I recently spotted a VAWT wind turbine development project at a local university, where they have designed a 5KW Alternator at only 115 rpm! The voltage output is 250VDC, after rectification. The alternator seems to be superbly designed and weights around 175 lbs.
My system voltage is 48V but I may change that to match up with this generator or step it down or rewind it for lower voltage. I don't see that a major issue.
Since my motive was to come up with a ultra-low turning HAWT turbine with very little noise, I am investigating if this alternator can solve my quest.
I would like to know if a 3-blade conventional 5KW turbine rotor from another commercial wind turbine manufacturer would be of any good match for this alternator, since it is such a low speed?
I notice that most of the other 5KW Battery charging models on the Market have rotor diameters in the region of 5-6.5 meters (16-21 footers) and are rated at least 250 rpm or more, in most case around 350 rpm!
I can go for a larger rotor diameter, if that helps, meaning 22,or 23 footer. The alternator is said to be good up to 220 rpm where it would produce around 9 KW or more.
If it can be done without problems, what about the efficiency of the resulting turbine?
Matching Generator to a rotor is the key issue here, but still my weakest point. Any advice on this issue would be appreciated.
Thanks for reading,
Usman.
