Re: Afordable BLDC drives (was Re: nubie questions)

[Colin Dedman <cjd121@rsphy1.anu.edu.au>]

PETER VANDERWAL wrote:
> >
> > One of the advantages of playing with very small EV's (like I do) is
> > that high-performance AC drives, or BDC motors, become vaguely
> > affordable ... for the smaller motors that I play
> > with (up to 3HP) the better BDC motors will clean blow the pants off a
> > poor old brush motor. You want some specs to back that up? Just ask.
> >
> 
> Ok dish, specs, price, availability etc.  I want a 1 to 1.5 hp BLDC drive
> real bad. :-)

Hi Peter,

I said "vaguely affordable". Anyway, here are some BDC motors that will
certainly "blow the pants off" a brushed motor of the same weight and
RPM.

(a) Unique Mobility DR086S 16-pole BDC 
    4.3 HP cont. @ 5000RPM, 3.9kg, 94% eff
    US$3695 last time I looked, and that's without a controller!
    OK, that's not even vaguely affordable, but makes the point
    that brush motors can't hope to beat the best BDC motors.

(b) Kollmorgen RBE-03010-C 12-pole BDC
    700W cont. @ 2900RPM, 3.4 kg, about 90% eff
    MFM make similar motors, which I believe Chris Pollard used
    on an e-bike. Price for frameless motor is something like
    US$1000, and build your own controller.

(c) Litton BN42-43AF, 8-pole BDC
    824W cont. @ 3849RPM, 4.0kg, about 90% eff
    Guess about US$1000 without controller.

(d) Build your own brushless, ironless NeFeB disk motor.
    Expect similar power/weight to (b) & (c), but peak eff=95%,
    and >90% eff over an 8:1 range of power, which is impossible
    with an iron motor, much less with a brushed motor.  


Best regards, Colin