VOLTRONIC POWER VM III 4000VA INVERTER PROBLEM WITH VOLTAGE STABLIZER

[RASHID]

Dear All Friends,

I install new voltronic power VM III 4000VA inverter at my home in Mardan Pakistan. The inverter is working good with or with out utility power

At my city in peak summer months, utility voltage droop up to 150Volts, so we install a voltage stabilizer on the input of the house and connect the output of the stabilizer to the house.

My problem is when I connect the stabilizer out put to the input of the inverter, my stabilizer is start making sound and draw more current then the normal.

if I individually run the invertor direct from utility power, its good. if I disconnect the inverter I/p and o/p and connect stabilizer to the house load, its working good without any sound and extra current.

if I connect I/p of inverter to utility and from the same line I jump and give power to the stabilizer with out any o/p on the inverter and stabilizer, my stabilizer in start making sound and start taking 2Amp current, please find the attached for batter under standing.

The main problem both of them is not properly working together with or with out load.

I got another new inverter from the dealer and new stabilizer only for test purpose but the result is the same.

Please need support from an engineer to solve my problem

 

New Microsoft Word Document (2).docx

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Really depends rather a lot on what kind of stabiliser is in use, what kind of topology. I would expect it is some kind of transformer type setup configured to boost the voltage whenever it drops too low. And even then, I have no idea why the inverter would dislike that or get into some kind of resonating noise oscillation or whatever it is that you are hearing.

It could also be that the stabiliser attempts to correct the power factor, and that connecting the inverter changes the power factor. You measured the current at 2 amps, but it might well be that the current is out of phase with the voltage and that it does not represent the expected 300W-400W draw you might expect.

[Gnome]

 

1 hour ago, RASHID said:

At my city in peak summer months, utility voltage droop up to 150Volts, so we install a voltage stabilizer on the input of the house and connect the output of the stabilizer to the house

What is the voltage stabilizer? There are 3 types of products that make this possible: Auto-transformer (two sub-types here, constantly adjustable and fixed), Constant Voltage Transformer and Inverter (AC -> DC -> AC).

Anything else is fake and doesn't really work

Depending on which you have it could have different reasons why it is behaving the way it is.

EDIT: Worth noting the inverter would be silly because the VM III itself is an inverter with a change-over from utility

Edited July 11, 2018 by Gnome

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51 minutes ago, Gnome said:

There are 3 types of products

Thanks for enumerating them. I did google around a bit but couldn't spend too much time on the answer. I did see one article that explained that voltage stabilisers (properly defined, though I'm sure marketing takes some liberties) aren't really much good at regulating. They are used where you have a pretty constant voltage that is too low or too high, and then you use a buck or boost transformer setup to add or subtract a couple volts. If you use an auto-transformer for this (typically with a stepper motor), then of course it becomes constantly adjustable. I've seen this sort of thing used at utility scale to swap transformer windings and regulate the voltage.

Agree with you noting that the VMIII, if it works with the double-conversion as noted previously, is already a voltage regulator/stabiliser in itself.

Edit: I'm beginning to doubt that the VMIII uses double-conversion. The spec sheet lists a 15ms or 20ms transfer time...

Edited July 11, 2018 by plonkster

[Guest]

29 minutes ago, plonkster said:

15ms or 20ms transfer time...

Then it is not a double-conversion no.

There is no break at all with online UPS'es, ever, unless the batteries die.

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2 minutes ago, The Terrible Triplett said:

Then it is not a double-conversion no.

I think you asked on a previous thread why not more makers are doing this. I thought of another reason: Cost. With the change-over type, you can often use the same transformer and switching gear in reverse to do the charging. With a fully-online double-conversion type, you need double the components.

[Gnome]

4 minutes ago, plonkster said:

I think you asked on a previous thread why not more makers are doing this. I thought of another reason: Cost. With the change-over type, you can often use the same transformer and switching gear in reverse to do the charging. With a fully-online double-conversion type, you need double the components.

Or components with a lot more capacity.

The simplest double conversion topology is battery chargers and an inverter running off of the batteries (or DC directly).

But I do know some devices use a double conversion topology that consists of a AC -> DC converter with a switch between battery DC bus and AC supplied DC bus.

[Guest]

11 minutes ago, plonkster said:

With a fully-online double-conversion type, you need double the components.

To my limited knowledge of all things electrical, bar how to blow them up, which is a skill mind you, you have 2 parts:

1) Charger part from AC to batteries to charge a 72 or 96v bank consisting of a bunch of small 7-9ah batteries. Seldom do you find 24/48v ones.
2) Inverter part from batts back to AC.

