T-Pain Is On A Boat: Re: [Electric Boats] Hardy VFD

Monday, August 3, 2009

Re: [Electric Boats] Hardy VFD

I'd pay $4000 for one right now. The only caveat would be you could
not use lead-acid with it. The Peukerts effect would cripple your amp
hour rating. The amp draw per cell would be astounding. But again I
would buy one right away! Then I could have one simple high amp hour
LiFePo4 48V bank instead of six lower amp hour 48v banks that I need
right now. Easier to charge easier to wire, less connections to fail.
Would all around make my life less complicated!

On Aug 3, 2009, at 11:10 AM, Mark Stafford wrote:

> Chris S,
> You have a great idea and product potential: 48volt DC in, variable
> three phase 460 AC voltage out. 250amp DC continuous, 750amp max
> draw. This "Hardy VFD" (your email name) would match many batteries,
> many AC motors, many gensets, under 70' sailboats and under 20'
> runabout powerboats. Most importantly from a sales volume
> perspective, this imaginary VFD could crack the huge recreational
> fishing market (primary & trolling propulsion from the same motor/
> prop with genset support for distance).
>
> Any manufacturers interested?
>
> Mark Stafford
>
> --- In electricboats@yahoogroups.com, "hardy71uk" <p0054107@...>
> wrote:
> >
> > I predict that AC motors WILL become universal in cars and
> boats .AC controllers are now readilly available from industry .What
> we really need to make it easy is a controller than takes a low
> voltage DC in direct from your batteries and puts out a variable
> three phase Ac Line voltage to power an inexpensive standard rugged
> induction motor.Thats to say the missing link is a variable
> frequency low to high voltage inverter (VFD)
> >
> > Chris S
> > --- In electricboats@yahoogroups.com, Matthew Geier <matthew@>
> wrote:
> > >
> > > Arby Bernt wrote:
> > > > Locomotives use AC drive systems due to the complexity of
> coupling the engine to the drive wheels. Before AC coupling was
> available, the slip between the drive wheels and the track was
> nearly impossible to control, as the friction of a non-slipping
> drive wheel can transmit more force than than a slipping wheel. By
> comparing the rotation of a drive wheel to a static wheel, the speed
> difference can be maintained at under 0.5%.
> > >
> > > Most of the world's railway 'diesel electrics' are DC motored. AC
> > > motors have only come in over the last 10 years and then only at
> the big
> > > end. Railways have been reluctant to switch from series DC motors.
> > > 'Switchers' would still mostly be series connected DC motors, AC
> > > traction motors are still working their way down the feeding
> chain.
> > >
> > > Even then they are not all induction motors - the French were
> big on
> > > Synchronous motors with slip rings for a while - I presume so
> they could
> > > control the current in the rotor coils.
> > >
> > > EMD apparently built their first AC motored locomotive in 1987,
> but the
> > > first big order wasn't till '93. The same source says at 2005 ,
> 50% of
> > > the market was still DC motored, EMD's split was 60% AC, 40%DC.
> > >
> > > Sounds sort of like us electric boaters - those 'new fangled AC
> motors'
> > > are still not quite trusted yet :-)
> > >
> >
>
>
>

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