Comparable to MPP inverters able to sync generator with solar?

[fastline]

I very much realize Victron has their "power assist", but I have yet to find a common 'term' for the ability of an inverter to sync and use both generator and solar power, or grid for that matter. Maybe a "hybrid" does this?

Being in the engineering field, I understand a lot of what they are doing, but always left in the dark on details from OEMs.

I have been looking to try an MPP for years. They are out of Taiwan, NOT China, and I think this stupid "MrPOWR" "Vevor" or whatever do their best to copy their stuff but their software is totally fubar. I actually have one of those knockoff MPPT chargers and I own it for free since it is a total POS. They didnt even want it back...lol

I am just curious if anyone knows the common tech where they are synchronizing power sources and combining them? It is very much what I want to explore but I can imagine all the power runs through the IGBT output stage so inrush will be limited, unlike a common relay that would allow a 'pass through' from shore power.

I'm also trying to see if anyone has seem a comparable company to MPP? I am always frustrated with the lack of data and support. Only one guy supports them in the USA and he is too busy to talk. One thing that just burns me with the MPP piece I am looking at is the low 160V Voc voltage for solar. That really limits me! I don't like to parallel anything on a small setup!

 

[timselectric]

You are looking for an off grid AIO with the SUB function. Or a hybrid AIO with AC coupling ability.

 

[timselectric]

Victron grid assist is a totally different function.

 

[DIYrich]

Off-grid inverter can draw power from grid (one direction). "Hybrid" can also export to grid.

If an inverter has a generator connection, it will be able to synch to it. If it can synch to a generator, it should be able to synch to the grid too. You CANNOT use grid and generator simultaneously. The inverter synchronizes to the power source. It cannot synchronize two different power sources.

 

[fastline]

Well, there really has not been good, standardized terminology. Someone starts it, and others sort of follow. Like "SUB", I understand that is a priority setting, but means nothing in terms of ability.

Only thing I can guess is a "double conversion" unit. I guess the nice part of that design is you will get consistent voltage/frequency on the output.

So far, it looks like Growatt 'may' do this on some models but still unclear. I am also looking at Renogy only because I have one of their small 1000W brick inverters and it's been running perfect for years, though it seems VERY trippy on the GFI. I recently powered a large audio receiver in which they charge up a bank of caps on start up. It did not OL, it says it tripped the GFI. After a few attempts, it will finally run the receiver but that shi& won't fly in a bigger AIO.

 

[DIYrich]

Why do you want to run the generator when the grid is connected? Drawing power power than your utility feed can deliver?

 

[fastline]

Why do you want to run the generator when the grid is connected? Drawing power power than your utility feed can deliver?

This won't be grid connected. In most inverters, they use a transfer switch so when AC is present, they activate a transfer switch, which completely removes solar and battery from powering the load at all. I'm sure the internal solar charger will still charge batteries, but my goal is to allow the generator to 'sync' to the output as a supplement. One of the MPPs does this, but find it hard to believe only Victron and MPP does this?

Basically they run a double conversion where even if you are feeding AC in, that is rectified as DC and then re-modulated as AC sine. This allows the inverter to constantly create perfect AC, regardless of source.

I have never been able to talk to an engineer with Victron but my assumption is they manipulate the frequency slightly to allow an AC source to supplement the load. Basically if two sources are in 'sync' and running at perfect frequency together, they will share a load 50/50, in a perfect world. But as the frequency is manipulated, one will 'pull' the other. So a generator running at 60.1hz will 'pull' another one running at 60.0hz. Kind of a 'tow rope' effect.

This is how I believe OEMs are able to set a generator size. They look at incoming KW and manipulate the frequency to make the generator 'pull' to that load criteria.

Obviously any generator will need to have very stable voltage and frequency to make this possible.

The other use here is exactly what Victron advertises for campers where they can run a 30A shore power and add in additional solar to power more loads than is available from a 30A/120V connection.

 

[SignatureSolarJames]

I very much realize Victron has their "power assist", but I have yet to find a common 'term' for the ability of an inverter to sync and use both generator and solar power, or grid for that matter. Maybe a "hybrid" does this?

Being in the engineering field, I understand a lot of what they are doing, but always left in the dark on details from OEMs.

I have been looking to try an MPP for years. They are out of Taiwan, NOT China, and I think this stupid "MrPOWR" "Vevor" or whatever do their best to copy their stuff but their software is totally fubar. I actually have one of those knockoff MPPT chargers and I own it for free since it is a total POS. They didnt even want it back...lol

I am just curious if anyone knows the common tech where they are synchronizing power sources and combining them? It is very much what I want to explore but I can imagine all the power runs through the IGBT output stage so inrush will be limited, unlike a common relay that would allow a 'pass through' from shore power.

I'm also trying to see if anyone has seem a comparable company to MPP? I am always frustrated with the lack of data and support. Only one guy supports them in the USA and he is too busy to talk. One thing that just burns me with the MPP piece I am looking at is the low 160V Voc voltage for solar. That really limits me! I don't like to parallel anything on a small setup!

production line is in Shenzhen. design is by voltronic tiawan. power Mr is the same line as the rest of voltronic customers including MPP. all that is in tiawan is a nice office building which I have had team members stay at.

