To anyone who has been thinking of using an induction motor as the generator instead of a permanent magnet generator (PMG), here is what I've learned:
• The project could be cheaper; especially if a used induction motor can be found (they are sometimes given away for free).
• The project won't require special tooling like a lathe to modify a motor, nor a mould to cast an epoxy stator.
• You will save the cost of permanent magnets, but the capacitors may cost almost as much.
• Low wind speed performance won't be good unless you use a lot of capacitors.
• You should test your system to make sure it's stable at full power.
• You should design protection against the induction generator going off-line in strong winds. Have a braking or furling system that can immediately shed the power coming to the rotor.
• Equip the bank of capacitors with a way to loose heat.
• Don't expect spectacular efficiency.
I suppose that doesn't make it sound easy.
Challenging may be a better word. Let's also bear in mind that PM generators are more commonly in DIY projects, for good reasons. Larger industrial turbines can use induction generators because large-scale projects have more regulatory constraints, and need more control and safety systems anyway, therefore the complexities that I've noted above are par for the course for Vestas and Siemens.
Below, I've attached a more detailed write-up of what I've done and what I observed.
IG_vs_PMG_Sparweb__2022-04-11_.pdf (509.43 kB - downloaded 73 times.)
