Hi all. My first post. I am looking to convert our boat and may have some questions. I do know a bit about motor drives though.
Depending on the construction sound may originate in the iron plates that shape the magnetic field - these can oscillating due to induced forces (eddy currents). Transformers make this noise. Other noise sources may come from misalignment in shaft and bearings. It is entirely possible a better controller will reduce noise. Things to optimize would be modulation frequency and the shape of the excitation current - modulation can go probably up but maybe down: you are trying to get away from a resonance frequency. A different controller that can handle the current and the motor type should be a suitable drop-in replacement, but make sure it is wired correctly. If you have low-frequency noise I'd look at a different motor mount to decouple motor movement from the hull as previously suggested. You may need an appropriate coupling for motor to drive shaft too.
Willem
On 13/05/14 01:41, luke.wolbrink@gmail.com [electricboats] wrote:
> Thanks for the great insight, I read a patent application sometime ago
> that referred to "rounding" off the edges of a square wave to help
> smooth out the chop. I've also read that going with a sine-wave
> reduces efficiency as you are only at full power per phase for a short
> time vs. square waves.
But the magnetics in the motor will force a sine wave like curve anyway.
The sharp edges of the square wave end up as heat, not motor power. Some
sort of 'modified sine wave' shape is probably best.
Large traction motor drives now all attempt at least some sort of wave
shaping.
>
> Does anyone know if a goldenmotor product would be compatible with a
> higher-end controller like the Gen4? Would it be plug-and play or
> would I need to fiddle with settings to mate the two?
>
All motor / controller combos probably need some tuning. The manufacture
of my controller actually made specific recommendations as to settings
to drive my motor. (Alltrax driving a Perm 132)
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