I recently moved to on an off-grid farm, where they have this turbine 'Stream Engine Easy Tune Generator'. It's been laying here around for a while, but never got installed.
I know a bit of electricity and have some experience with solarenergy, so I have been studying the manual and as much information as possible about micro hydro technology.
I'm trying to understand this machine, install it and have some extra power during wintertimes. (The turbine can be active constantly during winter, in summer only during weekends)
There is already a 24V battery system wth solar panels, a windmill and an inverter.
I came to the point where I want to know how to transmit the power from the turbine to the batteryshed, which is quite a distance from the turbine (60 meters).
If I understood correctly, it's possible to configure the voltage-current ratio by wiring coils in series or parallel in combination with star/delta wiring.
The manual states that when the machine is wired "series-delta", Nominal voltage is 24 volts or 48 volts, and generates a maximum current of 17A. (This 17Amps max. would be ideal for the long cable in combination with a MPPT controller i guess...)
In the "Nozzle Flow Chart Flow" in the manual I can see the turbine can go as fast as 4140RPM.
This would be a maximum of 3105Watts - it states you get around 750Watts per 1000RPM.
Am I thinking correctly by assuming only the voltage increases and current stays 'clipped' at 17Amps when the turbine speeds up to max RPM? (At presumably 182V)?
And I have also this question (assuming transmitting AC over long distances is more efficient than DC):
In the junction box of the turbine, the 3-phase AC-output is wired to a rectifier. So hooking up directly up to a battery is possible. But i'm not able to do that because of the long distance.
Can i relocate this rectifier and place it near the inputs of the charge controller? So i can transmit unrectified (AC) output over the cables?
There is no efficiency difference using ac or DC over a distance. Its only about the amount of resistance in the wire and the amount flowing through it or amps, possibly overheating the wire or causing to much voltage drop. You need high voltages to over come this ac or dc. They just use ac in power lines because transformers can step the voltage down to a useable amount. DC does not have that luxury, however recently they have come out with charge controllers that can take up to 600 volts dc and step it down to charge your batteries