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Proposed electric sailboat system

wargames

That isn't bad at all, problem is by boat is 28,000 pounds and 43 feet long, i would require their 30kw motor kit.

Their 30kw is $14.5K
 
Two 48V batteries connected in series. Two 48V MPPT, each with an array of PV panels. One or two inverters running off 48V.
Just need equipment that is isolated, doesn't care of negative or positive of battery is grounded. Which is probably many. my SMA allow that.
Amps? That's just how many strings of batteries in parallel.
boat is big but not big enough to support that, its a monohull not a cat.
 
This really looks like diesel powered ”sail”boat with electric drivetrain :unsure:
You could say that about any sailboat with a diesel motor. (i.e., the vast majority of them) But you can shut of the motor and continue on wind power. That makes it a sailboat.

IMHO we will be hearing a lot more about diesel-electric auxiliary propulsion systems for sailing yachts.
 
boat is big but not big enough to support that, its a monohull not a cat.

(edit) Scratch my previous reply, I misread GP.

OK, I see why you went for the induction motor now, it might not be very efficient but it gives you the power you want at the voltage you want. That said, maybe don't give up on a higher voltage system so easily. I had the same idea as @Hedges when I was casting about for ways to feed my 48 volt batteries and only seeing controllers rated for ten times the amps my panels deliver. I eventually did find a suitable controller (Victron 100/20-48) so I put that idea aside. But I couldn't think of any reason why it wouldn't work. Nor did I find any report of somebody doing it, so there's that. But then, there it was again, apparently from the mouth of someone more clueful than me.

Your complaint is about the number of panels, not the series controllers is that right? How about these panels, 72 volts, you only need two.
 
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Right. Your concept looks good to me now that I have increased my own level of understanding (still a long way to go though...) You're going to have lots of capability, lots of range, and it's a conservative system but not archaic, far from it. You'll likely end up being able to cruise up nonchalantly to some stranded pure electric boat and offer them a tow.

One day it's going to make sense to swap out the induction motor for a more efficient BLDC, but that day is not quite here yet according to my recent impromptu web survey.

Another way to get more than 48 volts to your motor from a 48 volt system is, let the motor controller do the boost. I can't say there are no BLDC controllers out there that can already boost - there's not much chatter about that, specs are terse, design documentation is essentially nonexistent, and I'm not at the point where I can read the schematics to that extent - but this is certain to become a thing sooner or later. After all, a BLDC controller is essentially a fancy inverter. There must be lots of folks who want their 48 volt DC system to drive a 72 or 96 volt three phase motor, including you and me.
 
One thing i will need to do when putting in this motor is replace the prop https://vicprop.com/displacement_size_new.php

Data Input​

Waterline length in feet:36 feet
Beam at the waterline in feet:13 feet
Hull draft in feet (excluding keel):6.3 feet
Vessel weight in pounds:28000 lbs
Engine Horsepower:35 HP
Number of engines:1
Total Engine Horsepower:35 HP
Engine R.P.M. (max):1600 RPM
Gear Ratio:1.7:1
Shaft R.P.M. (max):941 RPM
Number of shaft bearings (per shaft):1
Desired speed in Knots:8 knots

Horsepower Calculations​

This will calculate the maximum horsepower and torque available at the prop(s).
Total available horsepower at the engine(s):35 HP
Total available torque ft/lbs at the engine(s):115 ft/lbs
Horsepower loss of 3% per gearbox:- 1.1 HP
Horsepower loss of 1.5% per shaft bearing:- 0.5 HP
Total horsepower available at the propeller(s):33.4 HP
Total torque ft/lbs available at the propeller(s):187 ft/lbs

Speed & Power Calculations​

Basic displacement speed and horsepower required
Displacement hull speed (1.34 X sqrt of waterline length):8.04 Knots
Minimum horsepower required at propeller(s) for Hull speed:61.1 HP
Calculations based on desired speed and available HP
HP required at propeller(s) for desired 8 knots speed:55 HP
Estimated maximum speed with existing 35 horsepower:
This is the speed we will use for the propeller size.
6.76 Knots
At this point it is important to note that all of the calculations above are based on full RPM and HP. Most engines are rated to run at a percentage of thier full RPM. This is what will determine your maximum cruising speed. The propeller sizing calculations below are based on 90% of full RPM. This gives the engine some reserve power to allow for variable loading in the vessel.

Propeller Size​

Number of blades​
Diameter (inches)​
Pitch (inches)​
2 Blade​
22.2​
X​
14.0​
3 Blade​
21.1​
X​
13.9​
4 Blade​
19.8​
X​
13.6​
 
What voltage is your genset outputting ?
Mines 240v. But i really want everything to be a 110v system. As such I am considering step-down transformer. This will also allow me to plug into 240v shore power if there is no 110v hookup.

image.png

Considering this as the step down transformer I am considering (as it would give me a bunch outlets if i ever want to hook up directly for some specific reason)
 
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http://www.centralmainediesel.com/diesel-generators.asp these are the generators i am considering, the 5700watt one to be accurate.

With a victron inverter you can go in and swap some wires around and accept 240v from shore.
Nice price on the generators, ae they going to hold up though in a marine environment?

I dont think the Victron Quadro will accept either 110v or 220v AC input:
AC inputs (2x) Input voltage range: 90-140 VAC Input frequency: 45 – 65 Hz Power factor: 1
Reads to me 2x 110v AC input, unless it can take split phase 220v, but shore power wont be that from countries that supply it will be single phase (i believe)
Victron make a Autotransformer to do this (same really as what i am suggestion)

Thats why I think I am going to put a transformer before the Invertor/Chargers to take care of whatever i get and just convert it to 110v :D
 
The generator is going be stuck in the laserette and probably going to build a quiet box. so weather enough proof
 
Hmm.

My personal preference is to run a pair of inverters for bigger loads.
I'd definitely work at doubling up the system - dual inverters, controllers, etc.
You'd have redundancy and could spare from one to the other if needed.
 
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