Reactive Power Continuum.

[TinMan]

I decided to have another look at reactive power-following on from Luc's work.
I will be using the 3 phase smart drive motor for my PMA in this setup.

First i must tell everyone that today i almost met my maker.These smart drive motors(PMA's) can really pack a wallop. While trying different cap/transformer configurations,i accidently touched the cap/transformer tank-one clip lead in each hand. For the first couple of seconds i couldnt move-everything was just flashing. Then i got thrown against the back of the work shop door. After about 10 minutes of just lying there,not being able to move much,i managed to drag my sorry ass of the floor . I now have two burn marks on my finger's,and a rib cage that feels like i was hit by a car. So anyone trying this,dont be an idiot like myself,and turn the ruddy machine OFF before disconecting and reconecting wires.

OK,below is the first video of my setup. This was actually going to be a mok up of a QMoGen,but after seeing something interesting,i decided to go all the way with some real reserch.I should have the second video up tonight,and i must say ATM the results seem quite promising.
https://www.youtube.com/watch?v=besmc4pgKjs

[Matt Watts]

http://www.youtube.com/watch?v=besmc4pgKjs

Hope that electrical bite is your last one for a great while.  I know I'm overdue for my next one--probably why my big caps are sitting there in my bin waiting for me to do something stupid with them.

Anyway, glad you're back on your feet.


Mapping...

While you are doing this, might be good to map RPM, and frequency/milliseconds.  This will help a lot when you go to choose a capacitor to tweak the phase angle.

Luc and I worked a lot on the reactive power stuff.  There is definitely something there, but it is extremely difficult to wrap your head around it.  One thing for sure, use the smallest value shunt resistor you can find for taking amperage readings.  Even a full ohm can screw your impedance up and make you think you have a phase shift much larger than you really have.  I have a 30 watt 0.12 ohm that works pretty well so far.

The other thing I highly recommend is to draw out your circuit and make at least 12 copies of it.  What you will do is annotate each copy for each 30 degrees of a wave cycle.  Study it very closely.  When you see, for example, a current (voltage across the shunt), but no voltage across the source, think carefully about what that means.  It isn't obvious, but if you study it, it will talk to you and you can make the right adjustments.

Looking good.  Some of the best videos on the net.  Hope to see a breakthrough.


M@


P.S.   One other thing.  If you really want to learn this stuff inside and out, set a goal you want to achieve right up front.  My goal was to hold the current lagging voltage by 90 degrees, or power factor of zero.  You may not reach you goal, but I promise you, you will know exactly what obstacles are in your way.

[TinMan]

Hope that electrical bite is your last one for a great while.  I know I'm overdue for my next one--probably why my big caps are sitting there in my bin waiting for me to do something stupid with them.

Anyway, glad you're back on your feet.


Mapping...

While you are doing this, might be good to map RPM, and frequency/milliseconds.  This will help a lot when you go to choose a capacitor to tweak the phase angle.

Luc and I worked a lot on the reactive power stuff.  There is definitely something there, but it is extremely difficult to wrap your head around it.  One thing for sure, use the smallest value shunt resistor you can find for taking amperage readings.  Even a full ohm can screw your impedance up and make you think you have a phase shift much larger than you really have.  I have a 30 watt 0.12 ohm that works pretty well so far.

The other thing I highly recommend is to draw out your circuit and make at least 12 copies of it.  What you will do is annotate each copy for each 30 degrees of a wave cycle.  Study it very closely.  When you see, for example, a current (voltage across the shunt), but no voltage across the source, think carefully about what that means.  It isn't obvious, but if you study it, it will talk to you and you can make the right adjustments.

Looking good.  Some of the best videos on the net.  Hope to see a breakthrough.


M@


P.S.   One other thing.  If you really want to learn this stuff inside and out, set a goal you want to achieve right up front.  My goal was to hold the current lagging voltage by 90 degrees, or power factor of zero.  You may not reach you goal, but I promise you, you will know exactly what obstacles are in your way.

What i really need to do is learn how to calculate the power factor correctly. VA is no problem,but i need the power factor to calculate watts from VA.

Anyway,here is the second video. Take note as to what happens as the speed is increased.

https://www.youtube.com/watch?v=BwEdF2R2zeQ

[Farmhand]

Hi Tinman, I'm Assuming you will get the baseline input VA as well as the baseline input Watts, then we can see the change in VA, as real watts in the load increases under normal use with "no tuning capacitors", and with capacitors and the difference in the relationship between VA and Watts out in both cases. That could show something interesting.
I think it's important to see the VA in relationship to watts out. ie. if I can get total watts out to remain the same and drop the total watts consumed but doing so increases VAR substantially somehow then that would be seen as not so good to me. Not that it matters what I think. But to go to extremes if a 1 kVA genny is powering a 200 Watt load and the VA provided by the genny needs to be 900 VA because 700 VAR is produced then it's an issue.

It's not all about Watts consumed and Watts output, it also about plant capacity and running costs in dollars for us and the power company if they are involved to provide the original VA. I think. One reason I keep saying we should leave the grid out of it and use AC power we generate ourselves from our own source of energy. Like a bank of batteries powering a DC motor driving a generator. Or some other method, A petrol driven mechanical generator still cannot turn reactive power back into fuel, so I'm a bit confused what is the point to it all. No matter.

I'm seeing a 10 Watt light with an unknown power consumption and a minimum input of over 30 Watts.

..

[TinMan]

A petrol driven mechanical generator still cannot turn reactive power back into fuel, so I'm a bit confused what is the point to it all. No matter.

I'm seeing a 10 Watt light with an unknown power consumption and a minimum input of over 30 Watts.

..

Yes-you have missed the point.
The point is to see if we can draw from a generator/altinator without placeing a load on the prime mover. At this point in time it would seem that it is very possable.Now ,unlike Luc's setup where he used a standard generator which had exciter windings,and i pointed out to him that this is where his non reflective power was coming from,we have a PMA with no exciter winding's. But here is the catch-->while my test show i can draw 10 watts+plus without any reflection shown on the prime mover,we still use 41.8 watts of power to turn the generator at the desired speed to achieve this 10 watts output.If i disconect the drive belt to the generator so as only the motor is running,then i only get a power draw of 17 watts. So 17 watts plus 10 watts is 27 watt's.This means that we are using 14.8 watts just to spin the generator at the desired speed. Im guessing this is the result of eddy currents within the laminated steel core. A ferrite core would remove a lot of this loss-but not all.

But here is something to think about. If we can draw current from a generator without a mechanical load being reflected onto the motor,could we design a motor where a mechanical load can be placed on the motor without it reflecting on the electrical input?. i see no reason why the opposite couldnt work.