rotoverter for power generation

[steve_chow]

Hi

I am using the same setup as you mention but having problem running alternator as load.
using  capacitor bank for tuning, with no load it takes about 17 MF 370 Volts for run cap and using 270 MF 370 volts for start cap.
Power input from 12 volt battery is about 40 watts.

are you saying we can not use alternator as load in RV mode ?
I though As per RV 7.5 hp convert to 1.8 hp which should   give at least 1k watts of power from alternator ..?

regards
Chow

[wattsup]

@steve_chow

We can never say for sure, like in your case you are using a magnet rotor and not the standard rotating coil like I have tried. Also my trials were with a 5 hp drive motor, you are using a 7.5hp.

For my standard alternator, I had even taken out and modified the regulator which gave me direct access to supply a variable voltage to the rotor coil, but even then the alternator just did not want to make juice unless you had real horsepower behind it. Alternators are serious shit and I would not use them again for anything but to use only the stator and work towards making a non-turning alternator.
                                             
Most RV set-ups use two identical motors, one as a drive, the other as a generator and the reason this works is because the generator is not really a generator but a motor that is being used as an inefficient generator, hence it will produce just enough juice and create not as much drag as an alternator.

Ever wonder why manufacturers don't use alternators in their gas run portable home generators. I would suspect that a generator coming from a home type gas generator would be the most suitable for RV simply because they were designed to be efficient.

It's a learning process and I surely do not have all the answers.

[steve_chow]

@wattsup


I did test with RV setup..
PM - Baldor- 7.5 hp, 3 phase
Alternator -7.5 hp , 3 phase

Test data-

PM run with alternator without cap in alternator side.

input voltage =120 Volts
input current = 0.2 amps
run cap-=17.5 mic 370 volts
RPM~1765

PM run with alternator and cap 22.5 mic in alternator side
PM:
input voltage -120 volts
input current~2.2 amps
RPM ~same
Alternator:
Alternator output with 22.5 mic capacitor
output voltage = 208 volts
output current =13.6 amps
RPM~same

I am thinking to charge battery from alternator output but I need transformer 10:1 ratio
then I can get 20 volts AC with high amps to charge 12 volts battery bank.
But problem is I can not find the transformer which can stepdown 200 volts to 20 volts AC

Do you think I will get the same output from Alternator if I use load as battery bank....
If I do then I can get almost 2K watts of extra power !!!!! is it possible ?

please advice..

regards

Chow

[Nali2001]

Hi Chow,
So you say you have an input of 264watt and are getting 2828.8watt from the alternator?
May I ask you how you measured the alternator output. I mean are the volts and amps in phase?
Lots of people measured a big circulating amperage in the Rv alternator. Problem only is that it is totally out of phase with the voltage.


Kind regards,
Steven

[steve_chow]

Hi Steven

Alternator wired in Y , I used 142.5 mic cap between wire 1 and 3.
Current measurement from 1 and 3 about ~13.6 amps
Voltage measurement between wire 3 and 2 about 206 volts...
I was using 16 gage wire to connect Capacitor with alternator and 16 gage  wire was almost melting then I had  to change
to 12 gage , now running cool ...
Please advice...

regards

Chow