Turbine Generator Design


#21

Electrocraft (maybe pittman?) Had a pmdc cheatsheet type of design manual to help spec servomotors, which was on the internet a long time ago…
https://books.google.ca/books?id=gMAgBQAAQBAJ&pg=PR15&lpg=PR15&dq=electrocraft+dc+motor+application&source=bl&ots=6RwLIcYxuu&sig=f6LQ7Z50gVPtwvt8zaxYALRBlCQ&hl=en&sa=X&ved=0ahUKEwjNucrGsejTAhULxmMKHZ4mCG84ChDoAQhFMAI#v=onepage&q=electrocraft%20dc%20motor%20application&f=false


#22

fascinating project


#23

You could dump a lot of load into one of these but for long-term use, keep in mind you’re between the Scylla of auto-shutoff and the Charybdis of boiling dry. :wink:


#24

Thanks!

I will probably be using some kind of heavy duty steam cleaner that produces super heated steam to power it.


#25

Note that I was advocating using the kettle for a dump load to get rid of excess electricity, but if you can closed-loop it that’s good too :wink:


#26

:joy: I understand now.


#27

Are you using any CFD to assist in the design?


#28

Solidworks flow simulation. Hasn’t been very handy yet though.


#29

Interesting what they’re doing, converting car alternators into pm generators. I would’ve thought that at 10000 rpm your ideal motor would look more long and narrow like a dremel motor, rather than a short fat alternator. But if they’re rewinding and customizing the magnets for that, maybe its for real…


#30

ooh rewinding alternators sounds like even more fun than transformers


#31

I’d like to figure out a way to convert split ring into slip ring motors. Surprisingly nothing about it on the google. Probably simple but I’m so lazy.


#32

If permanent magnets are being spun, even slip rings are no longer required. Stator coils can deliver power (motor) or receive power (alternator). If DC is needed, active rectification (aka synchronous rectification) is more efficient than split rings.


#33

True enough, but these devices you describe are just stepper motors…unless you know something I don’t which I strongly suspect is the case…


#34

I was thinking more of Brushless DC motors, but now that you mention it, yes, stepper motors are also brushless.
BLDC motors are engineered for smooth continuous torque (vs the accurate discrete steps and high holding torque of a stepper). BLDCs are usually operated like a brushed motor, rotor lagging stator, for maximum torque. As always, the best choice depends on application.


#35

Piknpull is having 50% off next week, so an alternator for $12 or starter for $10…


#36

Completely unrelated (and apologies in advance if this thread gets hijacked) but every time I see the word “Turbine” in the title I can’t help but think of the “Turbo Encabulator”


#37

Yeah, ok. But in all seriousness, even if a split ring motor is simpler to drive, electronically, the arcing that occurs can play havoc on the digital circuitry. Plus bringing​ the commutation under software control opens up all kinds of possibilities.