A pumping load should work ok over a modest speed range. The volts/cycle should remain constant and the power absorbed by the pump should follow speed cubed I think.
I haven't had time to look in depth at your article. If you are interested in lower winds then you should not need a monster alternator.
When properly matched 16 pole with single magnets should manage that with reasonable efficiency up to near 2kW perhaps even more. The more magnets and copper you through at it the higher the efficiency and the lower the stator heating, so the higher wind speed you can go to before furling.
I would have been tempted to try 20 poles of single magnets rather than double up on the magnets. You make better use of the magnets by increasing the pole number with decent spacing rather than using very long thin magnets that are too widely spaced at the outside and crowded at the centre.
You will need to choose your voltage to match the volts/cycle of the motor ( aim for 60 Hz at 240v if it is N.America).
It is unlikely that you will manage to start the motor in low winds, I just have no idea what the starting requirements will be at low volts -low frequency. You may need to let the blades have a run for it and bring the motor on line to use the inertia of the blades to start it. Once started it may run down to speeds where the pump can no longer manage the lift. You will have to do a fair bit of experimenting, which you may be able to do with a conventional alternator driven at the same volts/cycle from a variable speed source rather than build the pmg first.
Once you have sorted the pump characteristics then you have a far better idea what the alternator needs to do.
You will have to limit the motor to full load determined by the pump, beyond that you will need to bring in a dump load or furl. Choice of pump characteristic and motor size may be quite critical. I think with careful choices you can produce a perfectly satisfactory scheme but expect a lot of unforeseen things, this is probably new ground.
Flux
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