Report KD 747 has been reviewed. The magnets size 40 * 10 * 4 mm as used for the generator frame size 112 have been replaced by magnets size 40 * 10 * 5 mm because the original magnets were no longer at stock at Enes Magnets. A new chapter 7 has been added to report KD 747. The title of the chapter is: "Ideas about a 42-pole generator made from a 7.5 kW, 6-pole motor frame size 160". The armature of this generator makes use of 84 magnets size 40 * 10 * 10 mm. The magnet costs are about € 166 which is very low for a PM-generator of this size. The original winding and the original motor shaft can be used. This shaft has a diameter of 42 mm and a length of 110 mm. It might be possible to use this generator for the VIRYA-5B3 which is described in report KD 710.
i would be concerned about anything that's going to go over 200hz in real life. adequate margin has to be ensured so that you can stop the turbine.
I still have my 30 pole machine using 50x6.25x3mm magnets (actually 2" by 1/4" by 1/8). originally it was a 6 pole 1/3rd hp induction motor,
it produces 120vac 4 amps at 400hz and 1750 rpm pretty efficiently, but you can short circuit the windings, and only produce 9 amps at that frequency, only drawing maybe 100-120 watts of shaft power.
i have a bigger lathe i could test it in.. i wonder if capacitors in series with the generator would enable short circuiting the motor to actually stop a turbine, or if it needs a critical resistance in series to match the inductance.