So they are supposed to be "cheaper", as the charger is blerrie small like +-2amps at high volts, if I recall correctly, as per the one I wanted to "convert".

If there was 96v MPPT's ... :-) 

4 minutes ago, Gnome said:

Or components with a lot more capacity.

It "feels" like my 1600va Victron inverter (without a charger) has similar inside to a 2400va APC online double conversion UPS, ignoring the charging circuit board'jie'.

Bar the bigger coil around the V. The APC has small goeters.

Edited July 11, 2018 by Guest

[Guest]

Here is a PDF on what's inside, more complex than most solar inverters.

Most of the space inside are batteries.

http://www.age.co.za/Portals/0/UPS/APC SMART UPS.pdf

[Gnome]

APC products are overpriced. They aren't bad quality, the price is just far too high for what you get.

For example Smart UPS range. They have a 3amp charger and its duty cycle of the components cannot support 100% runtime. So even if you hooked up more batteries you would have a thermal runaway situation.

Additionally they also have transformers inside those UPS that are severely undersized. It can handle the rated KA (wires are thick enough on the windings) but the core is small to save money, so they have fewer windings and thus your magnetization current is pretty high (the fewer windings on a core the more current is required to magnetize the core). Thus the transformer is burning around 50 watts by just being plugged in (and gets so hot it burns you hand).

 

[Guest]

18 minutes ago, Gnome said:

APC products are overpriced.

O absolutely, and 2-5min on full power, it is pretty useless, bar waiting for generator start.

So what you do is wait for someone to have to replace the batts, once price is quoted, people dump them on the spot, buy bigger cheaper UPS that can run for hours. 

20 minutes ago, Gnome said:

Thus the transformer is burning around 50 watts by just being plugged in

It irritates the dinges out of me ... that wasted +-50w.

But my system cannot operate without a UPS, and the APC does have a very clean sine wave AND I got them for a blerrie good price,

22 minutes ago, Gnome said:

For example Smart UPS range. They have a 3amp charger and its duty cycle of the components cannot support 100% run-time. So even if you hooked up more batteries you would have a thermal runaway situation.

Here I'm confused? 

Online double conversion UPS run 24/7/365 for years on end.

I'm not sure how the small bank can be kept charged though, load powered, on continuous high loads.
 

[Gnome]

5 minutes ago, The Terrible Triplett said:

Online double conversion UPS run 24/7/365 for years on end.

I'm not sure how the small bank can be kept charged though, load powered, on continuous high loads.
 

Yeah there are two types of SmartUPS, the online and line interactive. The line interactive I was speaking of.

The online kind is overpriced beyond belief. It is like R20k for a 1.5kVA unit IIRC and they have really loud fans.

But yes, the online kind can run 24/7 and the online version doesn't have the same cheapo transformer (in fact it is a high frequency design whereas the line interactive is low frequency with a huge mains transformer).

[zaroky]

It depend on the charging amper when utility is connect to the inverter

[Guest]

1 hour ago, Gnome said:

... line interactive ...

O yes, line interactive is not designed to run 24/7 ... at all.

1 hour ago, Gnome said:

R20k for a 1.5kVA

APC Smart-ups On-line 20000VA Rt From R139 259.95 incl VAT ... 

As I said before, once them batts are to be replaced one time too many, because they are so expensive, the UPS, for such a short run time, you pick them up for a apple and a onion.

If only you can get a MPPT that can charge a 96v battery bank, now that would be nice - online double conversion solar inverter. :-)

3 hours ago, plonkster said:

I thought of another reason:

So maybe the high tech inside them, may be the expensive part. 

[seant]

Talking about wasted power the 3kva APC unit with no load draws about 3A from the 48v pack and the 5kva is nearly double that. Now the 3kva has 8  by 4.5Ah batteries made up in two packs but at full power of 2.2Kw plus an additional idle power draw of about 150 there is no wonder the practical  run time is about 2 minutes.  Oh and then your batteries are fairly stuffed too so the next time you might get only about a minute runtime.

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Okay, so guys, when @RASHID comes back and tell us the type of stabiliser, are we any closer to guessing why? I half suspect you might have more success asking this question at AEVA.

My best guess is that the inverter/charger on its own, when charging the batteries, might be skewing the power factor, and maybe this voltage stabiliser is one one of the better ones, maybe it tries to correct power factor... maybe it is supposed to draw 2A to do this.

Does anyone know the power factor of the Axpert while charging? I know only that on the Victron inverters there are two settings. The normal one has a power factor of 1, but when you turn on the "weak grid" option the power factor is no longer 1.

In other words, the answer might be that this is completely normal. Perhaps test the stabiliser with another poor-power-factor load in parallel, eg an induction motor of a couple hundred watts?