Been there, seen it.

 

[fastline]

production line is in Shenzhen. design is by voltronic tiawan. power Mr is the same line as the rest of voltronic customers including MPP. all that is in tiawan is a nice office building which I have had team members stay at.

Been there, seen it.

That is quite interesting! From what I gathered, a lot of this comes down to software. I've read several places where the PowMr looks the same but does not work well at all and I have one of their brand new 60A MPPT chargers that is basically a paper weight! The electrics inside might be OK, but you can fidget with it for hours just to get some sort of output. Then it will go right to float.

I am always trying to get down to who is actually making what, and what actually works correctly. Don't even get me started with China. They have been rip off artists for decades but USA companies just won't learn. The second you send them a drawing, they go to work on a copy.....all while saying "we keep vewy sav fo u, u no wuwee"..... I know this because every one of my own production designs that my company built in the USA were ripped off by China. Every single one! We still get calls for product support and I tell them to call China......

But I mean, even with Victron, I am sure all their board work is done in China. PCBs, board population, etc.

 

[timselectric]

In most inverters, they use a transfer switch so when AC is present, they activate a transfer switch,

You are describing an AIO (All In One).
An inverter just converts DC to AC.

 

[timselectric]

It depends on what you want it to do. Before you can choose a certain unit.
Victron is the only one with grid assist.
You can set the incoming AC limit. And it adds to that from the battery, to cover the loads.
Anything with SUB (Solar Utility Battery) mode. (Mostly Voltronics built) can use all solar available. And cover the rest from the AC input. If the loads are covered, and there is still excess solar available. It will charge the batteries. Battery isn't used unless there isn't enough solar, and/ or AC input.
There's several ways to go. And different equipment for each use case. But first, you have to decide what you want it to do.

 

[fastline]

It depends on what you want it to do. Before you can choose a certain unit.
Victron is the only one with grid assist.
You can set the incoming AC limit. And it adds to that from the battery, to cover the loads.
Anything with SUB (Solar Utility Battery) mode. (Mostly Voltronics built) can use all solar available. And cover the rest from the AC input. If the loads are covered, and there is still excess solar available. It will charge the batteries. Battery isn't used unless there isn't enough solar, and/ or AC input.
There's several ways to go. And different equipment for each use case. But first, you have to decide what you want it to do.

I am confused as you say Victron is the only one with "grid assist", or maybe just the terminology? Or maybe the architecture is different? Maybe it truly does sync the sine waves as AC? Which would certainly be more efficient!

I really tend to wonder if the Voltronics goods are just rectifying the utility (grid or generator) power and it is put on the DC buss and basically all power is pulled from the nominal DC battery bank. Literally no different than if I coupled a stand alone AC/DC battery charger to feed the bank, as was another option I am considering as an alt.

Basically I this is an off-grid setup. In most cases, the battery bank and solar will be able to cover the loads, but when either weather conditions are not good or I know I will need more power than I can to pull against the batteries, I want to run a much smaller inverter generator such as my Honda 3000 or even my smaller 2300. The utility AC input will hold the batteries topped off and serve the AC loads while solar is at a minimum.

Basically this is what I do now but I need to upgrade and an AIO unit is able to do more things on the fly. Right now I have to run a transfer switch so normally I serve all my AC load with solar and batteries through an inverter. When demand will just be too high or solar is poor, I transfer over to a generator that feeds the panel, and I switch in a battery charger that tops the batteries while serving the AC loads.

This issue above is that for example, I might need to run 2000W of AC loads, yet solar is only producing 1000W today. I would like to make full use of that solar and only add 1000W of generator power, thus largely saving my wallet from fuel expense!

I hope that makes sense. I tend to struggle with explanations.

 

[timselectric]

I am confused as you say Victron is the only one with "grid assist", or maybe just the terminology? Or maybe the architecture is different? Maybe it truly does sync the sine waves as AC? Which would certainly be more efficient!

Grid assist is a function that only Victron provides.
I described how the different functions worked above.
I'm not sure how it does it internally. Either way gives you the functionality. Although synchronization should be more efficient.

 

[fastline]

Grid assist is a function that only Victron provides.
I described how the different functions worked above.
I'm not sure how it does it internally. Either way gives you the functionality. Although synchronization should be more efficient.

There is a test video on YT that proves the MPP LV-MK does it as well. Just not certain how each does it, and that is something I always get crickets on. OEMs don't talk about designs. I am just supposed to throw big dollars at a mystery box. Schneider is the worst!

 

[timselectric]

There is a test video on YT that proves the MPP LV-MK does it as well. Just not certain how each does it, and that is something I always get crickets on. OEMs don't talk about designs. I am just supposed to throw big dollars at a mystery box. Schneider is the worst!

Link to the video, please. As I am not aware of any other manufacturer providing that specific function.

