T-Pain Is On A Boat: Re: [Electric Boats] Re: Diesel Generators for electric conversion

Monday, August 10, 2009

Re: [Electric Boats] Re: Diesel Generators for electric conversion

<Start TV infomercial voice>

Your "ideal one box system" already exist you just need to switch the
DC generator and traction motor to AC.

"Xantrex XW6048" This 6000 watt inverter/charger would have hookup
for 2 and 3 pole AC generators, plus auto switch from shore power to
48v battery pack, and then to generator as needed. Would three stage
charge the batteries automatically from solar, wind, generator and
shore power at 60 amps. All in one box with a 5 year warranty with
years of proven service. Your generators/motors chooses would be
higher quality and cheaper (AC is just more common) After buying your
direct drive Industrial sealed 220 volt 4KW AC induction motor and
controller both designed to work in very unforgiving factor setting.
Your total system lose would be very similar to the mars motors and
mechanical gearbox used now. The Xantrex is 97% efficient which is
about equal to the lose from the gear box. Plus you would have 2000
watt left over for house loads!

But wait these is more! If you want redundancy just buy two smaller
3000 watt units and run them in parallel mode. Or if you don't like
Xantrex buy your units from Outback! Same great features and a 2 year
warranty! But wait there is even more! AC Ground fault plugs or 120
and 220 are cheap and easy to add to the system!

All for the low low low price of $3500!!!! (not including traction
motor, controller, generator, solar cells, cables, small children,
or batteries. )

<End TV infomercial voice>

Umm Yeah.

On Aug 10, 2009, at 11:46 AM, Dave Hackett wrote:

> 4KW @ 48v = 100A (minues losses, etc). Looking at the torque curve
> for say
> the Perm 132 @ 48v/100A = 20Nm with a rotational speed of 2203RPM.
> So, if
> you had an ICE with the same output, how fast would your boat go
> given the
> various weather conditions? That's the simple math. IMO, as long as
> the
> electrical system matches the ICE system (or does better) you will
> have the
> same performance with the benefits of using only electric
> (hopefully) a good
> portion of the time - meaning total cost of ownership goes down.
>
> The challenge is the components. How do you get 48v from a generator
> into
> the motor without going through the batteries, and if you did go
> through the
> batteries, how do you prevent overcharging? Then, how do you get a 48v
> battery bank to run it when not using the generator and how do you
> charge
> the bank (AC, 48vDC, solar)? All the variables mean more components,
> which
> drives the cost up and makes the system vulnerable to breaking down.
>
> IMO, the ideal system is a 48v bank ~400AHr, 48v DC generator, solar
> panel
> or wind generator inputs and all the components that make it work
> integrated
> into 1 box (possibly liquid cooled). When the bank gets past 50-80%
> (depending on battery type), the generator kicks in and does the bulk
> charging. The wiring is plug and play and it all fits in a space
> equal to a
> normal ICE engine. I think the electric motor and components have
> come a
> long way towards this goal in the past few years but literally no
> work has
> been done on the generator side.
>
> DaveH
>
>

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