, but the lenght of it doesn't influe of lamp light.
I haven't noticed any heating.