Roto Verter

[ashtweth]

Ash,

I have a plan to build resonance motor (worked as an alternator) on RV mode, but in 1 phase AC motor. Do you think it will work ?
From the RV documentation, I saw (from panacea replication) the motor which worked as alternator wired in 1 phase setup. So, I thought if I have 2 (identical) motor, I will get the same way as if I work in 3 PH motor.

What do you think ?

Rev.

Hi Rev, yes you can create resonance from the induction 1 PH motor it will not be as much VARS to convert into usable watts as the 3PH but it is still possible, also the 1PH does not have as much of an impedance so i imagine you will need bigger caps for it .

[revizal]

New RV setup on 2 HP 3 PH motor

Hi All,

I try RV mode on a 2 HP 3 PH AC Induction Motor today. I got a good result (less than 100 mA drawing current) on idle. But (may be someone can explain/tell me) why there is a humming sound around the cap when the start cap + running caps being connected to motor lead ? And this sound gone since I disconnect/switch off the start cap without any change in RPM.

Here is my video link:

YouTube - RV-2 HP 3 PH AC induction Motor

Rev.

[ashtweth]

Hi Mart, Rev and all.

Great Vid Rev , imagine if your induction motor had a permanent magnet rotor... There would be no slip loss and it would probably be around 100% efficient.
They have made an induction motor here with a PM rotor
(YouTube - Ingersoll Rand Hybrid Permanent Motor (HPM))

This was the RV concept years ago, but we never could get one machined plus you have to be careful of the magnetic DRAG if you make one (read compilations). With an AC motor control or hacked frequency driven inverter and a PM rotor, you would have a superior induction motor.

Now i think the noise is because of the resonance and the semi resonant state, you will notice this when you hook your alternator up if you do, that the "hum" is where it gets in/out of the resonance and sweet spot.

Don't forget you will probably only get 1/4 (as your driving it at one quarter of the voltage rating) at the shaft, with a 2HP that will not be much but still will have a power factor close to 1. (maybe up to 94% efficient).

With that at idle and a half a HP load you could run that from a solar panel
If you re grease your bearings with low friction lube it will be more efficient also don't forget to take off rear cooling fan if you have not already .

Wish there was easy inverter hacks to do, i woild love to see tha frquency driven,

@mart, i just need to check with Andrew (Panacea techie) what rating to get, sorry i missed your Q yesterday man.

Ash

[ashtweth]

Hi Rev, i just found soe good advice on the EVGRAY yahoo group for first timers from Dan.

-------------------------

This is where I bought my caps. I had those shipped to Europe.
http://www.surpluscenter.com/sort.as...09010712164650
<http://www.surpluscenter.com/sort.as...tname=electric
&keyword=EMRC> &catname=electric&keyword=EMRC
I bought 3-4 each of the following values: 50, 30, 20, 10, 5, 2, 1, .5 µF.
You can build a simple cap-box with DPDT switches.
Make sure you add a 1M bleed resistor across each cap, so they discharge
automatically (**** happens if you would touch those... the big onces can be
lethal when charged - take care!!)

If you have only electrolytic caps, do not use those for an extended period,
but just for a small test (some minutes).
Microwave caps are good as well (leave the bleed resistor in place),
although the cap value is fairly low - you would need to many...

The motors you listed are 400 (delta) / 690 (wye) volt, 4 pole (1400rpm),
50Hz. Wire your first motor for 690V (so wye), and feed it with approx 1/4V
of that. For your first test, you can even hook it up directly to the grid
(230-240V). So grid to phase A & B, and run caps to phase B & C. You will
need more caps to get the thing starting (also across B & C). Once your
prime-mover is running, remove the 'start caps'.

As Kone said, you'll need about 100µF run caps. But I guess it will be less
as you run on higher voltages, so could be even only 30µF. This just need to
be tested on your particular motor. Add or remove caps until you get the
lowest draw (ideally less than 30W). Clean bearings and remove fan (fan
alone takes 25W).

Once you have your first motor running (as prime mover) in RV mode, start
putting your 2nd motor (called Alt or alternator). Connect the shafts
face-to-face. Wire that motor for 400V, so in delta (reason is no to
generate too high voltages - stay safe). Gradually add run caps on the Alt
across 2 of the 3 phases, until it starts to 'generate'. You will notice
that - different sound - current flowing (put amp or clamp meter & measure
voltage). Add caps until you get high circulating current running. Whilst
you do that you will need to adjust the run caps on the primary mover. Do
this carefully and slowly. Learn as you go and understand the thing - don't
go too fast as these are dangerous toys. (Hector would say : zziippppp
ripppppp);

Once you master this, go to the next level and tune further the Alt, try
extracting power - read the compilations for this. Its all in there.

PS: I did once a test with a 2800rpm prime-mover, connected to a 1400rpm Alt 230V delta. This means that the Alt was effectively running at 2800rpm, so I got double frequency (close to 100Hz), but also double voltage. So I got
close to 470V. At the diode plug I got 1320 VDC !!

-Dan

[revizal]

Thank you very much Ash. It was a great info for my project.

Rev.

[revizal]

Hi Rev, i just found soe good advice on the EVGRAY yahoo group for first timers from Dan.

