Toroidal mpp / eg4 inverters

[realpinochet]

I saw the video Will just did for the new EG4 split phase....the idle usage is unacceptable by a long shot. Why do the mpp and growatt style inverters idle so high with and without a transformer? He mentioned toroidal transformers and from research Schneider, Victron, Outback ...etc use this style. It appears from google they are much more efficient, uses less space, weigh less and decreases line noise. Can't EG4 squeeze one or maybe two of something like this into their inverters..one for each leg for split phase models? Seems like it would reduce the stress on the inverter overall and specifically with surges, logically it would improve both performance and life expectancy. I'd assume if a company was working with the manufacture directly and buying in quantity they could get the price down on these a lot.

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[nc73]

These were made to be affordable and the efficiency is not that far off. Not sure what everyone is talking about high idle usage. I don't see it as a problem at all. I find ways to use up the solar and battery since I make more than I use. These are meant for big batteries and if you have small capacity get the other EG4 model. That said I don't notice the idle consumption on my lvx..same idle consumption as the EG4 of course.

 

[Steve_S]

If looking for Torodial INverter/Chargers you are looking for LOW FREQUENCY (LF) not HF which are cheaper, lighter and do not have a torodial core which is heavy & $$.

Below is my Samlex EVO-4024 Low Frequency Inverter @ 94% Efficiency. You can see the coil transformer.
Link To: https://samlexamerica.com/products/ProductDetail.aspx?pid=575

Here is my Yiyen (*OEM) APC-3024 Low Frequency "Value" Inverter/Charger (88% Efficient)
* They make for resellers/vendors labeled.
Link to: https://www.yiyen.com/product/apc-series-pure-sine-wave-inverter-charger/

 

[realpinochet]

These were made to be affordable and the efficiency is not that far off. Not sure what everyone is talking about high idle usage. I don't see it as a problem at all. I find ways to use up the solar and battery since I make more than I use. These are meant for big batteries and if you have small capacity get the other EG4 model. That said I don't notice the idle consumption on my lvx..same idle consumption as the EG4 of course.

The HF versions of mpp style idle pretty high to..imho.

 

[Hedges]

What are their idle power and rated power?

I'm trying to do a 3-phase step-up transformer, and seeing pretty high currents, saturating not sine wave. Even when I ran the step-down.
Maybe 800VA (don't know if real loss or imaginary reactive) for a 30kVA transformer.
Lot of cost and performance tradeoffs in everything. I realize the several inches space all around transformer inside enclosure could be to reduce eddy current losses in sheet metal, not just cooling. Could be interesting to measure current in inverter chassis, and power consumption with/without enclosure.
How the inverter deals with out of phase reactive currents may be one of the idle loss issues.

 

[realpinochet]

If looking for Torodial INverter/Chargers you are looking for LOW FREQUENCY (LF) not HF which are cheaper, lighter and do not have a torodial core which is heavy & $$.

Below is my Samlex EVO-4024 Low Frequency Inverter @ 94% Efficiency. You can see the coil transformer.
Link To: https://samlexamerica.com/products/ProductDetail.aspx?pid=575

Here is my Yiyen (*OEM) APC-3024 Low Frequency "Value" Inverter/Charger (88% Efficient)
* They make for resellers/vendors labeled.
Link to: https://www.yiyen.com/product/apc-series-pure-sine-wave-inverter-charger/

Being new to this I'm not sure how long midnight has been promising that rosie inverter...but they say it's HF with surge capacity of a LF. Here's a video of it being tested and it appears to have two toroidal's in it. While it did not start this guys massive compressor it did better than I would have thought. I assume they (midnight) are working more on it. If those are indeed toroidal coils on the right side and still remain HF then why can't others do this and increase their surge capacity while at the same time clean up the single a little as they are said to do. The article I read did say toridals are more expensive to manufacture than the other style transformer ...but what are we talking about in today's modern manufacturing process as these things have been around for a long time? A hundred dollars more? Mable some bigger caps and a torridal or two could make mpp/eg4 up their game. Some might say they are just deye-ing to do it.

 

[realpinochet]

Are those toroidal's on the right side?

 

[chess-equality]

I recently discovered that there are many more pure Chinese toroidal brands (if you can live with that). Not sure though if they're all LF or hybrid.

TBB Power, and JNGE. TBB seems to be known as they have installations in the EU and Africa. Locally, the brand KREON is a DIY product.

Personally I 'm using a SNADI (not Sandi) toroidal, but I bought from a local dealer and not from Ali. The local dealer has warranty.