 

[DIYrich]

This won't be grid connected. In most inverters, they use a transfer switch so when AC is present, they activate a transfer switch, which completely removes solar and battery from powering the load at all. I'm sure the internal solar charger will still charge batteries, but my goal is to allow the generator to 'sync' to the output as a supplement. One of the MPPs does this, but find it hard to believe only Victron and MPP does this?

Basically they run a double conversion where even if you are feeding AC in, that is rectified as DC and then re-modulated as AC sine. This allows the inverter to constantly create perfect AC, regardless of source.

I have never been able to talk to an engineer with Victron but my assumption is they manipulate the frequency slightly to allow an AC source to supplement the load. Basically if two sources are in 'sync' and running at perfect frequency together, they will share a load 50/50, in a perfect world. But as the frequency is manipulated, one will 'pull' the other. So a generator running at 60.1hz will 'pull' another one running at 60.0hz. Kind of a 'tow rope' effect.

This is how I believe OEMs are able to set a generator size. They look at incoming KW and manipulate the frequency to make the generator 'pull' to that load criteria.

Obviously any generator will need to have very stable voltage and frequency to make this possible.

The other use here is exactly what Victron advertises for campers where they can run a 30A shore power and add in additional solar to power more loads than is available from a 30A/120V connection.

No. The transfer switch disconnects the grid and attaches the generator. PV and battery stay connected, if done correctly.

With a Generator, the inverter will pull what it can't supply to load from pv. Good inverters can charge the battery with excess from the generator. Bad inverters transfer load to the generator and get out of the way.

The trick is when load is less than pv, and batteries are fully charged. With DC PV, the inverter can reduce PV production

With AC PV, the inverter has to first disconnect the generator, and then modulate frequency to reduce AC PV production. The inverter can't modulate frequency when the generator is connected. The generator calls the show when connected.

For off grid, no transfer switch. You are always connected to the generator. Generator connection is typical for off-grid inverters.

Double conversion is not typical. Modular systems use DC pv. And only convert when supplying loads. AC PV is connected directly to loads, and inverter either supplements, or takes excess and converts to dc to charge batteries.

Generators run at a target frequency. When loads increase, voltage and frequency drop, and more fuel is sent to generator to bring back up to frequency. If load drops, frequency and voltage increase, and less fuel is sent. There are other controls that adjust voltage, but it all ends up as load on the generator. Two generators can synch up as you describe. AC PV doesn't work that way. AC PV follows the frequency, and increases voltage to push current. If frequency is too high, that is the signal to stop producing.

 

[fastline]

For Tim, who asked for a link. About 4min in. Basically this thing works to create perfect output, BUT probably at an efficiency loss, which I don't care about. Lots of people get spun about perfect power but don't realize most electronics take it right back to DC anyway!

Basically all I want is the ability to plug in a small generator and "supplement" my loads against the PV/battery system, not knock them offline and step in to do it all. I know my setup will be right at the limit regarding PV for my loads. The battery bank will certainly hold things for a bit and let me know I need to supplement. I then just want to throw a small generator in, only when needed like hot, cloudy days.

 

[timselectric]

For Tim, who asked for a link. About 4min in.

Not the same as Victron grid assist.
SUB is the same as I described above.
USB mode can supplement grid/generator with solar.
But the demonstration didn't even show that functionality.
Does not say what happens when there is no solar.
But I would guess that it reverts to battery only, just like SUB mode. Only when AC and solar aren't available.

 

[HRTKD]

The Victron system can fire up the generator automatically if the generator supports a remote start. My system has both a generator and Victron components. But I haven't connected the dots to enable the Victron side to start the generator. I'm probably missing an Onan interface to make that happen.

With the Victron Cerbo GX, Multiplus, SmartSolar and the shunt (any model), it's possible to limit the overall charge amps from all sources that the Cerbo GX can communicate with.

 

[cul8rm8]

Off-grid inverter can draw power from grid (one direction). "Hybrid" can also export to grid.

If an inverter has a generator connection, it will be able to synch to it. If it can synch to a generator, it should be able to synch to the grid too. You CANNOT use grid and generator simultaneously. The inverter synchronizes to the power source. It cannot synchronize two different power sources.

I've been looking for some directions on how my own setup can work or not work. I have a MPP Solar MPI plus 5kw hybrid inverter that has 5kw of panels, 10.2kw of pylontech batteries and I have now purchased a 7kw generator as my final bit of backup. I was hoping to cable my generator in but now have doubts that it will auto start when my batteries get to 12% or so. As I am still connected to the grid, can I presume it will not automatically start until the grid is down?
I was hoping it would auto start even though grid is connected, any ideas folks? ?

Ok , I have managed to get my inverter to automatically start the generator (vis dry contact switch). It startts when the battery voltage dtops tp 48.5 v ( using solar assistant) The problem I still have is that the batteries are still depleting and will most likely shut down at the specified shutdown voltage . When the generator kicks in, it does not charge the batteries at all.

Still none the wiser in how i get the generator to power the house as well as the batteries.