Design Help

[chainsaw]

 Help! I am in the process of building a dual axis alternator for use in hydro. It's 300 ft from hydro site(120gpm 25ft head) to 24v battery bank. What would be the best winding to use in order to utilize smallest wire size for transmission. Should hydo have its own charge contoller or could I use existing mx60 and input the hyro with existing 48v solar? Or should I use direct(hydro) connection to the battery and use diversion feature on the mx60 to prevent overcharge?

[Flux]

From the point of view of line loss there is a strong case for generating at 48v and using the mx60 to charge the 24v battery. I can't say that I would be happy to use the same mx60 with solar panels and hydro in parallel, although it might work it does raise a few issues that I would not be too happy about.

300 ft is not that terribly far for 24v but cable loss would have to be watched. With wind you can tolerate some cable drop to improve matching but with hydro you should be able to design for an excellent match.

Personally I think you could buy one hell of a lot of cable for the price of another mx60, just a matter of choice.

If you fit the hydro generator with a voltage clamp you may well be safe to run in parallel with the solar. I don't know enough about the mx60 to advise you.

Flux

[chainsaw]

If I wind for 48 volt 3 phase output, should I rectify at the battery or at the hydro unit or does it make any difference with respect to wire size for the 300 ft. I agree about not using the mx60 with solar. How do you determine loss by not using mppt controller?

[Nando]

This is a case of a miss use of a low voltage generator

120. gpm = 7.56 l/s
     
25. feet = 7.6 meter
    
    

watts = 7.56 * 7.6 * 6 ( g* efficiency)= 344 watts

Generate around 120 volts AC and use 3 transformers to bring the voltage down as needed.

Losses can be reduced to about 5 - 7 % from generator to diodes output.

Use a Turgo turbine attached directly to a generator like an ECM motor as a generator ( 1 HP ).

Water velocity = sqroot( 2 * 7.6 * 9.81) = 12,2 meter/sec

Turbine peripheral speed = 6.1 m/s

For a 100 mm turbine

6.1/(pi* diameter) 6.1/(3.14 * 0.1) = 19.4 RPS

RPM = 19.4 * 60 = 1160

EVEN A 110 MM turbine will do !!

Easy to start and maintain, also logical for distance transmission with low losses.

The cost of the magnets may be higher than the cost of the ECM in Ebay, and you have the generator well built and the Turgo from www.h-hydro.com .

If you need further assistance email direct to me. I have done many hydros.

Nando