Power Transmission

Discussion in 'General Electronics Chat' started by hydro, Oct 8, 2007.

  1. hydro

    Thread Starter New Member

    Oct 8, 2007
    I am installing a small (2 to 3kW) hydro electric turbine system at my home.

    The alternator produces a nominal 60 VAC per leg with two three-phase WYE winding sets, or 6 hot leads of 60 V / 5 amps / 300 watts per "leg." It's wound WYE, so there are 6 wires total.

    I want to step this up to 480 / 600 VAC in order to be able to afford the 4,800' of wire needed to cover an 800' run between the turbine site and the loads, then step it back down. The turbine maker suggested using 6 single phase 1/10 - 10/1 transformers per end since 3 phase xfmrs generally don't come is such small sizes. Basically, he said to wire a transformer between leads 1 and 2, another between 2 and 3 and another between 3 and 1, and then doing the same to step things down on the far end.

    Anyone care to comment on this idea?
  2. thingmaker3

    Retired Moderator

    May 16, 2005
    It will work, but I'd go with 8:1 transformers instead of 10:1. Your conductors will be rated for 600V maximum, and the 10:1 transformers would give no safety margin. You might also consider 8:1 transformers for step-up and 4:1 or 2:1 for step-down, depending on your specific application.

    Micro-hydro is awesome, ain't it?:D
  3. hydro

    Thread Starter New Member

    Oct 8, 2007
    Thanks! I get it re: using different windings for step down, makes sense. I thought it would work but I'm an RF / satellite guy and appreciate the back up when working with real power.

    Micro hydro - so far - has been a lot of fun. I've already got 7kW of inverter using 2kW of solar on site - it basically runs about 90% the house - but I bought the place for the water potential of the two creeks next to the home. I have two other turbines, both smaller, that are permanent magnet field jobs and deliver 250W of DC through built-in bridges with the head and flow available for them - a little "stream engine" and a LH1000, both by Paul Cunningham. This larger one is a Nautilus by Ron Macleod that'll use the 5CFS outflow of an existing flow-thru pond with 9 feet of head. By the time all's done, I'll have to keep the Christmas lights on 24/7/365 just to use the watts! :)
  4. recca02

    Senior Member

    Apr 2, 2007
    using separate transformers also has its own advantages (one disadvantage is it is expensive). in case of failure of any single phase the rest of the phases can still work.