-------------------------


Once you have your first motor running (as prime mover) in RV mode, start
putting your 2nd motor (called Alt or alternator). Connect the shafts
face-to-face. Wire that motor for 400V, so in delta (reason is no to
generate too high voltages - stay safe). Gradually add run caps on the Alt
across 2 of the 3 phases, until it starts to 'generate'. You will notice
that - different sound - current flowing (put amp or clamp meter & measure
voltage). Add caps until you get high circulating current running. Whilst
you do that you will need to adjust the run caps on the primary mover. Do
this carefully and slowly. Learn as you go and understand the thing - don't
go too fast as these are dangerous toys. (Hector would say : zziippppp
ripppppp);


-Dan

Hi Ash,

I almost complete my project on RV motor. Just ordered a motors mounting which could able to adjust 2nd motor position on it. I've tried adapt to run the other motor (my last small water pump motor) with a belt. It seems enough to hold 2 motors.

How about if I connect next motor with a belting. Could I still get a resonant alternator on it ?
Or it must run face-to-face setup only ?

Rev.

[ashtweth]

Hi Rev, sorry guys just got in. Mart i have the value of the Pot for you, here will post tonight.

Rev, yes you can add a belt, it will have a slight LOSS as friction etc, but some already coupled an RV with a belt, you can even step it up (gear pulley etc) and get it to go faster, dont forget to TUNE Run cap in prime mover.

Ash

[revizal]

Hi Rev, sorry guys just got in. Mart i have the value of the Pot for you, here will post tonight.

Rev, yes you can add a belt, it will have a slight LOSS as friction etc, but some already coupled an RV with a belt, you can even step it up (gear pulley etc) and get it to go faster, dont forget to TUNE Run cap in prime mover.

Ash

OK Ash. I will use a belt to drive my alternator first. And will go next with head to head coupling to see different effect of setup. I'm waiting for a 3 HP 3 PH 2850 RPM motor to set as the motor on this experiment. My last motor 2 HP 3 PH (lower RPM) will choose as the alternator. May be tomorrow will be come to me.

Thank you for your very usefull information here.

Rev.

[ashtweth]

For Mart.

24mm size pot as its for the signal, this should be fine

[theremart]

RE: Size of pot

For Mart.

24mm size pot as its for the signal, this should be fine

Ok, but I need the wattage of the pot, ohms are given.

Also can I move the pot while the motor is running? Do I use a scope to tune it ?

Thanks!

[ashtweth]

Mart the pot is specified for 100K in the document, try a half a watt one.
As for tuning, you can tune the frequency up SLOWLY, and let the motor catch up to speed, do not turn it down when its operating, be careful switching in caps, you could blow the inverter from BEMF.

You tune it by the following procedure specified, in the compilations.
The higher the frequency the lower the capacitance needed (RUN CAP).

Ash

[theremart]

RE: so far so good.

Mart the pot is specified for 100K in the document, try a half a watt one.
As for tuning, you can tune the frequency up SLOWLY, and let the motor catch up to speed, do not turn it down when its operating, be careful switching in caps, you could blow the inverter from BEMF.

You tune it by the following procedure specified, in the compilations.
The higher the frequency the lower the capacitance needed (RUN CAP).

Ash

Ash,

Ok, I have installed the 100K pot, I have hooked up the killo watt meter to this and sometimes it comes on other times it does not, when it does come on and the killo watt metter is working, i can see the frequency move around.

I have plugged in a light, and the inverter power it just fine...

Any suggestions for my first power up of the inverter? My plan is put the run cap on, get the motor up to speed then turn the run cap off then note the power of the motor after that.

Thanks for your help.

Mart

[theremart]

Frequency drive inverter now working!

I played around with the pot on the hacked inverter, I found it draws from 2.3 amps at 12.3V on my battery up to about 11 Amps.

As I increased the amps from 2.3amps to 11 amps the motor spun at faster revs. So, I could tune this per a set load which is kinda nice.

This is progress so far. I have had many headaces to get so far as I had to fix things that I missed on the inverter, and I also took apart the motor again and removed the seals on the bearing. I have cleaned them far better than ever before with the carb cleaner and put the duralube inside.

On a side note, my killa watt meter stopped working after I was testing the output of the inverter... hope I just blew a fuse.

[revizal]

Hi Ash and All,

After a couple of days to do some business I made a test on RV mode to have resonance effect on 2nd motor as alternator. I have 3 PH 3 HP motor that I used as a prime mover driving the 2 HP 3 PH motor (act as alternator) via a belt.

I found the main thing on the system is speed/RPM. If I could get speed with lowest power input, I will get higher voltage on the alternator. And I'm sure we could control the output frequency thru this speed too. We tune the capacitor to have lowest power input on PM with the fastest we can get to get power output.

Yes Ash, I got it. My first target is to sure the resonance work on the alternator and I got that. Next target is to tune the system with my capacitor available. We'll se..

Here is the video link:

YouTube - RV-Coupled 3 PH Motor as Alternator

Thank you very much for your previously info on RV setup.

Rev.

[ashtweth]

Hi Rev, keep going its easy after this first stage and you automatically get an intuitive sense on tuning. The extraction circuits are well advanced and takes a lot of patience, this is see you have
Please post your progress ALSO over here too Bro
(all the RV engineers strangely only converse at this group)
EVGRAY : zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz