Bench testing of Kragten axial alternator

Adriaan Kragten has tested one of his small alternator designs and published results showing it is compatible with a 1.02m diameter rotor for a low power wind turbine.

A new chapter 6, “Generator measurements”, has been added to public report KD 678. A teacher of a technical school has built the 8-pole generator of the VIRYA-1.02 and I have measured this generator on my test rig for a 12 V battery load. The torque level of the generator appeared to be lower than expected but the matching in between rotor and generator is still acceptable. The maximum electrical power for the rated wind speed of 8 m/s is about 24 W.

Email from Adriaan

About hugh

I live off-grid in NW Scotland and have spent my life playing with wind turbines. I also love small hydros. Hands on renewable energy is my thing and I like to learn and to share my experiences.
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1 Response to Bench testing of Kragten axial alternator

  1. hugh says:

    today 21st Sept, Adriaan writes as follows:
    Dear Hugh

    Today I have reviewed report KD 678 in which the VIRYA-1.02 rotor and the measurements perfomed on the 8-pole axial flux PM-generator are described. I have added a new chapter 7 in which I have analysed where the generator losses are going. It appears that the copper losses are the largest and that the iron losses in the steel stator sheet are only small. Report KD 679 gives the design calculations for a 2-bladed rotor which has a design tip speed ratio of 4.25. It therefore matches better with the measured generator curves than the 3-bladed VIRYA-1.02 rotor which has a design tip speed ratio of 3.5.

    Adriaan Kragten

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