We're back in the land of compromise and optimise! As a general rule, running a motor fast (i.e high voltage), at a low current, tends to be more efficient than running it slow (low voltage) at a high current, for the same power output. There are some limits to this, though. Permanent magnet motors have an upper rpm limit that's set by the mechanical strength of the rotor and the eddy current losses in the stator.
There are other problems with running a motor at high voltage and rpm, like increased reduction drive losses, higher noise levels and not least, electrical safety. Generally, voltages above about 60V start to get into the region where electric shock can be a concern, especially for those with low skin resistivity (or around salt water......).
The big advantage of doubling the voltage for a given power is the halving of the current and the quartering of the resistive losses, with the associated heating that goes with it, so generally it's a reasonable approach.
Jeremy
--- In electricboats@yahoogroups.com, Michael Mccomb <mccomb.michael@...> wrote:
>
> I've just glanced around a bit and wonder what people would think of upping the voltage in the Motenergy 913 in order to get extra power from it? Obviously one would have to take some extra precautions with that voltage but perhaps with the throwing of a few switches that spliced in a different controller and reconfigured the batteries one could get extra power? I was thinking of temporary reconfiguring but in that event I guess the gearing would be wrong to a fairly great degree. Perhaps a permanent reconfiguring to 96v???Â
>
>
>
No comments:
Post a Comment