 

[Steve_S]

I use a Midnite Class SCC & their E-Panels - all predate their latest offerings and I stopped following them or interacting with them.
I can tell you that the Torodial Coil itself, in my Samlex weighs in at 55 Lbs, it is a beastly thing. It can run my compressor without a blink and also ran my Mig Welder just fine.

An HF inverter in my world just would not do.

 

[realpinochet]

What are their idle power and rated power?

I'm trying to do a 3-phase step-up transformer, and seeing pretty high currents, saturating not sine wave. Even when I ran the step-down.
Maybe 800VA (don't know if real loss or imaginary reactive) for a 30kVA transformer.
Lot of cost and performance tradeoffs in everything. I realize the several inches space all around transformer inside enclosure could be to reduce eddy current losses in sheet metal, not just cooling. Could be interesting to measure current in inverter chassis, and power consumption with/without enclosure.
How the inverter deals with out of phase reactive currents may be one of the idle loss issues.

I'd have to look but even the non transformer ones run like 60/70 watts.

 

[chess-equality]

Are those toroidal's on the right side?

This is toroidal:

 

[realpinochet]

I use a Midnite Class SCC & their E-Panels - all predate their latest offerings and I stopped following them or interacting with them.
I can tell you that the Torodial Coil itself, in my Samlex weighs in at 55 Lbs, it is a beastly thing. It can run my compressor without a blink and also ran my Mig Welder just fine.

An HF inverter in my world just would not do.

I plan on 6848 or radian..but I still could use some EG4's on certain projects if they can step up output and surge capabilities. I'm curious why they seem to be stuck at 6ish kw output while others including growatt have released much higher ones. I can't remember his name..one of the midnight guys robin or something that comes here said there's no reason a HF inverter can't have high surge capabilities. Wonder how they are trying to achieve it?

 

[chess-equality]

I use a Midnite Class SCC & their E-Panels - all predate their latest offerings and I stopped following them or interacting with them.
I can tell you that the Torodial Coil itself, in my Samlex weighs in at 55 Lbs, it is a beastly thing. It can run my compressor without a blink and also ran my Mig Welder just fine.

An HF inverter in my world just would not do.

About right; mine's (3kw) listed at 22 kg.

 

[realpinochet]

This is toroidal:

Right...it just looks like those are two small ones on the right side...maybe not?

 

[chess-equality]

An HF inverter in my world just would not do.

I also have a HF but I oversized it to 5kw (surge 10kw) running a 1kw load.

 

[Hedges]

Different

I can't remember his name..one of the midnight guys robin or something that comes here said there's no reason a HF inverter can't have high surge capabilities. Wonder how they are trying to achieve it?

I think basic difference is HF inverters can only transfer as much power as the inductor stores.
Transformers can transfer massive amount of power, just more IR drop in windings and transistors.
(How true sine wave inverters deal with their inductors would be part of the trick. MSW and old Trace multi-tap transformers wouldn't have to think about that.)

 

[WattAboutThat]

I would not try it - but would it be possible to purchase a toroidal transformer and use it to replace the transformers in the 6000ex?

 

[chess-equality]

Can't EG4 squeeze one or maybe two of something like this into their inverters..one for each leg for split phase models?

I think EG4 doesn't manufacture these in-house and source them from China.

 

[realpinochet]

I think EG4 doesn't manufacture these in-house and source them from China.

They do, so does mpp but they both seem to put their own small touch on them. Vendors that rebrand can work with the manufacturer to make these better inverters for sure.

 

[RCinFLA]

A big thing lacking on these Chinese LF inverters is some LF transformer primary side high frequency PWM pre-filtering. They rely pretty much on low frequency transformer leakage inductance for the inductance in the L-C high frequency PWM filtering, with just a capacitor placed across secondary winding of LF transformer. This also results in requiring higher capacitance for secondary side filter capacitor giving greater reactive current through inverter at no load which also increases losses.

A low frequency toroid transformer is not the primary reason for low idle power, however, a low freq toroid transformer has lower leakage inductance so the option to use it for HF PWM filtering is not there so a primary side HF inductor for pre-filtering of HF PWM is a necessity. So indirectly, the toroid transformer drives the requirement to use primary side pre-filtering series inductor for HF PWM filtering which is the primary reason for lower idle power.

The picture enclosed by chess-equality in above reply does have the series primary side inductor although it is likely not a great way to mount it coaxially together with the main power transformer as there may be some cross coupling pickup between the main transformer and primary series inductor.

That primary side inductor is also carrying the large 2x AC line frequency inverter ripple current which puts a heavy magnetic low frequency bias on the inductor core. It has to be able to take that large magnetic bias without saturating its core which would cause the filtering inductance to collapse to low value.